As a typical toxic heavy metal， cadmium has extremely strong accumulative properties. It can trigger acute toxic reactions in livestock and poultry， and is more likely to cause long-term potential chronic toxic damage， posing a severe and persistent threat to the growth， development and physiological functions of livestock and poultry. Though the trace element selenium is present in extremely low concentrations in animal bodies， it plays an irreplaceable physiological role and is crucial for maintaining the normal physiological metabolism of the organism and ensuring healthy growth. In recent years， numerous studies have shown that selenium can antagonize the toxicity of cadmium. This paper mainly summarized the research reports on cadmium-induced programmed cell death in animals and the mechanism of selenium’s antagonistic effect， with the aim of providing references for the prevention and control of cadmium pollution and the research and application of selenium.

Skeletal muscle fiber type transformation represents an important adaptive response of skeletal muscle to changes in nutrient availability, exercise load and metabolic microenvironment, and is typically accompanied by coordinated adjustments in energy metabolism characteristics and contractile function. Leucine, as a key branched-chain amino acid, not only serves as a substrate for protein synthesis but has also been increasingly recognized as an important metabolic signaling molecule that can mediate intracellular signal transduction through specific G protein-coupled receptors (GPCRs). Current studies indicate that certain GPCRs can sense extracellular leucine and its related metabolic signals, thereby activating calcium-dependent signaling pathways, energy-sensing axes, and associated transcriptional regulatory networks, and participating in the regulation of skeletal muscle cellular metabolism. Therefore, it is mechanistically plausible that GPCR-mediated leucine signaling may influence the cellular metabolic state and transcriptional regulatory networks, thereby playing a potential role in skeletal muscle fiber type transformation. In addition, leucine and its metabolites exert multiple biological functions in signal regulation, protein synthesis, and degradation balance, and may collectively participate in the coupling regulation among “nutrient signaling, metabolic networks and phenotypic expression”. This review summarized the metabolic processes of leucine and the related signal transduction pathways involved in skeletal muscle fiber type transformation, outlined recent advances in the role of GPCR-mediated leucine sensing in metabolic pathways and transcriptional regulatory networks, and further explored its potential involvement in skeletal muscle fiber type transformation. Additionally, key scientific questions as well as future research directions were highlighted, with the aim of providing a theoretical basis for exercise nutrition interventions, muscle development in livestock and meat quality improvement.

Ochratoxin A (OTA) is primarily produced by fungi of the genera Aspergillus and Penicillium, and its contamination has become a critical issue in feed safety that urgently requires resolution. Current strategies for OTA contamination control are primarily implemented from three aspects: first, inhibiting the colonization and proliferation of toxigenic fungi by using competitive microorganisms or substances with antifungal activity; second, blocking the biosynthetic pathway of OTA through the intervention of plant extracts, microbial metabolites and culture condition regulation; third, achieving efficient removal of already formed OTA via microbial degrading strains and their associated degrading enzymes. Through systematic screening of efficient OTA-degrading microorganisms and key degrading enzymes, combined with technologies such as synthetic biology, genetic engineering, and transcriptomics to elucidate their mechanisms of action, it is expected to provide more precise and reliable technical solutions for OTA pollution prevention and control. This paper systematically reviewed the physicochemical properties of OTA and its toxic effects in livestock and poultry, with a focus on the potential mechanisms of action in different target organs and physiological systems. Furthermore, starting from the regulation of toxigenic fungi, interruption of OTA biosynthesis, and contamination remediation, the existing multi dimensional prevention and control measures were summarized and categorized, aiming to provide a reference for the scientific, precise, and efficient control of OTA in feed and forage.

Semen quality directly affects the reproductive efficiency of sows and the health status of their offspring, and is therefore a key determinant of overall pig production efficiency. Dietary fiber has long been regarded as a “non-nutritive substance”. However, recent researches have progressively revealed that it not only exerts basic physiological functions such as promoting intestinal motility and optimizing microbial community composition, but also demonstrates significant ameliorative effects on boar semen quality. This review systematically summarizes the effects of dietary fiber on semen quality and its underlying mechanisms, aiming to provide theoretical guidance for the rational application of dietary fiber in the diets of breeding boars.[Chinese Journal of Animal Nutrition, 2026, 38(8):5563-5570]

In China’s pig production, the promotion and use of diversified diets of miscellaneous grains and meals provides an important technical guarantee for alleviating the shortage of feed resources and reducing the risk of food security. As the main nutritional component of non-grain feed raw materials, dietary fiber plays a key role in regulating intestinal health of pigs at different growth stages. Dietary fiber is degraded by microorganisms in the digestive tract to produce metabolites such as short-chain fatty acids, which can effectively regulate the energy metabolism of intestinal epithelial cells, promote cell proliferation and differentiation, and maintain the structural integrity and functional integrity of the intestinal barrier. At the same time, the effect of dietary fiber on intestinal physiology varies with its physical and chemical properties. Soluble dietary fiber is combined with water in the digestive tract of pigs, which makes the physical properties of chyme turn to a viscous state, thus delaying the transport rate of chyme in the intestinal lumen and prolonging the digestion and absorption time of nutrients. Insoluble dietary fiber can increase the transport rate of intestinal chyme, shorten the fermentation time of nutrients in the cecum and colon, and increase the output of chyme due to its low water-holding capacity. This paper summarizes the definition and classification system of dietary fiber, and focuses on its regulation on intestinal physiological state, microbiota and intestinal barrier function in pigs, in order to provide reference for the efficient utilization of unconventional feed resources and the regulation of intestinal health through dietary fiber nutritional characteristics to improve pig performance.

Weaning stress readily disrupts redox homeostasis in piglets, triggering intestinal and systemic organ damage that severely impairs growth performance. Taurine (Tau) is a conditionally essential amino acid with multiple biological functions, including anti-inflammatory and antioxidant effects, immune modulation, and promotion of growth and development. This review elucidates Tau’s core mechanisms in alleviating intestinal oxidative stress in weaned piglets across three levels: regulation of the glutathione (GSH)/glutathione disulphide (GSSG) antioxidant system, modulation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) antioxidant signaling pathway, and maintenance of normal mitochondrial function. It provides insights into the mechanisms underlying Tau’s antioxidant effects and offers guidance for its precise application in swine production.

With the upgrading of consumption levels, the dairy market exhibits a core trend of concurrent growth in overall demand and premiumisation of products. Among them, milk protein and milk fat are key milk components that determine the nutritional value and economic value of milk, and optimizing milk composition and yield has become a central objective for achieving profitability growth in dairy farming. Current research, through precise genetic analysis and targeted improvement, fundamentally aims to optimize the composition and content of milk components, this represents a key pathway and frontier for overcoming industrial bottlenecks and enhancing milk quality. This paper therefore systematically reviews the regulatory mechanism of encoded genes, non-coding genes and genetic polymorphisms on milk protein and milk fat in dairy cows, aims to reveal the underlying molecular mechanisms at multiple levels, thereby establishing a theoretical foundation for the genetic analysis and precise regulation of milk protein and milk fat.

Soybean meal is the primary source of protein in animal diet. Since China has long relied on imports for its soybean meal raw material (soybeans), it is highly susceptible to fluctuations in international soybean market prices; therefore, identifying viable alternatives is a pressing issue that needs to be addressed. The miscellaneous meal (cottonseed meal and rapeseed meal, et al) application in animal diet is limited due to issues such as imbalanced amino acid composition and antinutritional factors. Based on the theories of amino acid composition, rumen fermentation regulation and energy nitrogen balance, this paper systematically indicates the effects of miscellaneous meal and non-protein nitrogen feed replacing soybean meal on rumen microbiota, rumen fermentation parameters, nutrient digestibility, serum biochemical indices, growth performance and meat quality of meat sheep, reviews the research progress on the application of miscellaneous meal and non-protein nitrogen feed replacing soybean meal in sheep meat production, to promote the rational application of soybean meal reduction and replacement technology in meat sheep diets, and support the sustainable development of the livestock industry.

Brown adipose tissue plays a crucial role in maintaining the body temperature and energy metabolism of young animals through its unique thermogenic function. The development of fetal brown adipose tissue during the embryonic stage is closely related to the maternal active thyroid hormone triiodothyronine (T₃). Maternal T₃ enters the fetus through the placental transport system and thereby affects the development of fetal brown adipose tissue during pregnancy. T₃ promotes the proliferation and directed differentiation of brown adipose progenitor cells by binding to thyroid hormone receptors, thereby regulating brown adipose tissue development and controlling mitochondrial biogenesis and homeostasis through genomic and non-genomic pathways, ensuring the thermogenic basis. This article reviews the core role and molecular mechanism of maternal T₃ entering the fetus through the placental transport system and influencing the development of fetal brown adipose tissue during the later stages of pregnancy, revealing the developmental rules of fetal brown adipose tissue, and providing an important theoretical basis for nutritional regulation during the later stages of pregnancy in female animals and early health management of newborn animals.

Corn stover, an abundant agricultural by-product with substantial development potential, has therefore attracted increasing attention for valorization. However, its high degree of lignification and complex cell-wall structure remain major bottlenecks limiting its feeding value. Strategies including physical modification to reshape microstructure, chemical pretreatments to disrupt lignin-carbohydrate complexes and improve energy-nitrogen synergistic regulation, and microbial-enzymatic synergistic conversion can reduce cell-wall recalcitrance and release utilizable deconstruction products and nutrient fractions. After entering the rumen, these products may reshape the rumen microbiota, optimize volatile fatty acid composition, and participate in regulating the “microbiota-metabolism-immunity axis”, thereby potentially benefiting performance, health status and meat quality in ruminants. Accordingly, corn stover valorization may represent an important technology to mitigate food-feed competition and promote cost reduction and efficiency improvement in the livestock industry, showing broad application prospects in ruminant production. This review summarizes the constraint characteristics on fiber degradation of corn stover, key technologies for valorization to overcome cell-wall recalcitrance, and the regulation mechanism on performance of ruminants, and provides technical references for the rational utilization of corn stover resources.

Antler is an important economic trait of sika deer, and its yield and quality are directly related to the economic benefits. The rapid regeneration and growth of antler mainly depend on the proliferation and differentiation of cells in the growth center. Among these processes, the chondrogenic differentiation of antler mesenchymal stem cells (AnSCs) serves as an important cellular basis for antler tissue formation and growth and represents a key biological process affecting antler yield. Retinoic acid (RA) is the active metabolite of vitamin A, RA signaling pathway has attracted increasing attention for its role in regulating the fate of AnSCs. This review focuses on cellular differentiation and regulatory mechanisms involved in antler growth, systematically summarizes the composition and functions of the RA signaling pathway, and discusses its potential roles in AnSC differentiation and antler growth, aiming to provide a reference for vitamin A nutritional regulation in sika deer during the antler growth period and for improving antler yield.

Developing novel unconventional feed resources is a crucial approach to ensure national food security and alleviate the current competition between human food and animal feed. As a renewable resource, bamboo is abundant and rich in dietary fiber and functional bioactive compounds, offering great potential for use as livestock feed. This review summarizes the distribution, physicochemical properties, and key technologies for utilizing bamboo as animal feed. Physical, chemical, and biological pretreatment methods can effectively break down bamboo’s fibrous structure, improving its palatability and nutritional value. Studies have shown that adding appropriate amounts of bamboo powder, bamboo leaf extracts, or their fermented products to animal diets can enhance growth performance, nutrient digestibility, intestinal health, and product quality. However, challenges remain in the feed utilization of bamboo, including significant variation in raw material composition, high processing costs, and an unstable supply system. Future efforts should focus on establishing standardized databases for raw material composition, developing low-cost pretreatment processes, and building intelligent collection, storage, and transportation systems to promote large-scale application. This article provides valuable insights for the efficient utilization of bamboo resources in healthy animal production.

Fumaric acid serves multiple biological functions in animal feed as an acidifier, including lowering gastrointestinal pH, selectively inhibiting pathogenic bacteria, improving intestinal morphology and function, enhancing nutrient digestibility, modulating rumen fermentation patterns, acting as a hydrogen acceptor to reduce methane (CH₄) emission, and exerting antioxidant and immune-regulatory effects. In weaned piglets, fumaric acid effectively alleviates weaning stress, improves growth performance, and controls diarrhea. In poultry, it enhances growth and egg production, improves meat and egg quality, and strengthens stress resistance. In ruminants, its primary role lies in regulating rumen fermentation by increasing propionate proportion and suppressing CH₄ production. In aquaculture species such as Nile tilapia and Pacific white shrimp, fumaric acid also demonstrates potential for promoting growth, disease resistance and health regulation. Future research should focus on a deeper understanding of its mechanisms of action and the development of novel and highly efficient preparations. This review systematically summarized the research progress on biological functions of fumaric acid and its application in swine, poultry, ruminant and aquatic animal production, aiming to provide guidance for its scientific application.

Ovarian aging can lead to decreased fertility, endocrine disorders, and impaired systemic health in female animals. Its pathogenesis is closely associated with oxidative stress, immune inflammation, gut microbiota dysbiosis and hypothalamic-pituitary-ovarian axis dysfunction. Antioxidant probiotics, owing to their antioxidative, anti-inflammatory, and immunomodulatory properties, have become a frontier hotspot for research on delaying ovarian aging. These probiotics can alleviate ovarian inflammation by modulating gut homeostasis, repairing the intestinal barrier and reducing the entry of endotoxins into the bloodstream. Simultaneously, they regulate the levels of metabolites such as short-chain fatty acids, scavenge reactive oxygen species, and activate the endogenous antioxidant defense system. Furthermore, they inhibit granulosa cell apoptosis, preserve follicular reserve and improve ovarian function through multiple pathways. This review outlined the core mechanisms of ovarian aging and elaborated on the pathways through which antioxidant probiotics delay ovarian aging in female animals, aiming to provide a reference for related research and applications.

Lactic acid bacteria bacteriocins are peptides or proteins produced by the ribosomes of lactic acid bacteria. They possess characteristics such as bacteriostatic activity, environmental friendliness, safety and high efficiency, making them ideal alternatives to antibiotics. The low yield of bacteriocins has become the key factor limiting their large-scale application. Through effective techniques for strain improvement of bacteriocin-producing lactic acid bacteria, efficient and stable expression of bacteriocins can be achieved. Based on this, this paper reviewed 4 strategies for regulating the efficient expression of lactic acid bacteria bacteriocins: optimization of culture conditions, co-culture induction, heterologous expression and mutation breeding. The mechanisms and expression effects of these strategies were compared in depth. Furthermore, the research progress on the application of bacteriocin-producing lactic acid bacteria and their bacteriocins in feed was summarized. In addition, this paper also proposes prospects for the large-scale production of lactic acid bacteria bacteriocins and future development directions, aiming to provide a reference for the efficient expression of bacteriocins and their application in feed.

Bifidobacteria, as an important probiotic, plays a significant role in maintaining gut microbiota homeostasis, enhancing intestinal barrier function and regulating host immune responses. With the transition of animal husbandry towards green, efficient and antibiotic-free farming models, bifidobacteria has garnered widespread attention in the field of animal nutrition and health due to its high safety and diverse functionalities. bifidobacteria contributes to the maintenance of intestinal microecological homeostasis and immune balance by modulating gut microbial composition, strengthening intestinal barrier integrity and balancing immune responses. This review systematically summarizes the key biological functions and mechanisms of bifidobacteria, as well as its research progress in applications across various livestock and poultry production systems. Furthermore, it explores the potential and future directions for the rational development and precise application of bifidobacteria in animal nutrition regulation, aiming to provide a theoretical basis for its targeted utilization.

This experiment aimed to investigate the effects of dietary supplementation with different levels of fermented white distiller’s grains (FDG) on the growth performance, longissimus dorsi meat quality, amino acid composition, volatile flavor substances and fatty acid composition of finishing pigs. A total of 180 three-way crossbred (Duroc×Landrace×Yorkshire) growing barrows with an average initial body weight of (60.0±0.5) kg were selected and randomly divided into 6 groups, with 6 replicates per group and 5 pigs per replicate. On an air-dry basis, the dietary supplementation levels of FDG for the five groups of barrows were 0 (F0 group, as control group), 5% (F5 group), 10% (F10 group), 15% (F15 group), 20% (F20 group) and 25% (F25 group), respectively. The experimental period lasted 60 days. The results showed as follows: 1) there were no significant differences in average daily gain (ADG) and average daily feed intake (ADFI) among all groups (P>0.05). However, the feed-to-gain ratio (F/G) in the F25 group was significantly higher than that in the F0, F5 and F10 groups (P<0.05). Regression analysis showed that the lowest F/G of finishing pigs was achieved when the dietary supplementation level of FDG was 7.01%. 2) Total weight gain, production efficiency and gross profit showed a trend of first increasing and then decreasing with the increasing supplementation level of FDG, peaking in the F10 group, then gradually declining, and reaching the lowest level in the F25 group. 3) Dietary supplementation with different levels of FDG had no significant effects on the slaughter performance of finishing pigs (P>0.05). 4) Analysis of amino acid composition in the longissimus dorsi showed that the cystine content in the F15 group was significantly higher than that in the F0, F20 and F25 groups (P<0.05), and the lysine content was significantly higher than that in the F10 group (P<0.05). Moreover, the F15 group had the highest total contents of umami amino acids and essential amino acids. 5) Aldehydes were the main flavor components in the longissimus dorsi of finishing pigs, with relatively high contents in the F10 and F15 groups at 41.55% and 41.49%, respectively. 6) Analysis of fatty acid composition in the longissimus dorsi showed that the linoleic acid content in the F10 group was significantly higher than that in the F20 group (P<0.05). The total content of polyunsaturated fatty acids showed a trend of first increasing and then decreasing with the increasing supplementation level of FDG, reaching its highest value in the F10 group. In conclusion, dietary supplementation with 10% to 15% FDG does not decrease the growth performance of finishing pigs, while it can improve economic benefits and enhance the amino acid composition, fatty acid composition and flavor characteristics of the muscle.

