Yellow-feathered broilers are widely popular in the market due to their unique meat flavor, delicate taste and rich nutrient contents. With the improvement of living standards, consumers’ demands for chicken quality are becoming increasingly stringent, highlighting the significant value of strengthening nutritional regulation of meat quality. This article systematically analyzes the evaluation methods of chicken quality, covering multiple aspects such as sensory evaluation, physical properties, chemical components and multi-index comprehensive evaluation models. Additionally, from the perspective of nutritional regulation, it delves into the effects of amino acids, minerals, vitamins, oils, plant active ingredients, and unconventional feed ingredients on the meat quality of yellow-feathered broilers, providing scientific guidance for enhancing chicken quality and optimizing flavor characteristics in production practices.

Dark spots are a common eggshell defect with some light brown spots formed under certain conditions such as temperature and humidity time. It seriously affects the appearance of eggs that has caused a reduction in consumer’s willingness to purchase them, leading to huge economic losses in the egg industry. With the increasing demands of consumers for food safety and egg quality, the research of the causes and prevention of dark spots has become increasingly important. This paper provides a comprehensive review of the causes, variation patterns, evaluation methods, influences on egg quality and nutritional regulation to reduce the incidence of dark spots, aiming to serve as a valuable reference for the technological development to decrease the occurrence of dark spots.

As the main by-product of fuel ethanol production, corn distillers dried grains with solubles (DDGS) is rich in nutrients such as protein, fat and available phosphorus. It has become an important protein feed raw material to replace corn and soybean meal, and is widely used in the field of pig production industry. However, the processing technology and nutritional components of different kinds of corn DDGS are quite different, and their processing technology is still improving. In recent years, new processes and products have emerged. In this paper, the processing technology, product types, nutritional components, pig available energy value and amino acid digestibility of corn DDGS and the latest progress of its application in pig production were systematically summarized, in order to provide reference for the efficient utilization of corn DDGS.

Animal health is confronted with various problems, such as the increase in pathogenic bacteria and heat stress. These factors can easily lead to intestinal damage, immunosuppression and the occurrence of metabolic diseases in animals. Oligosaccharides are low-grade polymeric sugars formed by monosaccharides linked by glycosidic bonds, as a functional feed additive, can serve as prebiotics for the utilization of beneficial intestinal bacteria. Oligosaccharides can be metabolized by intestinal microorganisms and affect the metabolic function of the microbiota, which play important roles in improving intestinal barrier function, regulating the balance of intestinal microbiota, and controlling intestinal signaling pathways and immune responses. In this paper, we review the common types and structural characteristics of oligosaccharides, summarizes their regulatory effects on the animal gut health, and further elaborates on the possible signaling pathways and mechanisms of action of oligosaccharides from the aspects of antioxidant, host immunity and inflammatory pathways, in addition, we also review their application in the die of weaned piglets, to provide a reference is for the scientific application of oligosaccharides in animal production.

Curcumin is a natural polyphenolic bioactive compound extracted from the rhizomes of Curcuma plants, which possesses multiple remarkable biological functions, including anti-inflammatory, antioxidant, and immunomodulatory activities. In the production of weaned piglets, curcumin has been demonstrated to significantly improve growth performance, enhance immune regulatory functions, and maintain intestinal health. This paper summarizes research on the application dosage, functional targets, and mechanisms of action of curcumin, and systematically reviews its chemical structure, main extraction methods, in vivo absorption and metabolism, biological functions, and advances in its application research in weaned piglet production. The aim is to provide a theoretical basis for the application of curcumin in the nutritional regulation of weaned piglets.

Heat stress will induce a series of physiological reactions of broilers, seriously affect their health and production performance, and bring huge economic losses to the industry. Plant polyphenols, one of the most common active components in plant extracts, exhibit significant potential as feed additives for alleviating heat stress in poultry. However, further research is needed to elucidate their complex mechanisms of action and establish optimal dietary supplemental level. This article reviews the mechanism of plant polyphenols discussed from the aspects of anti-oxidation, relieving inflammation and regulating glucose and lipid metabolism, and the application in improving growth performance, meat quality and intestine health in heat-stressed broilers, so as to provide reference for the application of plant polyphenols in broiler breeding.

The rumen microbiota of ruminants plays a decisive role in host nutrient metabolism and performance. Environmental factors such as diet significantly alter the composition and metabolic activities of the rumen microbiota. However, recent studies have found that significant individual variations in rumen microbiota persist even under identical dietary conditions, and these variations are closely associated with host performance. This indicates that host genetic factors can regulate the rumen microbial community. This article systematically reviews the heritable characteristics of the rumen microbiota, potential mechanisms by which host genetics regulates rumen microbiota, and the impact of host genetics on economic traits mediated by the rumen microbiota. It aims to provide a theoretical foundation for further elucidating the molecular mechanisms through which host genetics influences performance via regulation of the rumen microbiome.

To meet the growing demand for animal products, energy-dense fat supplements are often included in ruminant diets to enhance production efficiency. Compared with saturated fatty acids (SFA), oils rich in unsaturated fatty acids (UFA) not only provide substantial energy but also have greater advantages in mitigating enteric methane emissions and improving the fatty-acid profiles of milk and meat. Among them, C18 unsaturated fatty acids (C18 UFA) are the most common and most extensively studied type in dietary oils. A substantial body of research indicates that C18 UFA can modulate the rumen microbial community and thereby alter rumen fermentation patterns. In general, dietary C18 UFA supplementation increases rumen propionate concentration, decreases acetate concentration and acetate-to-propionate ratio (A∶P), accompanied by reduced methane emissions, although responses vary among individuals and depend on dose. In addition, C18 UFA may also influence rumen pH by reducing the supply of fermentable substrates in the rumen or altering microbial activity; however, findings remain inconsistent. This review synthesizes recent studies on the effects of dietary C18 UFA supplementation on rumen microbiota, methane emissions and rumen fermentation, aiming to provide a theoretical basis for optimizing the technology of dietary oil supplementation in ruminants and promoting its efficient application in production practice.

Food-derived opioid peptides are a class of bioactive peptides generated by gastrointestinal proteolysis, possessing physiological functions analogous to endogenous opioid peptides. Representative β-casein-derived opioid peptides, particularly β-casomorphin-7 (BCM-7), can interact with the μ-opioid receptor (MOR). This interaction enables them to modulate intestinal mucus secretion, influence intestinal barrier integrity, inflammatory responses, and microbiota balance, thereby regulating the function of intestinal stem cells. Conversely, chronic or high-concentration exposure to opioid substances may impair intestinal epithelial repair capacity and increase permeability, facilitating the translocation of microbes and their metabolites to the basal lamina and triggering pro-inflammatory responses. This review summarizes the generation mechanisms of β-casein-derived opioid peptides and their impacts on intestinal barrier function, inflammation, and microecology. By integrating recent advances in intestinal stem cell research, it elucidates the potential mechanisms through which these peptides maintain and regulate intestinal health.

Lactiplantibacillus plantarum is a probiotic widely used in animal husbandry, characterized by its strong acid resistance, bile salt tolerance, adhesion capacity and broad-spectrum antimicrobial properties. Intestinal health plays a critical role in maintaining normal physiological functions, enhancing production performance and improving disease resistance in animals. L. plantarum promotes animal health by strengthening the intestinal barrier, modulating immune responses, optimizing microbial composition and synergizing with microbial metabolites. This paper systematically summarizes the molecular mechanisms by which L. plantarum regulates the intestinal microbial barrier, chemical barrier, physical barrier and immune barrier. Furthermore, it explores in depth the interaction mechanisms between L. plantarum and microbial metabolites such as short-chain fatty acids, bile acids and tryptophan. Additionally, the applications of L. plantarum as a fermentation agent and a disease prevention strategy in livestock farming are summarized. The aim of this review is to provide a theoretical foundation for the precise application of L. plantarum in intestinal health regulation and efficient animal husbandry practices.

The supply-demand contradiction of high-quality feed resources such as corn and soybean meal has become increasingly prominent, posing a significant constraint on the sustainable development of the animal husbandry. Rice bran, as the primary by-product of rice processing, is inexpensive and can serve as an unconventional energy feed material. Following oil extraction, defatted rice bran is obtained. However, the utilization of rice bran and defatted rice bran in livestock and poultry production is limited by their inherent nutritional deficiencies. Advanced physical or biological processing of rice bran or defatted rice bran enables the high-quality conversion of this low-value feed material, significantly enhancing their nutritional and feed value. This paper outlined the feeding nutritional characteristics, quality limitations and current application status of rice bran and defatted rice bran. It also provided a brief overview of research and applications related to their transformation into high-quality feed, aiming to provide reference for partially replacing soybean meal and corn in livestock diets and enhancing the feeding value of rice bran resources.

In the face of the global prohibition on antibiotics in feed, the pursuit of natural bioactive substances, such as plant extracts, is crucial for promoting livestock health and sustainable farming. Anthocyanidins, a class of flavonoid pigments widely found in plants, exhibit diverse biological activities, which have anti-inflammatory, antioxidant, and anti-tumor effects. This review presents a summary of the source structure, physicochemical properties, absorption and metabolism, anti-inflammatory, antioxidant, antitumor mechanisms and of anthocyanidins, as well as the current stage of the application of the study in livestock and poultry production, with the aim of promoting the development of new bioactive additives and the healthy and efficient breeding of livestock and poultry.

Scutellaria baicalensis flavonoids, as the primary bioactive components of the traditional Chinese medicinal herb Scutellaria baicalensis, exhibit significant antioxidant, anti-inflammatory, antimicrobial, and antiviral activities. They are expected to play a key role in the transformation and upgrading of the livestock and poultry industry, with broad application prospects. This paper systematically reviews the physicochemical properties of Scutellaria baicalensis flavonoids, deeply analyzes their digestive and metabolic processes as well as biological functions, and elaborates on the research progress of their relevant applications in livestock and poultry production, aiming to provide a reference for the rational development and application of Scutellaria baicalensis flavonoids in livestock and poultry production.

Microbial manufacturing is a process that utilizes microorganisms as “cell factories” to produce valuable biological products on a large scale through cultivation methods such as fermentation. By harnessing microbial systems to synthesize bioactive substances or create novel feed resources, this approach demonstrates considerable potential for applications in the livestock industry. For instance, microbial manufacturing enables the efficient production of single-cell protein materials, bioactive compounds and enzymatic preparations. This review outlines the development of microbial manufacturing, elucidates its concept and summarizes recent research advances in its application in animal husbandry, thereby providing a reference for future development and utilization of microbial manufacturing in livestock field.

This experiment was conducted to investigate the effects of citrus pulp yeast culture (CPYC) on growth performance, nutrient apparent digestibility and serum biochemical indices of growing pigs. A total of 96 growing pigs with an initial body weight of (28.10±0.99) kg were selected and randomly divided into 4 groups, with 6 replicates in each group and 4 pigs in each replicate (2 males and 2 females). Pigs in the control group (CON group) were fed a basal diet, those in the chlortetracycline (CTC) group were fed the basal diet+300 mg/kg CTC, and those in 1% CPYC group and 2% CPYC group were fed the basal diet+1% CPYC and the basal diet+2% CPYC, respectively. The experiment lasted for 49 days. The results showed as follows: 1) compared with CON group, there were no significant differences in the average daily gain and average daily feed intake of growing pigs at each stage in CTC group, 1% CPYC group and 2% CPYC group (P>0.05), and the diarrhea rate from days 1 to 49 was significantly decreased (P<0.05); the feed to gain ratio (F/G) in CTC group and 2% CPYC group showed a decreasing trend from days 1 to 21 (0.05≤P<0.10); the F/G in 1% CPYC group was significantly decreased from days 22 to 49 (P<0.05), and showed a decreasing trend from days 1 to 49 (0.05≤P<0.10). 2) Compared with CON group, the apparent digestibilities of crude protein, crude ash and phosphorus in 1% CPYC group and 2% CPYC group were extremely significantly increased (P<0.01), and the calcium apparent digestibility in 1% CPYC group was significantly increased (P<0.05). 3) Compared with CON group, the contents of serum total protein (TP) and albumin (ALB) in 1% CPYC group and 2% CPYC group were significantly increased (P<0.05), while the serum urea nitrogen (UN) content was significantly decreased (P<0.05). 4) Compared with CON group, the feed cost per kilogram of weight gain of growing pigs in CTC group, 1% CPYC group and 2% CPYC group was decreased by 5.68%, 9.39% and 2.72%, respectively. In conclusion, the dietary supplementation of CPYC can reduce the F/G and diarrhea rate of growing pigs, increase the nutrient apparent digestibility, increase the contents of serum TP and ALB, decrease the serum UN content, and enhance the economic benefits, and the appropriate supplemental level is 1%.

The experiment was conducted to investigate the effects of different proportions of dietary fermented wheat bran (FWB) on growth performance, nutrient apparent digestibility and meat quality of growing-finishing pigs. A total of 96 growing-finishing pigs with an initial body weight of (69.73±8.56) kg were selected and randomly divided into 4 groups, with 6 replicates in each group and 4 pigs in each replicate (2 males and 2 females). Each group was fed diets supplemented with 5% wheat bran (5% WB group), 5% FWB (5% FWB group), 10% FWB (10% FWB group), and 20% FWB (20% FWB group), respectively. The experiment lasted for 56 days. The results showed as follows: 1) compared with 5% WB group, the final body weight in 5% FWB group tended to be increased (P=0.082); compared with 5% FWB group, the final body weight in 20% FWB group was significantly decreased (P<0.05). From days 29 to 56, compared with 5% WB group, the average daily gain (ADG) in 5% FWB group was significantly increased (P<0.05); compared with 5% FWB group, the ADG in 20% FWB group was significantly decreased (P<0.05). From days 1 to 56, compared with 5% FWB group, the ADG in 20% FWB group was significantly decreased (P<0.05), and the feed to gain ratio in 10% FWB group and 20% FWB group was significantly increased (P<0.05). 2) From days 1 to 28, compared with 10% FWB group, the ether extract (EE) apparent digestibility in 20% FWB group was significantly increased (P<0.05). From days 29 to 56, compared with 5% WB group, the apparent digestibilities of crude protein, gross energy (GE), acid detergent fiber (ADF), dry matter, EE and crude ash (Ash) in 5% FWB group were significantly increased (P<0.05); compared with 5% FWB group, the apparent digestibilities of GE and ADF in 20% FWB group were significantly decreased (P<0.05); compared with 5% FWB group and 10% FWB group, the EE apparent digestibility in 20% FWB group was significantly increased (P<0.05); compared with 5% FWB group and 20% FWB group, the Ash apparent digestibility in 10% FWB group was significantly increased (P<0.05). 3) Compared with 10% FWB group, the backfat thickness in 20% FWB group was significantly decreased (P<0.05); compared with 5% FWB group and 10% FWB group, the cooking loss of longissimus dorsi in 20% FWB group was significantly decreased (P<0.05). Compared with 5% FWB group, the muscle fiber diameter in longissimus dorsi in 5% WB group, 10% FWB group and 20% FWB group was significantly decreased (P<0.05), while the muscle fiber density was significantly increased (P<0.05). 4) Compared with 5% FWB group and 20% FWB group, the acetic acid content in cecal content in 10% FWB group was significantly increased (P<0.05). In conclusion, an appropriate proportion of dietary FWB is beneficial for improving the growth performance and nutrient apparent digestibility of growing-finishing pigs. Although a higher proportion can improve the meat quality to a certain extent, it will have a negative impact on growth performance. It is recommended that the appropriate proportion of dietary FWB for growing-finishing pigs is 10%.

