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Milk fat is one of the main nutritional components in milk and a key index for price based on quality. However, mastitis severely impacts the performance of dairy cows, leading to reduced nutritional quality such as milk fat. Research reports that liver X receptor (LXR), a member of the nuclear receptor superfamily, can inhibit lipopolysaccharide (LPS)-induced mastitis and participate in regulating the expression of genes related to milk fat synthesis through a sterol regulatory element-binding protein 1 (SREBP1)-dependent mechanism, thereby promoting milk fat synthesis, suggested that LXR is expected to a novel target for treating mastitis and regulating milk fat synthesis in dairy cows. Plant extracts can serve as natural agonists of LXR, which can activate LXR, alleviate LPS induced mastitis,and enhance milk fat synthesis. This article primarily discussed the regulation and mechanisms of LXR in dairy cow mastitis and milk fat metabolism, to provide a theoretical basis for related research.
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Feed costs account for 60% to 70% of the total cost of dairy production. Improving feed efficiency is therefore a key strategy for reducing production costs and promoting the green and low-carbon development of the dairy industry. Rumen microorganisms serve as a central regulatory hub for energy and nitrogen utilization in dairy cows, and their community structure and metabolic functions directly determine feed efficiency. Meanwhile, estrogen is an important signaling molecule involved in the regulation of feed intake, remodeling of glucose and lipid metabolism, and maintenance of epithelial barrier homeostasis. Estrogen can interact bidirectionally with hindgut microbiota; however, the mechanisms underlying its interactions with rumen microorganisms and their regulatory effects on feed efficiency remain unclear. This review systematically summarizes the evaluation systems and stage-specific characteristics of feed efficiency in dairy cows, as well as the functional mechanisms by which rumen microorganisms contribute to the formation of a high-efficiency lactation phenotype. Particular emphasis is placed on the effects of dynamic changes throughout the entire lactation cycle on the identification of core microorganisms associated with feed efficiency. The theoretical basis and potential regulatory pathways of the “estrogen-rumen microbiota axis” are also discussed. Furthermore, based on the ruminal biotransformation characteristics and application effects of phytoestrogens, their feasibility as tools for mechanistic validation and nutritional regulation is evaluated. Finally, future research directions are proposed from four perspectives: stage-specific evaluation of feed efficiency, characterization of core microbial functional modules, validation of causal mechanisms, and precision nutritional regulation. This review aims to provide a theoretical basis for elucidating the microbial mechanisms underlying feed efficiency in dairy cows and for developing targeted regulatory strategies.
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Ruminococcus albus is one of the representative species of the Ruminococcus, and plays a critical role in enhancing fiber utilization in ruminants. Ruminococcus albus adheres to and de-grades fibrous substrates through a coordinated fiber-degradation system composed of dockerins, carbohydrate-binding modules (CBMs) and glycoside hydrolases (GHs). In addition, Ruminococcus albus exhibits considerable plasticity, and its abundance and functional activity can be modulated by dietary fiber composition, probiotics, vitamins, microelements, and various functional additives, thereby further influencing host productive performance. This review summarizes the structural and functional characteristics of the fiber-degrading system of Ruminococcus albus, as well as the regu-latory effects of major dietary factors on its abundance and activity, with the aim of achieving tar-geted utilization of Ruminococcus albus in production practice and providing a solid theoretical basis for optimizing feed utilization efficiency and improving production performance in ruminants.
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Sanguinarine is a natural benzophenanthridine alkaloid derived from various medicinal plants, which has attracted increasing attention in the fields of animal health and green breeding owing to its environmental friendliness and antibiotic-replacement potential. Sanguinarine possesses strong biological activities: alleviating oxidative stress by scavenging reactive oxygen species and enhancing antioxidant enzyme activities; reducing the expression of pro-inflammatory factors and mitigating tissue inflammatory injury via regulating inflammation-related signaling pathways; and promoting intestinal health by improving intestinal barrier structure and modulating the composition of gut microbiota. In practical production of swine, poultry, ruminants and aquatic animals, sanguinarine exerts beneficial effects including enhancing immune function, improving performance and increasing disease resistance. This paper systematically reviews the chemical characteristics and main physiological functions of sanguinarine, as well as its research progress in animal production, so as to provide references for its scientific application and further development in animal production.
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Animal-derived foods, including eggs, meat and dairy products, are abundant sources of high-quality proteins, fats and minerals, which are vital for the survival of consumers. Additionally, they serve as effective carriers for carotenoid deposition. Lutein, a naturally occurring carotenoid, has garnered significant interest in the fields of livestock production, food processing and functional food, owing to its diverse physical and physiological properties, such as pigmentation, antioxidant and anti-inflammatory effects, as well as vision protection. This review examines the mechanisms of enrichment, deposition patterns and bioavailability of lutein in animal-derived foods, thereby providing a reference foundation for the development of functional animal-derived foods enriched with lutein.
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Oxidative stress not only impairs the reproductive health of female animals and reduces reproductive performance, but also directly damages oocytes, inducing mitochondrial dysfunction and thereby affecting oocyte maturation, fertilization and subsequent embryonic developmental competence. As a key component of the female reproductive system, oocyte function is finely regulated by multiple factors. During maturation, appropriate levels of reactive oxygen species (ROS) participate in the regulation of oocyte growth, meiosis and related physiological processes. However, excessive accumulation of ROS disrupts intracellular redox homeostasis, leads to mitochondrial dysfunction, and ultimately impedes oocyte maturation, fertilization and early embryonic development. Certain nutrients can improve the oxidative stress status and overall quality of oocytes by modulating intracellular glutathione (GSH) content, reducing the B-cell lymphoma-2 related X protein (Bax)/B-cell lymphoma-2 (Bcl-2) ratio of apoptosis-related factors, and enhancing the expression of antioxidant genes such as superoxide dismutase (SOD) and catalase (CAT). This review systematically summarizes the mechanisms by which oxidative stress affects oocyte function, with a particular focus on recent advances and application prospects of nutritional interventions in alleviating oxidative stress and enhancing the developmental potential of porcine oocytes, aiming to provide a reference for improving porcine oocyte quality.
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The periparturient period is a critical transition phase from late gestation to early lactation in dairy cows, accompanied by severe metabolic challenges. During this period, dairy cows generally experience negative energy balance due to decreased dry matter intake and the sharply increased energy demand for the initiation of lactation. As a core driving factor, negative energy balance induces severe disorders in adipose tissue metabolism, including excessive lipolysis, inhibited lipogenesis, oxidative stress, imbalanced secretion of adipokines, and inflammatory infiltration in adipose tissue. This paper summarized the multi-level molecular regulatory network of adipose tissue metabolic disorders in periparturient dairy cows, as well as their multiple adverse effects such as metabolic diseases, impaired reproductive performance and immune function. Combined with the physiological characteristics and energy metabolism rules of periparturient dairy cows, this paper elaborated the important roles of precise pre- and postpartum nutritional regulation strategies in alleviating negative energy balance, improving adipose tissue function, ensuring dairy cow health and enhancing the economic benefits of dairy farms.
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Feed conversion efficiency (FCE) refers to the efficiency of animals converting feed into products and serves as a key indicator for evaluating feed utilization. Improving FCE is critical to reducing ruminant production costs and promoting green farming. Feed conversion ratio (FCR) and residual feed intake (RFI) are core indicators for assessing FCE. Ruminant FCE is mainly affected by nutritional regulation, rumen development and rumen microbiota. Reasonable matching of dietary concentrate-forage structure and balanced protein-energy supply can avoid excessive concentrate or protein causing digestive burden and microbiota imbalance, thus maintaining FCE; meanwhile, promoting early rumen development and maintaining a stable rumen microbiota can optimize rumen fermentation efficiency, enhance the production of volatile fatty acids, facilitate efficient nutrient conversion, and improve overall nutrient utilization. Ruminant FCE is affected by multiple factors, including genetics, nutrition, rumen development, rumen microbiota and feeding management. This paper systematically reviews and summarizes the research progress on these affecting factors, aiming to provide a reference for improving feed utilization efficiency in ruminant production and supporting the sustainable development of the livestock industry.
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Rumen microbiota form the fundamental basis for efficient feed conversion and health maintenance in ruminants. The rumen microbial community is primarily composed of four major groups: bacteria, fungi, protozoa and archaea. Through complex synergistic and competitive interactions, these microbial groups collectively participate in core metabolic processes including carbohydrate degradation, protein metabolism, volatile fatty acid production, and methanogenesis, thereby maintaining ruminal fermentation homeostasis and influencing host energy utilization efficiency. This review systematically summarizes the colonization processes, community structures, and functional characteristics of rumen microbiota in ruminants, and explores their regulatory mechanisms in host growth and productive performance. Furthermore, this review focused on the colonization patterns of microorganisms and the synergistic and competitive relationships among different microbial groups, analyzed the regulatory effects of exogenous factors such as dietary composition and feeding management on rumen microbial community structure, and summarized research progress on optimizing ruminal fermentation patterns, improving feed efficiency, and reducing methane emissions through nutritional interventions and microbial regulation strategies. This review aims to provide a theoretical foundation for the development of precision nutritional strategies and health management practices based on rumen microbiota in ruminants.
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Obesity has become one of the core health issues affecting canine well-being, and the chronic diseases it induces severely impair the quality of life and life expectancy of dogs. The pathogenesis of canine obesity is relatively complex, primarily involving energy metabolic imbalance, genetic inheritance, immune dysregulation and alterations in the gut microbiota. In recent years, to effectively prevent and treat canine obesity, significant progress has been made in clinical intervention studies, particularly in the field of nutritional regulation. Nutritional intervention strategies such as low-calorie diets, functional nutrients and metabolic-modulating foods not only facilitate weight loss in dogs but also ameliorate obesity-related health problems. This article reviewed the pathogenesis of canine obesity and the research progress of nutritional supplements in alleviating canine obesity, aiming to provide a reference for the prevention and treatment of this condition.
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Methionine is a sulfur-containing essential amino acid that serves not only as an important substrate for protein synthesis, but also as a methyl donor and a precursor for various bioactive substances. It possesses multiple biological functions, including immunomodulation, anti-inflammation, antioxidant defense and growth promotion. Studies have shown that methionine plays an important regulatory role in maintaining animal intestinal barrier function. This review summarizes the physiological functions of methionine and its effects on the intestinal mechanical barrier, chemical barrier, immune barrier, and microbial barrier, aiming to provide a theoretical reference for the scientific application of methionine in animal production.
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Limosilactobacillus mucosae (L. mucosae), a probiotic bacterium colonizing the animal intestinal mucosal layer, has garnered considerable attention in the field of animal intestinal health due to its exceptional intestinal adhesion capacity and multiple synergistic probiotic mechanisms. This review systematically summarized the core biological characteristics of L. mucosae, its regulatory mechanisms on animal intestinal health, and its application progress in animal production. Furthermore, it analyzed the current challenges in research and outlined future development directions, aiming to provide a theoretical foundation for the scientific application of L. mucosae in green livestock production and to offer new insights for the development and industrialization of related probiotic products.
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The complement system, an integral part of the innate immune system, consists of over 30 plasma proteins with enzymatic activities. It is cascade-activated via three major pathways: the classical pathway, the lectin pathway and the alternative pathway, and plays a pivotal role in host immune defense, inflammation regulation and immune homeostasis. Although the basic mechanisms of the complement system have been largely clarified, species-specific functional differences in livestock and poultry, as well as the precise mechanism of the complement system remain to be further elucidated. This review systematically summarizes the composition, activation pathways and tissue distribution of the complement system, with an emphasis of its functional mechanisms of complement in pathogen clearance, immune regulation and stress adaptation of livestock and poultry. Furthermore, it summarizes the regulatory effects and signaling pathways of key nutrients, such as vitamins, trace elements, plant polysaccharides and probiotics, on the complement system, aiming to provide a reference for the scientific regulation and application of the complement system in animal husbandry production.
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Resveratrol is a polyphenol widely distributed in natural plants. It possesses multiple biological activities including antioxidant, anti-inflammatory, antibacterial, antiviral, lipid-metabolism-regulating, anti-tumor and cardiovascular-protective effects, showing promising application potential in healthy livestock and poultry breeding. This paper reviews the sources, physicochemical properties and preparation methods of resveratrol, systematically illustrates its molecular mechanisms for exerting biological activities via regulating key signaling pathways such as silent information regulator 1 (SIRT1), nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor-κB (NF-κB), and summarizes its application effects in livestock and poultry production, so as to provide references for the scientific application of resveratrol.
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Bio-manufacturing (BM) technology, as an integral component of modern biotechnology, has demonstrated significant potential and value in animal husbandry in recent years, leading to its widespread adoption and application. BM feed additives refer to the use of biotechnology (such as fermentation engineering, enzyme engineering and synthetic biology, etc.) to produce feed additives on a large scale through the metabolic activities or catalysis of organisms, aiming to improve the performance of livestock and poultry, enhance the health level of the body, and reduce the dependence on antibiotic growth promoters. As global animal husbandry faces challenges such as resource scarcity, environmental pollution and antibiotic resistance, BM feed additives, as an efficient, safe and environmentally friendly new feed additives, present significant application potential. This paper provides a systematic review of the main types of BM feed additives and their mechanisms of action, with a focus on the development of safety evaluation systems and their application effects in livestock and poultry production, aiming to facilitate the scientific application of BM feed additives in animal husbandry.
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This experiment was conducted to determine the chemical composition contents of 10 kinds of wheat from different sources as well as the digestible energy (DE) and metabolizable energy (ME) in growing pigs, and to establish prediction models for DE and ME based on the effective chemical components. Thirty healthy “Duroc×Landrace×Yorkshire” (DLY) castrated boars with an initial body weight of (26.35±2.82) kg were selected and assigned in three 10×2 incomplete Latin square designs. The pigs were fed 10 wheat-based diets (wheat accounted for 97%), respectively, with 6 replicates per diet treatment and 1 pig per replicate. The experiment consisted of 2 periods, each lasting 12 days, including a 7-day adaptation period and a 5-day total collection period for feces and urine. The DE and ME of wheat in growing pigs were determined using the total collection of feces and urine method and the direct method. The results showed as follows: 1) as-fed basis, the average contents of dry matter (DM), crude protein (CP), ether extract (EE), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude ash (Ash), calcium (Ca), total phosphorus (TP), phytate phosphorus (PP), total starch (TS) and xylan as well as gross energy (GE) in the 10 kinds of wheat were 89.02% (88.48% to 90.27%), 12.00% (9.98% to 13.37%), 1.44% (1.25% to 1.59%), 2.17% (1.98% to 2.48%), 9.28% (8.74% to 10.19%), 3.03% (2.78% to 3.25%), 1.53% (1.46% to 1.64%), 0.04% (0.03% to 0.05%), 0.31% (0.27% to 0.35%), 0.20% (0.16% to 0.23%), 59.99% (58.48% to 62.43%), 7.07% (6.74% to 7.50%) and 16.13 MJ/kg (15.97 to 16.36 MJ/kg), respectively. 2) As-fed basis, the average values of DE and ME of the 10 kinds of wheat in growing pigs were 14.76 and 14.51 MJ/kg, respectively. 3) As-fed basis, DM, CP, CF and TS were the key predictors for available energy of wheat in growing pigs. The best prediction equation for DE was DE (MJ/kg)=0.104DM (%)+0.107CP (%)-0.523CF (%)+0.033TS (%)+3.365 [coefficient of determination (R2)=0.932, P=0.004], and the best prediction equation for ME was ME (MJ/kg)=0.055DM (%)+0.105CP (%)-0.636CF (%)+0.031TS (%)+7.888 (R2=0.922, P=0.006). In conclusion, based on the effective chemical components of wheat, prediction models for DE and ME in growing pigs were established in this experiment, which can provide a reference for improving the feed ingredient database and for precise application of wheat in swine diets in China.