This study aimed to investigate the effects of maternal dietary fatty acids balanced oil (FABO) supplementation on brain development and neuroinflammation in suckling piglets. Twenty-four Landrace×Large White sows with similar parity and backfat thickness were randomly divided into 2 groups with 12 replicates per group 1 sow per replicate. The experiment began from day 90 of gestation and continued until day 21 of postpartum. At day 21 of postpartum, one suckling piglet from each litter was selected in a 2×2 factorial experiment with dietary treatment of sows (2% soybean oil or 2% FABO) and lipopolysaccharide (LPS) challenge of suckling piglets (injected saline or LPS). All suckling piglets were grouped by dietary treatment of sows. Six suckling piglets in each group were injected intraperitoneally with 100 μg/kg BW LPS or saline. At 4 hour post-injection of LPS, the blood was collected. All suckling piglets were anesthetized and slaughtered, and the prefrontal cortex and hippocampus samples were collected for test. The results showed as follows: 1) LPS challenge significantly decreased the contents of glucose, total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol in plasma of suckling piglets (P<0.05); 2% FABO significantly increased the plasma glucose content of suckling piglets (P<0.05), and significantly alleviated the decrease of plasma triglyceride content induced by LPS challenge (P<0.05). 2) LPS challenge significantly increased the mRNA relative expression levels of heat shock protein 70 (HSP70), interleukin-6 (IL-6) in hippocampus and HSP70 in prefrontal cortex of suckling piglets (P<0.05); 2% FABO significantly decreased the mRNA relative expression levels of IL-6, HSP70 and cyclooxygenase-2 (COX-2) in prefrontal cortex and COX-2 in hippocampus of suckling piglets (P<0.05). 3) LPS challenge significantly decreased the mRNA relative expression levels of early growth response protein 1 (Egr1), brain-derived neurotrophic factor (BDNF) in prefrontal cortex of suckling piglets (P<0.05), and significantly increased mRNA relative expression level of nerve growth factor (NGF) in hippocampus (P<0.05); 2% FABO significantly increased the mRNA relative expression levels of NGF, BDNF, tropomyosin receptor kinase B (TrkB) and phosphatidylinositol-3 kinase (PI3K) in prefrontal cortex and hippocampus and cellular oncogene fos (c-fos) in hippocampus of suckling piglets (P<0.05). 4) LPS challenge significantly increased the mRNA relative expression level of cysteinyl aspartate proteinase-3 (Caspase-3) in prefrontal cortex and hippocampus of suckling piglets (P<0.05); 2% FABO significantly increased the mRNA relative expression level of B cell lymphoma-2 (Bcl-2) in prefrontal cortex and hippocampus of suckling piglets (P<0.05), significantly decreased the mRNA relative expression level of Caspase-3 in hippocampus (P<0.05), and significantly alleviated the increase of mRNA relative expression levels of Caspase-3 in prefrontal cortex, Bcl-2-associated X (Bax) in hippocampus and the protein relative expression of cleaved cysteinyl aspartate proteinase-3 (Cleaved Caspase-3) in prefrontal cortex and hippocampus induced by LPS challenge (P<0.05). 5) LPS challenge significantly decreased the activity of acetylcholinesterase (AChE) in hippocampus of suckling piglets (P<0.05); 2% FABO significantly increased the activity of AChE in prefrontal cortex and hippocampus of suckling piglets (P<0.05). In conclusion, the maternal dietary 2% FABO supplementation can promote the development and differentiation of brain, reduce neuroinflammatory response, and alleviate neuronal apoptosis induced by LPS in suckling piglets.

This experiment aims to explore the this experiment aimed to explore the alleviating effects and mechanisms of Lactobacillus plantarum postbiotics on Salmonella-derived lipopolysaccharide (LPS) -induced inflammation of weaned piglets. A total of 60 healthy “Duroc×Landrace×Large White” weaned piglets at 28 days of age with an initial body weight of (7.26±0.36) kg were randomly divided into 4 groups with 15 replicates per group and 1 piglet per replicate. The four groups were control (CON) group, PB group, LPS group and PB+LPS group. Piglets in the CON and LPS groups were fed a basal diet supplemented with 0.8% MRS medium, while those in the PB and PB+LPS groups were fed a basal diet supplemented with 0.8% Lactobacillus plantarum postbiotics. After 28 days of feeding, the piglets were challenged on day 29. The LPS and PB+LPS groups received an intraperitoneal injection of Salmonella-derived LPS at a dose of 30 μg/kg BW, while the CON and PB groups received an equal volume of sterile saline. Samples were collected 4 hours later. The results showed as follows: 1) compared with the CON group, jejunum weight in the LPS group was significantly decreased (P<0.05), while no significant difference was observed in the PB+LPS group (P>0.05). 2) Compared with the CON group, jejunal and ileal villus height and villus height to crypt depth ratio (V/C) in the LPS group were significantly decreased (P<0.05), while the jejunal and ileal crypt depth were significantly increased (P<0.05). Compared with the LPS group, jejunal villus height and V/C in both jejunum and ileum in the PB+LPS group showed significantly increased (P<0.05), and the jejunal and ileal crypt depth was significantly decreased (P<0.05). 3) Compared with the CON group, the mRNA relative expression levels of zonula occludens-1 (ZO-1) and claudin-1 in the ileum of the LPS group were significantly down-regulated (P<0.05), while no significant differences were observed in the PB+LPS group (P>0.05). 4) Compared with the CON group, levels of pro-inflammatory cytokines interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the ileum of the LPS group were significantly increased (P<0.05), while the level of anti-inflammatory cytokine interleukin-10 (IL-10) was significantly decreased (P<0.05). Compared with the LPS group, levels of IL-1β and TNF-α in the PB+LPS group showed significantly decreased (P<0.05), and level of IL-10 was significantly increased (P<0.05). 5) Compared with the CON group, the mRNA relative expression levels of apoptosis-associated speck-like protein (ASC), cysteine-aspartate protease-1 (Caspase-1), IL-1β and gasdermin D (GSDMD) in the ileum of the LPS group were significantly up-regulated (P<0.05). Compared with the LPS group, mRNA relative expression levels of ASC, Caspase-1, IL-1β and GSDMD in the PB+LPS group exhibited significantly decreased (P<0.05). 6) Compared with the CON group, the mRNA relative expression level of nuclear factor- kappa B (NF-κB) in the ileum of the LPS group was significantly up-regulated (P<0.05). Compared with the LPS group, mRNA relative expression levels of Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88) and NF-κB in the ileum of the PB+LPS group showed significantly decreased (P<0.05). In conclusion, dietary supplementation with Lactobacillus plantarum postbiotics alleviates the inflammatory response induced by Salmonella-derived LPS in weaned piglets by maintaining intestinal barrier function, modulating inflammatory cytokines, and inhibiting the activation of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and its upstream signaling pathways.

This study aimed to investigate the effects of cyclic heat stress on growth performance, jejunal morphology and jejunal mucosal transcriptome and metabolome of yellow-feathered broilers. A total of 120 male fast-growing yellow-feathered broilers aged 35 days with similar body weight were randomly allocated into two groups: a control group and a heat-stressed group. Each group consisted of 6 replicates with 10 birds per replicate. Birds in both groups were fed the same basal diet. The control group was reared at 26 ℃, whereas the heat-stressed group was subjected to a 7-day gradual temperature increase followed by a 14-day cyclic heat stress (32 to 35 ℃). The results showed as follows: 1) in comparison with the control group, the body weight at 56 days of age, average daily feed intake and average daily gain of broilers in the heat stress group decreased significantly (P<0.05), and the feed to gain ratio increased significantly (P<0.05). In addition, the jejunal villi in the heat-stressed group appeared sparse and fractured, and both villus height and the ratio of villus height to crypt depth were significantly reduced compared with the control group (P<0.05). 2) The jejunal mucosa transcriptome analysis showed that a total of 325 differentially expressed genes (DEGs) between the two groups were identified, which were mainly enriched in pathways such as C5-branched dibasic acid metabolism, cytokine-cytokine receptor interaction and cell adhesion molecules. Notably, the expression of genes C-C motif chemokine ligand 19 (CCL19), C-C motif chemokine ligand 21 (CCL21), interleukin-1 receptor 2 (IL1R2) and citrate decarboxylase 1 (ACOD1) were significantly upregulated in the heat-stressed group. 3) The jejunal mucosal metabolome analysis showed that a total of 16 differentially expressed metabolites (DEMs) between the two groups were identified. The levels of metabolites such as 1-palmitoyl-2-octadecenoic-sn-glycerol-3-phosphocholine, 2-oilyl-1-palmitoyl-sn-glycerol-3-phosphocholine, ethyl sulfate, α-ketoglutaric acid and biliverdin were significantly upregulated in the heat-stressed group. 4) The integrated transcriptomic and metabolomic analysis revealed that DEGs and DEMs in jejunal mucosa were co-significantly enriched in the C5-branched dibasic acid metabolism pathway. Correlation analysis further suggested that ACOD1 gene may mediate this pathway to regulate α-ketoglutarate production, thereby participating in the maintenance of energy and immune homeostasis. In summary, cyclic heat stress can induce metabolic and immune disorders in the jejunal mucosa of yellow feathered broilers, as evidenced by the enhancement of the C5 branched dibasic acid metabolism pathway and the activation of immune inflammatory pathways such as cytokine cytokine receptor interaction. These changes subsequently trigger intestinal immune and inflammatory responses, leading to jejunal villous atrophy and nutrient malabsorption, and ultimately suppressing growth performance.

This experiment was conducted to investigate the effects of dietary metabolizable energy (ME) and crude protein (CP) levels on growth performance, body size traits, slaughter performance and serum indices of commercial Jishan black chickens aged from 5 to 10 weeks, so as to determine the optimal dietary ME and CP levels for this chicken strain during 5 to 10 weeks of age. A total of 768 healthy 4-week-old commercial Jishan black chickens with similar body weights were selected and randomly allocated into 6 groups with 8 replicates per group and 16 chickens per replicate. A 3×2 two-factor experimental design was adopted, with three ME levels (11.30, 11.72 and 12.13 MJ/kg) and two CP levels (17.0% and 19.0%). The trial lasted for 6 weeks (5 to 10 weeks of age). The results showed as follows: 1) the final body weight and average daily gain in the 11.30 MJ/kg ME group were significantly lower than those in the 11.72 MJ/kg ME group (P<0.05), and the feed-to-gain ratio was significantly higher than that in the 11.72 and 12.13 MJ/kg ME groups (P<0.05). Dietary CP level and the interaction between ME and CP levels had no significant effects on growth performance (P>0.05). 2) The keel length in the 11.72 MJ/kg ME group was significantly higher than that in the 11.30 and 12.13 MJ/kg ME groups (P<0.05). Dietary CP level had no significant effect on body size traits (P>0.05). There was a significant interaction between dietary ME and CP levels on keel length (P<0.05). 3) The glandular stomach relative weight in the 11.72 MJ/kg ME group was significantly lower than that in the 11.30 and 12.13 MJ/kg ME groups (P<0.05), and the bursa of Fabricius relative weight in the 11.30 MJ/kg ME group was significantly higher than that in the 11.72 and 12.13 MJ/kg ME groups (P<0.05). Dietary CP level and the interaction between ME and CP levels had no significant effects on slaughter performance (P>0.05). 4) The serum contents of total protein, albumin, urea nitrogen, glucose and total cholesterol in the 11.72 MJ/kg ME group were significantly higher than those in the 11.30 and 12.13 MJ/kg ME groups (P<0.05), and the serum globulin content was significantly higher than that in the 11.30 MJ/kg ME group (P<0.05). The serum superoxide dismutase activity in the 12.13 MJ/kg ME group was significantly lower than that in the 11.30 and 11.72 MJ/kg ME groups (P<0.05). Dietary CP level had no significant effect on all serum indices (P>0.05). There were significant interactions between dietary ME and CP levels on serum urea nitrogen and glucose contents (P<0.05). Considering all indices comprehensively, it is recommended to maintain the dietary ME level at 11.72 MJ/kg and the CP level at 17.0% for commercial Jishan black chickens aged from 5 to 10 weeks.

This study was conducted to investigate the effects of supplementing novel acid protease in diets with different crude protein (CP) levels on growth performance, serum indices and intestinal health of broilers. A 2×3 factorial experimental design was adopted, including two dietary CP levels [normal CP (NP) and low CP (LP, CP reduced by 2 percentage points relative to the NP diet] and three supplemental levels of acid protease (0, 1 and 2 g/kg). A total of 288 one-day-old male Arbor Acres broilers with an initial body weight of (48.69±0.98) g were randomly assigned to six groups, with six replicates per group and eight broilers per replicate. The trial lasted for 42 days and was divided into two phases: the early stage (1 to 21 days of age) and the late stage (22 to 42 days of age). The results showed as follows: 1) compared with the NP diet, the LP diet significantly or extremely significantly increased average daily gain (ADG), average daily feed intake (ADFI) and feed to gain ratio (F/G) in the early stage (P<0.05 or P<0.01), extremely significantly decreased ADG in the late stage and European production efficiency factor (EPEF) over the whole trial period (P<0.01), and extremely significantly increased F/G during the whole trial period (P<0.01). Compared with no acid protease supplementation, the supplementation of 1 and 2 g/kg acid protease extremely significantly decreased the late-stage F/G (P<0.01) and extremely significantly increased the overall EPEF (P<0.01). 2) Compared with the NP diet, the LP diet significantly decreased breast muscle percentage (P<0.05) and extremely significantly increased abdominal fat percentage (P<0.01). Compared with no acid protease supplementation, the supplementation of 1 g/kg acid protease significantly increased breast muscle percentage (P<0.05). 3) Compared with the NP diet, the LP diet extremely significantly increased serum triglyceride and total cholesterol contents (P<0.01) and significantly decreased serum aspartate aminotransferase activity (P<0.05). Compared with no acid protease supplementation, the supplementation of 2 g/kg acid protease signifi-cantly increased serum total antioxidant capacity (P<0.05). 4) Compared with the NP diet, the LP diet significantly increased jejunal amylase activity and dry matter apparent metabolic rate (P<0.05) and significantly or extremely significantly decreased the villus height in the jejunum and ileum (P<0.05 or P<0.01). Compared with no acid protease supplementation, the supplementation of 2 g/kg acid protease extremely significantly increased duodenal chymotrypsin activity (P<0.01) and significantly increased jejunal trypsin activity, dry matter and gross energy apparent metabolic rates, as well as ileal villus height (P<0.05). 5) When fed the NP diet, compared with no acid protease supplementation, the supplementation of 2 g/kg acid protease extremely significantly increased the cecal microbial Sobs, Chao1, and Shannon indexes of 21-day-old broilers (P<0.01). Linear discriminant analysis effect size (LEfSe) analysis showed that the NP diet group specifically enriched microbiota related to Lactobacillus; the LP diet group co-enriched microbiota related to the class Clostridia. The NP diet supplemented with 2 g/kg acid protease specifically enriched microbiota such as Lachnospiraceae and Ruminococcaceae. In conclusion, reducing dietary CP level by 2 percentage points promoted feed intake and weight gain in the early stage of broilers but was detrimental to later growth and carcass quality. However, dietary supplementation with 2 g/kg of the novel acid protease improved cecal microbiota structure, and by enhancing digestive enzyme activity, nutrient apparent metabolic rates, and intestinal morphology, effectively alleviated the growth inhibition induced by the low-protein diet in the later stage and improved feed efficiency.

This study aimed to investigate the effects of dietary supplementation with different doses and forms of iodine on growth performance, immune organ indices, thyroid index, serum thyroid hormone levels and thyroid tissue morphology of broilers. A total of 640 one-day-old male Ross 308 broilers were randomly allocated into 8 groups, each with 8 replicates of 10 birds per replicate. A 2×4 factorial design was employed, consisting of two forms of iodine (coated calcium iodate and uncoated calcium iodate) and four doses of iodine (0.5, 1.0, 1.5 and 2.0 mg/kg), resulting in a total of 8 experimental diets. The adaptation period lasted for 7 days, and the formal experiment lasted for 42 days. The results showed as follows: 1) dietary supplementation with different doses of iodine significantly affected the average daily gain (ADG) of broilers from 8 to 28 days of age (P<0.05). The ADG of broilers in the 2.0 mg/kg group was significantly higher than that in the 0.5 and 1.0 mg/kg groups (P<0.05), but showed no significant difference compared with the 1.5 mg/kg group (P>0.05). Dietary supplementation with different doses of iodine also significantly affected the thymus index, thyroid index, and serum thyroid hormone levels, including triiodothyronine (T3), thyroxine (T4) and thyroid-stimulating hormone (TSH) (P<0.05). The 1.5 mg/kg level exhibited the most pronounced effects in increasing thymus index and serum T3 and T4 levels. Regarding iodine form, coated calcium iodate significantly increased the thymus index, thyroid index and serum T4 level compared with uncoated calcium iodate (P<0.05). However, histological observation revealed that when the doses of iodine reached 1.0 mg/kg or higher, thyroid follicle volume increased, and cell arrangement irregularity appeared at 1.5 and 2.0 mg/kg. In conclusion, under the conditions of this experiment, dietary supplementation with 1.5 mg/kg coated calcium iodate can achieve the optimal balance among promoting immune organ development, optimizing thyroid function and maintaining tissue health in broilers.