This experiment was conducted to investigate the effects of phytosterols on the growth performance, carcass traits, muscle quality and flavor of Xiangling pigs. A total of 28 healthy Xiangling pigs with normal growth and development, average body weight of (51.03±5.17) kg, were selected and randomly allocated into two groups of 14 pigs each. The control group was fed a basal diet, while the test group received the basal diet supplemented with 90 mg/kg phytosterols. The experiment lasted for 57 days. At the end of the experiment, six pigs from each group, with a body weight of approximately 95 kg, were selected and slaughtered for analysis. The results showed that no significant differences were observed in growth performance between the test group and control group (P>0.05). However, the lean percentage and the 24-hour muscle redness (a^*) value were significantly increased (P<0.05), while the water loss rate was significantly decreased in the test group compared with the control group (P<0.05). Compared with the control group, the contents of some flavor compounds in the muscle of the test group were increased; specifically, the sulfur compounds content increased by 20.79% and the organosulfur compounds content increased by 15.96%. The test group also showed higher contents of volatile metabolites, including alcohols, esters, ethers, ketones, and terpenoids, compared with the control group. The odor intensities of citrus, fruit and pineapple were higher in the test group than those in the control group. In conclusion, dietary supplementation with phytosterols can improve carcass lean percentage, muscle quality and flavor of Xiangling pigs.

This experiment aimed to investigate the effects of different dietary digestible energy (DE) and standardized ileal digestible lysine (SID Lys) levels on growth performance, nutrient apparent digestibility, serum biochemical indices, carcass traits, meat quality, and muscle protein metabolism of late finishing Chuanzang black pigs. The experiment employed a 2×3 factorial design, with two DE levels (12.97 MJ/kg and 13.39 MJ/kg) and three SID Lys levels (0.55%, 0.63% and 0.70%). A total of 90 Chuanzang black pigs, with an initial body weight of (89.65±8.75) kg, were randomly assigned into 6 groups, with 5 replicates per group and 3 pigs per replicate. The experiment lasted for 31 days, and a digestion trial was conducted from days 28 to 31 using the endogenous indicator method. The results showed as follows: 1) dietary SID Lys level had no significant effects on the growth performance and nutrient apparent digestibility (P>0.05). However, increasing dietary DE level significantly improved the average daily gain (ADG) and apparent digestibilities of ether extract and gross energy (P<0.05), while significantly reduced the feed-to-gain ratio (F/G) (P<0.05). 2) The serum urea nitrogen content showed decrease and then increase with dietary SID Lys level increasing (P<0.05). Increasing dietary DE level significantly reduced the serum alanine aminotransferase activity (P<0.05), while significantly increased the serum triglyceride content (P<0.05). 3) Dietary DE and SID Lys levels did not significantly impact carcass traits (P>0.05); however, the backfat thickness exhibited a trend of initial increase followed by decrease with dietary SID Lys level increasing (P=0.056). 4) The lightness value in longissimus dorsi muscle was decreased at 45 minutes post-slaughter with dietary SID Lys level increasing (P<0.05), and the marbling score was increased with dietary DE level increasing (P<0.05). 5) The mRNA relative expression levels of protein kinase B (AKT) and muscle RING-finger protein 1 (MuRF1) in longissimus dorsi muscle were upregulated with dietary DE level increasing (P<0.05). Furthermore, a significant interaction between dietary DE and SID Lys levels was observed for mammalian target of rapamycin (mTOR) mRNA relative expression level in longissimus dorsi muscle (P<0.05): when DE was 12.97 MJ/kg, the mTOR mRNA relative expression level was decreased with dietary SID Lys level increasing; however, at 13.39 MJ/kg DE, the mTOR mRNA relative expression level was increased with dietary SID Lys level increasing. The results indicate that dietary DE and SID Lys levels exert varying degrees of influence on growth performance, nutrient apparent digestibility, serum biochemical indices, and muscle protein metabolism of late finishing Chuanzang black pigs. Based on comprehensive evaluation indicators including ADG, F/G, and serum biochemical indices, et al, the optimal dietary DE and SID Lys levels for Chuanzang black pigs weighing 90 to 115 kg are 13.39 MJ/kg and 0.63%, respectively.

This experiment aimed to investigate the effects of dietary coconut oil (COC) replacing soybean oil on lipopolysaccharide (LPS)-induced liver injury and ferroptosis in piglets. A 2×2 factorial design was used, with the two factors being dietary treatment (3% soybean oil or 3% COC) and LPS treatment (intraperitoneal injection of LPS or saline). Twenty-four 28-day-old “Duroc×Landrace×Yorkshire” weaned piglets were randomly assigned to 4 groups with 6 replicates per group, and 1 pig per replicate. The specific treatments for each group were as follows: 1) control group (CON group), 3.0% soybean oil+intraperitoneal injection of saline; 2) COC group, 3.0% COC+intraperitoneal injection of saline; 3) LPS group, 3.0% soybean oil+intraperitoneal injection of LPS; 4) COC+LPS group, 3.0% COC+intraperitoneal injection of LPS. On day 28 of the trial, piglets received an intraperitoneal injection of LPS (100 μg/kg BW) or an equivalent volume of saline, and all piglets were slaughtered for sample collection 4 hours post-injection. The results showed as follows: 1) dietary supplementation with COC alleviated LPS-induced histopathological damage in the liver, manifested by reduced hepatocyte karyolysis, nuclear pyknosis, and inflammatory cell infiltration; 2) it significantly mitigated the LPS-induced increase in serum aspartate aminotransferase (AST) activity and the AST/alanine aminotransferase (ALT) ratio (P<0.05); 3) furthermore, it significantly suppressed the LPS-induced upregulation of the mRNA relative expression levels of the inflammatory cytokine genes interleukin-6 (IL-6) and interleukin-1β (IL-1β) in the liver (P<0.05); 4) it did not affect hepatic malondialdehyde (MDA) concentration, total antioxidant capacity (T-AOC), and glutathione peroxidase (GSH-Px) activity, but showed a trend toward decreasing superoxide dismutase (SOD) activity (P=0.054); 5) it significantly inhibited the LPS-induced increase in the mRNA relative expression level of long-chain acyl-CoA synthetase 4 (ACSL4) in the liver (P<0.05), and significantly alleviated the LPS-induced decrease in the protein relative expression levels of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) in the liver (P<0.05). These results indicate that dietary supplementation with COC can alleviate LPS-induced hepatic inflammation and injury in piglets, and inhibit the activation of the ferroptosis signaling pathway.

This experiment was conducted to study the standardized ileal digestibility (SID) of amino acids in soybean meal, rapeseed meal, peanut meal and corn gluten meal in Xianghuang chickens at 70 and 140 days of age. The experiment was conducted in two batches, and each sixty Xianghuang chickens aged 68 and 138 days were selected respectively and randomly divided into 5 groups (4 experimental groups and 1 endogenous group), with 6 replicates in each group and 2 chickens in each replicate (1 male and 1 female). The Xianghuang chickens in the four experimental groups were fed the experimental diets (with a crude protein content of 20%) prepared with soybean meal, rapeseed meal, peanut meal and corn gluten meal as the sole protein source, respectively, while those in the endogenous group were fed the nitrogen-free diet, and 0.5% titanium dioxide was added as an indicator to each group’s diet. After 40 hours of feeding, the posterior ileum chyme of the experimental chickens was collected and freeze-dried. The amino acid contents in the raw materials and ileum chyme were determined, and the apparent ileal digestibility (AID) and SID of amino acids in the four kinds of protein feedstuffs were calculated. The results showed that the SID of 15 amino acids in soybean meal, rapeseed meal, peanut meal and corn gluten meal in Xianghuang chickens at 70 days of age was 77.56% to 89.24%, 72.14% to 91.53%, 57.54% to 87.57% and 59.02% to 83.38%, which in Xianghuang chickens at 140 days of age was 82.87% to 94.29%, 82.64% to 96.64%, 71.43% to 97.77% and 70.19% to 96.65%, respectively. It can be seen that the amino acid SID in the four kinds of protein feedstuffs in Xianghuang chickens at 140 days of age is slightly higher than that in Xianghuang chickens at 70 days of age, and the amino acid SID in corn gluten meal in Xianghuang chickens is lower than that in soybean meal, rapeseed meal and peanut meal.

This study was conducted to investigate the effects of dietary supplementation with Scutellaria flavonoids (SF) on growth performance, meat quality and antioxidant capacity of broilers yellow-feathered broilers. A total of 320 one-day-old yellow-feathered male broilers (fast-growing) with similar body weight were randomly allocated into four groups, with 8 replicates per group and 10 birds per replicate. The control group was fed a basal diet, while the experimental groups were fed the basal diet supplemented with 150 (SF150 group), 300 (SF300 group), and 450 mg/kg (SF450 group) of SF, respectively. The trial lasted for 50 days. The results showed as follows: compared with the control group, dietary supplementation with 300 and 450 mg/kg of SF significantly reduced the feed-to-gain ratio (P<0.05); the pH of the breast muscle at 24 hours postmortem was significantly increased in all experimental groups (P<0.05), and the redness (a^*) value was significantly increased in the SF450 group (P<0.05); the content of plasma malondialdehyde (MDA) in the SF450 group and the activity of plasma lactate dehydrogenase (LDH) in the SF150 and SF300 groups were significantly decreased (P<0.05); the breast muscle total antioxidant capacity (T-AOC) in the SF300 and SF450 groups was significantly increased (P<0.05), and the activity of breast muscle total superoxide dismutase (T-SOD) was also significantly increased in the SF300 group (P<0.05); the mRNA relative expression levels of liver nuclear factor erythroid 2 related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were significantly increased in the SF300 group (P<0.05), while the mRNA relative expression level of liver glutathione peroxidase (GSH-Px) was significantly increased in the SF300 and SF450 groups (P<0.05). In conclusion, dietary supplementation with 300 mg/kg SF can significantly enhance the feed utilization efficiency and improve the antioxidant capacity of yellow-feathered broilers, thereby ameliorating meat quality, and these effects may be attributed to the activation of the Nrf2/HO-1 signaling pathway.

This experiment was conducted to investigate the effects of dietary propionic acid chromium on growth performance, meat quality, antioxidant capacity and immune function of yellow-feather broilers under heat stress. A total of 180 male yellow-feather broilers at 35 days of age with similar body weight were randomly divided into 3 groups with 6 replicates in each group and 10 broilers in each replicate. The control group (CON group) and heat stress group (HS group) were fed a basal diet, and the propionic acid chromium alleviation group (PAC group) was fed the basal diet supplemented with 0.2 mg/kg propionic acid chromium. The pre-experimental period lasted for 7 days, and the experimental period lasted for 14 days. At the beginning of the experimental period, the CON group was kept at normal temperature [(26±1) ℃] all day, and the HS group and PAC group was performed cyclic heat stress treatment [00:00—06:00 and 22:00—00:00, (30±1) ℃; 06:00—10:00 and 18:00—22:00, (32±1) ℃; 10:00—18:00. (34±1) ℃]. The results showed that: 1) compared with the CON group, the final body weight, average daily gain and average daily feed intake of the HS group were significantly decreased (P<0.05), the feed to gain ratio was significantly increased (P<0.05); the breast muscle weight and water holding capacity were significantly decreased (P<0.05); the plasma catalase activity and triglyceride content were significantly increased (P<0.05), and the plasma total antioxidant capacity and potassium ion, immunoglobulin A, immunoglobulin G contents were significantly decreased (P<0.05). 2) Compared with the HS group, the final body weight and average daily gain of the PAC group were significantly increased (P<0.05), the feed to gain ratio was significantly decreased (P<0.05); the breast muscle weight, water holding capacity and 24 h pH were significantly increased (P<0.05); the plasma catalase activity and albumin and triglyceride contents were significantly decreased (P<0.05), the plasma immunoglobulin G content was significantly increased (P<0.05), and the liver catalase activity was significantly increased (P<0.05). In conclusion, dietary supplemented with 0.2 mg/kg propionic acid chromium can alleviate the heat stress induced reduction in growth performance, improve the meat quality, and enhance the antioxidant capacity and immune function of yellow-feather broilers.

This experiment was conducted to investigate the effects of dietary Pueraria lobata polysaccharide (PLP) supplementation on growth performance, slaughter performance, meat quality and blood-related indexes of white-feathered broilers. A total of 336 healthy one-day-old Arbor Acres broilers with an initial body weight of (42.31±0.94) g were randomly assigned to four groups with six replicates per group and 14 birds per replicate (half males and half females). The control group was fed a basal diet and designated as group C, while the experimental groups were fed the basal diet supplemented with PLP at levels of 100, 200 and 400 mg/kg, which were designated as groups PS, PM and PL, respectively. The feeding trial lasted for 42 days. The results showed as follows: 1) compared with group C, the body weights of broilers in groups PM and PL were significantly increased at 21 and 42 days of age (P<0.05), the average daily gain (ADG) and average daily feed intake (ADFI) from 1 to 42 days of age were significantly increased (P<0.05), and the feed-to-gain ratio (F/G) was significantly decreased (P<0.05), among which the effect of adding 200 mg/kg PLP was the best at 42 days of age. 2) There were no significant differences in plasma biochemical indices among all groups (P>0.05). 3) Compared with group C, the dressing percentage of broilers in group PM was significantly increased by 4.29% (P<0.05), showing the best effect; there were no significant differences in other slaughter performance indices among all groups (P>0.05). 4) Compared with group C, the serum activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and total antioxidant capacity (T-AOC) of broilers in the experimental groups were significantly increased at 21 and 42 days of age (P<0.05), and the malondialdehyde (MDA) content was significantly decreased (P<0.05); however, only the serum contents of immunoglobulin G (IgG), immunoglobulin A (IgA) and immunoglobulin M (IgM) of broilers in group PM at 21 days of age were significantly increased (P<0.05). 5) Compared with group C, the serum contents of growth hormone (GH) and free tetraiodothyronine (FT4) in broilers of groups PM and PL were significantly increased at 21 and 42 days of age (P<0.05). 6) Compared with group C, the redness (a^*) value and pH_{24 h} of breast muscle and thigh muscle in broilers of groups PM and PL were significantly increased (P<0.05), the lightness (L^*) value of breast muscle and cooking loss of thigh muscle were significantly decreased (P<0.05), and the shear force of breast muscle and thigh muscle was significantly decreased (P<0.05). In summary, dietary supplementation of 200 to 400 mg/kg PLP can improve the growth performance of broilers, enhance serum antioxidant function, improve meat quality, and has no adverse effects on plasma biochemical indices. Among them, 200 mg/kg PLP can also improve serum immune performance and broiler dressing percentage, with good effects.

This experiment was conducted to study the effects of compound probiotics on growth performance, antioxidant capacity, immune function and intestinal microbiota of broilers. A total of 120 one-day-old Arbor Acres broilers were randomly divided into 2 groups, each consisting of 6 replicates with 10 broilers per replicate. The control group was fed a basal diet, and the experimental group was fed the basal diet supplemented with 200 mg/kg compound probiotics (Bacillus subtilis 1.0×10¹¹ CFU/g, Bacillus licheniformis 1.0×10¹¹ CFU/g, Enterococcus faecalis 2.0×10¹⁰ CFU/g, and Saccharomyces cerevisiae 2.5×10¹⁰ CFU/g). The experiment lasted for 42 days. The results showed that, compared with the control group, the diarrhea rate and mortality rate of broilers in the experimental group were significantly decreased (P<0.05); the activities of superoxide dismutase and glutathione peroxidase in serum were significantly increased (P<0.05), while the malondialdehyde content in both serum and liver was significantly decreased (P<0.05); the immunoglobulin M content in serum was significantly increased (P<0.05), while the contents of interleukin-6 and tumor necrosis factor-α in serum were significantly decreased (P<0.05); the beta diversity of cecal microbiota was significantly different (P<0.05); at the phylum level, the relative abundances of Firmicutes and Cyanobacteria in cecum were significantly increased (P<0.05), while the Bacteroidota relative abundance in cecum was significantly decreased (P<0.05); at the genus level, the relative abundances of Bacteroides, Alistipes and Ruminococcus_torques_group in cecum were significantly decreased (P<0.05), while the relative abundances of Faecalibacterium, Phascolarctobacterium and Lactobacillus in cecum were significantly increased (P<0.05). It is concluded that the dietary supplementation of compound probiotics can reduce the diarrhea rate and mortality rate of broilers, enhance the antioxidant capacity and immune function, and promote the health of animals by regulating intestinal microbiota.