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This study aimed to analysis the correlation of myosin heavy chain (MyHC) isoforms expression with meat quality traits and activities of energy metabolism key enzyme in longissimus dorsi of pigs, to provide a theoretical foundation for the genetic breeding of high-quality pork pig breeds and the improvement of pork quality. Selected six Min pigs and six Large White pigs with body weight of about 95 kg, the meat quality traits, MyHC isoforms expression and activities of energy metabolism key enzyme in longissimus dorsi of Min pigs and Large White pigs were measured, and the correlation between mRNA relative expression levels of MyHC isoforms and meat quality traits and activities of energy metabolism key enzyme were analyzed. The results showed as follows: 1) the backfat thickness and intramuscular fat content and meat color redness (a*) value in longissimus dorsi of Min pigs were significantly or extremely significantly higher than those of Large White pigs (P<0.05 or P<0.01), and the loin eye area, drip loss and shear force in longissimus dorsi were extremely significantly lower than those of Large White pigs (P<0.01). 2) The mRNA relative expression levels of MyHCⅠ, MyHCⅡa and MyHCⅡx in longissimus dorsi of Min pigs were significantly higher than those of Large White pigs (P<0.05), while the mRNA relative expression level of MyHCⅡb was significantly lower than that of Large White pigs (P<0.05). 3) The activities of succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) in longissimus dorsi of Min pigs were significantly higher than those of Large White pigs (P<0.05), while the lactate dehydrogenase (LDH) activity was significantly lower than that of Large White pigs (P<0.05). 4) The mRNA relative expression levels of MyHCⅠ, MyHCⅡa and MyHCⅡx were significantly positively correlated with meat color a* value (P<0.05), and significantly or extremely significantly negatively correlated with drip loss (P<0.05 or P<0.01); the mRNA relative expression levels of MyHCⅠ and MyHCⅡx were significantly or extremely significantly negatively correlated with loin eye area and shear force (P<0.05 or P<0.01); the mRNA relative expression level of MyHCⅡb was significantly or extremely significantly positively correlated with loin eye area, drip loss and shear force (P<0.05 or P<0.01), and significantly or extremely significantly negatively correlated with backfat thickness, intramuscular fat content and meat color a* value (P<0.05 or P<0.01).5) The mRNA relative expression level of MyHCⅠ was significantly positively correlated with activities of MDH and SDH (P<0.05), and significantly negatively correlated with LDH activity (P<0.05). The mRNA relative expression level of MyHCⅡb was significantly or extremely significantly negatively correlated with activities of MDH and SDH (P<0.05), and significantly positively correlated with LDH activity (P<0.05). In conclusion, there are differences in muscle fiber type composition in longissimus dorsi between Min pigs and Large White pigs, and these differences are the key factors responsible for the breed variations in meat quality traits and energy metabolism characteristics between the two breeds.
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This experiment aimed to investigate the effects of dietary supplementation with different levels of pyrroloquinoline quinone disodium (PQQNa2) on reproductive performance, antioxidant capacity, immune function and fecal microbiota of sows from late gestation to lactation. A total of 90 healthy “Landrace×Large White” crossbred sows on day 90 of pregnancy with similar backfat thickness and parity (2 to 7 parities) were randomly divided into 5 groups, with 18 replicates per group and 1 sow per replicate. The control group was fed a basal diet, and the experimental groups were fed the basal diet supplemented with 2, 4, 6, and 8 mg/kg PQQNa2, respectively. The experiment lasted from day 90 of pregnancy to day 21 of lactation (weaning). The results showed as follows: 1) compared with the control group, dietary supplementation with 6 mg/kg PQQNa2 significantly increased the backfat accumulation during pregnancy of sows (P<0.05); with the supplemental level of PQQNa2 increasing, the backfat accumulation during pregnancy and backfat loss during lactation of sows showed quadratic changes (P<0.05). 2) Compared with the control group, dietary supplementation with PQQNa2 tended to increase the weaning individual weight (P=0.086) and weaning litter weight gain (P=0.094) of piglets. 3) Compared with the control group, dietary supplementation with 6 mg/kg PQQNa2 significantly increased the total antioxidant capacity (T-AOC) and activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) in serum and placenta (P<0.05), and significantly decreased the malondialdehyde (MDA) content in serum and placenta (P<0.05). 4) Compared with the control group, dietary supplementation with 4 to 6 mg/kg PQQNa2 significantly increased the contents of immunoglobulin G (IgG), immunoglobulin A (IgA) and immunoglobulin M (IgM) in serum (P<0.05); dietary supplementation with 4 to 8 mg/kg PQQNa2 significantly increased the contents of interleukin-10 (IL-10), transforming growth factor-β (TGF-β) and lysozyme (LZM) in serum and placenta, as well as the secretory immunoglobulin A (sIgA) content in placenta (P<0.05), and significantly decreased the contents of interleukin-6 (IL-6), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) in serum, as well as the contents of IL-6 and TNF-α in placenta (P<0.05). 5) Compared with the control group, dietary supplementation with 2 to 8 mg/kg PQQNa2 significantly increased the colostrum whey IgG content and milk protein percentage (P<0.05), dietary supplementation with 4 and 8 mg/kg PQQNa2 significantly increased the colostrum whey IgA content (P<0.05), and dietary supplementation with 6 and 8 mg/kg PQQNa2 significantly increased the colostrum whey IgM content (P<0.05). 6) The results of linear discriminant analysis effect size (LEfSe) analysis showed that the fecal microbiota in 6 mg/kg PQQNa2 supplemental group was significantly enriched with unclassified_Christensenellaceae (P<0.05). In conclusion, dietary supplementation with an appropriate level of PQQNa2 from late gestation to lactation can improve the body condition of sows, increase the weaning individual weight and weaning litter weight gain of piglets, enhance the antioxidant capacity and immune function of both the dam and placenta, increase the colostrum immunoglobulin contents and milk protein percentage, and improve the fecal microbiota structure. Under the conditions of this experiment, the appropriate supplemental level of PQQNa2 in sow diets from late gestation to lactation is 6 mg/kg.
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This experiment was conducted to investigate the effects of dietary supplementation with Sargassum polysaccharide on growth performance, immune function, intestinal health and serum metabolites of weaned piglets. A total of 120 six-week-old castrated male “Duroc×Landrace×Yorkshire” piglets with similar body weight were randomly assigned to 4 groups, each with 10 replicates of 3 piglets per replicate. The control group was fed a basal diet, while the experimental groups were fed the basal diet supplemented with 0.10% (0.10% SP group), 0.25% (0.25% SP group) and 0.50% Sargassum polysaccharide (0.50% SP group), respectively. The trial lasted for 30 days. The results showed as follows: 1) compared with the control group, the average daily gain was significantly increased in all experimental groups (P<0.05). 2) Compared with the control group, the serum glucose and interleukin-6 contents were significantly decreased in 0.25% and 0.50% SP groups (P<0.05), and the serum cortisol content was significantly decreased in all experimental groups (P<0.05); the serum immunoglobulin A and immunoglobulin G contents were significantly increased in all experimental groups (P<0.05), and the serum immunoglobulin M content was significantly increased in 0.50% SP group (P<0.05). 3) Compared with the control group, the jejunal villus height was significantly increased and the jejunal crypt depth was significantly decreased in 0.25% and 0.50% SP groups (P<0.05). 4) Compared with the control group, the relative abundances of Bacilli (P=0.092) and Lactobacillales (P=0.082) in jejunum in 0.25% SP group showed a tendency toward increased, while the relative abundances of Peptostreptococcales-Tissierellales, Peptostreptococcaceae and Terrisporobacter in jejunum were significantly decreased (P<0.05). 5) Serum metabolomics analysis revealed that, compared with the control group, some fatty acids and their derivatives were significantly down-regulated (P<0.05), while some lysophospholipids, N-acyl amino acids, flavonoids, carvacrols and carotenoids were significantly up-regulated (P<0.05) in serum metabolites in 0.25% SP group. In conclusion, dietary supplementation with 0.25% Sargassum polysaccharide can improve immune function and intestinal health, and consequently enhance growth performance of weaned piglets, by promoting the colonization of beneficial bacteria such as Lactobacillus in jejunum and up-regulating serum metabolites including carvacrols and carotenoids.
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This study aimed to investigate the effects of partial replacement of soybean meal with fermented rapeseed cake on growth performance, blood indices, fecal microbiota and metabolites of Tibetan piglets. Thirty-nine healthy castrated male Tibetan piglets with initial body weight of (8.02±0.21) kg were randomly assigned to 3 groups with 13 replicates per group and one piglet per replicate. Piglets in the control group (CSD group) was fed a corn-soybean meal basal diet. The rapeseed cake group (RSCD group) and fermented rapeseed cake group (FRSCD group) were fed diets in which 25% nitrogen source of the basal diet was iso-nitrogenously replaced by rapeseed cake and fermented rapeseed cake, respectively. The pre-experimental period lasted for 7 days, and the formal experimental period lasted for 42 days. The results showed as follows: 1) there were no significant differences in growth performance indices among all groups (P>0.05). 2) Compared with the CSD group, the apparent digestibility of neutral detergent fiber (NDF), acid detergent fiber (ADF) and crude ash (Ash) in the RSCD group was significantly decreased (P<0.05); compared with the RSCD group, the apparent digestibility of NDF, ADF, ether extract (EE) and Ash in the FRSCD group was significantly increased (P<0.05). 3) Compared with the CSD group, the serum direct bilirubin (DBIL) content and total antioxidant capacity (T-AOC) in the RSCD group were significantly decreased (P<0.05), while the serum malondialdehyde (MDA) and triiodothyronine (T3) contents were significantly increased (P<0.05); compared with the RSCD group, the serum DBIL content in the FRSCD group was significantly increased (P<0.05), whereas the serum MDA and T3 contents were significantly decreased (P<0.05). 4) Compared with the CSD group, the absolute abundance of Actinomyces in feces of the RSCD group was significantly increased (P<0.05); compared with the RSCD group, the total fecal bacterial load in the FRSCD group was significantly decreased (P<0.05), the Firmicutes to Bacteroidetes ratio and absolute abundance of Bacillus were significantly increased (P<0.05), while the absolute abundances of Actinomyces and Corynebacterium were significantly decreased (P<0.05). 5) Compared with the RSCD group, fecal metabolites including epiprogoitrin, isobutyl isothiocyanate and glycocholic acid were down-regulated, while spermidine, 3-methylindole and L-phenylalanine were up-regulated in the FRSCD group. KEGG pathway enrichment analysis revealed that differential metabolites between RSCD and CSD groups were mainly enriched in amino acid metabolic pathways such as tryptophan, phenylalanine and tyrosine metabolism. In addition to amino acid metabolism pathways, differential metabolites between FRSCD and RSCD groups were also involved in sphingolipid metabolism, alpha-linolenic acid metabolism and biosynthesis of unsaturated fatty acids. In conclusion, replacing partial soybean meal with fermented rapeseed cake in diet exerts no adverse effects on growth and development, nutrient digestion and utilization as well as body health of Tibetan piglets. Compared with non-fermented rapeseed cake, fermented rapeseed cake can improve the composition of fecal microbiota and metabolites of Tibetan piglets, and contribute to maintaining intestinal homeostasis.
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This experiment was conducted to investigate the effects of dietary supplementation with Lactobacillus salivarius and mannan oligosaccharides, alone or in combination, on slaughter performance, meat quality and trace element contents in liver and kidney of yellow feathered broilers. A total of 360 healthy 1-day-old Shiqiza yellow feathered broilers with similar body weight were randomly divided into 4 groups, each with 3 replicates of 30 birds per replicate. The control group (CON group) was fed a basal diet, while the three experimental groups were fed the basal diet supplemented with 0.3% mannan oligosaccharides (MOS group), 8×109 CFU/kg Lactobacillus salivarius (SAL group) and 0.3% mannan oligosaccharides+8×109 CFU/kg Lactobacillus salivarius (MOS+SAL group), respectively. The trial lasted for 9 weeks, after which slaughter performance, meat quality, liver and kidney coefficients, and the contents of copper (Cu), iron (Fe), manganese (Mn), zinc (Zn) and selenium (Se) in the liver and kidney were determined. The results showed as follows: 1) no significant differences were observed in slaughter performance among all groups (P>0.05). 2) Compared with the CON group, the SAL group exhibited a significantly decreased muscle shear force (P<0.05), while the MOS+SAL group showed a significantly increased muscle water holding capacity (P<0.05). 3) No significant differences were found in liver or kidney coefficients among all groups (P>0.05). Compared with the CON group, the SAL and MOS+SAL groups showed significantly or extremely significantly increased hepatic Fe and Mn contents (P<0.05 or P<0.01), significantly decreased hepatic Zn content (P<0.05), and extremely significantly increased renal Cu, Fe and Mn contents (P<0.01); the MOS group exhibited extremely significantly increased hepatic Zn content (P<0.01) and significantly or extremely significantly increased renal Cu and Mn contents (P<0.05 or P<0.01); additionally, the MOS+SAL group showed significantly increased hepatic Se content (P<0.05). In conclusion, dietary supplementation with mannan oligosaccharides and/or Lactobacillus salivarius have no significant effects on slaughter performance in yellow feathered broilers. Regarding meat quality, supplementation with Lactobacillus salivarius alone can improve muscle tenderness, while combined supplementation with mannan oligosaccharides and Lactobacillus salivarius can improve muscle water holding capacity. Moreover, supplementation with mannan oligosaccharides and/or Lactobacillus salivarius alter the contents of Fe, Mn, Zn, Cu and Se in the liver and kidney to varying degrees, suggesting that long term application may interfere with trace element homeostasis in the liver and kidney.
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This experiment was conducted to investigate the effects of different proportions of high-protein corn on growth performance, slaughter performance, meat quality and intestinal health of broilers. A total of 1 280 one-day-old healthy Ross 308 broilers with similar body weight were randomly assigned to 4 groups (NC group, 20HPC group, 40HPC group and HPC group), with 10 replicates per group (5 replicates for males and 5 replicates for females) and 32 broilers per replicate. Broilers in NC group were fed a normal corn-soybean meal basal diet. In 20HPC group and 40HPC group, 20% and 40% high-protein corn was used to partially replace normal corn in the basal diet, respectively. In HPC group, normal corn in the basal diet was completely replaced by high-protein corn. The trial lasted for 39 days, which was divided into three phases: early phase (1 to 14 days of age), middle phase (15 to 25 days of age) and late phase (26 to 39 days of age). The results showed as follows: 1) there were no significant differences in growth performance indices among all groups at each phase (P>0.05). 2) The dressed percentage in HPC group was significantly higher than that in NC group, 20HPC group and 40HPC group (P<0.05), whereas no significant differences were observed in other slaughter performance indices and meat quality indices among all groups (P>0.05). 3) Compared with NC group, the relative length of ileum in 40HPC group and HPC group was significantly decreased (P<0.05), and the relative weight of ileum in HPC group was also significantly reduced (P<0.05); there was no significant difference in intestinal health score among all groups (P>0.05). 4) Compared with NC group, the HPC group showed no significant differences in the relative abundance of cecal bacterial phyla (P>0.05), but exhibited a significant reduction in the relative abundance of Ligilactobacillus (P<0.05). KEGG functional prediction of cecal microbiota revealed that the enrichment of amino acid metabolism pathway and energy metabolism pathway in HPC group was significantly higher than that in NC group (P<0.05). In conclusion, replacement of normal corn with high-protein corn in diets coupled with reduced dietary soybean meal inclusion exerted no significant effects on growth performance and meat quality of broilers, but it can increase dressed percentage, decrease relative length and weight of ileum, reduce the relative abundance of cecal Ligilactobacillus, and enrich amino acid metabolism pathway and energy metabolism pathway of cecal microbiota.
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This experiment was conducted to investigate the effects of compound of Helianthus tuberous L. polysaccharide and Lycium barbarum polysaccharide on growth performance, serum biochemical indexes, antioxidant function and expression of antioxidant-related genes in liver of broilers. A total of 330 one-day-old Arbor Acres (AA) male broilers were randomly divided into 5 groups with 6 replicates per group and 11 broilers per replicate. The control group was fed a basal diet, and the experimental groups were fed basal diets supplemented with 100 (group Ⅰ), 200 (group Ⅱ), 400 (group Ⅲ) and 800 mg/kg (group Ⅳ) compound of Helianthus tuberous L. polysaccharide and Lycium barbarum polysaccharide, respectively. The trial lasted for 42 days. The results showed as follows: 1) the body weight at 21 days of age of group Ⅱ and group Ⅲ was significantly higher than that of the control group (P<0.05), and the body weight at 42 days of age of group Ⅳ was significantly higher than that of the control group (P<0.05). During 1 to 42 days of age, the average daily gain of group Ⅰ, group Ⅱ, group Ⅲ and group Ⅳ was significantly higher than that of the control group (P<0.05), and the feed to gain ratio was significantly lower than that of the control group (P<0.05). 2) The contents of total protein, albumin and globulin in serum of group Ⅲ and group Ⅳ were significantly higher than those of the control group (P<0.05), and the serum triglyceride content was significantly lower than that of the control group (P<0.05). 3) The total antioxidant capacity (T-AOC) and activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in serum of group Ⅲ and group Ⅳ were significantly higher than those of the control group (P<0.05), and the serum malondialdehyde (MDA) content of group Ⅳ was significantly lower than that of the control group (P<0.05). 4) The T-AOC and activities of T-SOD, GSH-Px and CAT in muscle of group Ⅱ, group Ⅲ and group Ⅳ were significantly higher than those of the control group (P<0.05), and the muscle MDA content was significantly lower than that of the control group (P<0.05). 5) The mRNA relative expression levels of T-SOD and GSH-Px in liver of group Ⅲ and group Ⅳ were significantly higher than those of the control group (P<0.05). In conclusion, dietary supplementation of 400 and 800 mg/kg compound of Helianthus tuberous L. polysaccharide and Lycium barbarum polysaccharide can improve the growth performance of broilers, regulate the protein and lipid metabolism, improve the serum and muscle antioxidant enzyme activities, and improve the antioxidant function of broilers by up-regulating the expression of T-SOD and GSH-Px genes.