This experiment aimed to evaluate the standardized ileal digestibility (SID) of amino acids in two different sources of cottonseed protein (CSP1 and CSP2) and its fermentation and enzymatic hydrolysis products in yellow-feathered broilers, and to compare the effects of different modification methods. A total of 384 sixty-day-old medium-speed yellow-feathered roosters with similar body weight were randomly assigned into 8 groups with 8 replicates per group and 6 birds per replicate. Each group was fed a nitrogen-free diet or a diet containing CSP1, its fermented product (CSP1F), its enzymatic hydrolyzed product (CSP1E), CSP2, its fermented product (CSP2F), its keratinase-hydrolyzed product (CSP2E1), or its alkaline protease-hydrolyzed product (CSP2E2) as the sole protein source, respectively. All diets were supplemented with 0.50% titanium dioxide (TiO₂) as an exogenous indicator. The trial lasted for 4 days. At the end of the experiment, ileal digesta samples were collected from the broilers. Amino acid and TiO₂ contents in all diets and digesta samples were determined. The SID of amino acids in the ingredients was calculated using the nitrogen-free diet method. The results showed as follows: 1) in terms of the chemical composition of ingredients, compared with CSP1, CSP2 had higher crude protein content (61.04% vs 53.83%) and lower contents of crude fiber and free gossypol. Fermentation treatment increased the acid-soluble protein content (CSP1F: 17.02% vs 4.02%; CSP2F: 6.66% vs 5.14%) and decreased the free gossypol content (CSP1F: 162 mg/kg vs 383 mg/kg; CSP2F: 193 mg/kg vs 293 mg/kg). Enzymatic hydrolysis, especially for CSP1E, significantly increased the potassium hydroxide protein solubility and the contents of acid-soluble protein and water-soluble protein. 2) In terms of the amino acid composition of ingredients, CSP2 had higher total amino acid content (57.17% vs 45.78%) than CSP1. Fermentation generally decreased the amino acid contents. Among enzymatic hydrolysis treatments, only CSP1E significantly increased the total amino acid content (55.05% vs 45.78%), while the two enzymatic hydrolysates of CSP2 showed decreased the total amino acid content. 3) In terms of SID of amino acids, the SID of amino acids in the two sources of cottonseed protein ranged from 48.34% to 90.45%, with only the tryptophan SID being significantly higher in CSP2 than in CSP1 (P<0.05). Compared with CSP1, CSP1F significantly increased the SID of tryptophan (P<0.05) but decreased the SID of some non-essential amino acids; CSP1E significantly increased the SID of lysine, tryptophan, and alanine (P<0.05). Compared with CSP2, CSP2F only significantly decreased the SID of tryptophan (P<0.05); CSP2E1 significantly decreased the SID of most amino acids except histidine and arginine (P<0.05); while CSP2E2 had no significant effect on the SID of any amino acids (P>0.05). In conclusion, the cottonseed protein from different sources responds differently to modification processes, and the appropriate modification method should be selected based on ingredient characteristics in practical applications.

This study was conducted to determine the effective energy values of eight kinds of rapeseed meal in white-feathered broilers by combining the respiration calorimetry method with the substitution method, and to establish prediction equations for apparent metabolizable energy (AME) and net energy (NE) through multiple regression analysis. A total of 216 seven-day-old white-feathered broilers were randomly divided into 9 groups, including one corn-soybean meal basal diet group and eight tested diet groups with 20% rapeseed meal substitution. Each group had six replicates with four broilers per replicate. The experimental period lasted for 7 days, consisting of a 4-day preliminary trial period and a 3-day formal trial period (11 to 14 days of age). Continuous respiration calorimetry and digestion and metabolism trials were conducted during the formal trial period. The results showed that the average AME and NE values of eight kinds of rapeseed meal determined in white-feathered broilers were 9.40 and 4.93 MJ/kg, respectively. The established AME prediction equation of rapeseed meal in white-feathered broilers was: AME=1.767-0.110×crude fiber+4.398×starch-0.243×glucosinolate [coefficient of determination (R²)=0.939, root mean square error (RMSE)=0.130, P<0.001]. The NE prediction equation of rapeseed meal in white-feathered broilers was: NE=-1.209+0.477×AME-0.068×crude fiber+0.048×crude protein+0.102×crude ash (R²=0.999, RMSE=0.031, P<0.001). Cross-validation showed that the predicted values from the AME and NE prediction equations were close to the measured values, indicating that the prediction equations have high accuracy and can be applied to evaluate the effective energy values of rapeseed meal in white-feathered broilers.

This experiment aimed to investigate the effects of soybean lecithin (SPL) supplementation in low-energy diets on performance, egg quality, serum indices and liver health of aged laying hens. A total of 720 Jinghong No. 1 laying hens at 72 weeks of age with an average laying rate of approximately 83% were selected and randomly assigned to 9 groups in a completely randomized design, each group consisted of 8 replicates with 10 hens per replicate. The control group (CON group) was fed a basal diet with normal energy level; the L209 and L418 groups were fed experimental diets with energy levels reduced by 209 and 418 kJ, respectively; the experimental groups were fed experimental diets which supplemented with 0.16% (L209-S16 group), 0.24% (L209-S24 group), and 0.32% (L209-S32 group) SPL based on the diet of L209 group and supplemented with 0.30% (L418-S30 group), 0.50% (L418-S50 group), and 0.70% (L418-S70 group) SPL based on the diet of L418 group, respectively. The pre-experimental period lasted for 1 week, and the experimental period lasted for 12 weeks. The results showed as follows: 1) during weeks 1 to 12, the laying rate of L209-S32 group was significantly higher than that of CON group (P<0.05), and the feed to egg ratio of L418 group was significantly higher than that of other groups (P<0.05). 2) During weeks 1 to 12, the egg shape index of L209-S24 group and L209-S32 group was significantly higher than that of L418 group and L418-S50 group (P<0.05), the eggshell thickness of L418-S70 group was significantly higher than that of L209 group, L418 group and L418-S30 group (P<0.05), the albumen height of L209-S16 group, L418 group, L418-S30 group and L418-S70 group was significantly higher than that of CON group (P<0.05), the yolk color of L209-S24 group and L209-S32 group was significantly higher than that of L418-S30 group (P<0.05), and the Haugh unit of L418-S70 group was significantly higher than that of L209 group (P<0.05). 3) Compared with the L209 group, the serum total protein (TP) content of L418-S70 group was significantly increased (P<0.05), the serum albumin (ALB) content of other groups was significantly increased (P<0.05), and the serum high-density lipoprotein cholesterol (HDL-C) content of L209-S32 group and L418-S70 group was significantly increased (P<0.05). Compared with the L418 group, the serum total antioxidant capacity (T-AOC) of other groups was significantly increased (P<0.05). 4) Compared with the CON group, the liver crude fat content of other groups was significantly decreased (P<0.05). The liver histological examination results showed that the hepatocytes were neatly arranged with reduced lipid vacuoles and less inflammation in L209-S32 group and L418-S70 group; in contrast, the CON group, L209 group and L418 group exhibited marked hepatic steatosis and inflammatory infiltration. In conclusion, the SPL supplementation in low-energy diets can improve the performance, egg quality and liver health of aged laying hens. In the slight decrease energy diet (209 kJ reduction), the recommended SPL supplemental level is 0.32%; in the large decrease energy diet (418 kJ reduction), the recommended SPL supplemental level is 0.70%.

This study aimed to investigate the effects of hemoglobin peptide chelated iron on performance, egg quality and serum biochemical, immune parameters of laying hens during late laying period, and to evaluate the possibility of replacing inorganic iron with hemoglobin peptide chelated iron as a superior iron supplement. A total of 720 fifty-six-week-old Hy-Line Brown laying hens with similar laying rate and body weight were randomly divided into 6 groups with 8 replicates per group and 15 hens per replicate. The control group (group C) was fed a basal diet, the negative control group (group NC) was fed the basal diet supplemented with 60 mg/kg ferrous sulfate, and the experimental groups were fed the basal diets supplemented with 30 (group T1), 60 (group T2), 90 (group T3) and 120 mg/kg (group T4) hemoglobin peptide chelated iron, respectively. The pre-experimental period lasted for 2 weeks, and the experimental period lasted for 8 weeks. The results showed as follows: 1) the laying rate of groups T2, T3 and T4 was significantly higher than that of group C (P<0.05), and the laying rate of groups T3 and T4 was significantly higher than that of group NC (P<0.05); the feed/egg of group T4 was significantly lower than that of group C (P<0.05). 2) The eggshell color, eggshell thickness and eggshell strength of groups T2, T3 and T4 were significantly higher than those of groups C and NC (P<0.05). 3) The eggshell effective thickness of groups T2, T3 and T4 was significantly higher than that of groups C and NC (P<0.05). 4) The serum calcium content of groups T3 and T4 was significantly higher than that of group C (P<0.05), the serum phosphorus content of group T4 was significantly higher than that of groups C and NC (P<0.05), and the serum iron content of groups T3 and T4 was significantly higher than that of groups C and NC (P<0.05). 5) The serum immunoglobulin G (IgG) content of groups T2, T3 and T4 was significantly higher than that of group C (P<0.05), and the serum IgG content of group T4 was significantly higher than that of group NC (P<0.05). In summary, dietary supplemented with 60 to 90 mg/kg hemoglobin peptide chelated iron can improve the laying rate, egg quality and eggshell quality, and enhance the immune function of laying hens during late laying period.

This experiment was conducted to investigate the effects of dietary calcium and phosphorus levels on growth performance, slaughter performance, meat quality, nutrient apparent utilization rates and intestinal digestive enzyme activities of Langya chickens during fattening period. A total of 1 188 healthy 12-week-old meat product series Langya chickens were randomly divided into 9 groups with 6 replicates per group and 22 chickens per replicate. A 3×3 two-factor orthogonal experimental design was adopted, the dietary calcium levels were set at 0.55%, 0.65% and 0.75%, respectively, and the phosphorus levels were set at 0.50%, 0.60% and 0.70%, respectively. The pre-trial period lasted for 1 week, and the trial period lasted for 5 weeks. The results showed as follows: 1) the feed to gain ratio (F/G) of 0.65% calcium level group was significantly lower than that of 0.55% and 0.75% calcium level groups (P<0.05). The F/G of 0.60% phosphorus level group was significantly lower than that of 0.50% and 0.70% phosphorus level groups (P<0.05). 2) The full-eviscerated rate, breast muscle rate and abdominal fat rate of 0.65% calcium level group were significantly higher than those of 0.75% calcium level group (P<0.05). The slaughter rate, full-eviscerated rate, breast muscle rate, thigh muscle rate and abdominal fat rate of 0.60% phosphorus level group were significantly higher than those of 0.50% phosphorus level group (P<0.05). 3) The muscle drip loss of 0.65% calcium level group was significantly lower than that of 0.55% and 0.75% calcium level groups (P<0.05), the muscle shear force of 0.65% and 0.75% calcium level groups was significantly lower than that of 0.55% calcium level group (P<0.05), and the muscle redness (a^*) value of 0.65% calcium level group was significantly higher than that of 0.55% and 0.75% calcium level groups (P<0.05). The muscle pH_{45 min} of 0.60% phosphorus level group was significantly higher than that of 0.50% and 0.70% phosphorus level groups (P<0.05), the muscle drip loss of 0.60% phosphorus level group was significantly lower than that of 0.50% and 0.70% phosphorus level groups (P<0.05), and the muscle shear force of 0.50% and 0.60% phosphorus level groups was significantly lower than that of 0.70% phosphorus level group (P<0.05). 4) The crude protein and calcium apparent utilization rates of 0.65% calcium level group were significantly higher than those of 0.75% calcium level group (P<0.05). The crude protein apparent utilization rate of 0.60% phosphorus level group was significantly higher than that of 0.50% phosphorus level group (P<0.05), and the phosphorus apparent utilization rate of 0.60% phosphorus level group was significantly higher than that of 0.70% phosphorus level group (P<0.05). 5) The intestinal trypsin activity of 0.65% calcium level group was significantly higher than that of 0.55% and 0.75% calcium level groups (P<0.05). The intestinal lipase and trypsin activities of 0.60% phosphorus level group were significantly higher than those of 0.50% phosphorus level group (P<0.05). 6) Dietary calcium and phosphorus levels had significant interaction effects on the F/G, half-eviscerated rate, full-eviscerated rate, breast muscle rate, calcium apparent utilization rate and muscle pH_{45 min}, drip loss, shear force (P<0.05). In conclusion, the dietary appropriate calcium and phosphorus levels can improve the growth performance, slaughter performance, digestive function and meat quality of Langya chickens during fattening period. The dietary appropriate calcium and phosphorus levels for Langya chickens during fattening period are 0.65% and 0.60%, respectively.

This experiment was conducted to investigate the effects of daidzein (DAI) on jejunal morphology, barrier and inflammation-related gene expression, and cecal microbiota of Wenchang chickens. A total of 600 one-day-old female Wenchang chickens with an average body weight of (27.49±0.52) g were randomly assigned to 5 groups with 8 replicates per group and 15 chickens per replicate. The control group was fed a corn-soybean meal basal diet, while the experimental groups were supplemented with 500, 1 000, 2 000 and 4 000 mg/kg DAI in the basal diets, respectively. The trial lasted for 30 days. The results showed that compared with the control group: 1) the jejunal villus height was significantly increased in 500, 1 000, 2 000 and 4 000 mg/kg DAI groups (P<0.05), and the ratio of villus height to crypt depth was significantly increased in the 1 000 and 2 000 mg/kg DAI groups (P<0.05); 2) the mRNA relative expression level of Occludin in jejunum was significantly increased in the 1 000 and 2 000 mg/kg DAI groups (P<0.05), the mRNA relative expression level of interleukin-6 (IL-6) was significantly decreased in the 500 and 1 000 mg/kg DAI groups (P<0.05), and the mRNA relative expression level of tumor necrosis factor-α (TNF-α) was significantly decreased in the 500, 1 000 and 2 000 mg/kg DAI groups (P<0.05); 3) the Shannon index was significantly increased in the 500 and 1 000 mg/kg DAI groups (P<0.05), and the Simpson index was significantly increased in the 500, 1 000 and 2 000 mg/kg DAI groups (P<0.05); 4) the relative abundance of Firmicutes in the cecum was significantly increased in the 500 and 1 000 mg/kg DAI groups (P<0.05), whereas the relative abundance of Proteobacteria was significantly decreased in the 500 mg/kg DAI group (P<0.05); the relative abundance of Bacteroides was significantly increased in the 2 000 and 4 000 mg/kg DAI groups (P<0.05), and the relative abundance of Clostridia_UCG-014 was significantly increased in the 1 000, 2 000 and 4 000 mg/kg DAI groups (P<0.05). In conclusion, dietary supplemented with appropriate levels of DAI can maintain the structural integrity of jejunal villi, upregulate the expression of jejunal Occludin, downregulate the expression of IL-6 and TNF-α, and optimize the community structure of cecal microbiota. Based on the comprehensive results of this experiment, the appropriate dietary DAI supplementation level for Wenchang chickens aged 1 to 30 days is 500 to 1 000 mg/kg.

This experiment was conducted to investigate the effects of dietary crude protein (CP) and crude fiber (CF) levels on growth performance, nutrient apparent digestibility, serum biochemical indices, immune organ indices, jejunal tissue morphology and cecal microflora of Zi geese during brooding period, to determine the dietary CP and CF optimal requirements for Zi geese during brooding period, and to provide a theoretical basis for the geese breeding industry in Heilongjiang region. A total of 270 one-day-old Zi geese with good physical condition and no significant difference in body weight (P>0.05) from the same hatch were selected and randomly divided into 9 groups with 6 replicates per group and 5 geese per replicate. A 3×3 two-factor experimental design was adopted, dietary CP levels were 16.00%, 18.00% and 20.00%, respectively, and dietary CF levels were 3.50%, 5.50%, and 7.50%, respectively. The experimental period lasted for 4 weeks. The results showed as follows: 1) the final body weight, average daily gain (ADG) and average daily feed intake (ADFI) of 18.00% and 20.00% CP groups were significantly higher than those of 16.00% CP group (P<0.05), and the ratio of feed to gain (F/G) of 20.00% CP group was significantly lower than that of 16.00% and 18.00% CP groups (P<0.05); the final body weight, ADG and ADFI of 3.50% CF group were significantly higher than those of 5.50% and 7.50% CF groups (P<0.05). Dietary CP and CF levels had significant interaction effects on the final body weight, ADG and ADFI (P<0.05). 2) The apparent nutrient digestibility of crude protein, crude ash and ether extract of 18.00% and 20.00% CP groups were significantly higher than those of 16.00% CP group (P<0.05). 3) The serum uric acid (UA) content of 16.00% CP group was significantly lower than that of 18.00% CP group (P<0.05), and the serum alanine aminotransferase (ALT) activity of 16.00% and 18.00% CP groups was significantly lower than that of 20.00% CP group (P<0.05); the serum UA content of 3.50% CF group was significantly higher than that of 5.50% and 7.50% CF groups (P<0.05), and the serum ALT activity of 5.50% CF group was significantly higher than that of 3.50% and 7.50% CF groups (P<0.05). Dietary CP and CF levels had significant interaction effect on the serum ALT activity (P<0.05). 4) The bursa of Fabricius index of 16.00% CP group was significantly lower than that of 18.00% and 20.00% CP groups (P<0.05); the spleen index of 3.50% and 5.50% CF groups was significantly higher than that of 7.50% CF group (P<0.05), and the bursa of Fabricius index of 3.50% CF group was significantly higher than that of 5.50% and 7.50% CF groups (P<0.05). Dietary CP and CF levels had significant interaction effect on the spleen index (P<0.05). 5) The jejunal villus height (VH) and ratio of villus height to crypt depth (VH/CD) of 18.00% and 20.00% CP groups were significantly higher than those of 16.00% CP group (P<0.05); the jejunal VH and VH/CD of 3.50% and 5.50% CF groups were significantly higher than those of 7.50% CF group (P<0.05). Dietary CP and CF levels had significant interaction effects on the VH and crypt depth (CD) (P<0.05). 6) The cecal dominant phyla in all groups were Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria, and the dominant genera were Bacteroides and Faecalibacterium. The relative abundances of Firmicutes and Faecalibacterium in cecum was highest in 20.00% CP and 3.50% CF group. In conclusion, based on the comprehensive analysis of all indices, it is recommended that the dietary optimal levels of CP and CF for Zi geese during brooding period are 20.00% and 3.50%, respectively.

