Non medicinal parts of Chinese herbal medicine have the characteristics of wide sources, large resource reserves and low production costs. Due to its rich content of polysaccharides, flavonoids, volatile oils and other active substances, as well as its obvious anti-inflammatory, antioxidant and anti pathogenic microbial functions, it has attracted much attention. This article provides a comprehensive review of the active ingredients, biological functions and application in livestock and poultry production of non medicinal parts of Chinese herbal medicine, providing theoretical support for their high-value applications.

Lactic acid bacteria (LAB) represent one of the most important physiological microbiotas in the intestines of humans and animals, and are closely related to host health. Exopolysaccharides (EPS), a major secondary metabolite secreted by LAB, exhibit a variety of physiological functions, including immunomodulation, anti-tumor, antioxidant, antibacterial, antiviral activities, and modulation of gut microbiota, playing a significant role in regulating vital activities. Therefore, they have attracted extensive attention in the field of health and wellness. This paper provides a comprehensive overview of the latest advancements in LAB-derived exopolysaccharides (LAB-EPS), covering their types and structures, biosynthesis, extraction and purification, and biological functions, and discusses their potential applications in modern animal husbandry. The aim is to provide a theoretical foundation and reference for further research and practical applications of LAB-EPS.

In livestock and poultry production, factors such as intensive rearing, nutrient deficiencies, harsh environments, and pathogen attacks can induce stress responses. This leads to lipid oxidation and protein degradation in muscles, consequently resulting in deteriorated meat quality. Dietary supplementation with selenium can improve redox status, enhance overall health, and mitigate the adverse effects of stress on meat quality. This paper reviewed the research progress on the effects of selenium on meat quality of livestock and poultry, and summarized the mechanism how selenium affected meat quality, in order to provide references for improving meat quality via dietary selenium supplementation and in-depth research on its regulatory mechanisms.

Neutrophil extracellular traps (NETs), which are DNA-based fibrous networks released by neutrophils, play a dual role in pathogen defense: moderate formation helps capture and eliminate pathogens, whereas excessive release exacerbates tissue damage and inflammatory responses by releasing effector molecules such as proteases and reactive oxygen species. In livestock and poultry production, various factors including pathogen infection, metabolic diseases, and reproductive activities (such as conception) can induce the formation of NETs. In recent years, there has been growing interest in utilizing nutritional strategies to regulate NETs formation. This review summarizes the biological functions and mechanisms of NETs in livestock and poultry health, and discusses the potential application of nutritional interventions in modulating NETs formation, aiming to provide a theoretical basis for preventing and treating NETs-related diseases and promoting healthy farming practices.

α-mangostin, a xanthone compound extracted from the peel of Garcinia mangostana, exhibits antioxidant, immunomodulatory, anti-inflammatory and bacteriostatic functions. Practical studies in broilers production demonstrated that α-mangostin can enhance growth rate, improve intestinal health, reduce systemic inflammation and elevate meat quality, indicating its broad development and application prospects. This review summarized the biological functions and mechanisms of α-mangostin, as well as its application in broiler production, aiming to provide references for further development and utilization of α-mangostin.

Nutritional metabolic diseases in dairy cows, serving as a critical bottleneck constraining the sustainable development of dairy farming, exhibit pathological mechanisms closely associated with gut microbiota-mediated secondary bile acid metabolism. Secondary bile acids are metabolic derivatives transformed from primary bile acids through gut microbiota processing, playing pivotal roles in host nutrient metabolism and immune regulation. This review summarizes the biosynthetic pathways of secondary bile acids, delineates the interplay between bovine gastrointestinal microbiota and secondary bile acid metabolism, and specifically focuses on the mechanistic actions of secondary bile acids in modulating key nutritional metabolic disorders including fatty liver disease, ketosis, ruminal acidosis and postpartum paralysis, to provide a theoretical basis for nutritional intervention strategies of nutritional metabolic diseases in dairy cows.

Early weaning is a key management practice for improving sow production efficiency. However, the severe physiological and environmental stress associated with early weaning often impairs intestinal barrier function, disrupts the homeostasis of gut microbiota, and increases susceptibility to pathogens. Recent studies have demonstrated that porcine-derived probiotics can effectively prevent and alleviate intestinal damage induced by weaning stress through direct modulation of intestinal barrier function. Furthermore, when applied in fermented feed, these probiotics help degrade anti-nutritional factors and improve nutritional value, thereby indirectly optimizing the structure and function of the intestinal microbiota. As a result, the development and application of porcine-derived probiotics are regarded as a highly promising strategy for replacing antibiotics and enhancing intestinal health in piglets. This article systematically reviews the classification, mechanisms of action, and practical applications of porcine-derived probiotics in piglet production, aiming to provide a theoretical foundation for their effective use in mitigating weaning stress.