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This study was conducted to evaluate the effects of dietary supplementation of castor (Ricinus communis L.) leaf powder on growth performance, slaughter performance, nutrient apparent metabolic rates and serum indices of white-feathered broilers. A total of 240 healthy Cobb broiler female chicks at 8 days of age with uniform body weight were randomly assigned to 4 groups with 6 replicates per group and 10 chicks per replicate. The chicks in the 4 groups were fed experimental diets supplemented with 0 (control group), 0.50% (0.50% group), 1.00% (1.00% group) and 2.00% castor leaf powder (2.00% group), respectively. The experiment lasted for 35 days. The results showed as follows: 1) compared with the control group, dietary supplementation with 0.50% to 2.00% castor leaf powder had no significant effects on growth performance (P>0.05). 2) Compared with the control group, the thigh muscle percentage and the lightness (L*) value of breast muscle of the 0.50% and 1.00% groups were significantly increased (P<0.05), and the breast muscle percentage of the 1.00% group was also significantly increased (P<0.05). 3) Compared with the control group, the apparent metabolic rates of crude protein, crude fat and ash of the 0.50% and 1.00% groups were significantly increased (P<0.05); the apparent metabolic rate of calcium of the 0.50% and 2.00% groups and the apparent metabolic rate of total phosphorus of the 1.00% and 2.00% groups were significantly increased (P<0.05). 4) Compared with the control group, the serum triglycerides and total cholesterol of the 0.50%, 1.00% and 2.00% groups were significantly decreased (P<0.05). 5) The serum total antioxidant capacity, superoxide dismutase and glutathione peroxidase activities of the 0.50% group were significantly higher than those of the other groups (P<0.05). 6) Compared with the control group, the bursa of Fabricius index of the 0.50% group was significantly increased (P<0.05), and the relative length of ileum of the 0.50% and 1.00% groups were significantly increased (P<0.05). In conclusion, dietary supplementation with 0.50% to 2.00% castor leaf powder does not affect growth performance, but effectively improves nutrient apparent metabolic rates and slaughter performance. The optimal supplementation levels for antioxidant capacity and slaughter performance are 0.61% to 0.89%, while levels of 1.09% to 1.37% are more beneficial for regulating lipid metabolism and promoting organ development.
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This experiment was conducted to investigate the effects of dietary supplementation of Codonopsis pilosula-Glycyrrhiza uralensis extract on growth performance, slaughter performance, meat quality, serum indices and intestinal health of yellow-feathered broilers. A total of 200 healthy one-day-old yellow-feathered broilers with similar body weight were randomly divided into 5 groups with 4 replicates per group and 10 chickens per replicate. Broilers in the control group (NC group) were fed a basal diet, broilers in experimental groups were fed basal diets supplemented with 2 000 (CGE2000 group), 1 000 (CGE1000 group) and 500 mg/kg (CGE500 group) Codonopsis pilosula-Glycyrrhiza uralensis extract (active ingredients included total polysaccharides, glycyrrhizic acid, lobetyolin, liquiritin and total flavonoids), respectively, and broilers in the chlortetracycline group (CTC group) were fed the basal diet supplemented with 80 mg/kg chlortetracycline. The experiment lasted for 42 days. The results showed as follows: compared with the NC group, 1) the average daily gain during days 22 to 42 of CGE1000 group and CGE500 group was significantly increased (P<0.05), and the feed to gain ratio was significantly decreased (P<0.05); 2) the dressing percentage, half eviscerated yield percentage and bursa of Fabricius index of CGE2000 group, CGE1000 group and CGE500 group were significantly increased (P<0.05); 3) the shear force, drip loss and yellowness (b*) value in chest muscle of CGE2000 group, CGE1000 group and CGE500 group were significantly decreased (P<0.05), and the shear force, drip loss and lightness (L*) value in leg muscle were significantly decreased (P<0.05); 4) the serum total antioxidant capacity of CGE1000 group and CGE500 group was significantly increased (P<0.05), and the serum malondialdehyde content was significantly decreased (P<0.05); the serum superoxide dismutase activity of CGE2000 group and CGE1000 group was significantly increased (P<0.05); the serum immunoglobulin A, immunoglobulin G and immunoglobulin M contents of CGE1000 group were significantly increased (P<0.05); 5) the villus height in duodenum of CGE2000 group and CGE1000 group was significantly increased (P<0.05), and the crypt depth in duodenum of CGE500 group was significantly decreased (P<0.05); the villus height to crypt depth ratio (V/C) in ileum of CGE1000 group was significantly increased (P<0.05); 6) the relative abundances of Bacilli, Mediterraneibacter and Streptococcus in intestine of CGE1000 group were significantly decreased (P<0.05), and the relative abundances of Ruminococcus, Intestinimonas, Colidextribacter and Flavonifractor in intestine were significantly increased (P<0.05). In conclusion, dietary supplementation of 1 000 mg/kg Codonopsis pilosula-Glycyrrhiza uralensis extract can improve the growth performance and meat quality of yellow-feathered broilers by optimizing the intestinal morphological structure, enriching the beneficial intestinal flora and enhancing the body immune function and antioxidant capacity.
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This experiment aimed to investigate the effects of fermented preparation of Pseudostellaria heterophylla fibrous roots on growth performance, serum hormone indices and mRNA expression of related hormone in liver and jejunum of white-feathered broilers. A total of 180 one-day-old healthy female white-feathered broilers were randomly assigned to 4 groups with 3 replicates per group and 15 birds per replicate. The control group (group A) was fed a basal diet, and the experimental groups were fed basal diets supplemented with 1% (group B), 2% (group C) and 3% (group D) fermented preparation of Pseudostellaria heterophylla fibrous roots, respectively. The experiment lasted for 42 days. The results showed as follows: 1) compared with the group A, the body weight at 21 and 42 days of age of groups B, C and D was significantly increased (P<0.05), and the body weight at 21 and 42 days of age of group B was significantly higher than that of groups C and D (P<0.05); during 22 to 42 days of age and 1 to 42 days of age, compared with the group A, the average daily gain of group B was significantly increased (P<0.05), and the feed to gain ratio of groups B and C was significantly decreased (P<0.05). 2) At 21 days of age, compared with the group A, the contents of thyroxine (T4), growth hormone (GH) and insulin-like growth factor-Ⅰ (IGF-Ⅰ) in serum of groups B, C and D were significantly increased (P<0.05), and the serum triiodothyronine (T3) content of groups B and C was significantly increased (P<0.05). At 42 days of age, compared with the group A, the contents of GH and IGF-Ⅰ in serum of groups B, C and D were significantly increased (P<0.05), and the serum T4 content of groups B and D was significantly increased (P<0.05). 3) At 21 and 42 days of age, compared with the group A, the mRNA relative expression levels of IGF-Ⅰ and growth hormone receptor (GHR) in liver and jejunum of groups B, C and D were significantly increased (P<0.05). In conclusion, dietary fermented preparation of Pseudostellaria heterophylla fibrous roots can improve the growth performance of white-feathered broilers, regulate the endocrine function, and optimize the mRNA expression of related hormone in liver and jejunum, and the optimal supplemental level is 1%.
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This experiment aimed to study the effects of dietary supplementation with different levels of ferulic acid (FA) on the growth performance, intestinal morphology, and anti-inflammatory and antioxidant functions of broilers infected with Salmonella pullorum. A single-factor completely randomized experimental design was adopted in this study, a total of 192 one-day-old Arbor Acres (AA) male broilers were randomly allotted to 4 groups with 6 replicates per group and 8 chickens per replicate. Broilers in control group (CON group) and Salmonella infected group (ST group) were fed basal diets, while others in experimental groups were fed basal diets supplemented with 100 (ST+100 mg/kg FA group) and 200 mg/kg (ST+200 mg/kg FA group) ferulic acid, respectively. Broilers in ST group, ST+100 mg/kg FA group and ST+200 mg/kg FA group were orally infused with 1 mL Salmonella pullorum solution (concentration of 3×108 CFU/mL) at 7 and 9 days of age, and others in control group were orally infused with an equal amount of sterile nutrient broth. The experiment lasted for 21 days. The results showed that the ferulic acid had no significant effects on the growth performance, intestinal morphology, serum tumor necrosis factor-α (TNF-α) content, and liver total superoxide dismutase (T-SOD), catalase (CAT), glutathione peroxidase (GPx) activities and total antioxidant capacity (T-AOC) of broilers infected with Salmonella pullorum (P>0.05). The serum interleukin-1β (IL-1β) and interleukin-6 (IL-6) contents of ST group were significantly higher than those of CON group, ST+100 mg/kg FA group and ST+200 mg/kg FA group (P<0.05); the jejunal TNF-α, IL-1β and IL-6 contents of CON group and ST group were significantly higher than those of ST+100 mg/kg FA group and ST+200 mg/kg FA group (P<0.05), and the jejunal IL-1β and IL-6 contents of CON group were significantly lower than those of ST group (P<0.05), the jejunal IL-6 content of ST+100 mg/kg FA group was significantly lower than that of ST+200 mg/kg FA group (P<0.05); the liver malondialdehyde (MDA) content of CON group, ST+100 mg/kg FA group and ST+200 mg/kg FA group was significantly lower than that of ST group (P<0.05). In summary, dietary supplementation with ferulic acid has no significant effects on the growth performance and intestinal morphology of broilers infected with Salmonella pullorum, but can effectively alleviate the liver oxidative stress and intestinal local inflammatory reactions of broilers caused by Salmonella pullorum. Among them, the supplementation of 100 mg/kg ferulic acid has better effects.
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This study aimed to investigate the effects of dietary selenium source and selenium supplemental level on tissue selenium contents and antioxidant capacity of broilers. A 3 (selenium source)×3 (selenium supplemental level)+1 (control group) two-factor completely randomized design was adopted. A total of 780 one-day-old healthy Arbor Acres (AA) broiler cockerels were randomly allocated into 10 groups with 6 replicates per group and 13 birds per replicate. The control group was fed a corn-soybean meal basal diet without selenium supplementation; the three selenium sources in experiment were sodium selenite, selenomethionine and nano-selenium, and the three selenium supplemental levels were 0.10, 0.25 and 0.40 mg/kg, respectively. The experimental period lasted for 14 days. The results showed as follows: 1) the selenium source, selenium supplemental level and their interaction had significant effects on contents of selenium in plasma, breast muscle, liver and pancreas (P<0.05), the contents of selenium in plasma, breast muscle, liver and pancreas of 0.40 mg/kg selenomethionine group were significantly higher than those of other selenium supplementation group (P<0.05). 2) The selenium supplemental level had significant effects on activities of glutathione peroxidase (GPx) and thioredoxin reductase (TXNRD) in liver (P<0.05), the selenium source and selenium supplemental level interaction had a significant effect on pancreas GPx activity (P<0.05), the selenium source had a significant effect on liver selenoprotein P (SELENOP) content (P<0.05), and the selenium supplemental level had a significant effect on pancreas SELENOP content (P<0.05). 3) The selenium source and selenium supplemental level interaction had significant effects on mRNA relative expression levels of GPx1 and GPx4 in breast muscle (P<0.05), had a significant effect on mRNA relative expression level of iodothyronine deiodinase 1 (DIO1) in liver (P<0.05), and had significant effects on mRNA relative expression levels of GPx1, SELENOP, DIO1 and TXNRD2 in pancreas (P<0.05). In conclusion, the selenium deposition and antioxidant capacity in broilers exhibit tissue-specific variations depending on selenium source and selenium supplemental level, 0.40 mg/kg selenomethionine promotes tissue selenium deposition, the liver responds markedly to selenium supplemental level, whereas the pancreas is more sensitive to the type of selenium source, providing a critical basis for the rational selection of selenium source and selenium supplemental level.
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This experiment was conducted to analyze the amino acid apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of 10 wheat middlings from different sources in laying hens during peak laying period, and to establish prediction equations of amino acid SID based on physical characteristics and chemical component contents of wheat middlings. A single-factor experimental design was adopted. A total of 396 healthy 42-week-old Roman pink laying hens during peak laying period with similar body weight and egg production rate were selected and randomly divided into 11 groups with 6 replicates per group and 6 hens per replicate. One group was fed a nitrogen-free diet, and the other ten groups were fed semi-purified experimental diets formulated with 10 different sources of wheat middlings, respectively. All nitrogen-free and experimental diets were supplemented with 0.50% titanium dioxide (TiO2) as an exogenous indicator, and the experimental period lasted for 3 days. At the end of the experiment, all hens were stunned with carbon dioxide gas and slaughtered. Terminal ileal digesta were collected to determine amino acid and TiO2 contents for calculating amino acid AID and SID. The results showed as follows: 1) under the air-dry basis, the contents of gliadin (Gli), glutenin (Gln), albumin (Alb) and globulin (Glo) in protein fractions of 10 wheat middlings from different sources were 31.04% to 36.21% [coefficient of variation (CV)=4.34%], 37.52% to 46.80% (CV=8.45%), 30.53% to 36.31% (CV=5.23%) and 26.78% to 32.59% (CV=6.13%), respectively. 2) There were differences in amino acid SID of wheat middlings for laying hens during peak laying period. Among them, the average SID of threonine was the lowest at 70.50% (54.66% to 75.82%), and the average SID of tryptophan was the highest at 90.76% (86.57% to 94.24%). The coefficient of variation (CV) of methionine SID was the largest (18.45%), followed by aspartic acid (CV=15.03%), and the CV of SID for other amino acids did not exceed 15%. 3) In this experiment, prediction equations for SID of 9 essential amino acids except threonine were successfully developed. The prediction equations for valine, methionine, phenylalanine, histidine and tryptophan SID exhibited favorable performance (R2>0.900). Among them, the prediction equation for valine SID [Val SID =-647.48+6.63 dry matter (DM)-14.66 acid detergent fiber (ADF)+7.21 neutral detergent fiber (NDF)+8.66 Gli-5.54 Gln] had the highest fitting degree (R2=0.991, P<0.05). In conclusion, there were obvious differences in protein fractions and amino acid SID among 10 wheat middlings from different sources. Prediction equations for most essential amino acid SID can be accurately established based on physical characteristics and chemical component contents of wheat middlings, and the valine SID prediction equation showed the optimal performance.
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This study aimed to investigate the effects of salidroside (Sal) on the growth performance, slaughter performance, meat quality and antioxidant capacity of meat ducks under high stocking density (HSD) conditions. A 2×2 two-factor experimental design was employed, with two factors being stocking density and Sal supplemental level. Stocking density was set at two levels: normal stocking density (NSD) and HSD. Sal supplemental level was set at two levels: 0 and 60 mg/kg. A total of four groups were formed, each with 8 replicates. Stocking densities were as follows: from 1 to 14 days of age, NSD was 16 birds/m2 (0.06 m2/bird), and HSD was 32 birds/m2 (0.03 m2/bird); from 15 to 42 days of age, NSD was adjusted to 8 birds/m2 (0.13 m2/bird), and HSD was adjusted to 16 birds/m2 (0.06 m2/bird). A total of 576 healthy 1-day-old Cherry Valley male ducklings were selected for the 42-day trial, which was divided into two phases: 1 to 14 days of age and 15 to 42 days of age. The results showed as follows: 1) HSD significantly reduced body weight at 14 and 42 days of age, average daily gain (ADG) at all stages, and average daily feed intake (ADFI) during 1 to 14 days of age (P<0.05), while significantly increased feed-to-gain ratio (F/G) during 15 to 42 days of age and 1 to 42 days of age (P<0.05). Sal supplementation significantly reduced F/G during 1 to 14 days of age (P<0.05), and tended to increase ADG during 1 to 42 days of age (P=0.089) and decrease F/G during 1 to 42 days of age (P=0.075). 2) HSD significantly reduced live weight, carcass weight, semi-eviscerated weight, eviscerated weight, breast muscle weight, as well as dressing percentage, semi-eviscerated percentage and eviscerated percentage (P<0.05), while significantly increased abdominal fat percentage (P<0.05). Sal supplementation significantly increased live weight, carcass weight, eviscerated weight, semi-eviscerated weight and breast muscle weight (P<0.05). Significant interactions between stocking density and Sal supplemental level were observed for breast muscle weight and breast muscle percentage (P<0.05). 3) HSD significantly reduced breast muscle and leg muscle pH45 min and pH24 h, as well as leg muscle redness (a*) value at 24 h (P<0.05), while significantly increased breast muscle shear force and cooking loss (P<0.05). Sal supplementation significantly decreased breast muscle lightness (L*) value at 45 min, yellowness (b*) value at 24 h and shear force, as well as leg muscle drip loss and shear force (P<0.05), while significantly increased breast muscle pH24 h and leg muscle a* value at 24 h (P<0.05). Significant interactions between stocking density and Sal supplemental level were found for breast muscle L*, a* values at 45 min and shear force, as well as leg muscle a* value at 24 h, drip loss at 48 h and shear force (P<0.05). 4) HSD significantly decreased the activities of superoxide dismutase (SOD) and catalase (CAT) in breast muscle, as well as serum SOD activity (P<0.05), while significantly increased breast muscle malondialdehyde (MDA) content (P<0.05). Sal supplementation significantly increased serum SOD and glutathione peroxidase (GSH-Px) activities (P<0.05). A significant interaction between stocking density and Sal supplemental level was observed for serum GSH-Px activity (P<0.05). In conclusion, under HSD conditions, dietary supplementation with 60 mg/kg Sal can improve growth performance, enhance slaughter performance and meat quality, and strengthen antioxidant capacity of meat ducks.