This experiment was conducted to study the effects of dietary supplementation of chlorogenic acid on growth performance, body measurement parameters, nutrient apparent digestibility and serum indices of Xinjiang brown calves. Twelve 4-month-old weaned Xinjiang brown calves with similar body weight [(125.45±20.68) kg] were randomly divided into 2 groups with 6 calves in each group. The control group was fed a basal diet, and the test group was fed the basal diet+2 g/kg chlorogenic acid. The pre-experimental period lasted for 10 days, and the experimental period lasted for 90 days. The results showed as follows: 1) compared with the control group, the average daily gain of the test group showed an increasing trend during days 1 to 90 (P=0.091), and the feed to gain ratio showed a decreasing trend during days 1 to 30 (P=0.073). 2) Compared with the control group, the chest girth of the test group showed an increasing trend on day 90 (P=0.090). 3) Compared with the control group, the acid detergent fiber apparent digestibility of the test group was significantly increased (P<0.05), and the dry matter apparent digestibility showed an increasing trend (P=0.050). 4) Compared with the control group, the contents of total cholesterol and malondialdehyde in serum were significantly decreased (P<0.05), the serum immunoglobulin G content was extremely significantly increased (P<0.01), and the serum superoxide dismutase activity showed an increasing trend (P=0.051). In conclusion, dietary supplementation of 2 g/kg chlorogenic acid can increase the acid detergent fiber apparent digestibility and serum immunoglobulin G content, decrease the serum total cholesterol and malondialdehyde contents of Xinjiang brown calves during 4 to 6 months of age, and has a certain effect on improving growth performance and body antioxidant capacity.

This experiment was conducted to investigate the energy requirements of Simmental hybrid bulls during fattening period. Fifteen healthy Simmental hybrid bulls during fattening period aged (12.0±0.5) months with body weight of (461.57±30.62) kg were randomly divided into 5 groups with 3 replicates per group and 1 bull per replicate. The bulls in each group were fed five diets with different energy levels formulated to provide 80% (group Ⅰ), 90% (group Ⅱ), 100% (group Ⅲ), 110% (group Ⅳ), and 120% (group Ⅴ) of the combined net energy (NE_mf) required for an expected daily gain of 1 kg/d, respectively. The pre-trial lasted for 7 days, and the formal trial lasted for 41 days, including a 33-day feeding trial, a 4-day digestion and respiration metabolism trial, and a 4-day fasting metabolism trial. Feces and urine were collected using the total collection method. Oxygen consumption, carbon dioxide production, methane production, and urinary nitrogen content were measured through respiration metabolism trials, and prediction models for digestible energy (DE), metabolizable energy (ME), and net energy (NE) requirements were established. The results showed as follows: 1) there were no significant differences in growth performance among groups (P>0.05); the average daily gain (ADG) was gradually increased with dietary energy level increasing. 2) With the increase in dietary energy level, the DE, ME, NE, and digestibility and metabolizability of gross energy (GE) were gradually increased. The DE, ME, and NE in group Ⅴ were significantly higher than those in groups Ⅰ and Ⅱ (P<0.05), and the digestibility and metabolizability of GE in groups Ⅳ and Ⅴ were significantly higher than those in groups Ⅰ and Ⅱ (P<0.05). 3) The prediction models for DE, ME, and NE requirements of Simmental hybrid bulls during fattening period were: DE=0.811W^0.75+25.786ADG [coefficient of determination (R²)=0.983 8), ME=0.713W^0.75+23.254ADG (R²=0.981 0), and NE=0.494W^0.75+22.493ADG (R²=0.993 6), respectively (in the formula: W^0.75 represented metabolic body weight). In conclusion, this study established prediction models for energy requirements of Simmental hybrid bulls during fattening period, which can provide a reference for precise diet formulation in beef cattle.

This experiment was conducted to explore the effects of diets with different fatty acid composition on performance, milk flavor and fatty acid composition, and nutrient apparent digestibility of dairy cows. Using a paired design, 160 healthy Holstein dairy cows with parity of 1.38±0.56, milk yield of (35.96±5.96) kg, and lactation days of (83.53±28.23) days were selected and randomly divided into a control group and an experimental group, with 80 cows in each group. Among them, 80 dairy cows were in the peak lactation period (21 to 90 days postpartum), and 80 dairy cows were in the mid and late lactation period (91 to 200 days postpartum). The dairy cows in the control group were fed a diet supplemented with commercial fat product, while those in the experimental group were fed a diet supplemented with fatty acid balanced fat product. The main components of commercial fat product were palmitic acid (75%) and oleic acid (25%), with ether extract (EE) content of 95%; the fatty acid balanced fat product was a blend of 65% palm oil, 30% oleic acid and 5% flaxseed oil, with EE content of 75%, and had been treated with emulsification, antioxidation and rumen coating techniques. The trial lasted for 74 days, consisting of a 14-day adaptation period followed by a 60-day experimental period. The results showed as follows: 1) the milk to feed ratio and milk yield during the peak lactation period of dairy cows in the experimental group were significantly higher than those in the control group (P<0.05), and the downward trend of milk yield in the mid and late lactation period was gentler than that in the control group; 2) the contents of milk flavor substances in the experimental group were higher than those in the control group (P>0.05), and the milk flavor scores were better than those in the control group; 3) the contents of butyric acid, myristoleic acid, stearic acid and unsaturated fatty acids, as well as the ratio of unsaturated fatty acids to saturated fatty acids in milk in the experimental group were significantly higher than those in the control group (P<0.05); 4) the digestibility of fatty acid balanced fat product was significantly higher than that of commercial fat product (P<0.05), and there was no significant difference in metabolizable energy between the two products (P>0.05); 5) the total economic benefit in the experimental group was 3.80 yuan per day higher than that in the control group. In conclusion, dietary supplementation of fatty acid balanced fat product can not only increase the milk to feed ratio and milk yield during the peak lactation period of dairy cows, but also delay the decline in milk yield in the mid and late lactation period. At the same time, it has a positive effect on improving the flavor of milk. Compared with the commercial fat product, the fatty acid balanced fat product is more cost-effective and can improve the economic benefit of large-scale dairy farms in southern China.

This experiment was conducted to investigate the effects of rumen-protected glucose (RPG) supplementation in periparturient diets on lactation performance, rumen fermentation parameters and rumen microbiota of Holstein dairy cows. Forty healthy Holstein cows with similar parity (2.10±1.00), body condition score (3.30±0.40), previous lactation milk yield [(35.27±2.14) kg/d] and expected calving date [(23±3) d] were selected and randomly divided into two groups of 20 cows in each group. Cows in the control group were fed a basal diet, and those in the experimental group were fed the basal diet supplemented with 300 g/d of RPG. The experimental period lasted 6 weeks, consisting of a 3-week prepartum period and a 3-week postpartum period. The results showed as follows: 1) compared with the control group, no significant differences were observed in dry matter intake, milk yield, milk fat percentage, milk protein percentage, lactose percentage, somatic cell count, or milk urea nitrogen content during the postpartum period in the experimental group (P>0.05). 2) During the prepartum period, no significant differences were detected in rumen fluid pH, contents of ammonia nitrogen (NH₃-N), total volatile fatty acids (TVFA), acetate, propionate, isobutyrate, butyrate, valerate and isovalerate, and the acetate-to-propionate ratio between the two groups (P>0.05). During the postpartum period, compared with the control group, the rumen propionate content in the experimental group was significantly increased (P<0.05), and the acetate-to-propionate ratio was significantly decreased (P<0.05). 3) Compared with the control group, the Ace, Chao1, Shannon and Simpson indices of rumen microbial community in the experimental group during the postpartum period were significantly or extremely significantly decreased (P<0.05 or P<0.01), indicating a decline in species richness and diversity. Nonmetric multidimensional scaling (NMDS) analysis further confirmed a clear separation of community structure. 4) At the phylum level, Bacteroidetes and Firmicutes were the most abundant phyla in both groups during the postpartum period. Compared with the control group, the relative abundance of Firmicutes in the experimental group was extremely significantly decreased (P<0.01). At the genus level, Prevotella and Xylanibacter were the dominant genera in two groups during the postpartum period. The relative abundance of Prevotella in the experimental group was extremely significantly increased (P<0.01), while that of Xylanibacter was extremely significantly decreased (P<0.01). In summary, dietary supplementation of 300 g/d RPG during the periparturient period optimizes the rumen fermentation pattern, enhances propionate synthesis capacity, alters the rumen microbial community structure, and improves the supply of gluconeogenic substrates in postpartum dairy cows. These findings provide a microecological theoretical basis for alleviating negative energy balance in periparturient dairy cows.

This experiment was conducted to investigate the regulatory effects of rosemary extract on oxidative stress and lactation performance of plateau periparturient dairy cows. A total of 20 periparturient Holstein cows with similar previous lactation yield [(26.10±1.32) kg/d] and body weight [(550.3±13.9) kg] were selected and randomly divided into 2 groups with 10 replicates per group. Cows in the control group were fed a basal diet, while those in the rosemary group were orally administered with 20 g/(head·d) rosemary extract on the basis of the basal diet. The rosemary extract intervention period lasted 45 d, including a 15-d pre-trial period and a 30-d formal trial period (from 15 d prepartum to 15 d postpartum). After the intervention period, serum antioxidant indices, rumen volatile fatty acid contents, rumen microbial community structure and metabolite differences were determined, and lactation performance from 1 to 6 months postpartum was measured. The results showed as follows: 1) compared with the control group, the average milk yield of the rosemary group was significantly increased at the 2nd, 3rd and 5th months postpartum and during the overall 1 to 6 months postpartum (P<0.05). 2) Compared with the control group, the serum malondialdehyde content of the rosemary group was significantly decreased (P<0.05), while serum glutathione peroxidase activity was significantly increased (P<0.05). 3) Compared with the control group, the contents of acetate, propionate, butyrate, isovalerate and valerate in rumen fluid of the rosemary group were significantly increased (P<0.05). 4) Compared with the control group, the Chao1, Shannon and Simpson indexes of rumen microbiota in the rosemary group were significantly increased (P<0.05); the relative abundances of Bacteroidota, Anaerovibrio and Succiniclasticum were significantly increased (P<0.05), while the relative abundances of Proteobacteria, unidentified_Enterobacteriaceae and Pseudomonas were significantly decreased (P<0.05). 5) Compared with the control group, the contents of oleanolic acid, betulinic acid and lutein in rumen fluid of the rosemary group were significantly up-regulated (P<0.05). In conclusion, oral administration of 20 g/(head·d) rosemary extract during the periparturient period could enhance rumen volatile fatty acid content and microbial diversity, enrich beneficial microbiota and antioxidant metabolites, strengthen antioxidant capacity, and optimize lactation performance in plateau dairy cows.

This experiment was conducted to investigate the therapeutic effects of the combination of taurine (TAU) and propylene glycol (PG) on subclinical ketosis (SCK) in dairy cows. Forty-eight SCK dairy cows [7 days postpartum, serum β-hydroxybutyric acid (BHBA) concentration≥1.20 mmol/L] were randomly assigned to 4 groups with 12 cows per group. The detailed treatments were as follows: the PC group received no drug treatment; the TAU group was given 100 g of TAU by gavage daily from days 1 to 7; the PG group was given 500 mL of PG by gavage on days 1, 3, 5 and 7; and the TPG group received a combined treatment of TAU and PG, with the same administration regimens as described above. The experiment lasted for 14 days (7 days of treatment followed by 7 days of observation). The SCK cure rate, serum biochemical indicators (including energy metabolism, liver function and oxidative stress indicators), milk performance and reproductive performance were measured in each group. The results showed that during the experimental period, the average cure rate of SCK in the four groups ranked as TPG group>PG group>TAU group>PC group. The cure rate of SCK in the TPG group was extremely significantly higher than that in the PC group (P<0.01), and that in the PG group was significantly higher than that in the PC group (P<0.05), while there was no significant difference between the TAU group and the PC group (P>0.05). For serum energy metabolism indicators, treatment regimen had an extremely significant effect on the concentrations of BHBA, glucose (GLU) and non-esterified fatty acids (NEFA) (P<0.01), and the interaction between treatment regimen and sampling time had an extremely significant effect on GLU and NEFA concentrations (P<0.01). On day 14 after treatment, the TPG group showed the lowest serum BHBA and NEFA concentrations and the highest GLU concentration among all groups. For serum liver function indicators, treatment regimen had an extremely significant effect on aspartate aminotransferase (AST) activity, total bilirubin (TBIL) and total cholesterol (TC) contents (P<0.01), and the interaction between treatment regimen and sampling time had an extremely significant effect on TC content (P<0.01). On day 14 after treatment, the TPG group exhibited the lowest AST activity, TBIL and TC contents among all groups. For serum oxidative stress indicators, treatment regimen had an extremely significant effect on superoxide dismutase (SOD) activity, total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px) activity and malondialdehyde (MDA) content (P<0.01), and the interaction between treatment regimen and sampling time had an extremely significant effect on SOD activity, T-AOC and GSH-Px activity (P<0.01). On day 14 after treatment, the TPG group showed the highest SOD and GSH-Px activities and the lowest MDA content among all groups; its T-AOC was slightly lower than that of the PG group but higher than those of the TAU group and PC group. Compared with the PC group, the somatic cell count in the TPG group and TAU group was extremely significantly decreased (P<0.01), and milk fat rate and milk protein rate in the PG group were significantly increased (P<0.05). Although no significant differences in reproductive performance indexes were observed between each treatment group and PC group (P>0.05), all treatment groups showed numerically better values than PC group. In conclusion, the combined application of TAU and PG can effectively improve the cure rate of SCK dairy cows, alleviate negative energy balance, liver function impairment and oxidative stress, enhance milk performance, and present a trend of improving reproductive performance.

This experiment was conducted to investigate the effects of Aspergillus oryzae culture and Trichoderma longibrachiatum culture on growth performance, nutrient apparent digestibility, slaughter performance and meat quality of Arbas goats. Forty-eight healthy Arbas late-fattening goats of 24-month-old, with an initial body weight of (37.31±2.03) kg, were selected and randomly divided into 4 groups, with 12 replicates in each group and 1 goat in each replicate. The control group (CON group) was fed a basal diet, while the experimental groups were fed the basal diets supplemented with 2 g/(head·d) of Aspergillus oryzae culture (AOC group), Trichoderma longibrachiatum culture (TLC group), and mixed culture (Aspergillus oryzae culture and Trichoderma longibrachiatum culture were mixed in a ratio of 1∶1, ATC group), respectively. The pre-experiment lasted for 7 days and the formal experiment lasted for 40 days. The results showed as follows: 1) the total weight gain and average daily weight gain in AOC group were significantly higher than those in the other groups (P<0.05). 2) The apparent digestibility of crude protein (CP) and acid detergent fiber in AOC group, TLC group and ATC group was extremely significantly higher than that in CON group (P<0.01); the apparent digestibility of dry matter and neutral detergent fiber in AOC group was significantly higher than that in the other groups (P<0.05); there was no significant difference in the ether extract (EE) apparent digestibility among the groups (P>0.05). 3) The liver weight in AOC group was significantly higher than that in CON group and ATC group (P<0.05). 4) In longissimus dorsi, the values of meat color lightness (L^*), redness (a^*) and yellowness (b^*) in AOC group were extremely significantly higher than those in the other groups (P<0.01), and the dripping loss, cooking loss and EE content in TLC group were extremely significantly higher than those in the other groups (P<0.01). In belly meat, the pH in AOC group was significantly higher than that in the other groups (P<0.05), and the meat color L^* value and CP content were significantly higher than those in CON group (P<0.05); the drip loss and EE content in TLC group were significantly or extremely significantly higher than those in the other groups (P<0.05 or P<0.01). In biceps femoris, the pH in AOC group was significantly higher than that in CON group and TLC group (P<0.05), and the values of meat color L^*, a^* and b^* were extremely significantly higher than those in the other groups (P<0.01); the drip loss and cooking loss in TLC group were significantly higher than those in CON group and AOC group (P<0.05); the CP content in AOC group and TLC group was significantly lower than that in CON group and ATC group (P<0.05). In conclusion, dietary supplementation with Aspergillus oryzae culture can improve the growth performance, nutrient apparent digestibility and meat color of Arbas goats in the later fattening stage. Although dietary supplementation with Trichoderma longibrachiatum culture can increase the apparent digestibility of some nutrients, it will reduce the muscle water retention. There is no synergistic effect when the two are supplemented together.