The aim of this study was to evaluate the effects of dietary chitosan oligosaccharide (COS) supplementation on meat quality, postmortem muscle energy metabolism, antioxidant capacity and fatty acid composition in breast muscle of broilers under cyclic heat stress. A total of 192 male Arbor Acres (AA) broilers aged at 28 days with comparable body weight were selected and randomly divided into 4 groups, with 6 replicates per group and 8 chickens per replicate. The control group (CON group) was offered a basal diet, and the heat stress treatment groups received the basal diet supplemented with 0 (HS group), 200 (HSC₂₀₀ group) and 400 mg/kg (HSC₄₀₀ group) COS, respectively. The housing temperature in CON group was maintained at (24±1) ℃; for the heat stress treatment groups, the housing temperature was set at (34±1) ℃ from 10:00 to 18:00 and at (24±1) ℃ during the remainder of the day. The relative humidity was maintained at 65% to 75% throughout the trial. The experiment lasted for 14 days. The results showed as follows: 1) compared with CON group, the dressing percentage and half-eviscerated yield percentage in HS group were significantly decreased (P<0.05). Compared with HS group, the half-eviscerated yield percentage and abdominal fat percentage in HSC₄₀₀ group were significantly decreased (P<0.05). 2) Compared with CON group, the pH at 45 min and 24 h after slaughter and crude protein content in breast muscle in HS group were significantly decreased (P<0.05), and the drip loss and moisture content in breast muscle were significantly increased (P<0.05). Compared with HS group, the pH at 45 min and 24 h after slaughter in breast muscle both in HSC₂₀₀ group and HSC₄₀₀ group was significantly increased (P<0.05), and crude fat content in breast muscle in HSC₂₀₀ group was significantly increased (P<0.05). 3) Compared with CON group, the glycogen and glucose (GLU) contents in breast muscle in HS group were significantly decreased (P<0.05), and the lactic acid content and hexokinase (HK) activity in breast muscle were significantly increased (P<0.05). Compared with HS group, the glycogen and GLU contents in breast muscle both in HSC₂₀₀ group and HSC₄₀₀ group were significantly elevated (P<0.05), and the lactic acid content and HK activity in breast muscle were significantly decreased (P<0.05). 4) Compared with CON group, the malondialdehyde (MDA) content in breast muscle in HS group was significantly increased (P<0.05), and the activities of catalase (CAT), total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) in breast muscle were significantly decreased (P<0.05). Compared with HS group, the MDA content in breast muscle both in HSC₂₀₀ group and HSC₄₀₀ group was significantly decreased (P<0.05), and the activities of CAT, T-SOD and GSH-Px in breast muscle were significantly increased (P<0.05). 5) Compared with CON group, the contents of caproic acid, behenic acid, γ-linolenic acid, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)+DHA, the ratios of polyunsaturated fatty acids to saturated fatty acids (PUFA/SFA) and unsaturated fatty acids to saturated fatty acids (UFA/SFA), as well as the fatty acid unsaturation index (UI), peroxidation trend index (PI), nutrition value index (NVI), hypocholesterolemic to hypercholesterolemic ratio (HHR) and health-promoting index (HPI) in breast muscle in HS group were significantly decreased (P<0.05); furthermore, the contents of myristic acid and palmitoleic acid, along with the index of atherogenicity (IA) and index of thrombogenicity (IT) in breast muscle in HS group were significantly increased (P<0.05). Compared with HS group, the contents of myristic acid and palmitoleic acid in breast in both HSC₂₀₀ group and HSC₄₀₀ group were significantly decreased (P<0.05), and the contents of γ-linolenic acid, DHA and EPA+DHA, as well as the NVI, HHR and HPI were significantly increased (P<0.05); additionally, the UFA/SFA in breast muscle in HSC₂₀₀ group was significantly increased (P<0.05). In summary, the heat stress impairs the slaughter performance and breast muscle meat quality of broilers. COS ameliorates these detrimental effects by mitigating postmortem glycolysis, enhancing antioxidant capacity, and improving fatty acid composition and health indices in breast muscle. Under the experimental conditions of this trial, dietary supplementation of COS at 200 mg/kg demonstrates superior efficacy in enhancing breast muscle meat quality in heat-stressed broilers.

This experiment aimed to investigate the effects of in ovo injection of bovine serum albumin (BSA) on early growth performance, serum biochemical indices, intestinal morphology, and cecal microbiota of Ross 308 broilers. A total of 360 one-day-old embryonated Ross 308 broiler eggs were randomly divided into four groups (groups A, B, C and D), with 6 replicates per group and 15 eggs per replicate. On day 18 of incubation, amniotic cavity injections were administered as follows: group A received no treatment (control group), group B was injected with 0.5 mL of 0.85% saline solution, while groups C and D were injected with 0.5 mL of saline solution containing BSA at concentrations of 20 and 40 μg/mL, respectively. After hatching, chicks from all four groups were transferred to corresponding cages in a block order, with 6 cages per group and 12 chicks per cage. All birds were fed the same diet until 21 days of age. The results showed as follows: 1) compared with the control group, the body weight at 21 days of age and the average daily gain from 1 to 21 days of age were significantly increased in both groups C and D (P<0.05). 2) Compared with the control group, the serum contents of total protein, albumin, and total cholesterol at 21 days of age were significantly increased in groups C and D (P<0.05), while the serum alanine aminotransferase activity was significantly decreased in group D (P<0.05). 3) Compared with the control group, the jejunal villus height and villus height to crypt depth ratio at 21 days of age were significantly increased in groups C and D (P<0.05), and the duodenal villus height to crypt depth ratio was significantly increased in group D (P<0.05). 4) No significant difference in the α diversity of cecal microbiota was observed between groups C, D and the control group (P>0.05). However, β diversity analysis revealed significant changes in cecal microbiota structure (P<0.05). Compared with the control group, the relative abundance of Faecalibacterium was significantly increased in group C (P<0.05), while the relative abundances of both Faecalibacterium and Romboutsia were significantly increased in group D (P<0.05). The relative abundances of Faecalibacterium and Romboutsia showed significant or extremely significant positive correlations with average daily gain (P<0.05 or P<0.01). In conclusion, the in ovo injection of BSA on day 18 of incubation can enhance the early growth performance of broilers by improving serum biochemical indices, optimizing intestinal morphology, and modulating the composition of the cecal microbiota, with the injection of 0.5 mL of 40 μg/mL BSA in saline solution obtaining the better effects.

This experiment aimed to investigate the effects of different dietary metabolizable energy levels on the growth performance, slaughter performance, and body composition deposition of Xiangjia yellow broilers from 22 to 56 days of age, and to evaluate the metabolizable energy requirements of male and female Xiangjia yellow broilers from 22 to 42 days of age and 43 to 56 days of age. For trial 1, a total of 240 male Xiangjia yellow broilers [(500±10) g] and 240 female ones [(480±9) g] at 22 days of age were selected; the male broilers were randomly divided into 5 groups by body weight and fed diets with metabolizable energy levels of 11.92, 12.34, 12.76, 13.18 and 13.60 MJ/kg, respectively, while the female broilers were also randomly divided into 5 groups and fed diets with metabolizable energy levels of 11.72, 12.13, 12.55, 12.97 and 13.39 MJ/kg, respectively, with each group having 6 replicates and 8 broilers per replicate, and the trial period lasting 21 days. For trial 2, a total of 240 male Xiangjia yellow broilers [(1 670±17) g] and 240 female ones [(1 407±14) g] at 43 days of age were selected, with the grouping being the same as in trial 1; the male broilers were fed diets with metabolizable energy levels of 12.34, 12.76, 13.18, 13.60 and 14.02 MJ/kg, respectively, and the female broilers were fed diets with metabolizable energy levels of 12.13, 12.55, 12.97, 13.39 and 13.81 MJ/kg, respectively, with the trial period lasting 14 days. Results showed as follows: 1) from 22 to 42 days of age, with the increase in dietary metabolizable energy level, the average daily gain (ADG) of both male and female broilers showed an extremely significant quadratic response (P<0.01), while the average daily feed intake (ADFI) and feed-to-gain ratio (F/G) decreased extremely significantly in a linear manner (P<0.01). From 43 to 56 days of age, as metabolizable energy level increased, the ADG of male broilers exhibited extremely significant linear and quadratic responses (P<0.01), the ADG of female broilers decreased significantly linearly (P<0.05), and the ADFI and F/G of both male and female broilers decreased extremely significantly linearly (P<0.01). 2) From 22 to 42 days of age, the abdominal fat rate of both male and female broilers increased extremely significantly linearly with the elevation of metabolizable energy level (P<0.01). From 43 to 56 days of age, the abdominal fat rate of male broilers showed significant linear and quadratic responses as metabolizable energy level increased (P<0.05). 3) With the increase in metabolizable energy level, the energy deposition rate of female broilers from 22 to 42 days of age increased extremely significantly linearly (P<0.01). Based on the growth performance results, the metabolizable energy requirements of male and female broilers from 22 to 42 days of age are determined to be 1 412.54 and 1 263.07 kJ/d, corresponding to dietary metabolizable energy levels of 12.86 and 12.73 MJ/kg, respectively. For broilers from 43 to 56 days of age, the metabolizable energy requirements are 1 827.27 kJ/d for males and 1 554.23 kJ/d for females, with the corresponding dietary metabolizable energy levels being 13.43 and 13.16 MJ/kg, respectively.

This experiment was conducted to investigate the effects of dandelion flavonoids and Euglena powder on the growth performance, antioxidant capacity, and intestinal microbiota structure of Huxu chickens. A total of 960 one-day-old male Huxu chickens were randomly allocated into 4 groups, with 6 replicates per group, and 40 birds per replicate. Birds in the control group (CON group) were fed a basal diet, while the others were fed basal diets supplemented with 20 mg/kg enramycin (antibiotic group, AB group), 400 mg/kg dandelion flavonoids (dandelion flavonoids group, FN group), and 200 mg/kg dandelion flavonoids plus 200 mg/kg Euglena powder (dandelion flavonoids and Euglena powder group, FNEP group), respectively. The experiment lasted for 28 days. The results showed as follows:1) compared with the CON group, the feed to gain ratio (F/G) in each group was significantly decreased (P<0.05), and the final weight (FW) and average daily gain (ADG) in the FNEP group were significantly increased (P<0.05). 2) Compared with the CON group, the spleen index in the FN group was significantly increased (P<0.05), and the spleen index and liver index in the FNEP group were significantly increased (P<0.05). 3) Compared with the CON group, the plasma immunoglobulin G (IgG) content in each experimental group was significantly increased (P<0.05). 4) Compared with the CON group, the plasma glutathione peroxidase (GSH-Px) activity, liver total antioxidant capacity (T-AOC), and total superoxide dismutase (T-SOD) activity in each experimental group were all significantly increased (P<0.05), while the malondialdehyde (MDA) content in the jejunum was significantly decreased (P<0.05); compared with the AB group, the plasma T-AOC in the FN group and FNEP group was significantly increased (P<0.05), and the GSH-Px and T-SOD activities in plasma and liver, as well as the T-AOC and T-SOD activities in the jejunum of the FNEP group, were also significantly increased (P<0.05). 5) Compared with the CON group, the intestinal microbial α-diversity (Ace, Chao, Shannon, Sobs and Pd indexes) in the AB group was significantly decreased (P<0.05); compared with the AB group, the microbial α-diversity (Ace, Chao, Shannon and Sobs indexes) in the FN group and the microbial α-diversity (Shannon and Sobs indexes) in the FNEP group were significantly increased (P<0.05).6) Compared with the AB group, the relative abundance of Firmicutes in the other groups was significantly increased (P<0.05), while the relative abundance of Escherichia-Shigella was significantly decreased (P<0.05). In conclusion, the supplementation with dandelion flavonoids or a mixture of dandelion flavonoids and Euglena powder in the diet can improve the antioxidant capacity, increased the α-diversity of intestinal microbiota, reduce the abundance of harmful bacteria, and improve intestinal health, thereby enhancing the growth performance of Huxu chickens and showing beneficial effects as an alternative to antibiotics. In this experiment, the combination of dandelion flavonoids and Euglena powder showed better effects.

This experiment was conducted to analyze the apparent ileal digestibility (AID) and standard ileal digestibility (SID) of amino acids in 10 wheats from different sources for laying hens during peak laying period, and to establish prediction equations for amino acids SID based on physical properties and chemical composition of wheats. A single-factor experimental design was adopted, and 396 healthy 38-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. Each group was fed one type of nitrogen-free diet or 10 semi-purified experimental diets formulated with wheats from different sources. Titanium dioxide (TiO₂) at a concentration of 0.50% was added to both the nitrogen-free diet and experimental diets as an exogenous indicator. The experimental period lasted for 3 days. At the end of the experiment, all hens were stunned with carbon dioxide gas and slaughtered. The ileal chyme was collected by isolating the intestinal segments to determine the contents of amino acids and TiO₂, and then the amino acid SID was calculated. The results showed as follows: 1) the means of bulk density (BD), gross energy (GE), and contents of dry matter (DM), crude protein (CP), ether extract (EE), crude ash (Ash), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), total starch (TS), calcium (Ca) and total phosphorus (TP) of 10 wheats from different sources were 707.00 g/L, 15.59 MJ/kg, 87.14%, 13.24%, 1.54%, 1.89%, 2.03%, 11.44%, 2.19%, 53.56%, 0.08% and 0.31%, respectively. 2) The coefficient of variation of amino acid contents in wheat was mostly between 5% and 10%. Among essential amino acids, the mean contents of methionine, lysine, tryptophan and threonine were 0.18%, 0.33%, 0.24% and 0.34%, respectively. 3) The analysis results of amino acids SID in wheat for laying hens during peak laying period showed that among essential amino acids, tryptophan had the highest SID (mean: 93.10%), while methionine had the lowest SID (mean: 74.58%); among non-essential amino acids, proline had the highest SID (mean: 94.55%), and alanine had the lowest SID (mean: 78.66%). 4) Prediction equations for SID of 8 essential amino acids were established using the physical properties and chemical composition of wheats as predictors. Among them, the prediction equation for methionine SID [Met SID=-113.746+0.239BD+13.402EE-0.681ADF, coefficient of determination (R²)=0.762, P=0.027] had the highest goodness of fit. In conclusion, there are significant differences in chemical composition and amino acid SID among the 10 wheats collected in this experiment. The BD, ADF, EE, CP, and TS contents of wheats can be used as key factors for predicting the amino acids SID in wheat for laying hens during peak laying period, and the prediction equation for methionine SID has the best goodness of fit.