Quercetin, a pale-yellow natural flavonoid, is widely present in various vegetables, fruits, and medicinal plants, and it exhibits multiple biological activities including anti-pathogen, anti-inflammatory, anti-oxidant, anti-tumor, immunomodulatory, neuroprotective, and tissue-protective effects. As a natural feed additive, quercetin demonstrates significant application prospects in ruminant production. This paper reviewed recent advances in quercetin’s extraction methods, biological activities and regulatory effects on rumen fermentation, and its application research in ruminant production, aiming to provide a reference for its utilization in ruminant production.

Short-chain fatty acids (SCFAs), as the main metabolic products of plant fiber fermentation in the rumen, play an indispensable role in energy metabolism, nutrient absorption, regulation of immune response, and inhibition of inflammatory reactions. This review summarized the transmembrane transport mechanisms of SCFAs in ruminants, their immune regulatory functions, the interaction with intestinal microbial communities, and their potential application value in disease prevention and treatment. By exploring the effects of SCFAs on the nutritional metabolism and health status of ruminants, this review provided theoretical and practical basis for optimizing ruminant feed formulations, improving health level, and preventing related diseases.

Algae, with their high nutritional value and balanced amino acid profile, are increasingly emerging as a potential key protein source to replace fishmeal in the aquaculture feed industry. Previously, fishmeal was considered the go-to high-quality protein source for aquaculture, but supply shortages and rising prices have limited its use, driving the development of algae protein as a new solution. Research indicates that appropriately replacing fishmeal with algae protein (less than 80%) can benefit fish growth, enhance intestinal digestion and absorption, improve immunity, and enhance muscle quality; however, excessive replacement (80% or more) may inhibit physiological metabolism and damage tissue structure. Currently, the application of algae protein still faces challenges such as high production costs at scale, low digestibility, and anti-nutritional factors in algae sources. This paper comprehensively analyses the characteristics of several common algal proteins, their current application status, and technical challenges and summarizes relevant solution strategies, aiming to provide theoretical support and practical guidance for the research and application of fishmeal alternatives in aquaculture feed.

Garlic contains various nutrients such as carbohydrates, proteins, amino acids, and trace mineral elements, as well as bioactive substances such as sulfur compounds, polysaccharides, and polyphenols. Therefore, it has edible values such as enhancing aroma and flavor, promoting appetite, as well as medicinal values such as antioxidant, antibacterial, anti-inflammatory, and antiviral activities. This article reviews the main chemical components, physiological functions, and current applications of garlic and its derivatives in livestock and poultry production, and points out the key issues and future research directions in its industrial application, aiming to provide the references for improving the utilization value of garlic and promoting healthy breeding of livestock and poultry.

As a typical natural flavonoid, kaempferol has emerged as a key research focus in the field of natural feed additives due to its potent antioxidant, anti-inflammatory properties and synergistic effect in regulating intestinal microbiota balance. Kaempferol achieves free radical scavenging and targeted regulatory functions through its active groups (2,3-conjugated double bond, 4-ketone group, and 3',4'-catechol structure). Through microbiota-mediated glycoside hydrolysis and metabolite generation, it remodels microbial community structure, activates immune signaling pathways, enhances intestinal barrier function, and suppresses inflammatory responses. Kaempferol has demonstrated significant application potential in disease prevention and control, growth performance improvement, and reproductive performance enhancement in livestock, poultry and aquatic farming. This review comprehensively analyzes the mechanisms of kaempferol from the perspective of multi-level homeostatic regulation along the “microbiota-metabolism-immunity axis”, aiming to provide a theoretical foundation for the development of efficient and safe green feed additives and promote the advancement of green and healthy breeding.

Short chain fatty acids (SCFA), medium chain fatty acids (MCFA) and polyunsaturated fatty acids (PUFA) are common natural nutrients, they show good efficacy in regulating the intestinal health of animals. In this paper, common functional fatty acids such as SCFA, MCFA and PUFA were reviewed, and the regulatory role of these kinds of common fatty acids in animal intestinal health was discussed from the aspects of intestinal cell and tissue morphology, immune function and microbiota; and so on, in order to provide references for these kinds of common fatty acids in applications of animal intestinal health and animal production.