This experiment was conducted to investigate the effects of replacing inorganic trace elements with organic trace elements on growth performance, nutrient apparent digestibility and blood indexes of Wendeng dairy goat kids. A total of 45 healthy weaned male Wendeng dairy goat kids with similar body weight [(12.33±0.46) kg] were randomly allocated to 5 groups with 9 replicates per group and one kid per replicate. The blank control group (CN group) was fed a basal diet. The inorganic control group (ITM100 group) was fed the basal diet supplemented with 1 000 mg/kg inorganic trace elements, with the addition levels of iron, copper, zinc, manganese, selenium and cobalt being 64.46, 9.05, 45.92, 22.78, 0.21 and 0.32 mg/kg, respectively. The 50% organic group (OTM50 group), 75% organic group (OTM75 group), and 100% organic group (OTM100 group) were supplemented with 500, 750 and 1 000 mg/kg organic trace elements, corresponding to 50%, 75% and 100% of the inorganic trace element addition levels in the ITM100 group, respectively. The trial lasted for 67 d, including a 7 d pre-trial period and a 60 d formal trial period. The formal trial period was divided into two stages: early stage (days 1 to 30) and late stage (days 31 to 60). The results showed as follows: 1) over the whole trial period, compared with the CN group, the average daily gain (ADG) was significantly increased in the ITM100, OTM50, OTM75 and OTM100 groups (P<0.05), and the feed-to-gain ratio (F/G) was significantly decreased (P<0.05); compared with the ITM100 group, the ADG was significantly increased (P<0.05) in the OTM75 and OTM100 groups, and the F/G was significantly decreased (P<0.05). 2) The apparent digestibility of neutral detergent fiber and acid detergent fiber in the OTM50, OTM75 and OTM100 groups was significantly higher than that in the ITM100 and CN groups (P<0.05). 3) In the late trial stage, compared with the CN group, the blood red blood cell count and hemoglobin concentration were significantly increased in the ITM100, OTM50, OTM75 and OTM100 groups (P<0.05), and the blood mean corpuscular hemoglobin was significantly increased in the OTM75 and OTM100 groups (P<0.05). 4) In both early and late trial stages, the serum total protein (TP) and globulin (GLB) contents in the OTM75 and OTM100 groups were significantly higher than those in the CN group (P<0.05), while the serum urea nitrogen (UN) and total cholesterol (TCHO) contents were significantly lower than those in the CN group (P<0.05); moreover, in the later trial stage, the serum TP, GLB and albumin (ALB) contents in the OTM100 group were higher than those in the ITM100 group (P<0.05). 5) The activities of serum total antioxidant capacity and glutathione peroxidase in the OTM75 and OTM100 groups were significantly higher than those in the CN group in two stages (P<0.05), and the activities of serum total superoxide dismutase and copper-zinc superoxide dismutase were significantly higher than those in the other three groups in the late stage (P<0.05). 6) In the late trial stage, the serum immunoglobulin M and immunoglobulin A contents in the OTM75 and OTM100 groups were significantly higher than those in the CN group (P<0.05). In conclusion, supplementing organic trace elements at 50% of the inorganic trace element dosage used in the inorganic control diet for Wendeng dairy goat kids achieved growth-promoting effects equivalent to the 100% inorganic trace element. Supplementing organic trace elements at 75% and 100% of the inorganic trace element dosage further improved the growth performance, apparent nutrient digestibility, immune status and antioxidant capacity of kids.

This experiment was conducted to investigate the effects of dietary supplementation with Bacillus coagulans (BC) on growth performance, intestinal morphology and barrier function, and fecal microbiota of sheep challenged with enterotoxigenic Escherichia coli (ETEC). Fifteen Dorper sheep with a body weight of (26.41±2.07) kg were selected and randomly divided into 3 groups, with 5 replicates in each group and 1 sheep in each replicate. Sheep in the control group (CON group) and ETEC group were fed a basal diet, while those in BC group fed the basal diet supplemented with 10⁹ CFU/kg BC in the concentrate. The pre-trial period lasted for 14 days, and the formal trial period lasted for 60 days. On day 60 of the formal trial period, sheep in ETEC group and BC group were administered 1 mL ETEC bacterial suspension with a concentration of 1.0×10⁸ CFU/mL by gavage, while sheep in CON group were administered the same dose of sterile normal saline by gavage. Samples were collected at 24 h post-slaughter. The results showed as follows: 1) compared with ETEC group, the final body weight of sheep in BC group was significantly increased (P<0.05). 2) The villus structure in jejunum and ileum in CON group was intact, while obvious fractures and atrophic lesions occurred in villus structure in ETEC group, and the intestinal injury in BC group was relatively mild. In jejunal tissue, the villus height in ETEC group and BC group was significantly lower than that in CON group (P<0.05); the crypt depth in ETEC group was significantly higher than that in CON group and BC group (P<0.05); the villus height to crypt depth ratio in CON group was significantly higher than that in ETEC group and BC group (P<0.05), and the villus height to crypt depth ratio in BC group was significantly higher than that in ETEC group (P<0.05). In ileal tissue, the villus height in CON group and BC group was significantly higher than that in ETEC group (P<0.05); meanwhile, the villus height to crypt depth ratio in CON group was significantly higher than that in ETEC group (P<0.05). 3) In jejunal tissue, the zonula occludens-1 (ZO-1) mRNA relative expression level in BC group was significantly higher than that in CON group and ETEC group (P<0.05). In ileal tissue, compared with CON group, the interferon-γ (IFN-γ) mRNA relative expression level in BC group was significantly increased (P<0.05), the IFN-γ mRNA relative expression level in ETEC group was extremely significantly increased (P<0.01), and the tumor necrosis factor-α (TNF-α) mRNA relative expression level in ETEC group and BC group was extremely significantly decreased (P<0.01). 4) There was no significant difference in α diversity of fecal microbiota between ETEC group and BC group (P>0.05). The results of the linear discriminant analysis effect size (LEfSe) analysis indicated that the Firmicutes, Lactobacillaceae and Lactobacillus were significantly enriched in BC group (P<0.05), while the Spirochaetes, Treponema and Allobaculum were significantly enriched in ETEC group (P<0.05). In conclusion, dietary supplementation with BC can alleviate the damage to intestinal health of sheep caused by Escherichia coli challenge by improving intestinal morphology, upregulating the expression of tight junction protein-related genes, regulating the balance of inflammatory factors, and maintaining the stability of microbiota structure, thereby ensuring intestinal barrier function and immune homeostasis.

This experiment was conducted to investigate the effects of carvacrol and thymol compound additive (CTCA) on the growth performance, slaughter performance, meat quality, and blood physiological and biochemical indicators of fattening sheep. A total of 40 healthy 3-month-old small-tailed Han ewe lambs with similar body weight [(16.01±1.71) kg] were randomly divided into 2 groups, with 5 replicates per group and 4 lambs per replicate. The control group (CON group) was fed a total mixed ration (TMR, concentrate to roughage ratio of 7∶3), while the CTCA group was fed the TMR supplemented with 0.2% CTCA in the concentrate. The pre-feeding period lasted 14 days, and the formal experimental period lasted 114 days. The results showed that, compared with the CON group: 1) the final body weight, average daily gain and carcass weight of fattening sheep in the CTCA group were significantly increased (P≤0.05), while the feed-to-gain ratio was extremely significantly decreased (P<0.01); 2) the muscle drip loss in the CTCA group was significantly decreased (P<0.05); 3) the serum total antioxidant capacity was extremely significantly increased (P<0.01), the malondialdehyde content was extremely significantly decreased (P<0.01), the immunoglobulin G content was extremely significantly increased (P<0.01), the immunoglobulin M content was significantly increased (P<0.05), and the total superoxide dismutase activity showed an increasing trend (0.05<P<0.10) in the CTCA group; 4) the blood granulocyte percentage was significantly decreased (P<0.05), the lymphocyte percentage was significantly increased (P<0.05), and the mean corpuscular volume showed a decreasing trend (0.05<P<0.10) in the CTCA group. In conclusion, dietary supplementation with 0.2% CTCA in the concentrate can improve feed utilization efficiency, enhance body antioxidant capacity and immune function, and thereby improve the growth performance of fattening sheep.

This experiment was conducted to investigate the effects of feeding different prey fish during initial feeding stage on growth, survival, digestive physiology and antioxidant capacity of mandarin fish (Siniperca chuatsi) larvae. A total of nine culture net cages were arranged in this trial, each stocked with 2 000 three-day post-hatch mandarin fish larvae. The experimental units were randomly divided into three groups with three replicates per group. Larvae in three groups were fed with blunt snout bream (Megalobrama amblycephala), silver carp (Hypophthalmichthys molitrix) and barbel chub (Squaliobarbus curriculus) as initial prey fish, respectively, for a 12-day feeding trial. The results showed as follows: 1) among the three prey fish species, barbel chub possessed the highest crude lipid content and energy density, and its contents of C22∶6n-3 (DHA), C20∶4n-6 (ARA), lysine and arginine were higher than those of silver carp and blunt snout bream. 2) The final total length, final body weight, weight gain rate and specific growth rate of mandarin fish larvae in the barbel chub group were significantly higher than those in the silver carp group (P<0.05), and the survival rate was significantly higher than that in the blunt snout bream group and silver carp group (P<0.05). 3) The trypsin activity of mandarin fish larvae fed barbel chub was significantly lower than that of the blunt snout bream group and silver carp group (P<0.05), while pepsin and alkaline phosphatase activities were significantly higher than those of the blunt snout bream group and silver carp group (P<0.05). Histological observation indicated that the digestive system of larvae in this group developed more maturely, with a functional stomach initially formed. 4) The total antioxidant capacity of mandarin fish larvae in the barbel chub group was significantly higher than that in the blunt snout bream group and silver carp group (P<0.05), and superoxide dismutase activity was significantly higher than that in the silver carp group (P<0.05). In conclusion, barbel chub has a more comprehensive nutritional profile when served as initial feed, which can improve the growth performance, survival rate and antioxidant capacity of mandarin fish larvae, and facilitate the early development of their digestive system.

This study compared the muscle nutritional composition, intestinal digestive characteristics and gut microbiota structure among four varieties of common carp—Oujiang color common carp “Longshen No.2”, Xingguo red common carp, Hebao red common carp and Yuanjiang common carp—reared under identical conditions, aiming to comprehensively evaluate the germplasm characteristics of the new hybrid strain Oujiang color common carp “Longshen No.2”. Thirty healthy, uniformly sized individuals of each of the four varieties of common carp were selected, tagged and stocked in the same pond. During the rearing period, all fish were fed exclusively with the same commercially formulated pellet diet specifically designed for carp, under consistent aquaculture conditions. After one year of rearing, six individuals (n=6) from each variety—Oujiang color common carp “Longshen No.2” [average body weight: (870.28±44.70) g], Xingguo red common carp [average body weight: (862.75±48.32) g], Hebao red common carp [(840.58±27.18) g] and Yuanjiang common carp [(924.82±43.24) g]—were selected for subsequent index measurements. The results showed as follows: 1) no significant differences were observed in muscle protein and ash contents among the four varieties of common carp (P>0.05). The muscle fat content of Xingguo red common carp was significantly higher than that of the other three varieties (P<0.05). Oujiang color common carp “Longshen No.2” exhibited the highest muscle ash content, Hebao red common carp had the highest muscle protein content, and Yuanjiang common carp showed the highest muscle moisture content. The muscle fat and protein contents of Oujiang color common carp “Longshen No.2” were 3.90% and 16.63%, respectively, falling within the desirable range for edible palatability, and characterized by high protein and low fat. 2) A total of 17 amino acids were detected in the muscle of all four varieties of common carp. The essential amino acid index (EAAI) of Yuanjiang common carp and Oujiang color common carp “Longshen No.2” was higher than that of Xingguo red common carp and Hebao red common carp. A total of 20 fatty acids were identified in the muscle of the four varieties of common carp, with Xingguo red common carp showing significantly higher C20∶5n3 (EPA)+C22∶6n3 (DHA) content than the other three varieties (P<0.05). 3) Oujiang color common carp “Longshen No.2” had significantly longer intestinal villus length than Hebao red common carp and Xingguo red common carp (P<0.05), and it exhibited the highest intestinal lipase and trypsin activities, which were significantly higher than those of Hebao red common carp and Xingguo red common carp (P<0.05). 4) The dominant phyla in the gut microbiota of the four varieties of common carp were Pseudomonadota (formerly Proteobacteria), Bacillota (formerly Firmicutes), Cyanobacteria, Bacteroidota and Actinomycetota. 5) Significant differences in gut microbial community composition were observed between Oujiang color common carp “Longshen No.2” and the other three varieties of common carp at both the phylum level and genus level (P<0.05). In summary, Oujiang color common carp “Longshen No.2” possesses superior muscle nutritional quality, stronger digestive and absorptive capacity, and a relatively stable gut microbiota structure, demonstrating favorable germplasm characteristics and breeding potential.

This experiment was conducted to systematically evaluate the effects of xylo-oligosaccharides (XOS) on the growth performance and intestinal health of weaned meat rabbits. A total of 160 healthy weaned Hyla meat rabbits aged 35 days were randomly divided into 4 groups with 8 replicates per group and 5 rabbits per replicate. The control group was fed a basal diet, while the T1, T2 and T3 groups were fed the basal diet supplemented with 50, 100 and 200 mg/kg XOS, respectively. The pre-feeding period lasted 7 days, and the formal experimental period lasted 28 days. After the formal experimental period, a 7-day digestion trial was conducted using the total collection method to determine nutrient apparent digestibility. At the end of the feeding trial, intestinal contents and tissue samples were collected to determine intestinal digestive enzyme activities, cecal volatile fatty acid contents, digestive tract pH, intestinal morphology, and intestinal secretory immunoglobulin A (sIgA) content. The results showed the follows: 1) the feed-to-gain ratio (F/G) in the T2 group was significantly lower than that in the control group (P<0.05). 2) Compared with the control group, the apparent digestibility of crude protein (CP) in the T2 and T3 groups and the apparent digestibility of acid detergent fiber (ADF) in the T3 group were significantly increased (P<0.05), and the apparent digestibility of total phosphorus (TP) in the T1, T2 and T3 groups was significantly increased (P<0.05). 3) The activities of jejunal α-amylase, trypsin, lipase, and cecal cellulase in the T3 group were significantly higher than those in the control group (P<0.05), and the activities of ileal α-amylase and lipase in the T2 and T3 groups were significantly higher than those in the control group (P<0.05). 4) Compared with the control group, the jejunal and ileal villus height and villus height to crypt depth ratio in the T2 group were significantly increased (P<0.05), while the jejunal and ileal crypt depth were significantly decreased (P<0.05). 5) Compared with the control group, the gastric pH in the T1, T2 and T3 groups was significantly increased (P<0.05), while the cecal pH was significantly decreased (P<0.05). 6) The sIgA content in jejunum in the T3 group and in ileum in the T2 group was significantly higher than that in the control group (P<0.05). In conclusion, under the conditions of this experiment, dietary supplementation with 100 mg/kg XOS can reduce the F/G, improve nutrient apparent digestibility and intestinal digestive enzyme activities, and enhance intestinal mucosal immunity, exerting positive effects on growth performance and intestinal health of weaned meat rabbits.

This experiment was conducted to investigate the effects of drinking water supplemented with capillarisin on growth performance, intestinal tissue protein contents and cecal microbial metabolic function of Ira meat rabbits. A total of 160 healthy 35-day-old weaned Ira commodity meat rabbits with similar body weight were randomly divided into 4 groups with 40 replicates per group and 1 rabbit per replicate. All groups were fed the same basal diet, the control group received regular aquaculture water, and the experimental groups received water supplemented with 10 (test group Ⅰ), 20 (test group Ⅱ) and 30 mg/L (test group Ⅲ) capillarisin, respectively. The pre-experimental period lasted for 6 days, followed by a formal experimental period of 25 days. The results showed as follows: 1) compared with the control group, the final body weight and average daily gain of test group Ⅲ were significantly increased (P<0.05). 2) Compared with the control group, the contents of secretory immunoglobulin A (sIgA) and Occludin in jejunum of test group Ⅱ and test group Ⅲ were significantly increased (P<0.05); among them, the contents of sIgA and Occludin in jejunum of test group Ⅲ were significantly higher than those of test group Ⅱ (P<0.05). 3) Compared with the control group, the Chao1 index and Observed_species index of cecal microbiota of test group Ⅱ were significantly decreased (P<0.05). 4) Compared with the other groups, the signature species with the higher abundance of test group Ⅲ were Thauera_A, Rhodocyclaceae, CAG_793, UBA5905, and CAG_533. 5) Compared with the control group, the significantly up-regulated metabolic functional pathway of test group Ⅱ was the androstenedione degradation pathway Ⅰ (PWY-6944) (Adj-P<0.01), and the significantly up-regulated metabolic functional pathways of test group Ⅲ were the toluene degradation pathway Ⅳ (PWY-5178) and benzoyl CoA degradation pathway Ⅱ (CENTBENZCOA-PWY) (Adj-P<0.01). Compared with the control group, the significantly up-regulated metabolic functional pathways of test group Ⅲ were PWY-6944, PWY-5178 and CENTBENZCOA-PWY (Adj-P<0.01). 6) The species of cecal microbiota that up-regulated the enrichment of PWY-6944 metabolic functional pathway was Pseudomonas_E, and the species of cecal microbiota that up-regulated the PWY-5178 and CENTBENZCOA-PWY metabolic functional pathway was Thauera_A. In conclusion, the drinking water supplemented with 0.003% capillarisin can improve the final body weight and average daily gain of meat rabbits; it enhance the body defense capability by up-regulating the intestinal sIgA and Occludin contents; furthermore, it modulate the intestinal microbiota by improving the enrichment of PWY-6944, PWY-5178 and CENTBENZCOA-PWY metabolic functional pathways, thereby improving the intestinal environment and promoting intestinal health status.