The objective of this experiment was to investigate the effects of fermented Astragalus on growth performance and immune function of pekin ducks during 7 to 40 days of age. A total of 160 healthy 7-day-old Pekin ducks with similar initial body weight were randomly divided into 4 groups with 5 replicates per group and 8 ducks per replicate. The control group (CON group) was fed a basal diet, and the experimental groups were fed the basal diets supplemented with 10 g/kg Astragalus (AP group), fermented astragalus (FA group) and astragalus+bacterial solution (APB group), respectively. The experimental period lasted for 33 days. The results showed as follows: 1) compared with the CON group, the feed to gain ratio (F/G) of FA group and APB group was significantly decreased (P<0.05). 2) Compared with the CON group, the thymus, spleen and bursa of Fabricius indexes of FA group were significantly increased (P<0.05). 3) Compared with the CON group, the contents of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in jejunum of FA group and APB group were significantly decreased (P<0.05). 4) Compared with the CON group, the antibody titer to Paramyxovirus on 14 days after immunization of FA group was significantly increased (P<0.05). 5) Compared with the CON group, the contents of immunoglobulin M (IgM) and immunoglobulin G (IgG) in serum of FA group were significantly increased (P<0.05). In conclusion, dietary supplemented with fermented Astragalus can enhance the immune function of Pekin ducks by increasing immune organ indexes, increasing contents of IgM and IgG in serum, reducing contents of IL-1β and TNF-α in jejunum, thereby reducing the risk of intestinal inflammation, improving the antibody level against Paramyxovirus, and the effects are superior to Astragalus and Astragalus+bacterial solution.

This study aimed to investigate the effects of high copper-loaded Lactobacillus plantarum on growth performance, slaughter performance, lipid metabolism and meat quality of meat ducks. A total of 160 seven-day-old male Pekin ducks with similar body weight were randomly assigned to 4 groups with 5 replicates per group and 8 ducks per replicate. The control group was fed a basal diet, the experimental group Ⅰ was fed the basal diet supplemented with 0.4% Lactobacillus plantarum suspension (viable bacterial count was 1×10⁹ CFU/mL), the experimental group Ⅱ was fed the basal diet supplemented with 10 mg/kg copper sulfate pentahydrate, and the experimental group Ⅲ was fed the basal diet supplemented with 0.4% high copper-loaded Lactobacillus plantarum suspension (viable bacterial count was 1×10⁹ CFU/mL, copper enrichment amount was 0.19 μg/kg). The experiment lasted for 35 days. The results showed as follows: 1) compared with the control group, the feed-to-gain ratio (F/G) during 21 to 42 days of age and 7 to 42 days of age of experimental group Ⅲ was significantly decreased (P<0.05). 2) Compared with the control group, the dressed percentage of experimental groups Ⅰ and Ⅱ was significantly increased (P<0.05); the semi-eviscerated rate and eviscerated rate of experimental groups Ⅱ and Ⅲ were significantly increased (P<0.05), and the abdominal fat rate was significantly decreased (P<0.05). 3) Compared with the control group, the contents of total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol in serum of experimental group Ⅲ were significantly decreased (P<0.05). 4) Compared with the control group, the breast muscle brightness (L^*) value of experimental group Ⅱ was significantly decreased (P<0.05), and the breast muscle redness (a^*) value was significantly increased (P<0.05); the drip loss of experimental groups Ⅱ and Ⅲ was significantly decreased (P<0.05). 5) Compared with the control group, the breast muscle stearic acid (C18∶0) content of experimental groups Ⅰ, Ⅱ and Ⅲ was significantly decreased (P<0.05), the breast muscle palmitoleic acid (C16∶1) and oleic acid (C18∶1n9c) contents were significantly increased (P<0.05); the breast muscle saturated fatty acids (SFA) content of experimental group Ⅲ was significantly decreased (P<0.05), and the breast muscle monounsaturated fatty acids (MUFA) content was significantly increased (P<0.05). In conclusion, dietary high copper-loaded Lactobacillus plantarum can improve the growth performance and slaughter performance of meat ducks, promote lipid metabolism, and enhance meat quality.

This experiment aimed to investigate the effects of compound bacteria-enzyme cooperative fermented flaxseed meal on growth performance, slaughter performance, muscle fatty acid composition and antioxidant capacity of Wulong geese. A total of 180 one-day-old male Wulong geese with similar body weights were selected and randomly divided into 3 groups with 6 replicates per group and 10 geese per replicate. The control group was fed a diet supplemented with 5% flaxseed meal, the experimental group Ⅰ was fed the control group’s diet supplemented with 0.25% compound bacteria+0.025% compound enzymes, and the experimental group Ⅱ was fed a diet supplemented with 5% fermented flaxseed meal. The experimental period lasted for 10 weeks. The results showed as follows: 1) the average daily gain during brooding period, growing period and whole period and final body weight during brooding period and growing period of experimental group Ⅱ were significantly higher than those of control group and experimental group Ⅰ (P<0.05), and the feed to gain ratio during brooding period, growing period and whole period was significantly lower than that of the control group (P<0.05). 2) The live weight before slaughter, dressed weight, semi-eviscerated rate, eviscerated rate, breast muscle weight, leg muscle weight and sebum rate of experimental group Ⅱ were significantly higher than those of control group and experimental group Ⅰ (P<0.05), and the abdominal fat rate was significantly higher than that of experimental group Ⅰ (P<0.05). 3) The contents of triglycerides (TG) and low density lipoprotein-cholesterol (LDL-C) in serum of experimental group Ⅱ were significantly lower than those of control group and experimental group Ⅰ (P<0.05), and the serum high density lipoprotein-cholesterol (HDL-C) content was significantly higher than that of the control group (P<0.05). 4) The contents of α-linolenic acid (C18∶3n3), eicosapentaenoic acid (C20∶5n3), docosahexaenoic acid (C22∶6n3) and n-3 polyunsaturated fatty acid in breast muscle of experimental group Ⅱ were significantly higher than those of control group and experimental group Ⅰ (P<0.05), and the n-6/n-3 polyunsaturated fatty acid ratio was significantly lower than those of control group and experimental group Ⅰ (P<0.05). 5) The activities of superoxide dismutase, catalase, glutathione peroxidase and total antioxidant capacity in serum of experimental group Ⅱ were significantly higher than those of the control group (P<0.05), and the serum malondialdehyde content was significantly lower than that of the control group (P<0.05). In conclusion, dietary compound bacteria-enzyme cooperative fermented flaxseed meal can improve the growth performance and slaughter performance of Wulong geese, regulate the lipid metabolism, improve the muscle fatty acid composition, and enhance the body antioxidant capacity.

This experiment was conducted to study the effects of dietary phosphorus levels on laying performance, eggshell quality and plasma biochemical indices of laying pigeons. A total of 360 pairs of 12-month-old double-female paired Silver King pigeons were randomly divided into 6 groups with 5 replicates per group and 12 pairs per replicate. The pigeons were fed isocaloric, isonitrogenous and isocalcic experimental diets with available phosphorus levels of 0.08% (group 1), 0.19% (group 2), 0.30% (group 3), 0.42% (group 4), 0.53% (group 5) and 0.64% (group 6), respectively. The pre-test period lasted for 2 weeks, and the formal test period was 6 months, which was divided into three phases: early period (months 1 to 2), middle period (months 3 to 4) and late period (months 5 to 6). The results showed as follows: 1) dietary phosphorus levels significantly affected the average egg weight in the early period, as well as the egg number, egg weight and average daily feed intake throughout the entire period (P<0.05), and extremely significantly affected the egg number and egg weight in the middle period, and the feed-to-egg ratio in both the middle period and entire period (P<0.01). The average egg weight in the early period of groups 3, 4, 5 and 6 was significantly higher than that of group 1 (P<0.05); the egg number and egg weight throughout the entire period of groups 4, 5 and 6 were significantly higher than those of group 1 (P<0.05), their egg number and egg weight in the middle period were extremely significantly higher than those of group 1 (P<0.01), and their feed-to-egg ratio in the middle period and entire period was extremely significantly lower than that of group 1 (P<0.01). Among all groups, group 4 had the highest egg number and egg weight, and the lowest feed-to-egg ratio in the middle period, late period and entire period. 2) Dietary phosphorus levels significantly affected the eggshell percentage and eggshell thickness in the middle period (P<0.05), extremely significantly affected the eggshell weight in the middle period and late period, and the eggshell percentage and eggshell thickness in the late period (P<0.01), and had a tendency to affect the eggshell strength in the late period (P=0.092). The eggshell weight and eggshell thickness in the middle period, as well as the eggshell weight, eggshell percentage and eggshell thickness in the late period of group 1, were significantly or extremely significantly lower than those of groups 4, 5 and 6 (P<0.05 or P<0.01). 3) Dietary phosphorus levels significantly affected the plasma parathyroid hormone (PTH) concentration (P<0.05), but had no significant effects on the plasma phosphorus, calcium concentrations or alkaline phosphatase (ALP) activity (P>0.05). The plasma calcium concentration was the highest in group 4, while the plasma ALP activity and PTH concentration were the lowest in group 4. In summary, under the conditions of this experiment, the optimal dietary available phosphorus level for laying pigeons is 0.42%, at which the laying pigeons have the lowest feed-to-egg ratio, the highest egg weight, and improve eggshell quality.

This study aimed to investigate the effects of Propionibacterium metabolites preparation on performance, milk quality, nutrient apparent digestibility, rumen fermentation parameters and rumen microbiota of dairy cows. A total of 45 healthy high-yielding Holstein dairy cows with similar body weight and age, lactation days of (66.9±7.8) d and milk yield of (38.42±0.70) kg/d were randomly assigned to 3 groups with 15 replicates per group and 1 cow per replicate. The control group (group CON) was fed a basal diet, and the experimental groups were fed basal diets additional supplemented with 0.2% (group A) and 0.4% (group B) Propionibacterium metabolites preparation, respectively. The pre-experimental period lasted for 7 days, and the experimental period lasted for 56 days. The results showed as follows: 1) the dry matter intake during days 1 to 56 of group A was significantly higher than that of group CON and group B (P<0.05). 2) There were no significant differences in milk yield, milk quality, feed conversion efficiency and nutrient apparent digestibility among all groups (P>0.05), overall, the group A showed better results. 3) On day 28 and day 56, the rumen acetic acid/propionic acid of group A and group B was significantly lower than that of group CON (P<0.05), and the group A was the lowest; there were no significant differences in pH and contents of ammonia nitrogen, acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid and total volatile fatty acid in rumen among all groups (P>0.05). 4) At the phylum and genus levels, there were no significant differences in the relative abundance of dominant microbiota in rumen among all groups (P>0.05). At KEGG2 level, the relative abundance of metabolism of other amino acids in rumen microbiota metabolic pathways of group B was significantly lower than that of group CON and group A (P<0.05); at KEGG3 level, the relative abundance of glycolysis/gluconeogenesis in rumen microbiota metabolic pathways of group B was significantly higher than that of group CON and group A (P<0.05). In conclusion, dietary supplemented with 0.2% Propionibacterium metabolites preparation can improve the rumen fermentation parameters, milk quality and body health of dairy cows.

This experiment aimed to investigate the effects of cottonseed meal combined with coated urea on growth performance, nutrient apparent digestibility, serum biochemical indices and serum metabolites of Holstein bulls during growing period. Twenty-four healthy 5.5-month-old Holstein bulls with similar initial body weight [(180±5) kg] were randomly allocated to 2 groups with 3 replicates per group and 4 bulls per replicate. The control group was fed a basal diet, and the experimental group was used cottonseed meal and coated urea replacing about 7% soybean meal in the basal diet. The pre-experimental period lasted for 14 days, and the experimental period lasted for 180 days. The results showed as follows: 1) during whole experimental period, there were no significant differences in body weight (BW), average daily gain (ADG), average dry matter intake (ADMI) and feed to gain ratio (F/G) between 2 groups (P>0.05). The apparent digestibility of crude protein (CP), dry matter (DM) and neutral detergent fiber (NDF) of the experimental group was significantly higher than that of the control group (P<0.05). 2) The serum superoxide dismutase (SOD) activity at 8 months of age of the experimental group was significantly higher than that of the control group (P<0.05), the serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) contents at 10 months of age were significantly higher than those of the control group (P<0.05), the serum urea nitrogen (UN) content at 10 months of age was significantly lower than that of the control group (P<0.05), and the serum diamine oxidase (DAO) activity and D-lactic acid (D-LA) content were significantly lower than those of the control group (P<0.05). 3) A total of 112 differentially expressed metabolites (DEMs) were identified between 2 groups, mainly enriched in metabolic pathways such as arginine biosynthesis, cofactor biosynthesis, amino acid biosynthesis and glycosylphosphatidylinositol anchor biosynthesis, and the L-methionine, N-acetyl-L-glutamic acid and pyridoxal phosphate were key metabolites which affecting the growth and development of Holstein bulls during growing period. In conclusion, replacing 7% soybean meal in the basal diet with cottonseed meal combined with coated urea has no negative effect on growth performance of Holstein bulls during growing period, can regulate the serum DEMs related pathways, and improve the body metabolic status.

This experiment was conducted to study the effects of Cordyceps militaris mycelium fermentation culture residue on growth performance, disease incidence rates and intestinal microbiota of Holstein calves. Thirty healthy within 3-day-old Holstein newborn calves with successful passive immunity (serum immunoglobulin G content≥10 g/L) and body weight of (38.12±1.62) kg were randomly divided into 2 groups with 15 calves per group. The control group was fed a basal diet, and the experimental group was fed the basal diet supplemented with 10 g/(d·head) Cordyceps militaris mycelium fermentation culture residue. The pre-experimental period lasted for 7 days, and the experimental period lasted for 83 days. The results showed that there was no significant difference in average daily gain between 2 groups (P>0.05). Compared with the control group, the diarrhea and cold incidence rates of the experimental group were decreased, and the cold score was tended to decrease (P=0.058). The analysis of intestinal microbiota indicated that there was no significant difference in Alpha diversity between 2 groups (P>0.05), and the Beta diversity had significant difference (P<0.05). In the experimental group, the internal microbial community structure reshaped in Bacteroidota and Firmicutes, with significantly enriched in Erysipelotrichales, Sutterellaceae, Sutterella, Bacteroides massiliensis, Odoribacter and Bacteroides barnesiae, and with specific colonization of Campylobacterota and Desulfobacterota. The network analysis showed that compared with the control group, the numbers of nodes and edges of microbial interaction network were increased, and the complexity and stability were enhanced. The functional prediction results indicated that the metabolic pathways related to carbohydrate and galactose metabolism were significantly upregulated (P<0.05), such as PWY-7210, PWY-7198, GLUCARGALACTSUPER-PWY and GALACTARDEG-PWY. In conclusion, the Cordyceps militaris mycelium fermentation culture residue can improve the health status of Holstein calves through reshaping the intestinal microbiota structure, enhancing metabolic function, and improving microbial stability.

This experiment aimed to study the effects of rumen fluid transplantation and feeding compound probiotics on growth performance, serum biochemical indices and fecal microbiota structure of yaks. Thirty 8-month-old weaned yaks with similar body weight and good body condition were randomly divided into 3 groups with 10 yaks in each group. The control group (CK group) was fed a basal diet; the rumen transplantation group (RT group) was fed a basal diet, and conducted rumen fluid transplantation on the days 5, 3 and 1 before the start of the experiment; the compound probiotics group (CP group) was fed the basal diet supplemented with 0.2% compound probiotics. The experiment lasted for 60 days. The results showed as follows: 1) the final body weight, total weight gain and average daily gain of CP group were significantly higher than those of CK group (P<0.05), and the dry matter intake and feed to gain ratio of RT group and CP group were significantly lower than those of CK group (P<0.05). 2) The serum interleukin-1β (IL-1β) content of CP group was significantly lower than that of CK group (P<0.05), the serum catalase (CAT) activity of RT group and CP group was significantly higher than that of CK group (P<0.05), and the serum glutathione peroxidase (GSH-Px) activity of RT group was significantly higher than that of CK group (P<0.05). 3) The Chao1 index, Observed_features index, Shannon index and Simpson index of CP group were significantly higher than those of RT group and CK group (P<0.05). 4) At the phylum level, the fecal Firmicutes relative abundance of CP group and CK group was significantly higher than that of RT group (P<0.05). At the genus level, the fecal UCG-005 relative abundance of CK group was significantly higher than that of RT group (P<0.05), the fecal Monoglobus relative abundance of CP group was significantly higher than that of RT group (P<0.05), and the fecal Clostridium_sensu_stricto_1 relative abundance of RT group was significantly higher than that of CP group (P<0.05). 5) The KEGG functional prediction analysis revealed that compared with CK group, the translation, nucleotide metabolism and signaling molecules and interaction et al metabolic pathways were significantly enriched in RT group (P<0.05), and the nucleotide metabolism, amino acid metabolism and signaling molecules and interaction et al metabolic pathways were significantly enriched in CP group (P<0.05). In conclusion, the rumen fluid transplantation is more suitable for quickly improving the antioxidant capacity and feed utilization efficiency of yaks in the short term; while feeding compound probiotics is more beneficial for long-term maintenance of intestinal microbiota stability, enhancing anti-inflammatory response regulation ability, and promoting weight gain and improving feed utilization efficiency of yaks.