Gut health is extremely important for animal performance, and the banning of antibiotics as growth-promoting additives has made gut health problematic, which has led to an increasing demand for research into the mechanisms that affect gut health, as well as the screening of additives that promote gut health. However, on the one hand, animal testing is limited by ethical review, space and personnel; on the other hand, animal experiments are costly and time-consuming. Therefore, the use of intestinal organoid models, which contain a variety of intestinal cell types and can effectively simulate the physiological structure and function of the intestinal tract in vivo, is becoming more and more widespread. Intestinal organoids are a kind of in vitro cultures formed by self-renewal, differentiation, and assembly of intestinal stem cells under three-dimensional culture conditions. Although the culture of intestinal organoids in humans and mice has been very mature, there are still certain problems in the cultivation of intestinal organoids in feeder animals (especially for the regulation of intestinal organoids’ proliferation and differentiation in vitro) and their application at present. In this paper, we systematically review the isolation methods of intestinal crypt stem cells, and describe the influencing factors of the in vitro culture system of intestinal organoids and their application in animal production, with a view to providing a reference for the application of intestinal organoids in livestock and poultry production and research.

Taste is an important system involved in the sense of chemical properties of food in animals, and several basic gustation such as sweet, bitter, fresh, salty, sour and fatty are formed through the activation of different types of taste receptors. It has been demonstrated that taste receptors [e.g., taste receptor type 1 (T1R), taste receptor type 2 (T2R), fatty acid translocase (CD36) and G protein-coupled receptor 120 (GPR120), etc.] are not only present in the cells of taste buds but are also widely expressed in the cells of intestine, pancreas, adipose and other tissues. In recent years, it has been found that as key components of the chemosensory system, taste receptors are also involved in the dynamic homeostasis regulation of lipid metabolism through the sense of nutrients. Lipid metabolism is the core link to maintain energy homeostasis in animals, and its imbalance not only affects carcass quality and reproductive performance, but also is closely related to metabolic diseases such as obesity and diabetes. Therefore, this paper systematically reviewed the distribution of sweet, fresh, bitter and lipid gustatory receptors and their regulatory mechanisms on lipid metabolism in animals, which provided a new perspective for analyzing lipid metabolism network and laid a theoretical foundation for improving the production performance of livestock and poultry and intervention strategies for metabolic diseases.

Spermatogenesis is a highly sophisticated and precisely regulated biological process, which is extremely susceptible to interference from various intracellular and extracellular stimuli. As a crucial intracellular mechanism for substance clearance and recycling, autophagy can degrade damaged organelles and abnormal proteins, playing a key role in maintaining cellular homeostasis. Studies have shown that autophagy is closely related to male reproductive function, and the autophagic homeostasis of spermatogenic cells and somatic cells in the testis is the core basis for maintaining normal male reproductive function. This article reviews the research progress on the molecular mechanism of autophagy regulating sperm quality, influencing factors and its nutritional regulation, aiming to provide a theoretical reference for in-depth analysis of the physiological mechanism of sperm quality regulation and the development of efficient nutritional regulatory products.

This study was conducted to explore the effects of fermented Broussonetia papyrifera on the growth performance, serum biochemical indexes, slaughter performance, meat quality and muscle fiber characteristics of finishing pigs. A total of 90 hybrid pigs (Duroc×Landrace×Yorkshire) with the similar age and body weight were randomly divided into 3 groups, each group consisted of 3 pens (repetitions) and 10 pigs per pen. The pigs in control group were fed a basal diet, while those in FBP1 and FBP2 groups were fed experimental diets which supplemented with 5% and and 10% fermented Broussonetia papyrifera, respectively. The pre-test lasted for 7 days, and the formal test lasted for 60 days. The results showed as follows: 1) dietary supplementation with 5% or 10% fermented Broussonetia papyrifera showed no significant effects on the growth performance and slaughter performance of finishing pigs (P<0.05); 2) the contents of total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and urea nitrogen (UN) in the serum of finishing pigs in the FBP2 group were significantly decreased when compared with the control group (P<0.05); 3) compared with the control group, muscle water loss rate was significantly decreased (P<0.05), and cooked meat rate showed a decreasing trend in the FBP2 group (0.05<P<0.10), meanwhile, the contents of inosinic acid, aspartic acid and umami amino acids in the muscle of finishing pigs in the FBP2 group were significantly increased (P<0.05); 4) compared with the control group, both the FBP1 and FBP2 groups showed a significant increase in muscle fiber density (P<0.05) and a significant decrease in muscle fiber average area of finishing pigs (P<0.05). In summary, under the conditions of this experiment, dietary supplementation with 5% or 10% fermented Broussonetia papyrifera have no significant effects on the growth performance and slaughter performance of finishing pigs. Moreover, dietary supplementation with 10% fermented Broussonetia papyrifera can contribute to regulating serum biochemical status, improving meat quality, increasing the content of umami amino acids in muscle, and altering muscle fiber characteristics.