This experiment aimed to evaluate the digestibility parameters of Zanthoxylum bungenum leaves (ZBL) in meat rabbit diets and to investigate the effects of ZBL as a feed ingredient on growth performance, serum metabolism and intestinal health of meat rabbits. In experiment 1, the apparent digestible energy and nutrient apparent digestibility of ZBL in meat rabbit diets were determined using the total fecal collection method combined with the substitution method. In experiment 2, ninety-six 8-week-old Ira meat rabbits were randomly divided into two groups with eight replicates per group and six rabbits per replicate. Rabbits in control group were fed a basal diet, while those in ZBL group were fed an experimental diet in which 5% ZBL replaced wheat bran in the basal diet. The adaptation period lasted 7 days, followed by a 32-day experimental period. The results showed as follows: 1) the apparent digestible energy of ZBL in meat rabbit diets was 8.67 MJ/kg. 2) Compared with the control group, dietary supplementation with 5% ZBL had no significant effects on growth performance, slaughter performance, organ indices or intestinal morphological indices (P>0.05). 3) Compared with the control group, serum total antioxidant capacity (T-AOC), activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) in serum, and hepatic GSH-Px activity of the ZBL group were extremely significantly increased (P<0.01), while malondialdehyde (MDA) contents in serum and liver were extremely significantly decreased (P<0.01). 4) Compared with the control group, serum triglyceride (TG) content and aspartate aminotransferase (AST) activity of the ZBL group were significantly decreased (P<0.05), and serum total cholesterol (T-CHO) and urea (UREA) content, and alanine aminotransferase (ALT) activity were extremely significantly decreased (P<0.01). 5) Compared with the control group, no significant differences were observed in Ace index or Shannon index of cecal microbial community (P>0.05). At genus level, relative abundances of uncultured_Clostridium_sp_f_Ruminococcaceae, metagenome_g_UCG-005 and uncultured_bacterium_g_Anaerofilum in cecal microbial community of the ZBL group were significantly increased compared with the control group (P<0.05). 6) Serum metabolomics analysis revealed that 285 serum metabolites were significantly upregulated and 61 were significantly downregulated in the ZBL group compared with the control group. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of differential metabolites indicated that the differential metabolites were mainly enriched in valine, leucine and isoleucine biosynthesis; arginine and proline metabolism; glycine, serine and threonine metabolism; tryptophan metabolism; and D-amino acid metabolism, and other metabolic pathways. In conclusion, dietary supplementation with 5% ZBL in meat rabbit diets enhances antioxidant capacity, alleviates oxidative damage, improves lipid metabolism, promotes the proliferation of beneficial cecal microbial communities and improves intestinal health.

This experiment was conducted to evaluate the ameliorative effects of nuciferine-liposomes (NUC) on obesity in high-fat fed dogs, and to explore the possible mechanisms through gut microbiota and serum lipid metabolism. Twenty-four healthy male Beagle dogs, aged approximately 3 years and weighing (10.5±1.2) kg, were randomly assigned into four groups, with 6 dogs per group. Four groups were fed normal diet (ND group), normal diet supplemented with NUC (ND+NUC group), high-fat diet (HFD group), and high-fat diet supplemented with NUC (HFD+NUC group), respectively. After each meal, dogs in the ND+NUC group and HFD+NUC group received NUC suspension orally at 125 mg/kg body weight, whereas those in the ND and HFD groups received an equal volume of normal saline, twice daily. The pre- experimental period lasted 2 weeks, and the formal experimental period lasted 8 weeks. The results showed as follows: 1) compared with the HFD group, body weight gain, subcutaneous fat thickness and area of inguinal adipocyte of the HFD+NUC group were significantly lower (P<0.05); serum triglyceride and low-density lipoprotein cholesterol contents of the HFD+NUC group were also significantly lower (P<0.05). 2) Compared with the HFD group, Chao1 and Shannon indices of gut microbiota in the HFD+NUC group were significantly higher (P<0.05); the relative abundances of Firmicutes, Blautia and Lactobacillus in the HFD+NUC group were significantly higher (P<0.05), whereas those of Bacteroidetes, Bacteroides and Fusobacterium were significantly lower (P<0.05). 3) PICRUSt analysis indicated that NUC reversed high-fat diet-induced alterations in gut microbial gene functions, including downregulating the enrichment levels of lipid metabolism-related pathways such as glycerophospholipid metabolism, α-linolenic acid metabolism, peroxisome proliferator-activated receptor (PPAR) signaling pathway and lipopolysaccharide biosynthesis. 4) Compared with the HFD group, the levels of key lipid metabolites involved in glycerophospholipid metabolism and linoleic acid metabolism, including 1-arachidonoyl-lysophosphatidylcholine and palmitoleic acid, in the HFD+NUC group were significantly lower (P<0.05). In conclusion, NUC effectively ameliorates high-fat diet-induced obesity in dogs, as well as the associated dyslipidemia and fat accumulation. Its mechanism of action may involve the modulation of gut microbiota composition and serum lipid metabolite profiles, thereby restoring balance of the “gut microbiota-host metabolism” network.

This experiment was conducted to investigate the effects of Yucca schidigera extract on serum immune indices, intestinal barrier indices, and fecal microbiota of adult Ragdoll cats. Twenty healthy Ragdoll cats aged 2 to 5 years with a body condition score (BCS) of 5 were randomly divided into 2 groups with 10 replicates per group and 1 cat per replicate. The control group was fed a basal diet, and the experimental group was fed the basal diet supplemented with 0.5% Yucca schidigera extract (dry matter basis). The experiment lasted for 42 days. The results showed as follows: 1) there was no significant difference in average daily gain between the experimental group and the control group (P>0.05). 2) From days 22 to 42, the proportion of fecal scores <2 in the experimental group was 4.30%, which was lower than that in the control group (9.60%). 3) On day 21, compared with the control group, the serum lipopolysaccharide (LPS) content, serum diamine oxidase (DAO) activity and fecal calprotectin content in the experimental group were significantly decreased (P<0.05); on day 42, the serum intestinal fatty acid-binding protein (I-FABP) content in the experimental group was significantly decreased (P<0.05). 4) On day 21, the serum interleukin-1β (IL-1β) content in the experimental group was significantly lower than that in the control group (P<0.05). 5) At the genus level, on day 21, the relative abundance of Bacteroides in feces of the experimental group was significantly higher than that in the control group (P<0.05); on day 42, the relative abundance of Fusobacterium in feces of the experimental group was significantly higher than that in the control group (P<0.05). In conclusion, dietary supplemented with 0.5% Yucca schidigera extract can improve intestinal mucosal barrier function, modulate immune function and gut microbial community structure, and consequently enhance intestinal health in cats.

This study aimed to investigate the effects of hair beauty compound on hair and skin quality, serum indices, intestinal microbiota and fecal metabolites of British shorthair cats, and to elucidate the mechanism of hair beauty compound improving cat hair and skin quality via the “gut-skin axis”. Sixteen healthy 2.0 to 2.5 years adult British shorthair cats were randomly assigned to 2 groups with 8 cats in each group. The control group was fed a basal diet, and the experimental group was fed an experimental diet which supplemented with the hair beauty compound (0.50% concentrated fish oil, 0.10% evening primrose oil, 0.10% DL-methionine, 0.01% Haematococcus pluvialis powder and 0.02% sodium hyaluronate). The pre-experimental period lasted for 7 days, and the experimental period lasted for 35 days. The results showed as follows: 1) there were no significant differences in growth performance and nutrient apparent digestibility between two groups (P>0.05). 2) On day 21, the fecal score of the experimental group was significantly higher than that of the control group (P<0.05). 3) On day 21 and day 35, the hair score and breaking strength of the experimental group were significantly higher than those of the control group (P<0.05), and the hair scale height was significantly lower than that of the control group (P<0.05). 4) The skin moisture content and elasticity score of the experimental group were significantly higher than those of the control group (P<0.05). 5) The protein relative expression levels of Claudin-1 and Occludin in epidermal keratinocytes of the experimental group were significantly higher than those of the control group (P<0.05). 6) On day 35, the serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities of the experimental group were significantly higher than those of the control group (P<0.05), and the serum malondialdehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) contents were significantly lower than those of the control group (P<0.05). 7) Compared with the control group, the relative abundance of beneficial bacteria such as Parabacteroides in intestine of the experimental group was increased, and the relative abundance of harmful bacteria such as Negativibacillus was decreased. 8) The metabolomics results showed that the differential metabolites were primarily enriched in metabolic pathways including neuroactive ligand-receptor interaction, biosynthesis of unsaturated fatty acids, histidine metabolism, peroxisome proliferator-activated receptor signaling pathway, and linoleic acid metabolism. In conclusion, the hair beauty compound improves the hair and skin quality of cats by optimizing the microbial structure and activating lipid metabolism and immune-regulatory pathways through the “gut-skin axis”, thereby maintaining skin barrier homeostasis.

This experiment was conducted to investigate the effects of benzoic acid (BA) on oxidative damage in porcine intestinal epithelial cells (IPEC-J2 cells) induced by aflatoxin B₁ (AFB₁). In this experiment, the cell viability, reactive oxygen species (ROS) content, and antioxidant indices in IPEC-J2 cells were measured. The expression of genes related to the nuclear factor E2-related factor 2 (Nrf2) signaling pathway, inflammation, apoptosis, and tight junctions was determined by real-time fluorescence quantitative PCR (RT-qPCR). Molecular docking analysis was conducted to investigate the binding characteristics of BA with Kelch-like ECH-related protein 1 (Keap1), and the mechanism was verified using the Nrf2 inhibitor ML385. The results showed as follows: 1) compared with the control group, treatment with 10 μg/mL AFB₁ significantly reduced the IPEC-J2 cell viability (P<0.05), significantly increased the contents of ROS and malondialdehyde (MDA) (P<0.05), and reduced the total antioxidant capacity (T-AOC) (P>0.05); co-treatment with BA (5, 10 and 20 μg/mL) and AFB₁ could reverse the above changes, increased the cell viability (P>0.05), significantly reduced the contents of ROS and MDA (P<0.05), and 10 and 20 μg/mL BA significantly increased T-AOC (P<0.05). 2) In terms of molecular mechanisms, treatment with 10 μg/mL BA significantly upregulated the mRNA relative expression levels of NAD(P)H-quinone oxidase-1 (NQO1), Keap1, heme oxygenase-1 (HO-1), catalase (CAT), glutathione peroxidase (GSH-Px), and superoxide dismutase 1 (SOD1) (P<0.05); meanwhile, BA treatment could significantly downregulate the mRNA relative expression levels of inflammation-related genes [nuclear factor-κB p65 (p65), nuclear factor-κB inhibitor α (IκBα), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β)] and pro-apoptotic gene (Caspase-3) (P<0.05), and significantly upregulated the mRNA relative expression levels of Occludin and Claudin-1 (P<0.05). 3) Molecular docking showed that BA had a favorable binding affinity with the Keap1 protein. ML385 could reverse the protective effects of BA. In conclusion, BA exerts antioxidant effects by activating the Nrf2 signaling pathway in IPEC-J2 cells, while alleviating cellular inflammation and apoptosis and enhancing cellular barrier function, thereby alleviating cellular oxidative damage induced by AFB₁.

In order to elucidate the cellular heterogeneity, functional remodeling and intercellular communication dynamics in mammary tissue of dairy cows during the development of mastitis, this study investigated 39 Holstein dairy cows using a comprehensive approach including California mastitis test (CMT), pathogenic bacterial colony colorimetric detection, determination of inflammatory factor expression, histopathological observation and single-cell RNA sequencing (scRNA-seq) technology, and systematically analyzed the differential characteristics of healthy and inflammatory mammary tissue. The results showed as follows: 1) the majority of somatic cell counts in mammary gland ranged from negative to weakly positive, with most cases exhibiting mild to moderate inflammation; the identified predominant pathogens were Escherichia coli, coagulase-negative Staphylococci, Streptococcus agalactiae, and Staphylococcus aureus, with mixed infections accounting for 71.79% of cases. 2) Compared with the healthy group (Norm group), the mRNA relative expression levels of interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) in mammary gland in the subclinical mastitis group (SCM group) and the clinical mastitis group (CM group) were significantly increased (P<0.05), which were significantly higher in the CM group compared with the SCM group (P<0.05). 3) Histopathological analysis revealed extensive swelling, hemorrhagic foci, and marked expansion of alveolar lumens in mammary tissue in the CM group, accompanied by pronounced inflammatory infiltration. In contrast, the SCM group showed only mild local congestion with scattered inflammatory cells. 4) scRNA-seq analysis of mammary tissue identified 17 distinct cell clusters, comprising five major cell types: epithelial cells, endothelial cells, fibroblasts, myeloid cells, and lymphocytes. Differentially expressed genes (DEGs) and functional enrichment analysis revealed that upregulated genes in epithelial cells were mainly enriched in mitogen activated protein kinase (MAPK) and peroxisome proliferator-activated receptor (PPAR) signaling pathways, while endothelial cells were associated with tight junction and endocytosis pathways. Fibroblasts displayed high activity in inflammatory and apoptotic signaling pathways. Myeloid cells and lymphocytes were enriched in immune response and phagocytosis-related pathways. Further subclustering analysis found that epithelial subpopulations showed differential regulation in lipid metabolism and cell division, while myeloid subpopulations differed in immune response and autophagy-related regulation. Lymphoid and endothelial subpopulations were mainly involved in cell migration and immune responses. Moreover, the intercellular communication analysis demonstrated a significant increase in both the number and intensity of ligand-receptor interactions in inflamed mammary tissue. Notably, the enrichment of NOTCH signaling pathway in endothelial cells suggested their potential role in inflammation, and the cell adhesion molecule (CADM) pathway in epithelial cells and the urokinase-type plasminogen activator (PLAU) pathway in myeloid cells were also markedly activated. This study provides novel insights into the cellular heterogeneity and molecular mechanisms underlying bovine mastitis, offering a theoretical foundation for more accurate diagnosis and targeted therapeutic strategies.

This study was conducted to investigate the regulatory effect of alfalfa-derived miR159a (mtr-miR159a) on the inflammatory response of bovine mammary epithelial cells (bMECs) induced by lipopolysaccharide (LPS). After confirming that 50 ng/μL LPS treatment for 24 h successfully induced inflammation in bMECs, cells were transfected with mtr-miR159a mimic or NC mimic. At 24 h post-transfection, cells were stimulated with 50 ng/μL LPS for 24 h, followed by collection of cells and supernatants. Quantitative real-time PCR (qRT-PCR) was used to measure mRNA relative expression levels of inflammatory cytokine genes, apoptosis-related genes and proliferation-related genes. Enzyme-linked immunosorbent assay (ELISA) method was employed to determine inflammatory cytokine contents in supernatants. Cell viability and proliferation were evaluated by CCK-8 and 5-ethynyl-2'-deoxyuridine (EdU) methods, respectively, with the EdU-positive cell rate being calculated. In addition, bioinformatics analysis was performed to predict the target genes of mtr-miR159a, followed by GO functional annotation and KEGG pathway enrichment analysis of the predicted targets. The results showed as follows: 1) overexpression of mtr-miR159a significantly decreased the mRNA relative expression levels of interleukin-8 (IL-8), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in LPS-induced bMECs (P<0.05). Furthermore, overexpression of mtr-miR159a significantly reduced the contents of IL-1β and tumor necrosis factor-α (TNF-α) in the supernatants of LPS-induced bMECs (P<0.05), and extremely significantly decreased the contents of IL-6 and IL-8 (P<0.001). 2) Overexpression of mtr-miR159a significantly suppressed the expression of the apoptosis-related genes cysteine-aspartic protease 3 (Caspase3) and B-cell lymphoma-2-associated X protein (BAX) (P<0.05), while significantly promoted the expression of the anti-apoptotic gene B-cell lymphoma-2 (BCL2) (P<0.05), and extremely significantly enhanced cell viability (P<0.001). In addition, overexpression of mtr-miR159a extremely significantly promoted the expression of the proliferation-related genes cyclin D1 (CCND1) and cyclin D2 (CCND2) (P<0.01), significantly increased the expression of proliferating cell nuclear antigen (PCNA) (P<0.05), and extremely significantly elevated the percentage of positive cells (proliferating cells) (P<0.01). 3) The putative target genes of mtr-miR159a were mainly involved in biological processes such as protein ubiquitination, cell adhesion and protein transport, and were primarily enriched in the chemokine signaling pathway, leukocyte transendothelial migration, C-type lectin receptor signaling pathway, and bacterial invasion of epithelial cells. Overexpression of mtr-miR159a significantly suppressed the expression of CC chemokine receptor 5 (CCR5) (P<0.05), extremely significantly reduced the expression of CXC motif chemokine ligand 8 (CXCL8) and C-C motif chemokine ligand 2 (CCL2) (P<0.01), and significantly increased the expression of nuclear factor-kappaB inhibitor zeta (NFKBIZ) (P<0.05). In conclusion, mtr-miR159a may alleviate the occurrence of bovine mastitis by targeting CCR5 and thereby regulating the expression of key genes in the chemokine signaling pathway, ultimately attenuating the inflammatory response, maintaining normal cell proliferation, and inhibiting aberrant cell apoptosis in bMECs.