This experiment was conducted to investigate the effects of pelleted total mixed rations (PTMR) with different protein levels under the same metabolizable energy level on the growth performance and intestinal microbiota of Hu sheep. A single-factor experimental design was adopted, and 90 healthy 4-month-old Hu sheep rams with similar body weight [(27.09±1.83) kg] were randomly divided into 3 groups, and each group contained 3 replicate pens, with 10 sheep per pen. The three groups were fed PTMR with protein levels of 11.0% (trial group Ⅰ), 13.0% (trial group Ⅱ) and 15.0% (trial group Ⅲ), respectively, while the metabolizable energy level of all rations was 9.4 MJ/kg. The total experimental period was 75 days, including a 15-day pre-test period and a 60-day formal test period. The results showed as follows: 1) the final body weight and average daily gain (ADG) of Hu sheep in trial groups Ⅱ and Ⅲ were significantly higher than those in trial group Ⅰ (P<0.05). 2) For the Alpha diversity analysis of intestinal microbiota, there were no significant differences in Chao1, Ace, Simpson and Shannon indexes among the three groups (P>0.05); Beta diversity analysis indicated that the intestinal microbiota structures of trial groups Ⅱ and Ⅲ were similar, while both differed from that of trial group Ⅰ. At the phylum level, the relative abundance of Firmicutes in trial group Ⅲ was higher than that in trial groups Ⅰ and Ⅱ; the relative abundance of Bacteroidetes in trial group Ⅱ was higher than that in trial groups Ⅰ and Ⅲ; the relative abundances of Spirochaetota and Proteobacteria in trial group Ⅰ were higher than those in trial groups Ⅱ and Ⅲ. At the genus level, the relative abundance of Treponema in trial group Ⅰ was higher than that in trial groups Ⅱ and Ⅲ; the relative abundances of UCG-005 and Rikenellaceae_RC9_gut_group in trial group Ⅱ were higher than those in trial groups Ⅰ and Ⅲ. LEfSe analysis showed that Blautia was significantly enriched in trial group Ⅰ (P<0.05), Rikenellaceae, Rikenellaceae_RC9_gut_group and unclassified_Rikenellaceae_RC9_gut_group were significantly enriched in trial group Ⅱ (P<0.05), and Erysipelatoclostridiaceae was significantly enriched in trial group Ⅲ (P<0.05). In terms of functional prediction, the intestinal microbiota functions of Hu sheep did not change among the three groups. In conclusion, under the metabolizable energy level of 9.4 MJ/kg, the optimal protein level in PTMR for Hu sheep is 13.0%. PTMR with this protein level optimizes the intestinal microbiota structure, which not only ensures good growth performance but also effectively promotes beneficial bacteria and inhibits potential pathogenic bacteria, thereby maintaining the intestinal health of Hu sheep.

This study aimed to explore the effects of dietary different supplemental levels of N-carbamylglutamate (NCG) on growth performance, serum biochemical indices, slaughter performance and meat quality of Dorper and Hu hybrid F₁ lambs during fattening period. Sixty Dorper and Hu hybrid F₁ female lambs with similar body weight [(24.45±0.18) kg] were randomly allocated to 4 groups with 3 replicates per group and 5 lambs per replicate. The control group was fed a basal diet, and experimental groups Ⅰ, Ⅱ and Ⅲ were fed the basal diets supplemented with 0.05%, 0.10% and 0.15% NCG, respectively. The pre-experimental period lasted for 8 days, and the experimental period lasted for 70 days. The results showed as follows: 1) the final body weight and average daily gain of experimental groups Ⅰ, Ⅱ and Ⅲ were significantly higher than those of the control group (P<0.05). 2) The serum nitric oxide (NO) content of experimental groups Ⅰ, Ⅱ and Ⅲ was significantly higher than that of the control group (P<0.05), and the serum arginine (Arg) content of experimental groups Ⅰ and Ⅲ was significantly higher than that of the control group (P<0.05). 3) The loin muscle area of experimental groups Ⅰ, Ⅱ and Ⅲ was significantly higher than that of the control group (P<0.05), and the back fat thickness of experimental groups Ⅱ and Ⅲ was significantly higher than that of the control group (P<0.05). 4) The longissimus dorsi shear force of experimental groups Ⅰ, Ⅱ and Ⅲ was significantly lower than that of the control group (P<0.05), the longissimus dorsi cooking loss of experimental groups Ⅱ and Ⅲ was significantly lower than that of the control group (P<0.05), and the longissimus dorsi drip loss of experimental groups Ⅰ and Ⅲ was significantly lower than that of the control group (P<0.05). In summary, dietary supplementation of NCG can improve the growth performance, body health and economic benefits of Dorper and Hu hybrid F₁ lambs during fattening period. Under the conditions of this experiment, the dietary appropriate supplemental level of NCG is 0.15%.

This experiment was conducted to investigate the effects of Tribulus terrestris by-products (TTB) on rumen fermentation parameters and rumen microflora structure of Tan sheep. Sixty-eight healthy 3-month-old male Tan sheep lambs with an average body weight of (24.68±0.90) kg were selected, numbered, and randomly divided into four groups (17 lambs per group), with individual pen feeding. The four groups were fed experimental diets supplemented with 0 (control group), 5% (trial group Ⅰ), 10% trial group Ⅱ), and 15% (trial group Ⅲ) TTB, respectively. The pre-trial period lasted for 10 days, followed by a 60-day formal trial period. The results showed that: 1) compared with the control group, the molar ratio of propionate in trial group Ⅰ was extremely significantly increased (P<0.01), the molar ratios of isobutyrate and isovalerate in trial groups Ⅰ and Ⅱ were extremely significantly (P<0.01) and significantly decreased (P<0.05), respectively), the molar ratio of valerate in experimental groups Ⅰ and Ⅲ was extremely significantly decreased (P<0.01), and the molar ratio of butyrate in all trial groups was extremely significantly decreased (P<0.01). 2) No significant differences were observed in the Alpha diversity indexes of the rumen microflora among the groups (P>0.05). Principal coordinate analysis (PCoA) and non-metric multidimensional scaling analysis (NMDS) indicated that the rumen microflora structure of trial group Ⅰ was similar to that of the control group. 3) Compared with the control group, the relative abundance of Saccharofermentans in trial group Ⅰ was extremely significantly increased (P<0.01), and the relative abundance of Ruminococcus in three trial groups was extremely significantly decreased (P<0.01). 4) KEGG pathway enrichment analysis revealed that, compared with the control group, trial group Ⅰ exhibited significantly elevated relative abundances in pathways related to glycan biosynthesis and metabolism, endocrine systems, metabolism of terpenoids and polyketides, and energy metabolism (P<0.05). In conclusion, dietary supplementation with 5% TTB has a positive effect on rumen fermentation of Tan sheep, shifting the rumen fermentation pattern toward propionate production without negatively affecting the rumen microflora structure and diversity.

This experiment was conducted to study the effects of polyacrylamide and magnetized water on digestion and absorption in fore-stomach and small intestine of sheep. Six 3-year-old female small-tailed Han sheep with average body weight of (40.0±1.8) kg and installed permanent duodenal fistula and ileal fistula were selected, and conducted 3 experimental periods according to a 3×3 Latin square design. In 3 experimental periods, the control group was fed a basal diet, and drank ordinary well water; the polyacrylamide group (PAM group) was fed a basal diet supplemented with 2.0 g/kg polyacrylamide (dry matter basis), and drank ordinary well water; the magnetized water group (MW group) was fed a basal diet, and drank magnetized water (drinking freshly made). Each experimental period lasted for 20 days, including 16 days for adaptation and 4 days for sample collection. The results showed as follows: 1) compared with the control group, the free feed intake of dry matter and organic matter of PAM group and MW group were significantly or extremely significantly increased (P<0.05 or P<0.01). 2) Compared with the control group, the disappearance amounts of dry matter, organic matter, crude protein, cellulose and hemicellulose in fore-stomach of PAM group and MW group were significantly or extremely significantly increased (P<0.05 or P<0.01). 3) Compared with the control group, the arriving duodenum dry matter, organic matter, crude protein, microbial protein, rumen bypass protein and total amino acid contents of PAM group and MW group were significantly or extremely significantly increased (P<0.05 or P<0.01). 4) Compared with the control group, the arriving small intestine dry matter, organic matter, crude protein, calcium, phosphorus content and total amino acid contents of PAM group and MW group were significantly or extremely significantly increased (P<0.05 or P<0.01). In conclusion, the supplementation of polyacrylamide in diet and drinking magnetized water can improve the free feed intake of sheep, increase the nutrient fore-stomach disappearance amounts, and increase the arriving duodenum and small intestine nutrient contents, which is beneficial for the nutrient supply to host.

This experiment aimed to study the patterns of oxidative stress and inflammatory responses in horses during incremental exercise. Using an equine treadmill, an incremental exercise test was conducted with dynamic blood collection from seven Yili horses at different exercise load stages (3, 5, 7 and 9 m/s). Plasma antioxidant and immune parameters were measured to evaluate the levels of oxidative stress and inflammatory responses in the horses. The results showed that plasma total antioxidant capacity (T-AOC) was significantly higher at the 7 m/s stage compared with the 3 m/s stage (P<0.05), and plasma glutathione (GSH) content increased significantly when the exercise intensity increased from 5 to 7 m/s (P<0.05). In contrast, the activity of plasma glutathione peroxidase (GSH-Px) decreased significantly when the exercise intensity increased from 0 to 3 m/s (P<0.05). The activity of plasma catalase (CAT) showed a significant increase when the exercise intensity increased from 0 to 7 m/s (P<0.05). Furthermore, plasma interleukin-1β (IL-1β) content was significantly lower at the 7 m/s stage than that at the 3 m/s stage (P<0.05). The plasma T-AOC difference between the 3 and 5 m/s stages showed an extremely significant positive correlation with the competition time (P<0.01), the plasma GSH content difference between the 7 and 9 m/s stages showed a significant negative correlation with the competition time (P<0.05), and the plasma IL-1β content difference between the 5 and 7 m/s stages showed a significant positive correlation with the competition time (P<0.05). In conclusion, Yili horses dynamically adapt to treadmill incremental exercise at 3 to 5 m/s via total antioxidant system synergy, with 3 and 7 m/s identified as critical thresholds for significant inflammatory transition. This identifies a key window for oxidative-inflammatory management and training optimization.

This experiment was conducted to explore the effects of different concentrations of microplastics on the growth performance, liver oxidative damage and intestinal microbiota of yellow catfish (Pelteobagrus fulvidraco). A total of 360 healthy yellow catfish with a body weight of (2.63±0.03) g was selected and randomly divided into 4 groups, with 3 replicates in each group and 30 fish in each replicate. Each group was raised in water with microplastic (particle size 50 nm) concentrations of 0 [control group (CON group)], 100 (MP-100 group), 1 000 (MP-1000 group), and 10 000 μg/L (MP-10000 group), respectively, and fed the same basal diet. The experiment lasted for 21 days, and sampling was conducted on days 14 and 21 of the experiment, respectively. The results showed as follows: 1) after exposure to different concentrations of microplastics, the intestinal tract, gill filaments and liver of yellow catfish were damaged in varying degrees. 2) Compared with CON group, the weight gain rate (WGR) from days 1 to 14 in MP-100 group and MP-1000 group, as well as the WGR from days 1 to 21 in MP-1000 group, were significantly decreased (P<0.05), and the feed coefficient from days 1 to 21 in MP-1000 group and MP-10000 group was significantly increased (P<0.05). 3) Compared with CON group, on day 14, the reactive oxygen species (ROS) content in liver in MP-10000 group was significantly increased (P<0.05); on day 21, the activities of superoxide dismutase and glutathione peroxidase (GSH-Px) in liver in MP-10000 group were significantly increased (P<0.05), and the ROS content in liver in MP-10000 group was significantly increased (P<0.05). 4) Compared with CON group, on day 14, the tumor necrosis factor-α (TNF-α) content in liver in MP-1000 group and MP-10000 group was significantly increased (P<0.05), and the contents of interferon-γ (IFN-γ) and interleukin-10 (IL-10) in liver in MP-10000 group were significantly increased (P<0.05); on day 21, the contents of TNF-α and IFN-γ in liver in MP-10000 group were significantly increased (P<0.05), and the IL-10 content in liver in MP-100 group, MP-1000 group and MP-10000 group was all significantly increased (P<0.05). 5) At the phylum level, compared with CON group, on day 14, the Pseudomonadota relative abundance in intestine in MP-1000 group was significantly increased (P<0.05), while the Bacillota relative abundance in intestine in MP-10000 group was significantly decreased (P<0.05); on day 21, the Fusobacteriota relative abundance in intestine in MP-1000 group was significantly decreased (P<0.05). In conclusion, microplastics can induce the liver oxidative damage, inflammatory response and intestinal microbiota imbalance of yellow catfish, thereby delaying its growth.

This experiment aimed to investigate the effects of dietary glucose supplementation on the body weight, hemolymph biochemical indices and fat body proteome of silkworms (Bombyx mori). A total of 600 fifth-instar larvae (Jingsong×Haoyue) were randomly divided into one control group and three glucose supplementation groups, with three replicates per group and 50 larvae per replicate. Fresh mulberry leaves were uniformly coated with glucose solutions at concentrations of 0.2%, 2.0% and 20.0% for the three glucose supplementation groups, respectively, while the control group received leaves sprayed with an equal amount of distilled water. After air-drying, the leaves were fed to the silkworms. The trial lasted for 6 days, during which the body weight of the silkworms was measured daily. On day 6 of the fifth instar, the control group and 2.0% glucose supplementation group were selected for further analysis. Hemolymph was collected to determine biochemical indices including enzymes, glucose, uric acid, and triglyceride, etc. Fat body tissues were harvested for quantitative proteomic analysis using iTRAQ labeling technique. Differentially expressed proteins (defined as those with fold change≥1.5 or ≤0.67 and P<0.05) were screened and subjected to GO functional annotation and KEGG pathway enrichment analysis. The results showed that: 1) the 2.0% glucose supplementation group exhibited a 7.183-fold increase in body weight from day 0 (initial) to day 6, with accelerated weight gain during the later stage of the experiment (days 4 to 6). 2) The hemolymph glucose concentration in the 2.0% glucose supplementation group reached 2.207 mmol/L, which was significantly increased by 16.724% compared with the control group (P<0.05). The concentrations of uric acid, triglycerides, free fatty acids, total cholesterol, high-density lipoprotein and low-density lipoprotein were significantly elevated by 11.828%, 258.291%, 88.834%, 179.565%, 28.488% and 72.648%, respectively, compared with the control group (P<0.05). The activities of fructose-6-phosphate kinase, pyruvate kinase and xanthine oxidase were significantly increased by 58.025%, 279.147% and 22.940%, respectively (P<0.05), while hexokinase activity was significantly decreased by 63.604% (P<0.05), compared with the control group. 3) Proteomic analysis identified 16 170 peptides and 2 172 proteins, among which 115 differentially expressed proteins (55 up-regulated and 60 down-regulated) were screened for functional clustering analysis. 4) GO annotation revealed that the differentially expressed proteins were involved in cellular components, molecular functions, and biological processes. Specifically, the associated cellular components included intracellular organelles, cell membranes, and the extracellular matrix; the molecular functions included binding, structural molecular activity, and oxidoreductase catalytic activity; and the biological processes involved various metabolic processes (organic substance, cellular, nitrogen compound, small molecule metabolism, and biosynthesis), biological regulation, stress response, and cellular homeostasis. KEGG pathway enrichment analysis mapped the 80 differentially expressed proteins to 110 tertiary pathways that fall under six primary functional categories: metabolism, genetic information processing, environmental information processing, cellular processes, organismal systems, and human diseases. They were markedly enriched in substance energy metabolism (20.87%), signal transduction interaction (15.65%), and cuticle structure function (11.30%), underscoring key biological processes. 6) Protein-protein interaction network analysis of the 115 differentially expressed proteins identified ten high degree centrality proteins. Among them, ribosomal protein S9, ribosomal protein S18, and ribosomal protein L10A occupied the core positions of the network, indicating that ribosomal proteins played central roles in the physiological regulation of silkworm responding to continuous glucose supplementation. In summary, dietary supplementation with 2.0% glucose exacerbates the metabolic burden of sugar and lipids in silkworms by activating energy metabolism pathways in the fat body and induces the disordered expression of ribosomal protein S9 and adenylate kinase. These findings provide a reference for elucidating the metabolic regulatory mechanism of silkworm fat body.