The composition and addition ratio of carbohydrates in the diet had different effects on the growth and health of pigs, but the appropriate carbohydrate nutritional balance pattern in the diet for fattening pigs remained unclear. This experiment aimed to investigate the effects of different carbohydrate combinations in diets on growth performance, nutrient apparent digestibility, carcass traits and meat quality of fattening pigs. The experiment was conducted according to a L9 (3⁴) incomplete orthogonal design, and nine dietary carbohydrate combinations at different levels with three factors: the starch [with amylose to amylopectin ratios (AM/AP) of 1∶5, 1∶10, and 1∶20], non-starch polysaccharide (NSP, with addition amounts of 1%, 3%, and 5%, and inulin and cellulose mixed in a 1∶1 ratio) and oligosaccharide (with addition amounts of 500, 1 000 and 2 000 mg/kg, and fructo-oligosaccharide and mannan-oligosaccharide mixed in a 10∶1 ratio) were set. A total of 108 “Duroc×Landrace×Yorkshire” fattening pigs with an initial body weight of (77.00±7.64) kg were selected and divided into 9 groups according to the principle of consistent body weight and gender as well as random block, with 6 replicates in each group (3 replicates for males and 3 replicates for females), and 2 pigs in each replicate. The experimental pigs in each group were fed different experimental diets according to the orthogonal experimental design, respectively. The experiment lasted for 49 days. The results showed as follows: 1) different carbohydrate combinations in diets had no significant effect on the growth performance of fattening pigs (P>0.05). 2) Different carbohydrate combinations in diets had significant effects on the nutrient apparent digestibility of fattening pigs (P<0.05). The recommended dietary carbohydrate combination for fattening pigs to achieve the best nutrient apparent digestibility was as AM/AP of 1∶10 or 1∶20, NSP addition of 5%, and oligosaccharide addition of 500 or 1 000 mg/kg. 3) Different carbohydrate combinations in diets had no significant effect on the carcass traits of fattening pigs (P>0.05). 4) When the addition amount of NSP was 5%, the 24 h pH in longissimus dorsi of fattening pigs was significantly lower than that when the addition amounts of NSP were 1% and 3% (P<0.05). Based on the main effect analysis and integrating various indicators, it is recommended that the appropriate carbohydrate combination in the diet for fattening pigs is as AM/AP ratio of 1∶5, NSP addition amount of 5%, and oligosaccharide addition amount of 1 000 mg/kg.

This experiment aimed to evaluate the nutritional values of Zanthoxylum bungeanum leaves in pregnant sows using a digestion experiment and study their effects on reproductive performance of pregnant sows. In experiment 1, the digestible energy and apparent digestibilities of common nutrients were determined by the total feces collection method combined with the substitution method. A total of 24 “Landrace×Large White” crossbred sows with 3 parities on day 60 of pregnancy with consistent body condition were randomly divided into 2 groups (12 replicates in each group, with 1 sow in each replicate), and were fed the basal diet and the experimental diet (90% basal diet+10% Zanthoxylum bungeanum leaves), respectively. The experiment lasted for 10 days, with days 1 to 5 being the adaptation period and days 6 to 10 being the sample collection period. In experiment 2, sixty “Landrace×Large White” crossbred sows with 3 parities on day 30 of pregnancy with consistent body condition were randomly divided into 2 groups, with 30 replicates in each group and 1 sow in each replicate. The control group was fed the basal diet, while the experimental group was fed the experimental diet supplemented with 4% Zanthoxylum bungeanum. The experiment began on day 30 of pregnancy and lasted until the end of delivery. The results showed as follows: 1) the digestible energy of Zanthoxylum bungeanum leaves in pregnant sows was 13.78 MJ/kg. Compared with the basal diet group, there were no significant differences in the apparent digestibilities of dry matter, crude protein, ether extract, neutral detergent fiber and acid detergent fiber in the experimental diet group (P>0.05). 2) Compared with the control group, dietary supplementation of 4% Zanthoxylum bungeanum leaves had no significant effects on the backfat thickness and reproductive performance of pregnant sows (P>0.05). 3) Compared with the control group, dietary supplementation of 4% Zanthoxylum bungeanum leaves had no significant effects on serum immune and antioxidant indices (P>0.05). 4) Compared with the control group, dietary supplementation of 4% Zanthoxylum bungeanum leaves significantly increased the relative abundances of Colidextribacter, norank_o_WCHB1-41, CAG-196, Oribacterium, and norank_o_Oscillospirales in feces (P<0.05), and significantly decreased the relative abundances of [Eubacterium]_ruminantium_group, Streptococcus, Lachnospiraceae_AC2044_group, norank_f_Butyricicoccaceae, and Oscillospira in feces (P<0.05). In conclusion, dietary supplementation of 4% Zanthoxylum bungeanum leaves has no significant effects on the reproductive performance of pregnant sows, as well as on serum immune and antioxidant indices, and can improve the gut microbiota.