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This experiment used the comparative slaughter method and the factorial method to separately investigate the net energy for growth (NEg) requirement and the net energy for maintenance (NEm) requirement of Xupu female geese during 1 to 63 days of age, and established a prediction model for net energy (NE) requirement. In experiment 1, seventy-two 1-day-old healthy female geese were randomly divided into 4 replicates with 18 geese in each replicate. The trial lasted for 9 weeks, in which the body weight (BW) and body net energy (BE) of geese were measured weekly. A linear regression model was established with BW as independent variable and BE as dependent variable, and the slope represented the NEg requirement of Xupu female geese. Experiment 2 was conducted in two stages (1 to 28 days of age and 29 to 63 days of age) to study the NEm requirement of Xupu female geese, using ninety-six 1-day-old and seventy-two 29-day-old healthy female geese, respectively. Four groups were set: a free feeding group (control group) and 20%, 40% and 60% restricted feeding groups, each with 6 replicates and 4 or 3 geese in each replicate. During the mid-point of each stage (i.e. at 14 and 46 days of age), the excreta were collected continuously for 3 days to determine the apparent metabolizable energy (AME) of diets under different feeding levels. Net energy deposition (RE), metabolizable energy intake (MEi) and heat production (HP, HP=MEi-RE) were calculated. A regression model between lg(HP) and MEi was established: lg(HP)=a+b×MEi; the HP value when MEi=0 was defined as the NEm requirement of Xupu female geese. The results showed that BW, average daily feed intake (ADFI), feed-to-gain ratio (F/G) and BE of Xupu female geese were significantly increased with the age increasing (P<0.05), and the average daily gain (ADG) in 7 weeks of age was significantly higher than that in the other weeks of age (P<0.05). The NEg requirement of Xupu female geese during 1 to 28 days of age and 29 to 63 days of age were 9.75 and 10.64 kJ/g, respectively. Partial feeding restriction levels significantly affected the AME of diets (P<0.05). The NEm requirement of Xupu female geese during 1 to 28 days of age and 29 to 63 days of age were 426.58 and 467.74 kJ/(BW0.75·d) (BW0.75 represented metabolic body weight, the same below), respectively. This study indicates that the NEg and NEm requirements of Xupu female geese differs between the two stages of 1 to 28 days of age and 29 to 63 days of age. The NE requirement of Xupu female geese can be predicted based on BW and ADG, using the following prediction models: NE (kJ/d)=426.58×BW0.75+9.75×ADG (1 to 28 days of age) and NE (kJ/d)=467.74×BW0.75+10.64×ADG (29 to 63 days of age).
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This experiment order to compare the differences in proximate nutritional components and rumen degradation characteristics of forage triticale hay and oat hay in dairy cows. Four varieties (ZS1048, JS3rd, JS4th and JS5th) of forage triticale hay and two sources (domestic and imported) of oat hay were used as experimental materials. The proximate nutritional components were determined by proximate analysis method, and the ruminal degradation characteristics of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were evaluated using the nylon bag technique. The comprehensive values of those forages were further assessed by the membership function method. The results showed as follows: 1) the NDF and ADF contents of four varieties of forage triticale hay were significantly lower than those of domestic oat hay (P<0.05), while the CP content was significantly higher than that of domestic oat hay (P<0.05). The relative feed value (RFV) of JS3rd triticale hay (125.46) and imported oat hay (123.21) was significantly higher than that of the other varieties of forage triticale hay and domestic oat hay (P<0.05). 2) After 72 h of ruminal digestion, the DM, NDF and ADF degradabilities of JS3rd and JS4th triticale hay were significantly higher than those of domestic oat hay (P<0.05), while the NDF and ADF degradabilities of JS3rd triticale hay were significantly lower than those of imported oat hay (P<0.05). 3) The effective degradabilities of DM, CP, NDF and ADF of the four varieties of forage triticale hay were between those of domestic oat hay and imported oat hay, and the effective degradability of NDF of JS3rd triticale hay were significantly higher than those of ZS1048 and JS5th(P<0.05). 4) Based on the comprehensive evaluation of nutrient quality and ruminal degradation characteristics using the membership function method, the comprehensive value of the tested forages ranked as follows: JS3rd triticale hay>imported oat hay> JS4th triticale hay>JS5th triticale hay>ZS1048 triticale hay>domestic oat hay. These results indicate that the overall quality of JS3rd triticale hay is superior to that of imported oat hay, reaching the level of high-quality roughage. Although the overall quality of the other triticale varieties is inferior to that of imported oat hay, all of them are better than domestic oat hay and demonstrate the potential to serve as high-quality roughage. Therefore, forage triticale hay can be used as a local alternative or supplement to oat hay, providing richer roughage options for dairy farming.
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This experiment was conducted to investigate the effects of dietary supplementation with Echinacea purpurea extract on lactation performance, serum indices and rumen fermentation parameters and microbiota of dairy cows in mid-lactation. Sixty healthy Chinese Holstein cows with similar parity [(2.23±0.06) parities], milk yield [(36.17±0.39) kg/d] and days in milk [(184.63±1.93) d] were selected and randomly assigned to 4 groups with 15 replicates per group and one cow per replicate. Cows in the control group (CON group) were fed a basal diet, while those in the experimental groups were fed the basal diet supplemented with 3 (EP1 group), 6 (EP2 group) and 9 g/d (EP3 group) of Echinacea purpurea extract, respectively. The pre-trial lasted for 7 days, and the formal experiment lasted for 56 days. The results showed as follows: 1) compared with the CON group, the EP2 group had significantly higher milk yield, 3.5% fat-corrected milk (FCM) yield, energy-corrected milk (ECM) yield, feed efficiency and milk fat yield (P<0.05); 2) compared with the CON group, the EP2 and EP3 groups had significantly lower ruminal acetic acid molar proportion and acetic acid to propionic acid ratio (P<0.05), and significantly higher ruminal propionic acid molar proportion (P<0.05); 3) the EP2 group showed significant enrichment of FD2005, [Eubacterium]_xylanophilum_group, Oribacterium and Lachnospiraceae_NK4A136_group in rumen (linear discriminant analysis score>2, P<0.05); 4) compared with the CON group, the EP2 group had significantly higher serum glutathione peroxidase and superoxide dismutase activities (P<0.05). In conclusion, under the conditions of this experiment, dietary supplementation with 6 g/d Echinacea purpurea extract can effectively improve the feed efficiency and enhance the lactation performance of dairy cows in mid-lactation by enhancing antioxidant capacity, modulating rumen microbiota structure and optimizing fermentation patterns.
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This experiment was conducted to investigate the effects of coated cobalamin (CCA) and biotin (BI) on lactation performance, rumen fermentation, serum indices and liver forkhead box O (FoxO) signaling pathway in dairy cows. Sixty Holstein cows with 2 to 3 parities, similar milk yield [(40.52±5.38) kg] and days in milk [(31.50±8.45) d] were selected and randomly assigned to 4 groups according to a randomized block design, with 15 cows per group. Cows in the control group (CON group) were fed a basal diet, while those in CCA, BI and CCA+BI groups were fed the basal diets supplemented with 6.00 g/d CCA, 20 mg/d BI and 6 g/d CCA+20 mg/d BI, respectively. The pre-trial lasted for 10 days, and the formal trial lasted for 60 days. The results showed as follows: 1) supplementation with CCA or BI significantly increased the milk yield, 4% fat-corrected milk yield and feed efficiency (FE) (P<0.05); CCA supplementation significantly increased the milk fat, milk protein and milk lactose yields, as well as the milk cobalamin (CA) content (P<0.05). 2) Supplementation with CCA or BI significantly increased the rumen total volatile fatty acid (TVFA), acetate and propionate contents (P<0.05), and significantly decreased the rumen acetate to propionate ratio (P<0.05); there were significant interactive effects between CCA and BI on the rumen TVFA and propionate contents and acetate to propionate ratio (P<0.05). 3) Supplementation with CCA or BI significantly increased the serum glutathione peroxidase activity, total antioxidant capacity and propionate content (P<0.05). 4) Compared with CON group, the expression of liver AMP-activated protein kinase (AMPK), c-Jun N-terminal kinase (JNK) and phosphoenolpyruvate carboxykinase (PEPCK) was significantly up-regulated in CCA and CCA+BI groups (P<0.05). In conclusion, supplementation with CCA or BI can improve the lactation performance, FE and propionate supply in dairy cows; CCA regulates the liver gluconeogenesis metabolism through up-regulating the expression of AMPK, JNK and PEPCK.
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This study was conducted to compare the differences in growth performance, nutrient apparent digestibility, slaughter performance and meat quality among Angus steers, Jinnan cattle steers and Taihang Yun cattle steers under identical feeding conditions. A total of 45 healthy steers with similar ages and an initial body weight of (373±10) kg, including 15 Angus steers, 15 Jinnan cattle steers and 15 Taihang Yun cattle steers, were selected and randomly assigned to 3 groups based on breed, with 15 replicates per group and one steer per replicate. The whole trial lasted for 285 days, consisting of a 15-day preliminary feeding period and a 270-day formal trial period (9 months, from 14 to 22 months of age). All groups were provided with the same diet and unified feeding management throughout the experiment. The results showed as follows: 1) during the first 3 months of the trial, the average daily gain of Angus cattle was significantly higher than those of Jinnan cattle and Taihang Yun cattle (P<0.05), while the feed-to-gain ratio of Taihang Yun cattle was significantly lower than that of Angus cattle and Jinnan cattle (P<0.05). 2) In the first and second months of the trial, the apparent digestibility of dry matter of Angus cattle and Jinnan cattle was significantly higher than that of Taihang Yun cattle (P<0.05); the apparent digestibility of ether extract and acid detergent fiber of Angus cattle was significantly higher than that of Taihang Yun cattle (P<0.05). 3) The pre-slaughter live weight, carcass weight, net meat weight and net meat percentage of Angus cattle were significantly higher than those of Jinnan cattle and Taihang Yun cattle (P<0.05). 4) The yields of high rib and topside of Jinnan cattle and Taihang Yun cattle were significantly higher than those of Angus cattle, with significant differences among breeds (P<0.05). Tenderloin yield was ranked as Jinnan cattle>Taihang Yun cattle>Angus cattle, with significant differences among breeds (P<0.05). The carcass high-grade and high-quality meat yield of Jinnan cattle and Taihang Yun cattle were significantly higher than those of Angus cattle (P<0.05). 5) For longissimus dorsi muscle, the intramuscular fat (IMF) content of Angus cattle was significantly higher than that of Jinnan cattle and Taihang Yun cattle (P<0.05); Jinnan cattle had significantly higher protein and ash contents and significantly lower moisture content compared with Angus cattle and Taihang Yun cattle (P<0.05). The cooking loss of Angus cattle and Taihang Yun cattle was significantly higher than that of Jinnan cattle (P<0.05). The shear force ranked as Taihang Yun cattle>Jinnan cattle>Angus cattle, and the redness (a*) value ranked as Jinnan cattle>Angus cattle>Taihang Yun cattle, with significant differences among breeds (P<0.05). 6) For fatty acid composition in longissimus dorsi muscle, the contents of C14∶0 and C22∶1n9 ranked as Angus cattle>Taihang Yun cattle>Jinnan cattle, with significant differences among breeds (P<0.05); the C16∶0 and C18∶0 contents of Angus cattle were significantly higher than those of Jinnan cattle and Taihang Yun cattle (P<0.05); the C20∶0 and C24∶0 contents of Taihang Yun cattle were significantly higher than those of Jinnan cattle (P<0.05). The C18∶1n9c content and total monounsaturated fatty acid content of Angus cattle and Jinnan cattle were significantly higher than those of Taihang Yun cattle (P<0.05). In conclusion, under the consistent feeding and management conditions, Angus steers feature faster growth rate, higher nutrient apparent digestibility and superior slaughter performance as well as abundant fatty acids in muscle; Jinnan cattle steers have higher carcass high-grade meat yield, rich muscle amino acids and monounsaturated fatty acids, showing great potential for meat flavor formation; Taihang Yun cattle steers possess outstanding feed conversion efficiency, and their overall growth performance is better than that of Jinnan cattle steers.
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This experiment aimed to study on differences in rumen fermentation parameters and fatty acids composition of Simmental beef cattle under barn feeding and grazing conditions, to provide foundational data for rumen metabolic regulation. A total of 33 Simmental bulls with similar body weight, uniform body condition and good health were selected, including 17 bulls raised in confined barn feeding and 16 bulls raised in free grazing, divided into barn feeding group and grazing group, respectively. The results showed as follows: 1) the rumen fluid ammonia nitrogen (NH3-N) content of the grazing group was extremely significantly lower than that of the barn feeding group (P<0.01), while the pH, microbial protein (MCP) content and acetic acid/propionic acid were extremely significantly higher than those of the barn feeding group (P<0.01). 2) The polyunsaturated fatty acids (PUFA)/saturated fatty acids (SFA) and contents of n-3 PUFA, n-6 PUFA and PUFA in rumen fluid of the grazing group were extremely significantly or significantly higher than those of the barn feeding group (P<0.05 or P<0.01), the trans-oleic acid (C18∶1n9t) content was extremely significantly lower than that of the barn feeding group (P<0.01), the docosahexaenoic acid (C22∶6n3/DHA) and linoleic acid (C18∶2n6c) contents were extremely significantly higher than those of the barn feeding group (P<0.01), whereas the gamma-linolenic acid (C18∶3n6) content was significantly lower than that of the barn feeding group (P<0.05). 3) The rumen fluid C18∶1n9t content was extremely significantly positively correlated with dietary C18∶2n6c content (P<0.01), and the rumen fluid C18∶2n6c content was significantly positively correlated with dietary C18∶3n6 content (P<0.05). In conclusion, grazing can increase the rumen fluid pH, MCP content and acetic acid/propionic acid, reduce the NH3-N content, and improve the nitrogen utilization efficiency; at the same time, it can optimize the rumen fluid fatty acids composition, increase the PUFA content and PUFA/SFA, and regulate the contents of multiple key fatty acids; the correlation analysis confirms the biohydrogenation transformation pathway of dietary PUFA in rumen. Overall, grazing feeding is more conducive to improving rumen metabolic environment and fatty acid nutritional characteristics of beef cattle.