This experiment aimed to study the expression patterns and roles of plasma exosomal miRNA in pregnant sheep infected with Haemonchus contortus (H. contortus). Twenty Hulunbuir sheep aged (160±11) days with an average body weight of (35.0±1.2) kg were selected and underwent chemical deworming, estrus synchronization, and artificial insemination. Twenty-eight days after artificial insemination, 12 successfully impregnated sheep were selected and randomly divided into two groups (control group and infection group, n=6). The sheep from infection group orally administered of 10 000 infectious H. contortus while the control group did not. Calculation started with artificial insemination, and the entire experiment lasted for 126 days. During the experiment, blood samples were collected from the sheep via the jugular vein. After centrifugation, the upper plasma was obtained for the extraction, identification, and sequencing of exosomal miRNA; whole blood was collected for blood cell counting. The experimental sampling was divided into 5 periods, which were day 28 of pregnancy (day 1 of H. contortus infection), day 56 of pregnancy (day 28 of H. contortus infection), day 70 of pregnancy (day 42 of H. contortus infection), day 98 of pregnancy (day 70 of H. contortus infection), and day 126 of pregnancy (day 84 of H. contortus infection). The results showed as follows: during these 5 different pregnancy periods, there were more exosomal differentially expressed miRNA of sheep between the control group and infection group on day 28, 70 and 126 compared with day 56 and 98 after pregnancy. In the early stages of sheep pregnancy, H. contortus infection led to an upregulation in the expression of more exosomal miRNA in plasma; in the late stages of sheep pregnancy, it led to a downregulation in the expression of more exosomal miRNA in plasma. Functional annotation of the target genes of the exosomal differentially expressed miRNA revealed that these genes were mainly enriched in the immune process of host animals, including lysosomes, phagosomes, proteasomes, antibody processing and presentation, and adenosine monophosphate-activated protein kinase (AMPK) signaling pathways. Meanwhile, from the early stage of infection to the peak stage of infection, these differentially expressed miRNA were mainly significantly correlated with the counts of immune cells in the blood of sheep (P<0.05); in the late stage of infection, these differentially expressed miRNA were mainly significantly correlated with the counts of red blood cells and platelets in the blood of sheep (P<0.05). Among them, bta-miR-7 might be a potential biomarker for the peak period of H. contortus infection in pregnant ewes, because the expression level of bta-miR-7 on days 56 and 70 of pregnant was significantly negative correlated with the hemoglobin content and the counts of some immune cells in the blood of sheep (P<0.05). The findings of this study provide a theoretical basis for using miRNA as potential biomarkers for detecting parasitic infection in animals and as targets for vaccine therapy, which helps to provide a new reference for the treatment of parasitic diseases.

This experiment investigated the mechanism by which glutamine alleviates acute cold stress-induced lung injury in chicks, focusing on the cold-inducible RNA-binding protein (CIRP)-Toll-like receptor 4 (TLR4)-inositol-requiring enzyme 1 (IRE1) signaling pathway. Ninety-six 1-day-old Shengze 901 chicks were randomly divided into 4 groups: the acute cold stress group (ACS group), the glutamine intervention group (Gln group), the inhibitor intervention group (TAK-242 group), and the combined intervention group (Gln/TAK-242 group). Each group consisted of 6 replicates with 4 chicks per replicate. Chicks in the Gln group and Gln/TAK-242 group were supplemented with 1.2% glutamine in drinking water from 1 day of age. Chicks in the TAK-242 group and Gln/TAK-242 group were intraperitoneally injected with 200 μL/bird TAK-242 working solution (equivalent to 3 mg/kg BW of TAK-242) at 6 days of age, while those in the ACS group and Gln groups were injected with an equal volume of normal saline. Immediately after injection, all four groups were subjected to 12 h of acute cold stress at (12±1) ℃, followed by sample collection and analysis. The results showed as follows: 1) the combined intervention of glutamine and TAK-242 showed significant or highly significant interaction effects on the activities of catalase (CAT) and glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), malondialdehyde (MDA) content, the levels of diamine oxidase (DAO) and interleukin-6 (IL-6), as well as the mRNA relative expression levels of glucoseregulated protein 78 (GRP78), Creactive protein (CRP), DAO, IL-6, and C/EBP-homologous protein (CHOP) in lung tissue (P<0.05 or P<0.01). 2) Main effect analysis revealed that glutamine intervention significantly or extremely significantly elevated the activities of CAT and superoxide dismutase (SOD) (P<0.05 or P<0.01), while it significantly or extremely significantly reduced the levels of CIRP, DAO, IL-6 and tumor necrosis factor-α (TNF-α), as well as the mRNA relative expression levels of CIRP, TLR4, IRE1, GRP78, nuclear factor-κB (NF-κB), CRP, DAO and IL-6 in lung tissue (P<0.05 or P<0.01). TAK-242 intervention extremely significantly increased the activity of SOD and the level of interleukin-10 (IL-10) (P<0.01), and significantly or extremely significantly reduced the levels of DAO and TNF-α, together with the mRNA relative expression levels of TLR4, IRE1, GRP78, NF-κB, CRP, DAO, IL-6 and CHOP in lung tissue (P<0.05 or P<0.01). 3) Compared with the Gln group, the Gln/TAK-242 group showed an extremely significant increase in SOD activity and IL-6 level (P<0.01), and an extremely significant decrease in TNFα level as well as in the mRNA relative expression levels of TLR4, GRP78, DAO and IL-6 in lung tissue (P<0.01). Relative to the TAK-242 group, the Gln/TAK-242 group exhibited a significant or extremely significant elevation in T-AOC and SOD activity (P<0.05 or P<0.01), and a significant or extremely significant reduction in TNF-α level and the mRNA relative expression levels of CIRP, TLR4 and NF-κB in lung tissue (P<0.05 or P<0.01). It is suggested that the mechanism of glutamine alleviating acute cold stress injury in lung tissue of chicks may be mediated by CIRP-TLR4-IRE1 signaling pathway to mediate NF-κB pathway.

This experiment aimed to investigate the effects of supplementing different concentrations of ferulic acid (FA) on the antioxidant function of primary sheep hepatocytes and to elucidate the mechanism of action from the perspective of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway mediating ferroptosis. Five groups were established: a control group, FA250 group, FA500 group, FA750 group, and FA1000 group, treated with 0, 250, 500, 750, and 1 000 μg/mL FA for 24 hours, respectively, with six replicates per group. The results showed as follows: 1) compared with the control group, FA had no significant effects on the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the cells (P>0.05). 2) Compared with the control group, FA significantly reduced the cellular reactive oxygen species (ROS) level and malondialdehyde (MDA) content (P<0.05), while significantly increased the activity of superoxide dismutase (SOD) and the content of reduced glutathione (GSH) (P<0.05); FA at concentrations of 500, 750, and 1 000 μg/mL significantly enhanced the total antioxidant capacity (T-AOC) and glutathione reductase (GR) activity (P<0.05); FA at 500 and 1 000 μg/mL significantly increased the glutathione peroxidase (GSH-Px) activity (P<0.05). 3) Compared with the control group, FA significantly reduced the total iron content in primary sheep hepatocytes; as the FA concentration increased, the total iron gradually decreased (P<0.05); FA at 500, 750, and 1 000 μg/mL significantly down-regulated the mRNA relative expression level of the ferritin heavy chain 1 (FTH1) (P<0.05); FA at 250, 500, and 750 μg/mL significantly down-regulated the mRNA relative expression levels of transferrin receptor 1 (TFR1), six-transmembrane epithelial antigen of prostate 3 (STEAP3), lysophosphatidylcholine acyltransferase 3 (LPCAT3), and arachidonate 15-lipoxygenase (ALOX15) (P<0.05), while significantly up-regulating the mRNA relative expression levels of glutathione peroxidase 4 (GPX4) and solute carrier family 3 member 2 (SLC3A2) (P<0.05); notably, 1 000 μg/mL FA significantly up-regulated the mRNA relative expression levels of TFR1, STEAP3, LPCAT3, and ALOX15 (P<0.05). 4) Compared with the control group, FA at 750 and 1 000 μg/mL significantly increased the ratio of protein relative expression levels of phosphorylated AKT (p-AKT) to AKT (P<0.05), while FA significantly down-regulated the protein relative expression level of Kelch-like ECH-associated protein 1 (Keap1) (P<0.05). In conclusion, in primary sheep hepatocytes, FA inhibits ferroptosis and enhances the antioxidative stress capacity of the hepatocytes by activating the PI3K/AKT signaling pathway, which subsequently regulates downstream ferroptosis-related pathways including iron metabolism, GPX4 expression, and lipid peroxidation levels. Under the conditions of this experiment, FA at a concentration of 750 μg/mL demonstrated the most significant effects.

This experiment aimed to investigate the differences in plasma metabolites, hormones, and biochemical indices among dairy cows with different milk protein yields, in order to evaluate the roles of these biochemical markers in milk protein synthesis. Based on milk protein yield, cows were divided into a high milk protein yield group (HMP group, monthly average milk protein yield>41.09 kg) and a low milk protein yield group (LMP group, monthly average milk protein yield<36.16 kg). Three Holstein dairy cows with similar lactation stage, body condition, and parity were selected for each group. Plasma biochemical indices, hormone profiles, and metabolomic data were measured. The results showed that the concentrations of total cholesterol (TC), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) and the activity of alanine aminotransferase (ALT) in plasma of the HMP group were extremely significantly decreased (P<0.01), and the content of urea nitrogen(UN) in plasma of the HMP group was significantly decreased (P<0.05), indicating that dairy cows with high milk protein yield had better liver metabolic efficiency and nitrogen utilization ability. Plasma metabolomics analysis results revealed that 145 and 157 differential metabolites were identified in the positive and negative ion modes, respectively [P<0.05, variable importance in projection (VIP)>1]. Under the positive ion mode, metabolites such as dodecanoic acid and 2-phosphoglycerate were significantly enriched in the HMP group, whereas metabolites including lyso-phosphatidylcholine 18∶2 (LPC 18∶2) and glycerophosphocholine were significantly enriched in the LMP group. The concentrations of prolactin (PRL) and estriol (E3) in plasma of the HMP group were significantly higher than those of the LMP group (P<0.05), while the concentration of growth hormone (GH) in plasma of the HMP group was significantly lower than that of the LMP group (P<0.05). KEGG pathway enrichment analysis indicated that glycosphingolipid metabolism, alpha-linolenic acid metabolism, and sphingolipid metabolism pathways were significantly enriched. In conclusion, the low milk protein yield dairy cows have increased liver metabolic load due to overactivation of glycerophospholipid metabolism, while the high milk protein yield dairy cows have a significant advantage in milk protein synthesis due to the synergistic effect of efficient lipid metabolism, optimized nitrogen utilization and specific hormone regulatory network, which may be the key metabolic basis for the difference in milk protein synthesis between the low and high milk protein yield dairy cows.

This experiment aimed to construct and evaluate near-infrared spectroscopy (NIRS) prediction models for conventional nutritional components of mixed silage forage in the Chongqing region based on two algorithms. Using NIRS technology, the study utilized 120 samples of mixed silage forage prepared from hybrid Pennisetum and Sesbania cultivated in the Chongqing region in specific proportions. Among these, 100 samples were selected as the calibration set and 20 samples as the prediction set. Prediction models for moisture (M), crude protein (CP), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and crude ash (Ash) content in mixed silage forage were established based on the support vector machine (SVM) algorithm and the partial least square (PLS) algorithm, respectively. The predictive performance of the two models was compared using the relative prediction deviation (RPD) as the evaluation criterion. The results showed that the overall performance of the NIRS prediction models for conventional nutritional components constructed based on the SVM algorithm was superior to that of the models constructed based on the PLS algorithm. The prediction accuracy of the SVM model for the contents of seven conventional nutritional components in mixed silage forage reached acceptable or higher level. It demonstrated particularly better fitting performance for indicators with stronger nonlinear relationships, such as ADL and Ash contents. In conclusion, based on the RPD evaluation criterion, the SVM model exhibits superior comprehensive prediction capability for mixed silage forage quality compared with the PLS model.

This study aimed to quantitatively evaluate the effects of rumen degradable starch (RDS) on nutrient digestion, rumen fermentation, and lactation performance in dairy cows using a Meta-analysis approach. A systematic literature search was performed across the PubMed, Web of Science, and Science Direct databases, and a total of 83 eligible publications involving 328 datasets were finally included. The results showed that: 1) grain species and processing methods significantly affected the digestive characteristics of dietary starch (P<0.05). Among different grains, wheat had the highest ruminal starch degradability (81.33%), whereas corn exhibited the lowest value (54.73%). Compared with dry-ground, dry-rolled and steam-flaked treatments, high-moisture treatment resulted in the highest ruminal starch degradability and total-tract starch digestibility in corn-based diets. In addition, steam-flaked treatment significantly increased the ruminal starch degradability and total-tract starch digestibility in barley- and sorghum-based diets compared with dry-rolled treatment (P<0.05). 2) The rumen was the primary site for starch digestion. The total-tract starch digestibility was linearly and positively correlated with RDS degradability [coefficient of determination (R²)=0.94, P<0.001], while it was linearly and negatively correlated with the amount of rumen-escape starch (RES) (R²=0.74, P<0.001). The ruminal neutral detergent fiber (NDF) degradability was linearly and negatively correlated with RDS degradation amount (R²=0.87, P<0.001). In contrast, the ruminal nitrogen degradation amount (R²=0.87, P=0.067) and microbial crude protein (MCP) synthesis amount (R²=0.88, P<0.001) were linearly and positively correlated with RDS degradation amount. 3) RDS degradation amount affected lactation performance by regulating the ruminal acetate-to-propionate ratio. With the increase in RDS degradation amount, the ruminal acetate-to-propionate ratio decreased linearly (R²=0.72, P<0.001), the 4% fat-corrected milk (4% FCM) yield increased linearly (R²=0.95, P<0.001), and the milk fat percentage decreased linearly (R²=0.84, P<0.001). Moreover, quadratic relationships were observed between the dietary NDF/RDS and both ruminal acetate-to-propionate ratio (R²=0.77, P<0.001) and milk fat percentage (R²=0.81, P<0.001). In conclusion, dietary RDS improves milk yield by promoting ruminal propionate-type fermentation, but excessive RDS inhibits fiber degradation and milk fat synthesis. Therefore, optimizing the dietary carbohydrate structure is essential to balance rumen health and lactation performance in dairy cows.