This experiment was conducted to investigate the effects of sodium butyrate treatment on the differentiation and myofiber type transformation of bovine skeletal muscle satellite cells (SMSCs), and to clarify the regulatory role of the adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling pathway in the process of sodium butyrate treatment bovine SMSCs. The optimal sodium butyrate treatment concentration (1.0 mmol/L) was determined using the CCK-8 assay, the real-time quantitative PCR and Western blotting techniques were employed to systematically examine the mRNA and protein expression of myogenic differentiation marker genes [myogenic (MYOG) and myogenic factor 6 (MYF6)] and muscle fiber type transformation marker genes [four myosin heavy chain (MyHC) isoforms (MyHCⅠ, MyHCⅡa, MyHCⅡb and MyHCⅡx)] after sodium butyrate treatment, and an AMPK signaling pathway inhibitor (5 μmol/L) was used to explore the effects of sodium butyrate on bovine SMSCs differentiation and myofiber type transformation through the AMPK pathway. The results showed as follows: 1) compared with 0 d, the sodium butyrate treatment for 2 and 4 d significantly or extremely significantly up-regulated the mRNA and protein relative expression levels of MYOG and MYF6 (P<0.05 or P<0.01), extremely significantly up-regulated the mRNA expression levels of MyHCⅠ and MyHCⅡa and protein relative expression level of slow MyHC (P<0.01), extremely significantly down-regulated the mRNA expression level of MyHCⅡb and protein relative expression level of fast MyHC (P<0.01), indicating that sodium butyrate treatment could effectively drive the differentiation process of bovine SMSCs, and specifically induce the slow myofiber formation. 2) Compared with 0 d, the sodium butyrate treatment 2 and 4 d extremely significantly up-regulated the mRNA expression levels of AMPK signaling pathway marker genes [AMPKα1, AMPKα2, silent information regulator 1 (SIRT1) and peroxisome proliferator activated receptor-γ coactivator-1α (PGC-1α)] (P<0.01), indicating that sodium butyrate treatment could activate the AMPK signaling pathway. 3) The addition of AMPK signaling pathway inhibitor extremely significantly inhibited the mRNA expression levels of AMPKα1, SIRT1, AMPKα2, MYOG, MYF6, MyHCⅠ and MyHCⅡa (P<0.01); the co-treatment of sodium butyrate and AMPK signaling pathway inhibitor extremely significantly alleviated the promoting effects of sodium butyrate on the mRNA expression of MYF6, MYOG, MyHCⅠ and MyHCⅡa (P<0.01), and extremely significantly alleviated the inhibitory effects of sodium butyrate on the mRNA expression of MyHCⅡb and protein expression of fast MyHC (P<0.01), indicating that the AMPK signaling pathway played a non-negligible regulatory role in sodium butyrate induced differentiation and myofiber formation in bovine SMSCs. In conclusion, sodium butyrate promotes the differentiation of bovine SMSCs and the formation of slow myofibers, and this regulation may be mediated through the AMPK signaling pathway.

This experiment aimed to investigate mitigative effects of Acanthopanax senticosus polysaccharides (ASPS) on lipopolysaccharide (LPS)-induced mechanical barrier injury in porcine intestinal epithelial cells (IPEC-J2 cells). Firstly, flow cytometry was used to detect cell apoptotic rate for screening the appropriate concentration of ASPS, and the trans-epithelial electrical resistance (TEER) was measured by Transwell assay to determine the optimal LPS treatment duration. Then, IPEC-J2 cells were divided into four groups (3 replicates per group). Control group were cultured with RPMI medium for 48 h continuously; LPS group were first cultured with RPMI medium for 36 h and then stimulated with 250 μg/mL LPS for 12 h; ASPS+LPS group and ASPS group were pretreated with 1 000 μg/mL ASPS for 36 h, and then stimulated with 250 μg/mL LPS for 12 h and cultured with RPMI medium for 12 h, respectively. After above treatment, cells were collected for observation of cell morphology, determination of lactate dehydrogenase (LDH) activity, and detection of the relative expression levels of tight junction proteins, apoptosis- and autophagy-related proteins by Western blot. Finally, the control group, LPS group, LPS+3-methyladenine (3-MA) group, ASPS+LPS group and ASPS+LPS+3-MA group (three replicates per group) were set up to observe the changes in autophagy signaling pathways. After treatment, cells were collected to detect the relative expression levels of tight junction proteins and autophagy-related proteins. The results showed as follows: 1) pretreatment with 600, 800 and 1 000 μg/mL ASPS significantly decreased the cell apoptotic rate (P<0.05), with 1 000 μg/mL ASPS showing the best effect. 2) At LPS treatment durations of 6, 12 or 18 h, LPS significantly reduced TEER (P<0.05); after pretreatment with 1 000 μg/mL ASPS, the TEER was significantly increased at all LPS treatment durations (P<0.05), and the protective effect of ASPS was the best at the LPS treatment duration of 12 h. 3) Compared with the control group, LPS treatment resulted in increased cell sparseness, vacuolization and necrosis, and LDH activity was significantly increased (P<0.05); the relative expression levels of Occludin, zonula occludens-1 (ZO-1) and B-cell lymphoma-2 (Bcl-2) were significantly down-regulated (P<0.05), while relative expression levels of Caspase-3, B-cell lymphoma-2-associated X protein (Bax) and microtubule-associated protein light chain 3 (LC3)-Ⅱ as well as the LC3-Ⅱ/LC3-Ⅰ ratio were significantly up-regulated (P<0.05). Pretreatment with 1 000 μg/mL ASPS for 36 h reversed the above changes. 4) Compared with the control group, relative expression levels of phosphorylated phosphatidylinositol 3-kinase (p-PI3K), phosphorylated protein kinase B (p-AKT) and phosphorylated mammalian target of rapamycin (p-mTOR) were significantly increased after LPS induction (P<0.05), and pretreatment with 1 000 μg/mL ASPS for 36 h reversed the above changes, while co-incubation with 3-MA further decreased the above indicators. In conclusion, ASPS may regulate autophagy and apoptosis in IPEC-J2 cells through inhibiting the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway, thereby alleviating LPS-induced mechanical barrier injury in IPEC-J2 cells.

This study was conducted to evaluate the effects of dietary supplemented with minerals, vitamins, fatty acids and plant extracts on drip loss of pork using a Meta-analysis, aiming to provide a scientific basis for improving pork water holding capacity through nutritional strategies. Relevant studies concerning the regulation of pork drip loss by dietary nutrient supplementation were collected by searching Chinese (CNKI and Wanfang) and English (Web of Science and Science Direct) databases. After screening based on inclusion and exclusion criteria, data were extracted and subjected to Meta-analysis using Review Manager 5.3 software. The results showed as follows: 1) regarding minerals, dietary supplemented with magnesium, selenium and chromium significantly decreased the drip loss of pork (P<0.05), while dietary supplemented with calcium and zinc showed no significant effect on the drip loss of pork (P>0.05); 2) regarding vitamins, dietary supplemented with vitamin E significantly decreased the drip loss of pork (P<0.05), while dietary supplemented with vitamins B₃ and D showed no significant effect on the drip loss of pork (P>0.05); 3) regarding fatty acids, dietary supplemented with conjugated linoleic acid showed no significant effect on the drip loss of pork (P>0.05); 4) regarding plant extracts, dietary supplemented with resveratrol, proanthocyanidins and oregano oil significantly decreased the drip loss of pork (P<0.05), while dietary supplemented with curcumin, chlorogenic acid, betaine, tea polyphenols and Astragalus polysaccharides showed no significant effect on the drip loss of pork (P>0.05). In conclusion, dietary supplemented with magnesium, selenium, chromium, vitamin E, resveratrol, proanthocyanidins and oregano oil contributes to reducing the drip loss and improving the water-holding capacity of pork.

The purpose of this experiment was to compare the composition differences and flavor characteristics of volatile organic compounds (VOCs) of breast muscle between Xiangdong chickens and Cobb broilers and between different genders of Xiangdong chickens. The gas chromatography-ion mobility spectrometry (GC-IMS) combined with multivariate statistical analysis were used to analyze VOCs composition in breast muscle, and the flavor characteristics were evaluated using relative odor activity value (ROAV). The results showed that 45 VOCs were identified between different genders of Xiangdong chickens, and 47 VOCs were identified between Xiangdong chickens and Cobb broilers, these compounds were mainly aldehydes, ketones, alcohols, esters, and furans. The total VOCs content in Xiangdong chickens was significantly higher than that in Cobb broilers (P<0.05), and male Xiangdong chickens was significantly higher than female Xiangdong chickens (P<0.05). Based on P<0.05 and variable importance in projection (VIP)>1, 15 sex related differential VOCs and 16 breed related differential VOCs were identified. ROAV analysis showed that Xiangdong chickens showed more pronounced sweet, fatty and mushroom like aromas than Cobb broilers, and male Xiangdong chickens showed more pronounced sweet, mushroom like, roasted and fatty aromas than female Xiangdong chickens. In conclusion, Xiangdong chicken shows superior volatile flavor characteristics compared with Cobb broiler, and sex is an important factor affecting flavor quality, and male Xiangdong chickens show better flavor than female Xiangdong chickens.

This study aimed to establish a mouse model that effectively simulated the key clinical features of enteropathogenic Escherichia coli (EPEC) infection and to characterize the associated gut microbiota. Twenty four 3-week-old male BALB/c mice of specific pathogen free (SPF) grade were selected. After 4 days of acclimatization feeding, they were randomly divided into a control group (CK group) and a model group (EPEC group) with 12 mice in each group (n=12). Mice in both groups were provided with sterile water containing a mixture of antibiotics ad libitum for 3 consecutive days. On day 4, this was replaced with ordinary sterile water. From days 5 to 7, mice in CK group were intragastrically administered sterile phosphate buffered saline (PBS) twice daily (20 μL/g BW), while mice in EPEC group were synchronously administered an equal volume of EPEC bacterial suspension at a concentration of 1.7×10¹⁰ CFU/mL. On day 8, sampling analysis was conducted. The results showed as follows: 1) on day 3 post-infection, mice in EPEC group exhibited moderate diarrhea symptoms, with a diarrhea score of 2.14 and a body weight change rate of -9.11%. 2) Compared with CK group, the serum contents of malondialdehyde, immunoglobulin A (IgA), tumor necrosis factor-α (TNF-α), zonulin and D-lactic acid (D-LA) in EPEC group were extremely significantly increased (P<0.01), and the serum immunoglobulin M (IgM) content was significantly increased (P<0.05); meanwhile, the serum total antioxidant capacity was extremely significantly decreased (P<0.01), and the serum total superoxide dismutase activity was significantly decreased (P<0.05). 3) No pathological damage was observed in the duodenum of mice in either CK group or EPEC group. In EPEC group, the jejunum exhibited epithelial necrosis and exfoliation, and the ileum showed villus atrophy, disruption, and lamina propria exposure, with the villus height and the villus height to crypt depth ratio being extremely significantly decreased compared with CK group (P<0.01); in colon, epithelial necrosis, exfoliation, glandular structural disarray with inflammatory infiltration were observed, and the crypt depth was extremely significantly decreased compared with CK group (P<0.01). 4) Compared with CK group, the spleen index in EPEC group was extremely significantly increased (P<0.01). 5) Compared with CK group, EPEC group exhibited a significant increase in the relative abundances of Escherichia, Enterobacterales, Pseudomonadota, Gammaproteobacteria and Erysipelotrichales in cecum (P<0.05); conversely, a significant decrease in the relative abundances of Actinomycetota, Bacteroidota, Bacteroidia, Bacteroidales and Rikenellaceae_RC9_gut_group in cecum was observed (P<0.05). Meanwhile, EPEC group showed significantly upregulated relative abundances of pathways including cationic antimicrobial peptide (CAMP) resistance, propionate metabolism, biofilm formation-Escherichia coli, glutathione metabolism, beta-lactam resistance, valine, leucine and isoleucine degradation, and exopolysaccharide biosynthesis (P<0.05); conversely, the relative abundances of pathways for teichoic acid biosynthesis and glycolysis/gluconeogenesis were significantly downregulated (P<0.05). 6) Pearson correlation analysis revealed that the relative abundances of Pseudomonadota and Escherichia in cecum were extremely significantly positively correlated with diarrhea score, serum contents of TNF-α, D-LA, zonulin, IgM and IgA, and spleen index (P<0.01); conversely, the Bacteroidota relative abundance in cecum showed an extremely significant negative correlation with serum contents of IgM and TNF-α (P<0.01). In conclusion, a diarrhea model in BALB/c mice induced by EPEC was successfully established in this experiment. This model recapitulates key features such as diarrhea, attaching and effacing (A/E) lesions in intestine, and body weight loss. Furthermore, the characteristic gut microbiota and metabolic pathways associated with EPEC infection in mice are characterized. This study provides a valid animal model and relevant data for further investigation into the pathogenic mechanisms of EPEC and for evaluating potential prevention and control strategies.

This study aimed to investigate the preventive effects of exopolysaccharides from Lactobacillus plantarum cqf-43 (EPS43) on intestinal injury in mice infected with Salmonella Typhimurium (S. Tm). Following a 7-day acclimation period, 30 healthy mice with an average body weight of approximately 23 g were selected and randomly divided into three groups (n=10), which were the control group, model group and prevention group, respectively. The experiment lasted for 17 days. From days 1 to 14, the control and model groups received a daily oral gavage of 0.2 mL sterile water, while the prevention group received 0.2 mL of 0.02 g/mL EPS43 solution. On day 15, the control group was gavaged with 0.2 mL sterile saline, whereas the model and prevention groups were gavaged with 0.2 mL of 2.5×10¹⁰ CFU/mL S. Tm suspension. The results showed as follows: 1) compared with the control group, the body weight gain rate of mice in the model group was significantly decreased at 24 h (P<0.05) and extremely significantly decreased at 48 h (P<0.01) after infection with S. Tm. At 48 h, the body weight gain rate in the prevention group was extremely significantly increased compared with the model group (P<0.01). 2) Compared with the control group, the granulocytes in spleen of mice in the model group were diffusely infiltrated and multiple necrotic cellular debris were observed; compared with the model group, there were no obvious abnormalities in spleen tissue of mice in the prevention group. 3) Compared with the control group, the tumor necrosis factor-α (TNF-α) mRNA relative expression level in ileum of mice in the model group was extremely significantly increased (P<0.01). Compared with the model group, the TNF-α) mRNA relative expression level in ileum in the prevention group was significantly decreased (P<0.05). 4) Compared with the control group, the mRNA relative expression levels of Occludin (P<0.05) and Claudin-1 (P<0.01) in ileum of mice in the model group were significantly and extremely significantly downregulated, respectively. Compared with the model group, the Claudin-1 relative expression level in ileum in the prevention group was significantly increased (P<0.05). 5) Compared with the control group, the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) expression in ileum of mice in the model group was extremely significantly increased (P<0.01), and that in the prevention group was also significantly increased (P<0.05). Compared with the model group, the NLRP3 expression in ileum in the prevention group was significantly decreased (P<0.05). In conclusion, EPS43 can alleviate intestinal injury induced by S. Tm by modulating the expression of inflammatory factors, tight junction proteins, and NLRP3 in the ileum of mice, thereby reducing the splenic damage and body weight loss.

To screen for probiotic resources with potential adaptive advantages for ruminant gastrointestinal environments, one lactic acid bacterium was isolated from the rumen fluid of Wagyu cattle in this study. After species identification, its probiotic properties were systematically evaluated through in vitro experiments, and its metabolic characteristics were analyzed using untargeted metabolomics. The results showed that one lactic acid bacterial strain, designated GRJD005, was successfully isolated from Wagyu rumen fluid. Based on colony morphology and 16S rDNA gene sequence analysis, the strain was identified as Lactococcus lactis. The strain GRJD005 grew well at 37 ℃ and pH 7.0, entering the logarithmic growth phase at 4 h and reaching the stationary phase at 16 h. It grew normally in environments with pH≥5.0, but growth was significantly inhibited at pH≤3.0. The strain GRJD005 exhibited strong tolerance to both bovine and porcine bile salts. After being cultured for 24 hours at concentrations ranging from 0.1% to 0.6%, the survival rate of the strain GRJD005 was consistently higher than the initial value (100%). The survival rates of the strain GRJD005 exceeded 80% after 3-hour treatment in artificial gastric fluid, artificial intestinal fluid and artificial gastric and intestinal fluid. The strain GRJD005 demonstrated antibacterial activity against Salmonella enterica and Staphylococcus aureus. It was sensitive to nine antibiotics, including chloramphenicol, vancomycin and tetracycline, but resistant to erythromycin, gentamicin and ciprofloxacin. Non-targeted metabolomics analysis revealed significant enrichment of the strain GRJD005 in metabolic pathways such as secondary bile acid biosynthesis, 2-oxocarboxylic acid metabolism, and D-amino acid metabolism. The strain accumulated various metabolites related to stress adaptation and bioactivity, including lithocholic acid, lactic acid and spermidine, indicating a corresponding metabolic basis for its probiotic properties. In conclusion, Lactococcus lactis GRJD005 isolated from rumen fluid of Wagyu cattle in this study possesses good in vitro probiotic potential and safety, and can be further studied and developed as a candidate probiotic strain for ruminants.