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This experiment was conducted to explore the effects of diets with different proportions of distiller’s grains on calcium and phosphorus metabolism, serum indices and plasma metabolome in beef cattle. Six adult beef cattle fitted with rumen fistulas were used in a self-control experiment. The pre-experimental period lasted 14 days and the formal experimental period lasted 135 days. Only the first stage was equipped with a 14-day pre-experimental period, and the formal period of each of the 3 stages was 45 days. The diets in each stage maintained iso-energy, iso-nitrogen, iso-calcium and iso-phosphorus levels. In stage 1 (days 1 to 45), the animals were fed the diet containing 35% distiller’s grains (L group). In stage 2 (days 46 to 90), the animals were fed the diet containing 55% distiller’s grains (M group). In stage 3 (days 91 to 135), the animals were fed the diet containing 65% distiller’s grains (H group). The results showed as follows: 1) the apparent digestibility of calcium decreased significantly with the increasing proportion of distiller’s grains in diets (P<0.05), while no significant difference was observed in the apparent digestibility of phosphorus among groups (P>0.05). The serum calcium and calcitonin (CT) contents in the M group and the H group were significantly lower than those in the L group (P<0.05), and no significant difference existed between the the M group and the H group (P>0.05). The serum phosphorus and parathyroid hormone (PTH) contents increased significantly with the increasing proportion of distiller’s grains in diets (P<0.05). 2) The ruminal fluid pH in the H group was significantly lower than that in the L group and the M group (P<0.05), and there was no significant difference between the L group and the M group (P>0.05). The contents of lactic acid and lipopolysaccharide (LPS) increased significantly with the increasing proportion of distiller’s grains in diets (P<0.05). 3) The serum interleukin-1β (IL-1β) and interleukin-6 (IL-6) contents increased significantly with the increasing proportion of distiller’s grains in diets (P<0.05). 4) Seven differential metabolites were screened out via plasma metabolome analysis. Compared with the L group, the plasma levels of aldosterone and phorbol were significantly up-regulated in the H group (P<0.05), while choline, vitamin K1 epoxide, vanillin, creatine and ganoderic acid A were significantly down-regulated (P<0.05). Compared with the M group, the H group showed significantly up-regulated plasma aldosterone and phorbol (P<0.05), as well as significantly down-regulated vanillin, creatine and ganoderic acid A (P<0.05). When compared with the L group, only plasma aldosterone exhibited no significant difference in the M group (P>0.05), and the rest of differential plasma metabolites were significantly down-regulated (P<0.05). KEGG enrichment analysis revealed that the differential metabolites were enriched in pathways including amino acid metabolism, ubiquinone and other terpenoid-quinone biosynthesis, arginine and proline metabolism, aldosterone-regulated sodium reabsorption, drug metabolism-cytochrome P450, among others. In conclusion, high-proportion distiller’s grains diets can disrupt rumen homeostasis, disturb calcium-phosphorus metabolic balance and aggravate the inflammatory response of beef cattle.
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This experiment was conducted to investigate the effects of feeding a lactose-containing starter on growth and development, nutrient apparent digestibility and rumen fermentation parameters of calves. Twenty Holstein calves with similar body weight [(36±2) kg] and age (within 3 days of birth) were randomly assigned to two groups, with 10 replicates per group and one calf per replicate. The experiment lasted for 63 days. Calves in the control group were fed a conventional starch-based starter throughout the experiment; calves in the experimental group were fed a starter containing 44.40% lactose during the first stage (days 1 to 21) and a starter containing 8.88% lactose during the second stage (days 22 to 63). The results showed as follows: 1) compared with the control group, the experimental group had significantly higher starter feed intake during the first stage, as well as significantly higher dry matter intake during the first stage and whole trial period (P<0.05). Meanwhile, the body weight on day 21 and day 63, and the average daily gain and feed efficiency during the first stage and whole trial period in the experimental group were also significantly increased (P<0.05). 2) Compared with the control group, the experimental group showed significantly increased heart girth on day 21, and significantly increased withers height, hip height, body straight length, heart girth and abdominal girth on day 63 (P<0.05). 3) Compared with the control group, the dry matter (DM) apparent digestibility in the experimental group was numerically higher (77.44% vs. 70.60%), but the difference was not significant (P>0.05). 4) Compared with the control group, the experimental group had significantly higher total volatile fatty acid (TVFA), propionate, butyrate and valerate contents, as well as valerate molar proportion in rumen (P<0.05), and significantly lower acetate-to-propionate ratio and acetate molar proportion in rumen (P<0.05), while the rumen pH and ammonia nitrogen content showed no significant difference (P>0.05). In conclusion, compared with feeding a conventional starch-based starter, feeding a lactose-containing starter promotes growth and development, tends to improve DM apparent digestibility to some extent, increases rumen TVFA, propionate and butyrate contents, and improves rumen fermentation of calves.
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This study was conducted to investigate the effects of dietary supplementation with rumen-protected glucose (RPG) and cocamidopropyl betaine (CAPB) on growth performance, serum indices, and rumen fermentation parameters and microbial community of yaks under transportation stress. Eighteen 2.5-year-old male Maiwa yaks with an average body weight of (151.50±4.42) kg and good body condition were randomly divided into 3 groups with 6 replicates per group and 1 yak per replicate. The control (CON) group was fed a basal diet, and the other two groups were fed the basal diet supplemented with 1% RPG preparation (RPG group) and 1% CAPB preparation (CAPB group), respectively. The experimental period was 32 days, including 10 days before transportation, the transportation day and 21 days after transportation. The results showed as follows: 1)compared with the CON group, the percentage of body weight loss during transport of yaks in the CAPB group was significantly lower (P<0.05), and the dry matter intake (DMI) from 0 to 21 days after transportation of yaks in both the RPG and CAPB groups was significantly lower (P<0.05). 2) Compared with before commencement of transportation, the serum contents of lipopolysaccharide (LPS) and malondialdehyde (MDA) on the day after transportation were significantly higher (P<0.05), and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), and the total antioxidant capacity (T-AOC) were significantly lower (P<0.05). On day 21 after transportation, no significant differences were observed compared with before commencement of transportation (P>0.05). The serum LPS content and SOD activity of yaks in the CAPB group were significantly lower than those in the CON group before commencement of transportation, on the day after transportation and on day 21 after transportation (P<0.05). 3) Dietary supplementation of RPG and CAPB had no significant effects on rumen fermentation parameters or microbial diversity of yaks on day 21 after transportation (P>0.05). Linear discriminant analysis effect size (LEfSe) analysis revealed that the rumen of yaks in the RPG group was significantly enriched with the unclassified genus g__norank_f__Ethanoligenenaceae and the genus g__Ruminiclostridium, whereas the rumen of yaks in the CAPB group was significantly enriched with the genus g__Pseudobutyrivibrio. In conclusion, dietary supplementation of 1% CAPB preparation for 10 days before transportation shows preliminary potential in alleviating transportation stress in yaks; however, due to the limitation of a single-dose design and insufficient safety data, it cannot yet be recommended as a routine production strategy.
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This experiment was conducted to investigate the effects of dietary combined supplementation with guanidinoacetic acid (GAA) and Saccharomyces cerevisiae-cellulase complex (SCC) on the small intestinal development, digestive enzyme activities, serum biochemical indices and immune function of meat sheep. A total of 72 healthy crossbred weaned male lambs (Texel×Dorper) with similar age and an average body weight of (25.46±2.01) kg were randomly divided into 6 groups, with 4 replicates per group and 3 lambs per replicate. The control group (Con group) was fed a basal diet, while the T1 to T5 groups were fed the basal diet supplemented with 0.03% GAA, 0.06% GAA, 0.01% SCC, 0.03% GAA+0.01% SCC and 0.06% GAA+0.01% SCC, respectively. The pre test period lasted 7 days, followed by a formal experimental period of 60 days. The results showed as follows: 1) dietary supplementation with 0.06% GAA significantly increased serum total protein (TP) content (P<0.05); dietary supplementation with 0.01% SCC significantly decreased serum urea nitrogen (BUN) content and acid phosphatase (ACP) activity (P<0.05); there were significant interactive effects between GAA and SCC on serum TP, BUN, triglyceride (TG) contents and ACP activity (P<0.05), and the T5 group exhibited the best performance across all the above indicators. 2) Dietary supplementation with 0.06% GAA significantly increased serum lysozyme (LZM) activity (P<0.05); dietary supplementation with 0.01% SCC significantly increased serum immunoglobulin G (IgG) content and LZM activity (P<0.05), and significantly decreased serum tumor necrosis factor-α (TNF-α) content (P<0.05). Significant interactive effects between GAA and SCC were observed on serum LZM activity and the contents of IgG, TNF-α, complement 3 (C3) and complement 4 (C4) (P<0.05), with the T5 group exhibiting the best performance across all the above indicators. 3) Dietary supplementation with 0.03% and 0.06% GAA significantly increased duodenal amylase and jejunal lipase activities (P<0.05); dietary supplementation with 0.01% SCC significantly increased duodenal amylase and jejunal lipase activities (P<0.05). Significant interactive effects between GAA and SCC were observed on duodenal amylase, trypsin, and jejunal lipase activities (P<0.05), with the T5 group showing the highest activities among all groups. 4) Dietary supplementation with 0.06% GAA significantly increased duodenal villus height (VH) (P<0.05); dietary supplementation with 0.01% SCC significantly increased duodenal VH (P<0.05). Significant interactive effects between GAA and SCC were observed on VH and villus height to crypt depth ratio (V/C) in both duodenum and jejunum (P<0.05), and the T5 group exhibited the best values for these parameters. 5) Dietary supplementation with 0.06% GAA significantly increased the columnar cells (CC) and goblet cells (GC) counts in both duodenum and jejunum, while 0.03% GAA significantly increased duodenal CC count (P<0.05); dietary supplementation with 0.01% SCC significantly increased duodenal CC and GC counts as well as jejunal CC count (P<0.05). Significant interactive effects between GAA and SCC were observed on jejunal CC and GC counts (P<0.05), with the T5 group having the highest counts. In conclusion, dietary combined supplementation with 0.06% GAA and 0.01% SCC can effectively improve serum biochemical indices, promote small intestinal development, and enhance immune function of meat sheep.
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The aim of this experiment was to study the effects of dietary tea polyphenols (TP) on growth performance, slaughter performance, organ development and intestinal microbiota structure of Hu sheep. Sixty healthy male Hu sheep with age about 3 months old and similar body weight were selected and randomly divided into 4 groups with 15 sheep per group. Sheep in the control group (CON group) were fed a basal diet, and others in experimental groups were fed the basal diets supplemented with 400 (LTP group), 800 (MTP group) and 1 200 mg/kg (HTP group) TP, respectively. The pre-experimental period lasted for 10 days, and the experimental period lasted for 87 days. The results showed as follows: 1) compared with the CON group, the growth performance and slaughter performance of all experimental groups had no significant difference (P>0.05). 2) Compared with the CON group, the rumen weight of HTP group was significantly decreased (P<0.05), the duodenal villus height (VH) and villus height/crypt depth (VH/CD) of HTP group were significantly decreased (P<0.05), the jejunal VH and VH/CD of LTP group were significantly increased (P<0.05), and the ileal VH/CD of LTP group was significantly decreased (P<0.05). 3) Compared with the CON group, the muscle pH45 min of MTP group was significantly decreased (P<0.05), and the muscle redness (a*) value and water loss rate were significantly increased (P<0.05). 4) Compared with the CON group, the indexes of Ace, Chao, Simpson and Shannon in intestinal microbiota of all experimental groups were significantly increased (P<0.05). 5) At the phylum level, compared with the CON group, the relative abundance of Verrucomicrobia in intestine of LTP group and MTP group was significantly decreased (P<0.05), and relative abundance of Spirochaetes in intestine of MTP group was significantly increased (P<0.05). 6) At the genus level, compared with the CON group, the relative abundance of Christensenellaceae_R-7_group in intestine of LTP group and HTP group was significantly decreased (P<0.05), the relative abundances of Rikenellaceae_RC9_gut_group and Prevotellaceae_UCG-004 in intestine of HTP group were significantly increased (P<0.05), the relative abundances of Akkermansia and Mogibacterium in intestine of LTP group and MTP group were significantly decreased (P<0.05), and the relative abundances of Ruminiclostridium_1 and Ruminococcus_1 in intestine of MTP group were significantly increased (P<0.05). In conclusion, dietary TP do not affect the growth performance and slaughter performance of Hu sheep, the appropriate amount of TP supplementation can change the intestinal microbiota structure, improve intestinal development and meat color.
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This study aimed to investigate the effects of replacing inorganic trace minerals with organic trace minerals on apparent digestibility of trace elements, as well as trace element contents in blood, visceral organs and muscle of Wendeng dairy goat kids. Forty-five healthy weaned male Wendeng dairy goat kids with initial body weight of (12.33±0.46) kg were randomly assigned to 5 groups with 9 replicates per group and one kid per replicate in a single-factor experimental design. The control group (CON group) was fed the basal diet. The inorganic control group (IT100 group) received basal diet supplemented with 1 000 mg/kg inorganic trace minerals. The 50% organic trace mineral group (OT50 group), 75% organic trace mineral group (OT75 group) and 100% organic trace mineral group (OT100 group) were supplemented with 500, 750 and 1 000 mg/kg organic trace minerals in basal diet, respectively. The trial lasted for 67 d, including a 7-d adaptation period and a 60-d formal experimental period. The results showed as follows: 1) compared with the CON group, the apparent digestibility of copper (Cu) and manganese (Mn) was significantly increased in OT50 and OT75 groups (P<0.05), and the apparent digestibility of zinc (Zn) was extremely significantly increased in IT100, OT50, OT75 and OT100 groups (P<0.01); the contents of Cu, Mn and iron (Fe) in blood were extremely significantly increased in IT100, OT75 and OT100 groups (P<0.01); the contents of Fe and Zn in heart, Cu, Fe and Zn in liver, Cu, Mn and Zn in spleen, Fe, Zn and Mn in lung, Fe and Zn in kidney, and Cu, Fe, selenium (Se) and cobalt (Co) in muscle were significantly or extremely significantly increased in IT100, OT50, OT75 and OT100 groups (P<0.05 or P<0.01). 2) Compared with the IT100 group, the apparent digestibility of Cu was significantly increased in OT50 and OT75 groups (P<0.05); the contents of Cu in heart, Fe in liver and Mn in lung were significantly or extremely significantly increased in OT75 and OT100 groups (P<0.05 or P<0.01); the contents of Fe and Zn in lung and muscle were significantly or extremely significantly increased in OT100 group (P<0.05 or P<0.01). In conclusion, dietary supplementation with trace elements can improve the apparent digestibility of trace elements and the contents of trace elements in blood and tissues of Wendeng dairy goat kids. Compared with inorganic trace elements, organic trace minerals can further enhance the digestibility and tissue deposition of partial trace elements. Moreover, supplementing organic trace minerals at 75% of the inorganic trace mineral supplementation level achieves comparable performance to 100% inorganic trace minerals for most indices, and even better outcomes for partial indices, indicating its potential for reduced-dosage application.
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This experiment was conducted to explore the effects of individual or combined supplementation of Astragalus straw and Lactobacillus rhamnosus on growth performance, serum biochemical indices, antioxidant capacity, immune function and energy metabolism of lambs. Forty-eight healthy 3-month-old Hu lambs with an initial body weight of (18.59±0.06) kg were selected and randomly allocated into 4 groups with 12 lambs per group. All lambs were raised in individual pens. Lambs in the control group (C group) were fed a basal diet. Lambs in the Lactobacillus rhamnosus group (L group), Astragalus straw group (A group) and Lactobacillus rhamnosus+Astragalus straw group (LA group) received the basal diet supplemented with 109 CFU/d Lactobacillus rhamnosus, 4% Astragalus straw, and a mixture of 109 CFU/d Lactobacillus rhamnosus plus 4% Astragalus straw, respectively. The whole trial lasted for 100 days. The pre-experimental period lasted for 10 days, and the experimental period lasted for 90 days. A digestion and metabolism trial was carried out during the last 8 days of the experimental period. The results showed as follows: 1) compared with the C group, the average daily feed intake (ADFI) of lambs in the L and A groups increased significantly (P<0.05), and the average dry matter intake (ADMI) in the A group also increased significantly (P<0.05). 2) Serum glucose (GLU) and triglyceride (TG) contents in the L, A and LA groups were significantly lower than those in the C group (P<0.05); serum lactate dehydrogenase (LDH) and alanine transaminase (ALT) activities of lambs in the A group were significantly decreased compared with the C group (P<0.05), while serum albumin (ALB) content in the A and LA groups were significantly elevated (P<0.05). 3) Compared with the C group, serum glutathione peroxidase (GSH-Px) activity was significantly increased in the A group (P<0.05), and serum catalase (CAT) activity was significantly increased in the L group (P<0.05). 4) Serum immunoglobulin A (IgA) content in the L and A groups was significantly greater than that in the C group (P<0.05); serum immunoglobulin G (IgG) content in the L, A and LA groups was significantly higher than that in the C group (P<0.05), with the maximum value observed in the LA group. Only the A group exhibited significantly higher serum immunoglobulin M (IgM) content than the C group (P<0.05). Serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) contents in the L, A and LA groups were significantly lower than those in the C group (P<0.05). The serum interferon-γ (IFN-γ) content of lambs in the L and LA groups was significantly reduced relative to C group (P<0.05), whereas serum interleukin-10 (IL-10) content was significantly higher in LA group than C group (P<0.05). 5) The gross energy of diet (GE), urinary energy (UE), methane energy (CH4-E), digestible energy (DE) and metabolizable energy (ME) of lambs in the L and A groups were all significantly higher than those in the C group (P<0.05), while fecal energy(FE) in the A group was significantly lower than that in the C group (P<0.05). In conclusion, dietary supplementation with Astragalus straw or Lactobacillus rhamnosus can improve glucose and lipid metabolism, alleviate systemic inflammatory responses, and enhance antioxidant capacity, immune level and available energy in lambs. Although their combined use exhibits a certain synergistic effect on improving immunity, overall, individual supplementation yields superior results.