This study aimed to systematically elucidate the molecular mechanisms underlying the alleviating effects of Astragalus membranaceus on heat stress and weaning stress in calves by integrating network pharmacology and molecular docking approaches. Active components of Astragalus membranaceus were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and PubChem. Potential targets associated with calf heat stress and weaning stress were identified using GeneCards, TTD, and OMIM databases. Protein-protein interaction (PPI) networks were constructed via STRING, and the top 30 hub targets were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses using David, KOBAS, and ClueGO. Core gene clusters within the PPI network were identified using molecular complex detection (MCODE) for functional enrichment analysis. Subsequently, a “Astragalus membranaceus-active compound-target-pathway” network related to heat and weaning stress was constructed by integrating KEGG pathway enrichment results of core targets. Finally, molecular docking was performed to validate the binding affinity between 20 key active components of Astragalus membranaceus and critical target proteins. The results showed that a total of 20 active components of Astragalus membranaceus were identified, interacting with 764 potential targets, among which 81 were common targets associated with both Astragalus membranaceus and the two stress conditions. The PPI network consisted of 74 nodes and 347 edges, with 10 core targets screened. Enrichment analyses revealed significant involvement of pathways such as hypoxia inducible factor 1 (HIF-1), forkhead box O (FoxO), phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt), AMP-activated protein kinase (AMPK), endocrine resistance, and metabolic pathways, indicating that Astragalus membranaceus exerted its stress-alleviating effects primarily through these signaling pathways. The molecular docking verification results of 20 active components of Astragalus membranaceus and the corresponding proteins of 10 core target genes showed that 18 compound-target pairs exhibited binding free energies less than -7 kJ/mol, suggesting strong intermolecular interactions that may underpin the therapeutic efficacy. This study identifies key active compounds and target proteins of Astragalus membranaceus involved in modulating heat stress and weaning stress in calves, thereby clarifying its underlying mechanisms of action. The findings provide a theoretical basis for the application of Astragalus membranaceus as a feed additive to mitigate stress in calves under summer grazing conditions and offer guidance for future research and development in this field.

This study aimed to optimize the liquid bacterial-enzymatic synergistic fermentation process for fresh Maotai-flavor Baijiu lees and evaluate nutritional value of fermented fresh Maotai-flavor Baijiu lees for growing pigs, thereby providing a reference for its utilization in diets of growing pigs. A single-factor experiment was first conducted to investigate effects of five key factors (initial pH, fermentation time, water-to-feed ratio, bacterial-enzyme additive amount, and fermentation temperature) on the contents of hemicellulose, total sugar, and total acid. Based on the single-factor results, the fermentation process parameters were further optimized using a response surface methodology with hemicellulose content as the response value. The quality changes of fresh Maotai-flavor Baijiu lees before and after fermentation were assessed by determining nutrient levels, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and microbial 16S rRNA sequencing. The nutritional value for growing pigs was evaluated by determining the ileal digestibility of amino acids, total tract digestibility (TTD) of nutrients, digestible energy (DE), and metabolizable energy (ME). The results showed as follows: 1) the optimal fermentation process parameters determined with hemicellulose content as the response value were initial pH 5.7, fermentation time 28 h, water-to-material ratio 1.8, bacterial-enzyme additive amount 0.3%, and fermentation temperature 43.7 ℃. 2) Compared with unfermented fresh Maotai-flavor Baijiu lees, the fermented fresh Maotai-flavor Baijiu lees exhibited a significant increase of 10.74% in crude protein (CP) content (P<0.05) and a significant decrease of 21.02% in crude fiber (CF) content (P<0.05). SEM observation revealed a rougher surface with increased porosity and partial decomposition of the fibrous structure. FTIR analysis indicated a shift in protein secondary structure towards α-helix. Microbial community analysis showed that the fermented lees were predominantly composed of Enterococcus (62%) and Clostridium (25%). 3) The standard ileal digestibility of 17 amino acids, except for cystine, was significantly improved in the fermented fresh Maotai-flavor Baijiu lees compared to the unfermented fresh Maotai-flavor Baijiu lees (P<0.05). 4) Diets containing the fermented fresh Maotai-flavor Baijiu lees showed significantly increased TTD of CP, CF, and ash (P<0.05), while no significant differences were found in DE and ME compared to diets containing unfermented fresh Maotai-flavor Baijiu lees (P>0.05). In conclusion, liquid bacterial-enzymatic synergistic fermentation effectively improves the nutritional quality of fresh Maotai-flavor Baijiu lees and nutritional value of fermented fresh Maotai-flavor Baijiu lees for growing pigs.

This experiment was conducted to compare the nutritional value, fermentation quality and in vitro degradation characteristics of eight varieties (Ludan 638, Ludan 6221, Ludan 6606, Ludan 628, Ludan 650, Ludan 639, Ludan 658 and Denghai 605) of whole-plant corn silage, to screened the whole-plant corn silage varieties with high feeding value. Eight varieties of corn were selected to make the whole-plant corn silage, each variety had 6 replicates with 1 kg per replicate, fermented in the dark at room temperature for 45 days, and the conventional nutrient and mycotoxins contents, fermentation quality, nutrient in vitro degradation rates and degradation parameters were measured. The results showed as follows: 1) after ensiling, the contents dry matter, crude protein and water-soluble carbohydrate in Ludan 638 were the highest; the contents of organic matter and starch in Denghai 605 were the highest, and the contents of neutral detergent fiber and acid detergent fiber were the lowest; the dry matter, crude protein, water-soluble carbohydrate and starch in Ludan 6221 were the lowest, and the contents of neutral detergent fiber and acid detergent fiber were the highest. 2) After ensiling, the contents of deoxynivalenol and fumonisin in Ludan 638 were the lowest. 3) The pH of Ludan 639 was the lowest, and the acetic acid content of Denghai 605 was the highest. The content of lactic acid of Ludan 638, Ludan 639 and Denghai 605 was significantly higher than that of other varieties (P<0.05). The lactic acid/acetic acid of Ludan 638 was significantly higher than that of other varieties (P<0.05). 4) The effective degradability of dry matter (ED_DM) and effective degradability of organic matter (ED_OM) of Denghai 605 were significantly higher than those of other varieties (P<0.05), the effective degradability of crude protein (ED_CP) of Denghai 605 and Ludan 638 was significantly higher than that of other varieties (P<0.05), the effective degradability of neutral detergent fiber (ED_NDF) of Ludan 638 was significantly higher than that of Ludan 6221, Ludan 6606 and Ludan 650 (P<0.05). 5) The feeding value ranking was: Denghai 605>Ludan 638>Ludan 639>Ludan 650>Ludan 6606>Ludan 628>Ludan 658>Ludan 6221. In conclusion, Denghai 605 and Ludan 638 exhibit good nutritional value, fermentation quality and nutrient degradation characteristics, and the feeding value is high, they are suitable as silage corn varieties for cultivating in Shandong region.

This study employed an in vitro three-step method to investigate the effects of chitosan (COS) supplementation in low-protein diets with additional rumen-protected amino acids on in vitro rumen fermentation, nutrient degradation and antioxidant level of early-lactation dairy cows. Using a single-factor completely randomized experimental design, a total of 7 groups were set up, with 6 replicates in each group. The dietary protein level in the control group (CON group) was 17.4%, and the dietary protein levels in the low-protein diets were 15.5% and 14.5%, respectively. Meanwhile, the 15.5% low-protein diet was supplemented with 0.85% rumen-protected lysine (RPLys)+0.11% rumen-protected methionine (RPMet) (P1 group), and the 14.5% low-protein diet was supplemented with 0.65% RPLys+0.13% RPMet (P2 group). Moreover, on the basis of the diets in P1 and P2 groups, 1 500 and 2 000 mg/kg COS were added, corresponding to P1C1 group and P1C2 group as well as P2C1 group and P2C2 group, respectively. The in vitro three-step simulation (rumen-abomasum-small intestine) involved 24 h ruminal degradation, followed by 1 h abomasal and 24 h intestinal incubation. The results showed as follows: 1) compared with CON group, the dry matter (DM) in vitro degradation rate in rumen in P1 group was significantly increased (P<0.05), while there were no significant differences in the in vitro degradation rates of other nutrients, in vitro rumen fermentation parameters, and antioxidant level in rumen fluid (P>0.05). 2) Compared with CON group, the in vitro degradation rates of DM and crude protein (CP) in rumen in P1C1 group were significantly increased (P<0.05); the concentrations of bacterial protein, butyric acid, isobutyric acid, valeric acid, isovaleric acid and total volatile fatty acids in rumen fluid were significantly increased (P<0.05), while the acetic acid to propionic acid ratio in rumen fluid was significantly decreased (P<0.05); meanwhile, the glutathione peroxidase activity in rumen fluid was significantly increased (P<0.05), while the malondialdehyde content in rumen fluid was significantly decreased (P<0.05). From the above, it can be known that appropriately reducing the dietary protein level and supplementing rumen-protected amino acids have no negative effects on the in vitro degradation rates of nutrients, rumen fermentation and antioxidant level in rumen fluid of dairy cows. At the same time, the COS supplementation can promote the in vitro degradation rates of DM and CP in rumen, improve the rumen fermentation and enhance the antioxidant capacity in rumen.

This experiment was conducted to investigate the effects of fermentation substrate supplemented with different levels of Schizochytrium powder on the in vitro rumen fermentation characteristics and fatty acid (FA) composition in Albas white cashmere goats. Using rumen fluid from Albas white cashmere castrated male goats as donors, a single-factor completely randomized design was adopted. The experiment was divided into 5 groups based on the supplemental level of Schizochytrium powder in the fermentation substrate: control group (no addition, CON group), 0.5% supplemental group (SCM1 group), 1.0% supplemental group (SCM2 group), 1.5% supplemental group (SCM3 group) and 2.0% supplemental group (SCM4 group). There were 8 replicates per group, with one fermentation bottle per replicate. Various parameters were measured after 24 h of in vitro incubation. The results showed that: 1) compared with CON group, the SCM3 and SCM4 groups exhibited significantly lower pH and ammonia nitrogen (NH₃-N) concentration (P<0.05) of rumen fermentation broth, while the bacterial crude protein (BCP) concentration was significantly increased (P<0.05). The protozoal number was significantly reduced in the SCM4 group (P<0.05). 2) Compared with CON group, SCM3 and SCM4 groups showed a significantly decreased acetate-to-propionate ratio (P<0.05), and significantly increased concentrations of propionate, isobutyrate, isovalerate, and total volatile fatty acids (TVFA) (P<0.05). 3) Compared with CON group, concentrations of C20∶3n-3, C20∶5n-3, C22∶6n-3 (DHA), unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA) and UFA to saturated fatty acids (SFA) ratio (U/S) were significantly increased (P<0.05), while the C16∶0 concentration and the n-6/n-3 long-chain polyunsaturated fatty acid ratio (n-6 PUFA/n-3 PUFA) were significantly decreased (P<0.05) in SCM2, SCM3 and SCM4 groups compared to the CON group. Compared with CON group, the SCM3 and SCM4 groups had a significantly higher C18∶3n-3 concentration (P<0.05) and significantly lower C18∶0 and C24∶0 concentrations (P<0.05). Compared with CON group, the SCM4 group demonstrated significantly increased concentrations of C18∶2n-6c, C18∶3n-6 and polyunsaturated fatty acids (PUFA) (P<0.05). Compared with CON group, the concentrations of C18∶1n-9t and C18∶1n-9c were significantly elevated in SCM3 group (P<0.05). 4) The fermentation substrate supplemented with different levels of Schizochytrium powder improved the multiple-factors associative effects index (MFAEI), with the highest value observed in SCM3 group, followed by SCM4, SCM2, SCM1 and CON groups. In conclusion, supplemented with 1.5% to 2.0% Schizochytrium powder in the fermentation substrate can enhance in vitro rumen fermentation, optimize the FA composition in vitro of rumen fermentation broth, increase the concentrations of n-3 PUFAs such as C18∶3n-3, C20∶5n-3 and DHA, and reduce the concentrations of SFAs like C16∶0 and C18∶0, as well as n-6 PUFA/n-3 PUFA.

This study aimed to investigate the effects of reed silage replacing corn stalks on rumen degradation, fermentation parameters, and methane (CH₄) production in sheep using an automatic in vitro rumen fermentation system. Reed at the heading stage was ensiled, and silage samples were collected on days 7, 14, 30, and 60 post-ensiling for fermentation quality evaluation and conventional nutrient determination. Additionally, reed silage fermented for 30 days was used to replace corn stalks at proportions of 0 (control), 25%, 50%, 75% and 100%, respectively, followed by in vitro rumen fermentation trials using the automatic in vitro rumen fermentation system. The results showed that: 1) the contents of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) in reed silage showed no significant changes compared with those before ensiling, and there were no significant differences among different ensiling time points (P>0.05). 2) Compared with the control group, the in vitro rumen DM degradation rate, total gas production, and CH₄ production in the groups with 50%, 75%, and 100% reed silage substitution were significantly decreased (P<0.05); the in vitro rumen DM degradation rate in the 25% group showed no significant difference (P>0.05), but the CH₄ production was significantly reduced (P<0.05). 3) Compared with the control group, the total volatile fatty acid (TVFA) concentration in the in vitro rumen of the 50%, 75%, and 100% groups was significantly decreased (P<0.05), among which the molar proportion of acetic acid was significantly increased (P<0.05), while the molar proportion of propionic acid in the 25% group was significantly increased (P<0.05). In conclusion, replacing corn stalks with 25% reed silage can promote the shift of rumen fermentation towards a propionate-type pattern, reduce CH₄ emissions, and exert no negative effects on rumen substrate degradation.

This study aimed to improve the silage quality of Caragana korshinskii Kom. by evaluating the effects of different lactic acid bacteria additives on its nutritional composition, fermentation quality, and microflora. The experiment used three-year-old regrowth Caragana korshinskii Kom. at the flowering stage as the raw material. Four treatments were established: a control treatment (CK) and experimental treatments supplemented with Pediococcus pentosaceus (P. pentosaceus), Pediococcus acidilactici (P. acidilactici), and Levilactobacillus brevis (L. brevis), respectively, with three replicates per treatment. After 60 days of ensiling, samples were taken to determine nutritional components, fermentation quality, and microflora-related indicators. The results showed that compared to the CK treatment, only the P. acidilactici treatment significantly improved the silage quality of Caragana korshinskii Kom. This was primarily manifested by the lowest pH value, a 42.62% increase in lactic acid content compared to CK treatment, and a 4.6% reduction in neutral detergent fiber content. Furthermore, it effectively preserved the contents of water-soluble carbohydrates and crude protein, with all these changes reaching significant levels (P<0.05). Based on high-throughput sequencing analysis, compared with the CK treatment, the P. acidilactici treatment significantly decreased the Shannon index (P<0.05) and increased the relative abundance of the dominant strain Lactobacillus sanfranciscensis. Compared with other treatments, the P. acidilactici treatment showed a stronger enrichment trend in pyruvate metabolism and the pentose phosphate pathway. In conclusion, based on a comprehensive evaluation of nutritional components, fermentation quality, and microflora structure, the addition of P. acidilactici optimally enhance the silage quality of Caragana korshinskii Kom.