In this study, a strain of Limosilactobacillus reuteri was isolated from the feces of healthy Holstein calves, and its probiotic properties and whole-genome were analyzed to evaluate its potential as a probiotic for dairy cattle. Fresh fecal samples were collected from 30 healthy 7-day-old Holstein calves. Lactic acid bacteria were isolated and screened using traditional microbial isolation and purification techniques, and identified by molecular biology methods. Meanwhile, its growth characteristics, tolerance, antibacterial activity, antibiotic susceptibility, hemolysis and in vivo safety were evaluated, and whole-genome sequencing analysis was performed. The results showed as follows: 1) a strain of Limosilactobacillus reuteri was successfully isolated and designated as Limosilactobacillus reuteri KY-1; 2) the strain entered the logarithmic growth phase at 4 h of inoculation, reached the stationary phase at 14 h, and decreased the pH of MRS broth to below 4.0 at 24 h; 3) the strain exhibited a survival rate of >75.00% at pH 4.5 to 5.0, a survival rate of 25.65% in artificial gastric fluid, and a relative survival rate of 120.18% in artificial intestinal fluid; 4) the strain inhibited the growth of Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus, showed no hemolytic activity, and was susceptible to penicillin, ampicillin, ceftriaxone, tetracycline, erythromycin and chloramphenicol; 5) the whole-genome size of the strain was 2.38 Mb with a GC content of 38.23%, and a large number of genes involved in carbohydrate, amino acid and vitamin metabolism as well as antimicrobial substance synthesis were annotated. In conclusion, Limosilactobacillus reuteri KY-1 exhibits excellent probiotic properties and a high safety profile, and can be considered a candidate probiotic strain for dairy calves.

This study aimed to evaluate the probiotic properties and safety of five strains of lactic acid bacteria (Ligilactobacillus salivarius 05, Lacticaseibacillus chiayiensis AACE3, Lacticaseibacillus paracasei XLK401, Lacticaseibacillus casei AACE4 and Ligilactobacillus pabuli AACE5) and to explore their potential probiotic mechanisms through whole-genome analysis. The antibacterial activity, tolerance, surface characteristics, antibiotic resistance and hemolytic activity of the strains were evaluated using in vitro methods. Whole-genome sequencing was performed by combining Illumina (second-generation) and Nanopore (third-generation) sequencing technologies, and the genomes were annotated using various bioinformatics tools and databases to investigate the probiotic mechanisms and safety at the molecular level. The results showed as follows: 1) all five strains of lactic acid bacteria exhibited good antibacterial activity, tolerance to bile salts and simulated gastrointestinal fluids, as well as certain hydrophobicity and autoaggregation in vitro. 2) None of the five strains displayed hemolysis; except for Lacticaseibacillus chiayiensis AACE3, which was resistant to tetracycline and doxycycline, the other four strains were susceptible or intermediate to most antibiotics. 3) Whole-genome sequencing revealed that the genome sizes of the five strains ranged from 1.92 to 3.10 Mbp, with GC contents ranging from 33.51% to 47.17%. The phylogenetic tree indicated that Lacticaseibacillus paracasei XLK401 and Lacticaseibacillus casei AACE4 were closely related, while the other three strains were more distantly related. The five strains contained 468 core genes and 5 593 accessory genes, harbored a small number of tetracycline resistance genes, and no virulence genes were detected. Except for Ligilactobacillus pabuli AACE5, the other four strains all possessed bacteriocin gene clusters. All five strains encoded carbohydrate-active enzymes, among which Ligilactobacillus pabuli AACE5 encoded the highest number of glycoside hydrolases (639). All five strains contained probiotic genes related to acid tolerance, heat tolerance, oxidative stress resistance, protection and repair of DNA and proteins, and adhesion; and only Ligilactobacillus salivarius 05 harbored the MapA gene associated with autoaggregation. In conclusion, the five strains of lactic acid bacteria examined in this study exhibit good probiotic properties and safety, and can be considered as potential candidate strains for probiotic preparations.

This study aimed to investigate the effects of co-fermentation with Lactobacillus buchneri and cellulase on the nutrient composition, fermentation quality and microbial diversity of Cenchrus fungigraminus fermented total mixed ration (FTMR). The total mixed ration (TMR) of Cenchrus fungigraminus was used as the fermentation substrate, and sterile water (NC group), Lactobacillus buchneri at 1.0×10⁶ CFU/g (LAB group), cellulase at 10 U/g (CE group), and cellulase at 10 U/g combined with Lactobacillus buchneri at 1.0×10⁶ CFU/g (CE+LAB group) were added for anaerobic fermentation, respectively. The addition amounts of both enzyme and bacteria were based on the fresh weight of Cenchrus fungigraminus TMR, and each group had 8 replicates. After 45 days of fermentation, samples were collected, and the sensory quality of Cenchrus fungigraminus FTMR was evaluated, and its nutrient composition, fermentation parameters, mycotoxin contents and microbial diversity were determined. The results showed as follows: 1) the sensory quality of Cenchrus fungigraminus FTMR in all groups was good, with no mold contamination. The sensory evaluation grades of the three experimental groups (LAB group, CE group and CE+LAB group) were all grade Ⅰ (excellent), among which the CE+LAB group had the highest sensory evaluation score (20 points). 2) The contents of neutral detergent fiber (NDF) and hemicellulose (HC) in the three experimental groups were significantly lower than those in the NC group (P<0.05), and the acid detergent fiber (ADF) content in the CE+LAB group was significantly lower than that in the other groups (P<0.05). 3) Compared with the NC group, the pH and zearalenone (ZEN) content in the CE+LAB group and LAB group were significantly reduced (P<0.05), while the propionic acid and lactic acid contents were significantly increased (P<0.05); the acetic acid content in the three experimental groups was significantly increased (P<0.05), and the deoxynivalenol (DON) content was significantly reduced (P<0.05). The ammonia nitrogen (NH₃-N) content in the CE+LAB group and CE group was significantly lower than that in the NC group and LAB group (P<0.05). 4) At the phylum level, the relative abundance of Firmicutes in the CE+LAB group and LAB group was significantly higher than that in the CE group (P<0.05). At the genus level, the relative abundance of Lentilactobacillus in the CE+LAB group and LAB group was significantly higher than that in the NC group (P<0.05). 5) Correlation analysis showed that the relative abundance of Lentilactobacillus was extremely significantly positively correlated with acetic acid content (r=0.55, P<0.01), and significantly negatively correlated with NDF content (r=-0.35, P=0.04). In conclusion, the addition of Lactobacillus buchneri alone or in combination with cellulase can reduce the fiber content, maintain nutrient composition, increase organic acid contents, and enhance the relative abundance of Lentilactobacillus in Cenchrus fungigraminus FTMR. Moreover, the combined addition of the two shows better effects in fiber degradation and fermentation quality improvement.

This experiment was conducted to investigate the effects of ratios of reed canary grass (Phalaris arundinacea L.) to concentrate supplement on fermentation quality, microbial community and metabolites of fermented total mixed ration (FTMR). Based on dry matter (DM), reed canary grass and concentrate supplement were mixed and baled at ratios of 100∶0 (T1 group), 60∶40 (T2 group), 50∶50 (T3 group) and 40∶60 (T4 group), respectively. Twenty bales were prepared for each group, with each bale weighing 70 kg, and all bales were fermented in a cool and dry environment for 60 days. The results showed as follows: 1) with the increase of the proportion of concentrate supplement, the contents of DM, water-soluble carbohydrates, crude protein, crude ash, calcium and phosphorus in the raw materials and FTMR increased linearly (P<0.05), while the contents of neutral detergent fiber and acid detergent fiber decreased linearly (P<0.05). 2) The pH, ammonia nitrogen/total nitrogen (NH₃-N/TN), as well as lactic acid and propionic acid contents of FTMR showed a quadratic curvilinear change with the increase of concentrate supplement ratio (P<0.05); T3 group had significantly lower pH (P<0.05), significantly higher lactic acid content (P<0.05) than T1, T2 and T4 groups, and significantly lower NH₃-N/TN (P<0.05) than T1 and T2 groups. 3) The results of β-diversity analysis indicated that there were differences in microbial community structure between T2, T3, T4 groups and T1 group. At phylum level, Firmicutes was the dominant phylum in all four groups, with the highest relative abundance in T3 group; at genus level, Lactobacillus, Weissella and Leuconostoc were the dominant genera in all groups; at species level, the relative abundance of Lactobacillus curvatus in T3 group was significantly higher than that in T1, T2 and T4 groups (P<0.05), and the relative abundance of Weissella cibaria was significantly higher than that in T1 group (P<0.05). 4) Metabolomic analysis results showed that compared with T1 group, the up-regulated metabolites in T3 group included salicylic acid, arachidonic acid and 4-hydroxybenzoic acid, while the down-regulated metabolites included mannitol, N-methyltyramine and tyrosine. In conclusion, when the mixing ratio of reed canary grass to concentrate supplement is 50∶50, FTMR has higher relative abundance of beneficial microorganisms and effectively increased content of beneficial metabolites, along with the lowest pH, the highest lactic acid content and the lowest NH₃-N/TN, presenting the optimal fermentation quality.

This experiment was conducted to investigate the effects of mixed silage of chicory stems and leaves and corn stover at different ratios on silage fermentation quality and in vitro rumen fermentation characteristics. Fresh chicory stems and leaves were mixed with air-dried corn stover at mass ratios of 100∶0 (group Ⅰ), 95∶5 (group Ⅱ), 90∶10 (group Ⅲ), 85∶15 (group Ⅳ) and 80∶20 (group Ⅴ), with three replicates per group. After 60 days of ensiling, indicators related to sensory quality, nutritional components, fermentation quality and in vitro rumen fermentation characteristics were determined, and the membership function method was adopted for comprehensive evaluation. The results showed as follows: 1) with the increase of corn stover proportion, the contents of dry matter (DM), neutral detergent fiber (NDF) and acid detergent fiber (ADF) in mixed silage gradually increased, while the contents of crude protein (CP) and water-soluble carbohydrates (WSC) decreased gradually. 2) The pH of all silage groups ranged from 3.66 to 3.76. The butyric acid content and ammonia nitrogen to total nitrogen ratio (NH₃-N/TN) in group Ⅰ were significantly higher than those in other groups (P<0.05). Group Ⅲ exhibited significantly higher lactic acid content than other groups (P<0.05), with a fermentation quality comprehensive score of 95 and the best overall performance. 3) In vitro rumen fermentation results showed that, with the increase of corn stover proportion, total gas production, gas production rate, methane (CH₄) production and CH₄ production rate decreased gradually, while gas production and CH₄ production per gram of degraded substrate increased steadily. The contents of ammonia nitrogen (NH₃-N), propionic acid and butyric acid declined gradually. Total volatile fatty acid (TVFA) and acetic acid contents presented a trend of first increasing and then decreasing, with the maximum value observed in group Ⅲ. Additionally, the dry matter degradation rate (DMD), crude protein degradation rate (CPD), neutral detergent fiber degradation rate (NDFD) and acid detergent fiber degradation rate (ADFD) decreased progressively with the increasing of corn stover proportion. 4) The comprehensive evaluation via membership function method revealed the ranking of comprehensive value as follows: group Ⅲ (0.68)>group Ⅱ (0.63)>group Ⅰ (0.55)>group Ⅳ (0.51)>group Ⅴ (0.36). In conclusion, under the conditions of this experiment, the mixed silage prepared with chicory stems and leaves and corn stover at the ratio of 90∶10 possesses superior silage quality and favorable in vitro rumen fermentation performance, presenting great feeding potential for ruminants.

This experiment was conducted to investigate the effects of compound inoculant and fermentation time on quality and in vitro rumen fermentation characteristics of grape pomace and corn straw mixed silage. Grape pomace and corn straw mixed at a mass ratio of 2∶1 were used as raw materials for ensiling. Two treatments were set up, including control group (CK group, no inoculant added) and compound inoculant group (NB group, inoculated with Bacillus subtilis YCNL1, Bacillus subtilis N2-10 and Limosilactobacillus reuteri L), with six replicates per treatment. The mixture was sealed and fermented for 45 days, and samples were collected on day 1, 3, 5, 7, 15, 25, 35 and 45 for analysis. The results showed as follows: 1) for the mixed silage system with fixed ratio of grape pomace to corn straw, the contents of dry matter (DM), crude protein (CP, except on day 3) and ether extract (EE) in NB group were higher than those in CK group at all fermentation time points, while the contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF, except on day 1) were lower in NB group. Meanwhile, the pH and ammonia nitrogen/total nitrogen (NH₃-N/TN) of NB group were significantly lower (P<0.05), and the lactic acid content was significantly higher (P<0.05) compared with CK group. 2) Analysis of microbial community composition indicated that Proteobacteria was the dominant phylum in the early fermentation stage, while Firmicutes became predominant in the late fermentation stage at phylum level. At genus level, Acetobacter dominated in the early stage, and Lactobacillus was the dominant genus in the late stage of ensiling. 3) Results of in vitro rumen fermentation revealed that the in vitro dry matter degradability (IVDMD) and in vitro neutral detergent fiber degradability (IVNDFD) of mixed silage in NB group were significantly higher than those in CK group at all fermentation time points (P<0.05), and the in vitro acid detergent fiber degradability (IVADFD) of NB group was significantly increased on day 25 and 45 of fermentation (P<0.05). 4) The comprehensive evaluation based on membership function demonstrated that the NB group fermented for 45 days obtained the highest comprehensive membership function value of 0.61. In conclusion, for the mixed silage of grape pomace and corn straw at mass ratio of 2∶1, supplementation of compound inoculant could improve nutritional quality, fermentation quality and in vitro nutrient degradability of mixed silage; the mixed silage fermented for 45 days possessed the optimal comprehensive quality, which was recommended as the suitable fermentation time under this raw material ratio.

This experiment was conducted to investigate the effects of mixed fermentation of apple pomace and maize cobs in different proportions on nutrient contents, fermentation quality and microbiota. Fresh apple pomace and maize cobs were used as raw materials, and four groups were set up with apple pomace to maize cobs ratios of 8∶2 (A8S2 group), 7∶3 (A7S3 group), 6∶4 (A6S4 group) and 5∶5 (A5S5 group) based on dry matter basis, respectively. Each group had six replicates, with 500 g of material per bag. The moisture content was adjusted to 60%, and 5 mL of Lactobacillus acidophilus suspension at a viable count of 1×10⁸ CFU/mL was added. The mixtures were fermented anaerobically at room temperature in the dark for 45 days. The results showed as follows: 1) A5S5 group had the highest contents of water-soluble carbohydrates (WSC), and lower contents of neutral detergent fiber (NDF), acid detergent fiber (ADF) and crude ash in the mixed fermented feed. 2) The pH of the mixed fermented feed in each group was lower than 4.2, among which the pH in A6S4 group and A5S5 group was significantly lower than that in A8S2 group (P<0.05). The lactic acid content in A5S5 group was significantly higher than that in A6S4 group (P<0.05). 3) The ACE and Simpson indices of microbiota in A8S2 group were significantly higher than those in the other three groups (P<0.05); the principal coordinate analysis (PCoA) revealed significant difference in microbiota structure among the groups (P<0.05); the relative abundances of Liquorilactobacillus and Limosilactobacillus in A5S5 group were significantly higher than those in the other three groups (P<0.05). 4) Correlation analysis showed that the Limosilactobacillus relative abundance was extremely significantly positively correlated with WSC content [correlation coefficient (r)=0.66, P<0.01], extremely significantly negatively correlated with pH (r=-0.61, P<0.01), and significantly negatively correlated with NDF content (r=-0.53, P<0.05). In conclusion, the mixed fermentation of apple pomace and maize cobs at a 5∶5 ratio can reduce ADF and NDF contents, improve fermentation quality, and enrich beneficial bacterial groups such as Liquorilactobacillus and Limosilactobacillus.

This study aimed to establish a detection method for the 3-nitrooxypropanol (3-NOP) content in feed additive and premix by ultra-performance liquid chromatography (UPLC). Three batches of 3-NOP feed additive (containing 10% 3-NOP, with silicon dioxide as the carrier) and three kinds of 3-NOP premix (containing 0.50%, 0.75% and 1.00% 3-NOP, respectively, with rice chaff as the carrier) were selected. Samples were extracted using acetonitrile and water, and separated by Thermo Accucore Polar chromatographic column. The eluting was further carried out by gradient elution with 0.1% methanesulfonic acid aqueous solution and 20% acetonitrile mobile phase at a flow velocity of 0.20 mL/min, with a column temperature of 25 ℃, an injection volume of 1.6 μL, a detection wavelength of 210 nm, and quantification was performed using the external standard method. The results show that the linear range of 3-NOP detection was 1 to 200 μg/mL [coefficient of determination (R²)=0.999 6], the limit of detection (LOD) and limit of quantification (LOQ) were 40 and 150 mg/kg, respectively, the extraction efficiency was greater than 99%, the relative standard deviation (RSD) was 0.06% to 0.63%, and the recovery ranged from 99.74% to 101.97%. In conclusion, the UPLC method established in this study can be used to rapidly, efficiently and accurately detect the 3-NOP content in feed additive and premix, and has good application value for the evaluation of 3-NOP products.