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This experiment was conducted to investigate the effects of replacing different proportions of fish meal with Scenedesmus on the growth performance, serum biochemical indices and liver health of Songpu mirror carp (Cyprinus carpio var. Songpu mirror). Five isonitrogenous and isolipidic experimental diets were formulated by replacing 0, 25%, 50%, 75% and 100% of fish meal with 0, 3.19%, 6.38%, 9.56% and 12.74% of Scenedesmus, respectively, and were designated as C0 (control), S25, S50, S75 and S100, respectively. A total of 375 healthy Songpu mirror carp juveniles with an initial body weight of (3.52±0.40) g were fasted for 24 h and then randomly distributed into 15 aquarium net cages at 25 fish per cage. Every three cages were assigned to one group (five groups in total), and each group was fed one of the experimental diets for 8 weeks. The results showed that the weight gain rate (WGR) and specific growth rate (SGR) in the S25 group were significantly higher than those in the S75 and S100 groups (P<0.05), and the protein efficiency ratio (PER) was significantly higher than that in the S100 group (P<0.05). No significant differences in feed conversion ratio (FCR) were observed among all groups (P>0.05), with the lowest value found in the S25 group. The serum contents of total protein (TP), albumin (ALB) and high-density lipoprotein cholesterol (HDL-C) were all highest in the S25 group, with ALB content being significantly higher than that in the other groups (P<0.05). The serum alanine aminotransferase (ALT) activity in the S25 group was significantly lower than that in the S75 group (P<0.05), and the aspartate aminotransferase (AST) activity was significantly lower than that in all other groups (P<0.05). In the liver, the activities of superoxide dismutase (SOD), catalase (CAT), lipoprotein lipase (LPL), hepatic lipase (HL) and reduced glutathione (GSH) content in the S25 group were significantly higher than those in the other groups (P<0.05); the total antioxidant capacity (T-AOC) was significantly higher than that in all other groups except the control group (C0 group) (P<0.05); the adenosine triphosphate (ATP) content was significantly higher than that in all other groups except the S50 group (P<0.05). Meanwhile, the malondialdehyde (MDA) content in the liver of the S25 group was significantly lower than that in the S100 group (P<0.05), AST activity was significantly lower than that in all other groups (P<0.05), ALT activity was significantly lower than that in the S75 group (P<0.05), and fatty acid synthase (FAS) activity was significantly lower than that in the S75 and S100 groups (P<0.05). The serum and hepatic iron ion contents were both highest in the S100 group, significantly higher than those in the other groups (P<0.05). At the 25% replacement level, the expression of growth-related genes [growth hormone (GH), insulin-like growth factor 1 (IGF1)] and protein synthesis-related genes [S6 protein kinase 1 (S6K1), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT) and target of rapamycin (TOR)] were upregulated, activating the GH-IGF axis and PI3K-AKT-TOR signaling pathway to promote hepatic protein synthesis and metabolism; the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), copper/zinc superoxide dismutase (Cu/Zn-SOD), CAT, glutathione peroxidase 1a (GPx1a) and glutathione peroxidase 1b (GPx1b) were upregulated, while the expression of Kelch-like ECH-associated protein 1 (Keap1) was downregulated, activating the Nrf2-Keap1 antioxidant pathway; the expression of key fatty acid oxidation genes [stearoyl-CoA desaturase 1 (SCD1) and carnitine palmitoyltransferase 1 (CPT1)] were upregulated, while the expression of lipogenesis-related genes [FAS, sterol regulatory element-binding protein 1 (SREBP1) and peroxisome proliferator-activated receptor γ (PPARγ)] were downregulated, reducing hepatic lipid deposition. Concurrently, the expression of transferrin (TF) and transferrin receptor (TFRC) were upregulated, while acyl-CoA synthetase long-chain family member 4 (ACSL4) was downregulated, synergistically enhancing the resistance of the liver to ferroptosis. Histological observation of liver tissues revealed that hepatocytes in the S25 group were densely arranged, structurally intact, and free of vacuolation. In conclusion, replacing 25% of fish meal with Scenedesmus in the diet can improve the growth performance and serum biochemical indices of Songpu mirror carp, enhance hepatic metabolism and antioxidant capacity, alleviate hepatic lipid deposition, and increase resistance to ferroptosis.
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This experiment was conducted to study the effects of dietary protein level on growth performance, body composition, intestinal digestive enzyme activities and hepatopancreas antioxidant parameters of Acrossocheilus fasciatus, to explore the dietary appropriate protein level of Acrossocheilus fasciatus. A total of 1 050 Acrossocheilus fasciatus with an average body weight of 3.32 g were randomly divided into 7 groups with 3 replicates per group and 50 fish per replicate. Fish in seven groups were fed experimental diets with protein levels of 25%, 30%, 35%, 40%, 45%, 50% and 55%, respectively. The experimental period lasted for 8 weeks. The results showed as follows: 1) the final body weight and weight gain were significantly increased with dietary protein level (25% to 45%) increased (P<0.05), the feed efficiency was significantly increased with dietary protein level (25% to 40%) increased (P<0.05), and the protein retention efficiency was significantly decreased with dietary protein level (35% to 55%) increased (P<0.05). 2) According to the line regression analysis of weight gain and feed efficiency with dietary protein level, the dietary appropriate protein levels were 44.05% and 43.77%, respectively. 3) The body moisture content of dietary protein levels of 25% to 40% was significantly lower than that of dietary protein levels of 50% to 55% (P<0.05), and the body ether extract content was significantly higher than that of dietary protein levels of 50% to 55% (P<0.05). 4) The intestinal protease activity of dietary protein levels of 25% to 30% was significantly lower than that of dietary protein levels of 40% to 55% (P<0.05), and the intestinal amylase activity was significantly lower than that of dietary protein levels of 40% to 55% (P<0.05). 5) The hepatopancreas total superoxide dismutase activity of dietary protein levels of 25% to 30% was significantly lower than that of dietary protein levels of 40% to 55% (P<0.05), the hepatopancreas glutathione peroxidase of dietary protein levels of 35% to 45% was significantly higher than that of other dietary protein levels (P<0.05), and the hepatopancreas malondialdehyde content of dietary protein levels of 30% to 45% was significantly lower than that of other dietary protein levels (P<0.05). In conclusion, under the conditions of this experiment, according to the evaluation parameters of weight gain and feed efficiency, the dietary appropriate protein levels for Acrossocheilus fasciatus are 43.77% to 44.05%.
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This experiment was conducted to investigate the effects of different dietary lipid sources in low-fish meal diets on growth performance, lipid metabolism and intestinal health of juvenile rainbow trout (Oncorhynchus mykiss). A total of 375 healthy juvenile rainbow trout with similar body size were randomly divided into 5 groups with 3 replicates per group and 25 fish per replicate. Five isonitrogenous and isoenergetic experimental diets were formulated with fish oil (G1 group), soybean oil (G2 group), palm oil (G3 group), chicken oil (G4 group), and mixed oil (fish oil∶soybean oil∶palm oil∶poultry oil=1∶1∶1∶1, G5 group) as lipid sources, respectively. The feeding trial lasted for 8 weeks. The results showed as follows: 1) the survival rate in G4 group was significantly higher than that in other groups (P<0.05), the specific growth rate was not significantly different from that in G1 and G3 groups (P>0.05), and the feed conversion ratio was significantly lower than that in G2 and G5 groups (P<0.05); the weight gain rate in G3 group was significantly higher than that in other groups (P<0.05). 2) The whole-body crude lipid content in G2 group was significantly higher than that in G3 and G4 groups (P<0.05). The muscle contents of threonine, serine and glutamic acid in G4 group were significantly higher than those in other groups (P<0.05). The whole-body contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in G1 group were significantly higher than those in other groups (P<0.05). 3) The serum cholesterol (CHOL) content in G3 group was significantly higher than that in G1 and G2 groups (P<0.05), the serum total bile acid (TBA) content was significantly higher than that in G5 group (P<0.05), and the serum low-density lipoprotein cholesterol (LDL-C) content was significantly higher than that in other groups (P<0.05). The serum high-density lipoprotein cholesterol (HDL-C) content in G5 group was significantly higher than that in other groups (P<0.05). 4) The gene relative expression level of hepatic Δ6 fatty acid desaturase (Δ6 FAD) in G2, G4 and G5 groups was significantly higher than that in G1 group (P<0.05); the gene relative expression level of hepatic cytochrome P450 27A1 (CYP27A1) in G3 and G4 groups was significantly higher than that in G1, G2 and G5 groups (P<0.05); the gene relative expression levels of hepatic 6-phosphogluconate dehydrogenase (6-PGDH) and stearoyl-CoA desaturase b (SCDb) in G2 group were significantly higher than those in the other groups (P<0.05); the gene relative expression level of hepatic peroxisome proliferator-activated receptor α (PPARα) in G2 and G3 groups was significantly lower than that in G1, G4 and G5 groups (P<0.05). 5) The intestinal villus height in G2 group was significantly higher than that in other groups (P<0.05). The intestinal villus width in G4 and G5 groups was significantly higher than that in G1 to G3 groups (P<0.05). The intestinal muscularis thickness in group G3 was significantly lower than that in other groups (P<0.05). 6) Intestinal microbiota analysis revealed that G4 group had the lowest relative abundance of Proteobacteria, but the highest relative abundances of Bacteroidota and Bacteroides. G3 group exhibited the highest relative abundances of Proteobacteria and Paucibacter, while the relative abundance of Cetobacterium was the lowest. In conclusion, under low-fish meal diet conditions, chicken oil showed the best comprehensive effect compared with soybean oil, palm oil and mixed oil for replacing fish oil. It could significantly improve the survival rate and feed utilization efficiency of juvenile rainbow trout, promote muscle deposition of threonine and serine, regulate the expression of genes related to lipid metabolic compensation pathways, modulate serum biochemical indices and optimize intestinal microbiota structure.
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This experiment was conducted to investigate effects of dietary supplementation of different levels of sodium butyrate and nano-zinc oxide on growth performance, serum biochemical and antioxidant indices, and intestinal health of meat rabbits. A total of 720 healthy weaned meat rabbits aged 35 days with similar body weight [(833.45±38.42) g] were selected and randomly divided into 6 groups with 15 replicates per group and 8 rabbits per replicate (half male and half female). The control (CON) group was fed a basal diet, and the other 5 groups were fed a basal diet supplemented with 200 mg/kg enramycin (4%)+1 000 mg/kg chlortetracycline (15%) [positive control (PCN) group], 200 mg/kg sodium butyrate+80 mg/kg nano-zinc oxide [low-concentration (LCT) group], 400 mg/kg sodium butyrate+100 mg/kg nano-zinc oxide [medium-concentration (MCT) group], 600 mg/kg sodium butyrate+120 mg/kg nano-zinc oxide [high-concentration (HCT) group], or 800 mg/kg sodium butyrate+600 mg/kg nano-zinc oxide [ultra-high-concentration (UHCT) group], respectively. The pre-trial period lasted for 7 days, and the experimental period lasted for 35 days. The results showed as follows: 1) compared with the CON group, the final body weight and average daily gain of the MCT, HCT and UHCT groups were significantly higher (P<0.05), and the feed-to-gain ratio was significantly lower (P<0.05); the diarrhea rate and mortality of the MCT, HCT and UHCT groups were significantly lower (P<0.05). 2) Compared with the CON group, the villus height and villus height-to-crypt depth ratio in the duodenum and jejunum of the MCT, HCT and UHCT groups were significantly higher (P<0.05). 3) Compared with the CON group, the serum urea nitrogen (UN) content of the MCT, HCT and OHCT groups was significantly lower (P<0.05). 4) Compared with the CON group, the serum superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC) of the MCT, HCT and OHCT groups were significantly higher (P<0.05), and the serum malondialdehyde (MDA) content was significantly lower (P<0.05). 5) Compared with the CON group, the relative abundance of Firmicutes in the cecal contents of the MCT, HCT and OHCT groups was significantly lower (P<0.05); the relative abundance of Actinobacteriota in the cecal contents of the HCT and OHCT groups was significantly higher; the relative abundance of Verrucomicrobiota, Akkermansiaceae and Akkermansia in the cecal contents of the MCT and HCT groups was significantly higher (P<0.05); and the relative abundance of Eubacteriaceae in the cecal contents of the LCT, MCT and HCT groups was significantly lower (P<0.05). In conclusion, dietary supplementation of sodium butyrate and nano-zinc oxide can improve growth performance, enhance antioxidant capacity, improve intestinal morphology, and optimize structure of intestinal microbial community in meat rabbits. Under the conditions of this experiment, the recommended dietary supplementation level for meat rabbits is 600 mg/kg sodium butyrate+120 mg/kg nano-zinc oxide.
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This experiment was conducted to investigate the effects of dietary yeast culture (YC) supplementation on the growth performance, nutrient apparent digestibility and serum biochemical indicators of Ussuri raccoon dogs (Nyctereutes procyonoides) during growing period. A total of 120 healthy growing Ussuri raccoon dogs at the same age and with similar body weight were randomly divided into 4 groups with 30 replicates per group and one animal per replicate. The control group (group Ⅰ) was fed a basal diet, while the experimental groups (groups Ⅱ, Ⅲ and Ⅳ) were fed the basal diet supplemented with 0.5%, 1.0% and 2.0% YC, respectively. The pre-trial period lasted for 7 days, and the formal trial lasted for 56 days. The results showed as follows: 1) the final body weight of groups Ⅲ and Ⅳ was significantly higher than that of group Ⅰ (P<0.05); the average daily gain (ADG) of all experimental groups was extremely significantly higher than that of group Ⅰ (P<0.01), with group Ⅳ having the highest value; the feed-to-gain ratio (F/G) of all experimental groups was extremely significantly lower than that of group Ⅰ (P<0.01), with the greatest decrease observed in group Ⅳ. 2) No significant differences were observed in the apparent digestibility of dry matter, crude protein and ether extract among all groups (P>0.05). 3) In terms of nitrogen metabolism, the serum aspartate aminotransferase (AST) activity of all experimental groups was extremely significantly lower than that of group Ⅰ (P<0.01); the serum alanine aminotransferase (ALT) activity of group Ⅳ was significantly lower than that of groups Ⅰ and Ⅱ (P<0.05); the serum alkaline phosphatase (ALP) activity of group Ⅳ was extremely significantly lower than that of group Ⅰ (P<0.01); the serum urea nitrogen (UN) content of group Ⅳ was significantly lower than that of group Ⅰ (P<0.05); the serum albumin (ALB) content of group Ⅳ was extremely significantly higher than that of group Ⅰ (P<0.01). 4) In terms of lipid metabolism, the triglyceride (TG) content of group Ⅳ was significantly lower than that of groups Ⅰ and Ⅱ (P<0.05), the total cholesterol (CHO) and low-density lipoprotein cholesterol (LDL-C) contents were extremely significantly lower than those of group Ⅰ and Ⅱ (P<0.01), and the high-density lipoprotein cholesterol (HDL-C) content was extremely significantly lower than that of the other groups (P<0.01). 5) In terms of immune regulation, the serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) contents of group Ⅳ were extremely significantly lower than those of the other groups (P<0.01). 6) In terms of antioxidant capacity, no significant differences were observed in serum malondialdehyde (MDA) content, superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC) among all groups (P>0.05). In conclusion, under the conditions of this experiment, dietary supplementation with 2.0% YC can improve the growth performance, optimize nitrogen and lipid metabolism, and reduce the level of systemic inflammatory response in Ussuri raccoon dogs during growing period.