This experiment was conducted to study the nutritional components of six roughages (alfalfa hay, whole corn silage, peanut seedling, oat hay, wheat straw and alfalfa silage) from northern China and their degradation characteristics in rumen, so as to provide a reference for the rational utilization of roughage resources. Six typical roughages were collected, and their conventional nutrient contents were determined. Three healthy 8-month-old male Dorper sheep [(40±2) kg BW] fitted with permanent rumen cannulas were used as experimental animals to determine the rumen degradation rates of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) using the nylon bag technique. Ruminal degradation parameters were also calculated. The results showed as follows: 1) among the different types of roughages, DM contents of forage grasses and crop straws were significantly higher than that of silages, while ADF content of crop straws was significantly higher than those of forage grasses and silages. Alfalfa hay had the highest CP content; wheat straw had the highest ADF and NDF contents and the lowest CP content; alfalfa silage had the lowest NDF and ADF contents and a relatively high CP content, second only to alfalfa hay; peanut seedling had the highest ether extract (EE) and ash content. 2) Regarding rumen degradation rates, from sample time points of 4 to 48 h, the DM degradation rates decreased in order of silages > forage grasses > crop straws. Wheat straw had the lowest DM degradation rate and was significantly lower than the other roughages at sample time points of 4 to 30 h (P<0.05). There were no significant differences in CP degradation rates between silages and forage grasses at all time points (P>0.05), and both were higher than those of crop straws. At sample time points of 12 to 30 h, NDF degradation rate of alfalfa hay was significantly lower than that of oat hay (P<0.05), while no significant differences were observed among crop straws and silages (P>0.05). At sample time points of 48 to 72 h, NDF degradation rates of oat hay and whole corn silage were significantly higher than those of alfalfa hay, peanut vine and alfalfa silage (P<0.05). Wheat straw had the lowest ADF degradation rate, while alfalfa hay and whole corn silage exhibited relatively high ADF degradation rates. At sample time point of 24 h, ADF degradation rate of alfalfa hay was significantly higher than that of wheat straw (P<0.05). 3) In terms of degradation parameters, rapidly degradable fraction and effective degradability of DM, as well as the rapidly degradable fraction of CP, decreased in the order of silages>forage grasses > crop straws. Rapidly degradable fractions of CP in alfalfa silage and whole corn silage were significantly higher than those in peanut seedling and wheat straw (P<0.05). Effective degradability of CP in alfalfa silage was significantly higher than those in peanut seedling and wheat straw (P<0.05). In conclusion, forage grasses and crop straws have higher DM contents than silages, while crop straws have higher ADF contents than forage grasses and silages. Both forage grasses and silages exhibit better rumen degradation characteristics and effective degradability of DM and CP compared to crop straws.

This study aimed to screen high-yield carotenoid mutant strains of Rhodotorula mucilaginosa, and optimized their fermentation process, to enhance carotenoid synthetic ability. A combined mutagenesis method using ultraviolet (UV) and diethyl sulfate (DES) was applied to the mutagenesis breeding of Rhodotorula mucilaginosa strain preserved in the laboratory, and the high-yield carotenoid mutant strains were preliminarily screened through diphenylamine (DPA) plates and secondary screened through liquid fermentation. The single-factor and response surface experiments were employed to optimize fermentation conditions for mutant strains, including glucose concentration, organic nitrogen source ratio (peptone∶yeast powder), carbon to nitrogen ratio, sodium chloride concentration, inoculation amount and fermentation time. The results showed that a high-yield carotenoid mutant strain CS-15 was screened by ultraviolet and diethyl sulfate combined mutagenesis, with a carotenoid yield of 5.38 mg/L, which was 5.17 times higher than that of the original strain. The mutant strain CS-15 exhibited stable genetic traits over seven successive generations verification. Under the optimized fermentation conditions (glucose concentration 58.97 g/L, organic nitrogen source ratio 2∶1, carbon to nitrogen ratio 22.73, sodium chloride concentration 24.68 g/L, inoculation amount 5%, fermentation time 96 h), the carotenoid yield of mutant strain CS-15 reached 24.09 mg/L, which was 4.8 times higher than that of the original fermentation conditions, and 23.2 times higher than that of the original strain. In conclusion, the mutant strain CS-15 has good prospects for industrial application, and providing a theoretical foundation for the fermentative production of carotenoid using Rhodotorula mucilaginosa.

In this experiment, wheat was used as the research subject to investigate the effects of different particle sizes achieved through feed processing on the physicochemical properties, pelleting characteristics, and product quality of mash feed, aiming to provide data references for the broader application of wheat as a feed ingredient. A single-factor experimental design was adopted, wherein wheat was ground using a hammer mill with screen sizes of 1.0, 1.5, 2.0, 2.5 and 3.0 mm, respectively. The ground wheat was then mixed with other feed ingredients, such as soybean meal (ground with a 2.0 mm screen), to analyze the physical characteristics, hydration characteristics, gelatinization characteristics, and other physicochemical characteristics of the mash feed. Additionally, pelleting processing test was conducted. The results showed that: 1) wheat particle size significantly affected all physicochemical properties of the mash feed except for swelling capacity (P<0.05). As wheat particle size increased, the apparent density and tapped density of the mash feed first increased and then decreased, while the angle of repose and angle of internal friction consistently decreased; water absorption capacity and water solubility also showed a continuous decline; peak viscosity, trough viscosity, and final viscosity progressively decreased, whereas gelatinization time and gelatinization temperature consistently increased. 2) Wheat particle size significantly influenced the moisture content, protein dispersibility index, and gelatinizing properties of the mash feed after conditioning (P<0.05). With wheat particle size increasing, the moisture content of the conditioned mash feed decreased, while the protein dispersibility index increased; peak viscosity, trough viscosity, and final viscosity decreased, whereas gelatinization time and gelatinization temperature increased. 3) Wheat particle size significantly influenced pellet feed yield, forming rate, power consumption per ton of material, as well as pellet durability index, hardness, and starch gelatinization degree (P<0.05). As the wheat particle size increased, the power consumption per ton of material first decreased and then increased, the yield first increased and then decreased, while the forming rate, pellet durability index, hardness, and starch gelatinization degree consistently decreased. Therefore, an appropriate grinding particle size of wheat can improve the physicochemical properties and pelleting characteristics of the mash feed, thereby enhancing the quality of pellet feed.

This study aimed to investigate the antioxidant and immunomodulatory activities of cottonseed enzymolysis protein (CEP), and to elucidate the structural sequences of its potential functional peptides. Firstly, the amino acid composition and peptide molecular weight distribution of the CEP were determined. Subsequently, the antioxidant activity was evaluated by measuring the scavenging rates against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, hydroxyl radicals, superoxide anion, as well as the total antioxidant capacity. Finally, the immunomodulatory activity was examined using in vitro cultured macrophages and splenic lymphocytes, and the structure-activity relationship of characteristic functional peptides was analyzed in combination with molecular docking technology. The results showed as follows: 1) CEP contained 18 amino acids with a total content of 79.72%, including 8 essential amino acids accounting for 23.31%. Peptides with molecular weights≤500 Da and ≤1 000 Da constituted 51.67% and 71.99% in CEP, respectively. 2) Under the experimental conditions, the CEP effectively scavenged DPPH radicals, hydroxyl radicals, and superoxide anion, with the highest scavenging rates reaching 73.5%, 85.4% and 20.4%, respectively. The highest total antioxidant capacity was 0.598 μmol/mL. 3) Specific concentrations of the CEP could enhance both the phagocytic activity of macrophages and the proliferation capacity of splenic lymphocytes. At concentrations of 1.0 and 0.5 mg/mL, the CEP significantly increased the phagocytic index of macrophages compared with the positive control-0.02 mg/mL lipopolysaccharide (LPS) (P<0.05). At a concentration of 0.3 mg/mL, it also significantly elevated the stimulation index of splenic lymphocytes relative to 0.02 mg/mL LPS (P<0.05). Moreover, the CEP modulated the secretion of cytokines by macrophages, including interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-12 (IL-12), interleukin-2 (IL-2) and tumor necrosis factor-α (TNF-α). At concentrations of 0.5, 0.3 and 0.1 mg/mL, the CEP significantly promoted the secretion of the aforementioned cytokines (P<0.05), although the secretion remained significantly lower than those induced by 0.02 mg/mL LPS (P<0.05). 4) Liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with molecular docking identified 6 potential antioxidant peptides and 1 immunomodulatory peptide, among which 3 antioxidant peptides showed strong binding affinity to target proteins. In conclusion, CEP is rich in essential amino acids and small-molecular-weight peptides, and demonstrates notable antioxidant and immunomodulatory activities.

This experiment aimed to isolate and purify earthworm antimicrobial peptides (EAMPs), and to investigate their antimicrobial effects on Gram-positive bacteria, Gram-negative bacteria and fungi, as well as the effects of heat treatment temperature and storage time on their antimicrobial activities. Crude EAMPs from earthworm homogenate were precipitated with ammonium sulfate, isolated and purified by Sephadex G-100 column chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC), and molecular mass was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Moreover, the antimicrobial activities against Gram-positive bacteria, Gram-negative bacteria and fungi were detected, and the effects of heat treatment at 25, 37, 50, 80 and 100 ℃ for 20 minutes and storage for 180 days on the antimicrobial activities were observed. The results showed as follows: 1) the C component with antimicrobial activity obtained by RP-HPLC purification included two EAMPs of C1 and C2. The molecular mass of the C1 component was 11.2 ku, while the C2 component was further separated into two parts, with 11.4 and 9.3 ku, respectively. 2) The minimum inhibitory concentration (MIC) of C component against three Gram-positive bacteria, namely Staphylococcus aureus, Streptococcus pyogenes and Bacillus subtilis, were 0.14, 0.14 and 0.56 mg/L, respectively, and those for three Gram-negative bacteria, namely Escherichia coli, Salmonella Dublin and Shigella flexneri, were 0.56, 0.28 and 0.54 mg/L, respectively, while those for two fungi, namely Rhizopus oryzae and Aspergillus niger, were both 1.12 mg/L. 3) The antimicrobial activity of EAMPs was decreased with the increase of heat treatment temperature. When the temperature reached 100 ℃, their antimicrobial activity was significantly decreased (P<0.05). 4) The antimicrobial activity of EAMPs was decreased with the extension of storage time. When stored for 180 days, their antimicrobial activity was significantly decreased (P<0.05). In conclusion, the component C of EAMPs has broad-spectrum antimicrobial activity and can inhibit both Gram-positive and Gram-negative bacteria, but its antimicrobial effects on fungi are relatively weak. The antimicrobial effects of EAMPs remain stable after heat treatment at no more than 80 ℃ for 20 minutes and storage at 8 ℃ for 90 days.

This study aimed to evaluate the toxicity threshold, tissue residue patterns, and induced food safety risks of cyfluthrin in broiler diet. In experiment 1 (toxicity), eighty-four 1-day-old healthy male Cobb-500 broilers were randomly divided into 7 groups, with 6 replicates in each group, and 2 chickens in each replicate. Each group was fed a diet supplemented with 0 (control), 5, 25, 50, 100, 200 and 400 mg/kg cyfluthrin for 42 days, respectively. Growth performance, serum biochemical indices, and histopathological changes in the heart, liver, spleen and kidney were assessed. In experiment 2 (residue), seventy-two 1-day-old healthy male Cobb-500 broilers were randomly divided into 6 groups, with 6 replicates in each group, and 2 chickens in each replicate. Each group was fed a diet supplemented with 0 (control), 0.10, 0.25, 1.00, 5.00 and 25.00 mg/kg cyfluthrin for 42 days, respectively. Residual amounts of cyfluthrin in breast muscle and liver were determined using the QuEChERS-gas chromatography-mass spectrometry (GC-MS/MS) method and compared to China’s maximum residue limit (MRL, 10 μg/kg). The results of the toxicity experiment showed that dietary cyfluthrin below 50 mg/kg showed no significant adverse effects on broiler growth performance, serum biochemical indices and histopathology (P>0.05). At 100 mg/kg, the feed-to-gain ratio (F/G) during the 22 to 42 and 1 to 42 days of age periods was extremely significantly increased compared to the control group (P<0.01). Hepatic steatosis and necrosis were observed in the 400 mg/kg supplemental group, and mild degeneration and necrosis of renal tubular epithelial cells were observed in the 100 mg/kg supplemental group, establishing the lowest observed adverse effect level at 100 mg/kg. The residue study showed that cyfluthrin residues in breast muscle and liver were extremely significantly increased with dietary supplemental dosage (P<0.01). Detectable residues (13.25 to 72.87 μg/kg) exceeding the MRL (10 μg/kg) were found in both tissues when dietary cyfluthrin was≥0.25 mg/kg. In conclusion, dietary cyfluthrin below 100 mg/kg poses no significant adverse impact on broiler growth performance. However, dosage≥0.25 mg/kg (far below the toxicity threshold) causes residues in edible tissues to exceed safety limits. Trace contamination in diet, amplified through bioaccumulation, poses a significant risk to poultry meat safety. It is imperative to establish strict monitoring limits for cyfluthrin in feed.

This experiment was conducted to isolate a strain that can efficiently degrade deoxynivalenol (DON) from moldy corn and soil. The initial screening was conducted using styrene oxide as the sole carbon source, and the target strains with good growth were isolated through enrichment and purification culture. The re-screening was carried out using DON as the sole carbon source, and the degradation rate of DON by each strain was detected by enzyme-linked immunosorbent assay (ELISA). The morphological characteristics, staining properties and growth performance on solid medium were observed by using an oil immersion microscope, and the strains were identified by combining 16S rRNA gene sequencing. Furthermore, its more suitable growth conditions, bile salt and gastrointestinal fluid tolerance, as well as degradation mechanism were explored. The results showed as follows: 1) a strain of DON degrading bacteria was isolated from moldy corn and named BA-20, with DON degradation rate of (85.92±0.01)%. It was identified that BA-20 strain was Bacillus amyloliquefaciens. 2) The optimal growth temperature and pH of the isolated strain BA-20 were 37 ℃ and 7.0, respectively. Meanwhile, it had certain tolerance to bile salts with concentrations of 0.1% to 0.3%, simulated gastric fluid with pH=3, and simulated intestinal fluid with pH=8. 3) Based on the localization and qualitative analysis of active substances, it was speculated that the BA-20 strain mainly exerted the degradation effect on DON by secreting a protease. In conclusion, this study successfully isolates an efficient DON-degrading Bacillus amyloliquefaciens BA-20 from moldy corn, providing a candidate strain for the biological control of DON contamination and ensuring the safety of feed and food.

The objective of this study was to screen lactic acid bacteria with application value, isolated the strains from the post-hibernation initial feces of different reptiles, identified and evaluated the probiotic characteristics, to obtain candidate strains for microecological preparations. Strains were isolated from 25 reptile fecal samples using the plate streaking method, the potential pathogenic strains were excluded via hemolysis testing, the strains were identified based on biochemical characteristics and 16S rRNA gene sequence analysis. The screened strains were subjected to probiotic property assessments, including growth and acid production capacity, acid and bile salt tolerance capacity, antibiotic susceptibility, antibacterial activity, and auto-aggregation and hydrophobicity, and the safety of the candidate strains was evaluated via animal safety test. The results showed that 8 strains of lactic acid bacteria were successfully isolated and identified, with 4 strains of Enterococcus faecalis, 1 strain of Leuconostoc lactis, 1 strain of Lactobacillus fermentum, 1 strain of Vagococcus fluvialis, and 1 strain of Enterococcus faecium, respectively. The pH of bacterial suspensions of 8 strains of lactic acid bacteria was below 4.5 after 24 hours cultivation, indicated good acid production capacity. The 8 strains of lactic acid bacteria were sensitive to chloramphenicol and ampicillin. Strain L25 demonstrated superior performance compared to other strains in acid production capacity, acid and bile salt tolerance capacity and inhibitory capacity against Staphylococcus aureus, Escherichia coli and Salmonella. The animal safety test showed that strains L25 and L30 were safe. In conclusion, this study isolated 8 strains of lactic acid bacteria from the feces of various reptiles, among them, strain L25 possesses good probiotic properties, and can be considered a candidate strain for microecological preparations.