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This experiment was conducted to investigate the induction effects of continuous ammonia exposure on autophagy and necrosis in olfactory mucosal cells of white-feathered broilers under practical production conditions, and to elucidate the underlying molecular mechanisms. A total of 120 Arbor Acres (AA) broilers were randomly divided into a control group, a low-concentration group and a high-concentration group, with 4 replicates per group and 10 birds per replicate. All groups were exposed to ammonia for 6 hours daily in specific pathogen-free (SPF) poultry isolators. During the pre-experimental period (1 to 7 days of age), ammonia concentrations in all groups were maintained ≤5 mg/m3. From 8 to 49 days of age, the control group continued to be kept ≤5 mg/m3, while the low-concentration group was exposed to (15±2) mg/m3 during days 8 to 28 days of age and (30±2) mg/m3 during 29 to 49 days of age, and the high-concentration group was exposed to (30±2) mg/m3 during 8 to 28 days of age and (60±2) mg/m3 during 29 to 49 days of age. The results showed that during 29 to 49 days of age, the average daily feed intake (ADFI) and average daily gain (ADG) of broilers decreased with increasing ammonia concentration, and the high-concentration group exhibited significantly lower values than the control and low-concentration groups (P<0.05). At 28 and 49 days of age, compared with the control group, both the low- and high-concentration groups showed significantly increased numbers of inflammatory cells in the olfactory mucosa (P<0.05), accompanied by evident pathological damage, including cilia shedding, nuclear pyknosis, vacuolation and inflammatory cell infiltration. At both 28 and 49 days of age, the concentrations of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the serum were significantly elevated (P<0.05), and the protein expression level of cluster of differentiation 45 (CD45) in the olfactory mucosa was significantly upregulated in the low- and high-concentration groups compared with the control group (P<0.05). At 49 days of age, high-concentration ammonia exposure significantly increased the protein expression level of glial fibrillary acidic protein (GFAP) (P<0.05), while significantly decreased the protein expression levels of neuronal nuclei (Neun) and tyrosine hydroxylase (TH) in the olfactory mucosa (P<0.05). At 28 days of age, protein expression levels of protein kinase B (AKT) and mammalian target of rapamycin (mTOR) in the olfactory mucosa of the high-concentration group were significantly decreased compared with the control group (P<0.05); at 49 days of age, both the low- and high-concentration groups exhibited significantly decreased AKT and mTOR protein expression levels (P<0.05). At both 28 and 49 days of age, the protein expression levels of phosphatase and tensin homolog (PTEN) increased significantly with increasing ammonia concentration (P<0.05). At both time points, the high-concentration group showed significantly elevated protein expression levels of beclin-1 protein (Beclin-1) and autophagy-related protein-5 (ATG-5) in the olfactory mucosa (P<0.05). These results indicate that prolonged high-concentration ammonia exposure induces inflammatory responses in the olfactory mucosa of white-feathered broilers, activates PTEN, suppresses the AKT/mTOR signaling pathway, enhances autophagic activity, and ultimately triggers cell necrosis.
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This study aimed to investigate the dietary resistant starch on rumen epithelium morphology and inflammatory response of fattening sheep. Twenty-six healthy Hu lamb with similar body condition and body weight of (25.4±1.2) kg were randomly allocated into 2 groups with 13 sheep per group. The control group was fed a diet contained 35% (dry matter basis) native corn starch, and the experimental group was fed a diet contained 35% (dry matter basis) resistant corn starch. The pre-experimental period lasted for 15 days, and the experimental period lasted for 56 days. The results showed that compared with control group: 1) the final body weight and average daily gain of the experimental group were significantly increased (P<0.05), and the feed to gain was significantly decreased (P<0.05); 2) the rumen minimum pH and propionate concentration of the experimental group were significantly increased (P<0.05), and the lactate and acetate concentrations were significantly decreased (P<0.05); 3) the rumen Ruminococcus relative abundance of the experimental group was significantly increased (P<0.05), the Prevotella relative abundance was significantly decreased (P<0.05), and the bile acid metabolic pathway was enriched; 4) the bile acid concentration of the experimental group was significantly increased (P<0.05), the purines concentration was significantly decreased (P<0.05), and the secondary bile acid biosynthesis and purine metabolism pathways enriched; 5) the rumen papilla length in ventral sac and dorsal sac of the experimental group was significantly increased (P<0.05), the mRNA relative expression levels of Toll like receptor 4 (TLR4) and interleukin-6 (IL-6) in dorsal sac were significantly decreased (P<0.05), and the mRNA relative expression level of Claudin-1 in dorsal sac was significantly increased (P<0.05). Overall, the resistant starch can improve the rumen fermentation parameter, maintain the rumen epithelium morphology, reduce the epithelium inflammatory response, thereby enhance the growth performance of fattening sheep.
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The aim of this study was to establish a hydrogen peroxide (H2O2)-induced endoplasmic reticulum stress (ERS) model in bovine mammary epithelial cells (BMECs) by evaluating indicators related to ERS, oxidative stress and apoptosis, and to screen the appropriate treatment concentration and time. First, BMECs were treated with different concentrations (0, 600, 1 000, 1 500, 2 000 and 2 500 μmol/L) of H2O2 for 4, 6 and 8 h, respectively, and cell viability was measured (6 replicates per group) to determine the appropriate treatment time. On the basis of the selected treatment time (6 h), BMECs were randomly divided into six groups (6 replicates per group) and treated with the above concentration gradient of H2O2 for 6 h; then, indicators related to ERS, apoptosis and oxidative stress were measured to determine the appropriate treatment concentration. The results showed that at the H2O2 concentration of 1 000 μmol/L, cell viability was 89.59%, 79.31% and 78.93% after treatment for 4, 6 and 8 h, respectively, with no significant difference between 6 and 8 h (P>0.05). Compared with the control group (0 μmol/L group), when the H2O2 concentration reached 1 000 μmol/L, the mRNA relative expression levels of activating transcription factor 4 (ATF4), activating transcription factor 6 (ATF6), C/EBP homologous protein (CHOP), eukaryotic translation initiation factor 2α (eIF2α), glucose-regulated protein 78 (GRP78), protein kinase PKR-like endoplasmic reticulum kinase (PERK), cysteine-aspartic protease-3 (Caspase-3), and B-cell lymphoma-2-associated X protein (Bax), as well as the relative fluorescence intensity of reactive oxygen species (ROS), were significantly increased (P<0.05), while the mRNA relative expression level of B-cell lymphoma-2 (Bcl-2), and the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) were significantly decreased (P<0.05). In addition, the apoptosis rate was also significantly increased (P<0.05). When the H2O2 concentration was further increased, no significant changes were observed in the above indicators (P>0.05). In conclusion, treatment with 1 000 μmol/L H2O2 for 6 h can effectively induce ERS in BMECs, and the ERS model in BMECs is successfully established.
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This study was conducted to investigate the effects of different degrees of castration on lipid metabolism, gene expression related to nutrient transport and absorption and microbial community structure in jejunum of Junlian cattle. Eighteen healthy Junlian cattle aged 16 months with body weight of (292.35±28.71) kg were randomly assigned to the sham operation control group (SOG group), hemicastration group (HCG group) and full castration group (FCG group), with 6 cattle in each group. The pre-test period was 7 days and the formal test period was 90 days. The results showed as follows: 1) the glucose (GLU) content in jejunal tissue of the FCG group was extremely significantly lower than that of the SOG group and HCG group (P<0.01). The total cholesterol (TC) content in jejunal tissue ranked as SOG group>HCG group>FCG group, with extremely significant differences among groups (P<0.01). The triglyceride (TG) content in jejunal tissue of the HCG group was extremely significantly higher than that of the FCG group and SOG group (P<0.01). 2) Compared with the SOG group and HCG group, the relative content of C18∶1n-9t in jejunal tissue of the FCG group was significantly increased (P<0.05); compared with the HCG group, the relative content of C18∶2n-6c in FCG group was significantly decreased (P<0.05). 3) Compared with the SOG group and HCG group, the relative expression levels of fatty acid transport protein 4 (FATP4), sodium-glucose cotransporter 1 (SGLT1), glucose transporter 2 (GLUT2), diacylglycerol O-acyltransferase 1 (DGAT1), acyl-CoA:cholesterol acyltransferase 2 (ACAT2), Niemann-Pick C1-like 1 (NPC1L1) and sterol regulatory element-binding transcription factor 1 (SREBF1) in jejunal tissue of the FCG group were significantly increased (P<0.05). Compared with the SOG group, the relative expression levels of ATP-binding cassette transporter A1 (ABCA1), scavenger receptor class B type 1 (SRB1) and apolipoprotein B (APOB) in jejunal tissue of both the HCG group and FCG group were significantly increased (P<0.05). There were significant differences in the relative expression levels of cluster of differentiation 36 (CD36) and monoacylglycerol acyltransferase 2 (MGAT2) in jejunal tissue among the three groups (P<0.05), which followed the order of HCG group>FCG group>SOG group. There were significant differences in the relative expression levels of microsomal triglyceride transfer protein (MTTP), apolipoprotein A1 (APOA1) and apolipoprotein A4 (APOA4) in jejunal tissue among the three groups (P<0.05), which followed the order of FCG group>HCG group>SOG group. 4) Differential analysis of jejunal microbiota showed that at the phylum level, the relative abundance of Bacillota in the SOG group was significantly higher than that in the FCG group (P<0.05), and the relative abundance of Patescibacteria in the HCG group was significantly higher than that in the FCG group and SOG group (P<0.05). At the genus level, the relative abundance of Mogibacterium in the SOG group was significantly lower than that in the HCG group (P<0.05), while the relative abundance of Turicibacter was significantly higher than that in the FCG group and HCG group (P<0.05). The results of functional prediction indicated that compared with the SOG group, the abundances of amino acid metabolism and lipid metabolism pathways in the HCG group were significantly increased (P<0.05), while the abundance of membrane transport pathway was significantly decreased (P<0.05). In conclusion, different degrees of castration can significantly alter the characteristics of glucose and lipid metabolism in the jejunum of Junlian cattle, affect the expression of genes related to nutrient absorption and transport, and meanwhile reshape the jejunal microbial community and change its potential metabolic functions.
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The objective of this study was to establish a detection method for the lipocyclopeptide brevicidine (BRE) and investigate its enzymatic stability under simulated gastrointestinal conditions. Firstly, an ultra-performance liquid chromatography (UPLC) method was developed for the quantitative determination of BRE. Subsequently, BRE was incubated with simulated gastric fluid (SGF), simulated intestinal fluid (SIF) and lipase solution, and its residual concentration was measured at different time points (0, 0.5, 1.0, 2.0, 4.0 and 6.0 h) to evaluate stability using the established quantitative method. Furthermore, degradation products of BRE were identified using ultra-high performance liquid chromatography coupled with quadrupole/orbitrap high-resolution tandem mass spectrometry (UHPLC-Q-Exactive Orbitrap MS/MS). The results showed that BRE exhibited excellent linearity within the concentration range of 39.06 to 2 500.00 μg/mL, with a correlation coefficient (R2) of 0.999 9. The average spiked recovery ranged from 98.49% to 100.58%, and the intra-day and inter-day relative standard deviation (RSD) were 0.13% to 1.09% and 0.16% to 1.24%, respectively. The concentration of BRE remained unchanged after 6 h of incubation in SGF, but decreased by 45.16% and 55.80% after 6 h in SIF and lipase solution, respectively. In SIF, BRE underwent gradual hydrolytic ring-opening, whereas in the lipase solution, it was hydrolyzed and formed an adduct with tris-(hydroxymethyl)-aminomethane (Tris), along with the generation of an unknown polypeptide. In conclusion, the detection method developed in this study demonstrates good specificity and accuracy and is suitable for the quantitative analysis of BRE. Lipocyclopeptide BRE is resistant to degradation by gastric proteases but shows instability in SIF and lipase solution.
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This study used corn from different sources as the test material to determine its in vitro digestibility and energy values using an in vitro digestion method, and combined with in vivo metabolizable energy data obtained from previous animal metabolic trials, the dialysis performance of dialysis membranes made from different materials was evaluated to screen for suitable dialysis membranes for the current broiler in vitro digestion system. A total of four types of dialysis membranes made from different materials were used in this experiment, including polyethersulfone (PES) dialysis membrane (10 kDa), polyvinylidene fluoride (PVDF) dialysis membrane (20 kDa), polyacrylonitrile (PAN) dialysis membrane (20 kDa) and Viskase regenerated cellulose (hereinafter referred to as Viskase) dialysis tubing (14 kDa). Based on an in vitro digestion system simulating the physiological digestive juices of broilers, the in vitro dry matter digestibility (IVDMD), in vitro gross energy digestibility (IVGED) and enzymatic hydrolysate gross energy (EHGE) of corn from five different sources were determined, with five replicates per treatment. The results showed as follows: 1) dialysis membrane material extremely significantly affected the IVDMD, IVGED and EHGE of corn from the five sources (P<0.01). The IVDMD measured with Viskase was the highest (71.94%), significantly higher than that with PVDF (69.31%, P<0.05). The IVGED measured with PAN (81.94%) and Viskase (81.85%) were significantly higher than that with PES (80.94%, P<0.05). The EHGE measured with PVDF (15.25 MJ/kg DM) and Viskase (15.24 MJ/kg DM) were significantly higher than that with PES (15.03 MJ/kg DM, P<0.05). 2) The EHGE of corn from the five different sources were all higher than the apparent metabolizable energy (AME) but lower than the true metabolizable energy (TME). The smallest gap between EHGE and TME was observed with PVDF (15.25 MJ/kg DM vs. 16.50 MJ/kg DM), with a difference of 1.25 MJ/kg DM. The coefficients of variation (CV) for EHGE measured with PES and PVDF were relatively low, at 1.05% and 1.56%, respectively. 3) The prediction models for AME and TME of corn for broilers using PES-EHGE as the predictor were: AME=0.91×EHGE+1.20 [R2=0.93, residual standard deviation (RSD)=0.30, P=0.008] and TME=0.90×EHGE+3.01 (R2=0.96, RSD=0.21, P=0.004), respectively. Using PVDF-EHGE as the predictor, the models were: AME=0.60×EHGE+5.77 (R2=0.91, RSD=0.28, P=0.011) and TME=0.59×EHGE+7.58 (R2=0.92, RSD=0.34, P=0.010). In conclusion, under the conditions of this experiment, the EHGE of corn for broilers determined by the in vitro digestion method based on PES and PVDF dialysis membranes showed smaller CV and were closest to the in vivo metabolizable energy values, indicating that these two dialysis membranes are promising candidates for the broiler corn in vitro digestion system.
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This study aimed to analyze the conventional nutritional components, amino acids, fatty acids and bioactive substances in two by-products of Idesia polycarpa Maxim. var. vestita Diels, namely Idesia polycarpa meal and Idesia polycarpa seed meal, by using conventional analytical methods, atomic absorption spectrometry, gas chromatography and other techniques. The results showed as follows: 1) compared with Idesia polycarpa seed meal, the contents of crude protein, ether extract, ash, calcium and total phosphorus in Idesia polycarpa meal were extremely significantly or significantly higher (P<0.01 or P<0.05); the contents of crude fiber, neutral detergent fiber, acid detergent fiber and acid detergent lignin in Idesia polycarpa meal were extremely significantly or significantly lower (P<0.01 or P<0.05); no significant difference in gross energy was observed between the two by-products (P>0.05). 2) The ratios of essential amino acids to non-essential amino acids in Idesia polycarpa meal and Idesia polycarpa seed meal were 66.87% and 77.23%, respectively, which were close to the ideal protein pattern recommended by FAO/WHO. 3) Both by-products were rich in linoleic acid (C18∶2n6c), and the main trace elements in the two by-products were iron (Fe), copper (Cu), manganese (Mn) and zinc (Zn). The contents of heavy metal elements including lead (Pb), mercury (Hg), arsenic (As), cadmium (Cd) and chromium (Cr) were lower than the limits specified in the Hygienic Standard for Feeds (GB 13078—2017). 4) In Idesia polycarpa meal, the contents of tannins, total flavonoids and total polyphenols were 44.52, 26.63 and 4.3 g/kg DM, respectively; in Idesia polycarpa seed meal, the corresponding values were 46.92, 18.67 and 5.1 g/kg DM, respectively. In conclusion, Idesia polycarpa by-products are rich in amino acids, fatty acids, fiber and mineral elements, and contain plant polyphenols and flavonoids as bioactive substances; therefore, they can be developed and utilized as feed ingredients.
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This experiment was conducted to compare the effects of different variety, elicitor treatment and processing method on isoflavone content in red clover. A total of 307 different varieties of red clover were selected as research subjects, the formononetin, biochanin A and total isoflavone contents were measured by high-performance liquid chromatography (HPLC), to assess varietal and origin differences; the foliar application of salicylic acid and methyl jasmonate was performed to evaluate the elicitor induced isoflavone enrichment in red clover; the effects of liquid nitrogen grinding, drying at 65 °C, natural air-drying, juice extraction and silage on isoflavone contents and isoflavone retention rates were compared. The results showed as follows: 1) there were larger differences in isoflavone contents among different varieties, with total isoflavone contents ranging from 0.03 to 25.67 mg/g dry matter (DM); there were statistical differences in the total flavonoid content of red clover varieties from different regions (P=0.009), but the effect size was small (η2=0.045), indicating limited regional contribution to total variation. 2) The treatments of methyl jasmonate and salicylic acid significantly increased the total flavonoid content by 27.48% and 75.69%, respectively (P<0.05). 3) Among the different processing methods, juice extraction, natural air-drying and silage did not significantly affect the total isoflavone contents and isoflavone retention rates. In conclusion, the isoflavone contents in red clover are affected by variety, the salicylic acid and methyl jasmonate can effectively enhance isoflavone accumulation, and appropriate processing methods can maintain isoflavone stability.
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This study aimed to investigate the relationship between metabolites of Enterococcus faecium from different beef cattle breeds and their in vitro probiotic properties, and to reveal the associative mechanisms among strain origin, probiotic phenotype and metabolic function at the metabolite level. In this experiment, three dominant lactic acid bacteria strains were isolated from the rumen fluid of Simmental×Hereford crossbred cattle, Wagyu cattle and Hereford cattle, and named GRJD002, GRJD003 and GRJD004, respectively. Species identification was performed through morphological observation, Gram staining and 16S rDNA sequence analysis. Subsequently, non-targeted metabolomics technology was employed to analyze the differential metabolites and related metabolic pathways among the strains, and key probiotic phenotypes were systematically determined. The results showed as follows: all three strains were identified as Enterococcus faecium. Metabolomics analysis revealed that the metabolites of strain GRJD002 were significantly enriched in amino acid biosynthesis and metabolism pathways; the metabolic characteristics of strain GRJD003 were concentrated in secondary bile acid biosynthesis and polyunsaturated fatty acid metabolism pathways; while the metabolism of strain GRJD004 was active in glycerophospholipid metabolism and biofilm formation-related pathways. Determination results of probiotic properties showed that strain GRJD002 was sensitive to multiple antibiotics, including chloramphenicol and vancomycin. strain GRJD003 exhibited the strongest bile salt tolerance and antibacterial activity. strain GRJD004 demonstrated the best artificial gastrointestinal fluid tolerance and self-aggregation ability. Further correlation analysis revealed significant synergistic “phenotype-metabolism” differences among the strains, which were highly correlated with their respective host origin characteristics. In conclusion, Enterococcus faecium strains derived from different beef cattle breeds exhibit significant host-adaptive characteristics at the metabolic level and influence their probiotic functions through metabolism-phenotype association mechanisms.
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This study was conducted to analyze the conventional nutrient contents of corn gluten meal (CGM) from different regions in China, evaluate its nutritional value in yellow-feathered broilers by in vitro biomimetic method, and explore the correlation between conventional nutrient contents and enzyme-hydrolyzed gross energy (EHGE). A total of 11 CGM samples from diverse regions were collected, and the contents of conventional nutrients such as crude protein (CP) and ether extract (EE) as well as amino acids and mineral elements were determined, Additionally, in vitro dry matter digestibility (IVDMD), in vitro crude protein digestibility (IVCPD), in vitro gross energy digestibility (IVGED) and EHGE were measured using a monogastric animal simulated digestive system. The results showed as follows: 1) the gross energy (GE) of CGM was 22.94 MJ/kg, the CP content was 57.71%. The coefficients of variation of EE, crude ash (Ash) and neutral detergent fiber (NDF) were relatively high, which were 46.48%, 26.90% and 21.15%, respectively. 2) The total amino acid content of CGM was 58.76%, in which the lysine content was 0.90%, the methionine content was 1.42%, the leucine content was 10.44%, and the glutamic acid content was 11.63%, with coefficients of variation of 5.26%, 11.22%, 3.46% and 2.69%, respectively. 3) The contents of calcium and phosphorus of CGM were 526.79 and 5 000.51 mg/kg, with coefficients of variation of 52.37% and 14.10%, respectively. The contents of copper and zinc were 23.40 and 30.30 mg/kg, with coefficients of variation of 17.17% and 34.13%, respectively. 4) Using the monogastric animal biomimetic digestion system to simulate the digestion process of yellow-feathered broilers, the EHGE of CGM was 19.09 MJ/kg, and the IVDMD, IVCPD and IVGED were 82.61%, 81.83% and 83.19%, respectively. In summary, significant variations are observed in the contents of some nutrients among CGM samples from different regions. Moreover, the EHGE of in vitro bionic digestion is extremely significantly positively correlated with EE content. The results can provide references for the application and precise formulation of diversified diets.
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This study aimed to optimize the process parameters for calcium oxide (CaO) treatment of corn stover using orthogonal design and response surface methodology, and to evaluate its ruminal degradation characteristics. Taking CaO addition level, moisture content and treatment time as the main factors, a three-factor, five-level L25 (53) orthogonal experimental design was adopted. The contents of neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) were dimensionless and then weighted in a ratio of 3∶3∶4 to construct a comprehensive evaluation index for screening the optimal combination. On this basis, single-factor experiments were conducted to analyze the trend of ADL content and determine the suitable range of each factor. Furthermore, the Box-Behnken response surface methodology was applied to establish a quadratic regression model with ADL content as the response value, thereby determining the optimal treatment conditions. Subsequently, three Holstein dairy cows fitted with ruminal cannulas were selected for in situ nylon bag experiment to compare the ruminal degradation characteristics of dry matter (DM), NDF and ADF of raw stover and optimally treated stover at different incubation times, and the degradation kinetic parameters were fitted. The results showed as follows: 1) the order of influence intensity of each factor on the comprehensive score was CaO addition level>treatment time>moisture content; 2) the response surface model fitted well and the lack of fit was not significant (P>0.05), and the determined operable optimal conditions were CaO addition level of 6%, moisture content of 50%, and treatment time of 4 d; 3) the nylon bag experiment showed that compared with untreated corn stover, the ruminal degradability and effective degradability of DM, NDF and ADF of optimally treated corn stover were all extremely significantly improved (P<0.01). In conclusion, optimization of CaO treatment parameters can reduce the ADL content of corn stover and improve its ruminal degradation characteristics, thereby enhancing its ruminal utilization efficiency.
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This experiment was conducted to investigate the effects of mixed fermentation with bacteria and enzyme on nutritional value, rumen degradation characteristics and in vitro fermentation of palm kernel meal (PKM). The experiment consisted of three parts: 1) using a mixture of PKM and wheat bran (8∶2) as the fermentation substrate, anaerobic fermentation was carried out by adding Bacillus subtilis, Lactobacillus plantarum, Saccharomyces cerevisiae and acid protease. The nutrient contents and amino acid composition were determined. 2) The nylon bag technique was used for rumen degradation trial, with PKM group and fermented palm kernel meal (FPKM) group set up to determine the rumen degradation rates and degradation parameters of nutrients. 3) Using in vitro fermentation, total mixed ration (TMR) in which soybean meal was replaced in equal proportions by 0 (control group, CK group), 2.5% (2.5% FPKM group) and 5.0% FPKM (5.0% FPKM group) were used as fermentation substrates, and the gas production, fermentation parameters and nutrient degradation rates were measured. The results showed as follows: 1) compared with PKM, the contents of crude protein (CP) and soluble protein (SP) in FPKM were extremely significantly increased (P<0.01), while the contents of neutral detergent fiber (NDF), neutral detergent insoluble nitrogen (NDIN), acid detergent fiber (ADF), acid detergent insoluble nitrogen (ADIN) and acid detergent lignin (ADL) were significantly or extremely significantly decreased (P<0.05 or P<0.01). Compared with PKM, the contents of lysine, methionine, threonine and glycine in FPKM were significantly or extremely significantly increased (P<0.05 or P<0.01). 2) Compared with the PKM group, the effective degradabilities of dry matter (DM), CP and NDF in the FPKM group were significantly increased (P<0.05), and the rapidly degradable fractions of CP and ADF were significantly increased (P<0.05). 3) Compared with the CK group, the molar proportion of propionic acid in rumen in vitro fermentation was extremely significantly decreased in the 2.5% FPKM and 5.0% FPKM groups (P<0.01), while the molar proportion of isobutyric acid was extremely significantly increased (P<0.01); in the 5.0% FPKM group, the molar proportions of butyric acid and isovaleric acid were extremely significantly increased (P<0.01), and the acetic acid to propionic acid ratio was significantly increased (P<0.05); in the 2.5% FPKM group, the molar proportion of butyric acid was extremely significantly increased (P<0.01), and the total volatile fatty acid (TVFA) content was significantly increased (P<0.05). In conclusion, under the conditions of this experiment, mixed fermentation with bacteria and enzyme treatment can improve the nutritional value of PKM and enhance the ruminal degradation efficiency of nutrients; under in vitro conditions, replacing soybean meal with 2.5% FPKM can increase the molar proportions of butyric acid and isobutyric acid as well as the TVFA content in rumen.
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Machine-harvested cotton residue was used as the raw material. Enterococcus faecium, Bacillus licheniformis and Bacillus amyloliquefaciens were selected as fermentation strains, while laccase, cellulase and lignin peroxidase were adopted as enzyme preparations. This study aimed to optimize the parameters for bacteria enzyme co-fermentation of machine harvested cotton residue and provide a theoretical basis for preparing high quality fermented feed. An L49(64) orthogonal experimental design was applied in this test. The four factors included bacterial composition (A), enzyme composition (B), bacterial inoculation amount (C) and enzyme inoculation amount (D), with six levels of 0 (1), 5% (2), 10% (3), 15% (4), 20% (5) and 25% (6). Nutrient components and fermentation indices were determined, and the technique for order preference by similarity to ideal solution (TOPSIS) was used to comprehensively obtain the suitable conditions for bacteria enzyme co-fermentation of machine-harvested cotton residue. The results showed that the optimal fermentation parameter combination for fermenting machine harvested cotton residue was Enterococcus faecium inoculation amount of 10% and cellulase inoculation amount of 10% (A3B3C3D3). Under this optimal combination, the contents of crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), dry matter (DM), crude ash (Ash), acid detergent lignin (ADL), cellulose (CE), hemicellulose (HC), ammonia nitrogen (NH3-N), water soluble carbohydrate (WSC) and pH were 13.34%, 1.29%, 44.54%, 42.94%, 60.50%, 26.26%, 3.58%, 8.17%, 2.59%, 4.74%, 4.62% and 6.45 respectively. Compared with raw machine-harvested cotton residue, the contents of NDF, ADF, CE, HC, ADL and EE decreased by 12.30, 4.38, 5.01, 6.31, 2.80 and 1.94 percentage points, respectively, while the CP content increased by 6.65 percentage points. In summary, under the experimental conditions of this study, the optimal combination was Enterococcus faecium inoculation amount of 10% and cellulase inoculation amount of 10%, which could effectively modify the cellulose structure and improve the nutritional value and fermentation quality of machine-harvested cotton residue feed.
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The purpose of this experiment was to develop vegetable waste fermented feed, and to screen out the optimal fermentation process of vegetable waste mixed with non-conventional feed ingredients by optimizing the fermentation conditions. A orthogonal experimental design was adopted, the effect of fermentation quality of vegetable waste fermented feed was studied based four important factors of moisture, time, substrate and strains, each factor set 3 levels, moisture contents were 55%, 60% and 65%, fermentation time were 7, 10 and 14 days, fermentation substrates were Ⅰ [vegetable waste+subsidiary material 1 (corn germ meal∶rice husk=1∶1)], Ⅱ[vegetable waste+subsidiary material 2 (spray-dried corn husk∶rice husk=1.5∶1)] and Ⅲ[vegetable waste+subsidiary material 3 (wheat bran∶rice husk=2∶1)], and fermentation strains were A (Sikangbao Ⅰ of Weikang Probiotics Co., Ltd.), B (feed fermentation agent of Oukebaike Biotechnology Co., Ltd.) and 0 (no added), respectively, each treatment set 3 replicates. The results showed as follows: 1) among various fermentation factors, the impact of time was the greatest [range (R)=0.169], the strain was the second (R=0.101), and the impacts of substrate and moisture were relatively weak (R=0.061 and R=0.052). The optimal fermentation process conditions for vegetable waste fermented feed were as follows: the moisture content was 55%, the fermentation time was 7 days, the fermentation substrate was substrate Ⅲ, and the fermentation strain was strain A. 2) The overall safety of heavy metals contents of vegetable waste fermented feed raw materials and nitrites and mycotoxins contents of vegetable waste fermented feed were controllable, and it had the potential to be applied to animal production on a large scale. 3) In the composition of the microbial community, Levilactobacillus was the core dominant genus. In summary, the optimal fermentation process conditions for vegetable waste and non-conventional feed ingredients is: moisture content of 55%, fermentation time of 7 days, substrate III and strain A; and the Levilactobacillus is the core dominant genus in vegetable waste fermented feed.
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The aim of the study was to investigate the effects of varieties (Nongwang 501 and Chengjiang 30) and harvest parts (stem and leaf) on nutritive value, molecular structure and rumen in vitro fermentation characteristics of cowpea residues. The feeding value of cowpea residues was systematically evaluated using conventional nutrient analysis, Cornell net carbohydrate and protein system (CNCPS), Fourier transform infrared spectroscopy (FTIR) and an in vitro digestive trial. The results showed as follows: 1) the dry matter (DM), crude protein (CP), crude ash (Ash), soluble crude protein (SCP) contents in the stem of cowpea residues were significantly lower than those in the leaf (P<0.05), and the carbohydrate (CHO), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), hemicellulose and cellulose contents were significantly higher than those in the leaf (P<0.05). 2) The total carbohydrate peak area (TCA), cellulosic-compounds peak height (CECH) and cellulosic-compounds peak area (CECA) in the stem of cowpea residues were significantly higher than those in the leaf (P<0.05), and the total peak area of amide region, peak height of α-helix and peak height of β-sheet were significantly lower than those in the leaf (P<0.05). 3) The rumen in vitro fermentation dry matter degradability (DMD) and ammonia nitrogen (NH3-N), acetic acid, propionic acid, butyric acid, total volatile fatty acids (TVFA) in the stem of cowpea residues were significantly lower than those in the leaf (P<0.05). 4) The correlation analysis revealed the peak height of amide Ⅰ/amide Ⅱ region, peak area of amide Ⅰ/amide Ⅱ region, peak height of α-helix/β-sheet were significant or extremely significant negatively correlated to the CP, butyric acid, acetic acid, and TVFA contents (P<0.05 or P<0.01), and significant or extremely significant positively correlated to the 48 h cumulative gas production (P<0.05 or P<0.01). In conclusion, the nutritional composition of cowpea residues is not affected by variety, enabling uniform harvesting across different varieties; the cowpea steam contains higher structural carbohydrates, while the leaf contains higher protein content and digestibility, it is recommended to harvest and utilize in different parts when conditions permit.
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This experiment was conducted to investigate the effects of coix seed extract (CSE) on in vitro gas production, rumen fermentation parameters and microbiota of Guanling cattle. Using Guanling cattle bulls as rumen fluid donors, a single-factor completely randomized experimental design was adopted. CSE was added to the basal diet at levels of 0 (CK group), 0.1% (0.1%CSE group), 0.2% (0.2%CSE group) and 0.4% (0.4%CSE group) on a dry matter basis as fermentation substrates for in vitro fermentation trial. Each substrate treatment consisted of 6 replicates (6 syringes), with an additional 3 blank control syringes containing no substrate. Gas production volumes were recorded at 2, 4, 6, 8, 10, 12, 24, 36, 48, 72 and 96 h of fermentation to calculate gas production and fermentation kinetic parameters. For each substrate treatment, 6 replicates (6 syringes) were used to sample at 24 h of fermentation for the determination of rumen fermentation parameters, cellulase activities, volatile fatty acid concentrations and microbial community composition. The results showed as follows: 1) gas production in the CK group was significantly higher than that in all CSE-supplemented groups within 48 h (P<0.05), and the gas production rate decreased linearly with increasing CSE supplementation level (P<0.05). 2) The pH in the 0.2%CSE group was significantly lower than that in the CK group and 0.1%CSE group (P<0.05), while the microbial crude protein (MCP) content was significantly higher than that in the other groups (P<0.05). 3) The concentrations of butyric acid and total volatile fatty acids (TVFA) in the 0.1%CSE group were significantly lower than those in the CK group (P<0.05). 4) The Ace and Chao1 indexes in the 0.2%CSE group were significantly lower than those in the other groups (P<0.05). Furthermore, the relative abundances of Butyrivibrio and Prevotellaceae_YAB2003_group in the 0.2%CSE group were significantly higher than those in the CK group (P<0.05). Spearman correlation analysis revealed that MCP and TVFA were significantly positively correlated with Escherichia-Shigella (P<0.05). In conclusion, CSE can inhibit in vitro rumen gas production, improve rumen fermentation parameters and modulate microbial community structure of Guanling cattle. Under the conditions of this experiment, the optimal supplementation level of CSE is 0.2%.