This experiment aimed to investigate the effects of dietary supplementation of glycyrrhizic acid (GA) on body weight gain, immune function, antioxidant capacity and intestinal health of weaned piglets challenged with enterotoxigenic Escherichia coli (ETEC) K88. Forty 21-day-old Duroc×Landrace×Large White weaned piglets with similar body weight and the same parity were selected and randomly divided into 4 groups using a 2×2 two-factor design, with 10 replicates in each group and 1 pig in each replicate. The control group (CON group) and ETEC group were fed a corn-soybean meal type basal diet, while GA group and GA+ETEC group were fed the basal diet+400 mg/kg GA. The experiment lasted for 21 days. From day 19 to day 21 of the experiment, 10 mL of ETEC K88 bacterial solution with a concentration of 1×10⁹ CFU/mL was administered to piglets in ETEC group and GA+ETEC group for 3 consecutive days, while CON group and GA group were administered the same amount of sterile phosphate buffer solution. The results showed as follows: 1) dietary supplementation of 400 mg/kg GA significantly increased the body weight on day 21 and average daily gain from days 1 to 21 (P<0.05). 2) ETEC K88 infection significantly increased the contents of interleukin-1β in serum and interferon-γ in jejunal mucosa (P<0.05), and significantly decreased the contents of interleukin-10 and immunoglobulin G in serum (P<0.05); dietary supplementation of 400 mg/kg GA significantly reduced the contents of interleukin-1α, interleukin-2 and tumor necrosis factor-α in serum (P<0.05), and significantly increased the secretory immunoglobulin A content in jejunal mucosa (P<0.05). 3) ETEC K88 infection significantly reduced the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in liver (P<0.05). Dietary supplementation of 400 mg/kg GA significantly increased the activities of SOD and catalase in serum (P<0.05), and significantly reduced the malondialdehyde content in serum (P<0.05). Meanwhile, it significantly increased the activities of SOD and GSH-Px, the total antioxidant capacity, and the mRNA relative expression levels of GSH-Px1, GSH-Px4 and nuclear factor E2-related factor 2 (Nrf2) in liver (P<0.05). 4) ETEC K88 infection significantly reduced the villus height to crypt depth ratio in duodenum and jejunum (P<0.05), and significantly increased the crypt depth in duodenum and jejunum (P<0.05); dietary supplementation of 400 mg/kg GA significantly increased the villus height and villus height to crypt depth ratio in duodenum and jejunum (P<0.05), and significantly reduced the crypt depth in duodenum and jejunum (P<0.05). 5) ETEC K88 infection significantly reduced the mRNA relative expression levels of Occludin in duodenum, and zonula occludens-1 (ZO-1) and Occludin in jejunum (P<0.05), while dietary supplementation of 400 mg/kg GA significantly increased the Occludin mRNA relative expression level in jejunum (P<0.05). 6) Dietary supplementation of 400 mg/kg GA tended to increase the Firmicutes relative abundance in colon (P=0.076), and significantly reduced the Proteobacteria relative abundance in colon (P<0.05); meanwhile, it tended to increase the relative abundances of Lactobacillus (P=0.070) and Ligilactobacillus (P=0.093), and to decrease the relative abundances of Escherichia-Shigella (P=0.059) and Clostridium_sensu_stricto_1 (P=0.084). In conclusion, dietary supplementation of 400 mg/kg GA can increase the body weight gain of weaned piglets, enhance immune function and antioxidant capacity, and promote intestinal health, thereby alleviating the negative effects caused by ETEC K88 infection.

This experiment was conducted to investigate the effects of ozone and sorbic acid for drinking water disinfection on the growth performance, serum indices and intestinal health of laying hens during the brooding period. A total of 1 080 7-day-old healthy Hy-Line brown laying hen chicks were selected and randomly divided into 3 groups, with 6 replicates in each group and 60 chickens in each replicate. The control group drank well water provided by the breeding farm, while the ozone group and the sorbic acid group disinfected the drinking water through the water line with an ozone water line cleaning machine and a sorbic acid drinking water disinfectant, respectively. The experimental period was 8 weeks. The results showed as follows: 1) during weeks 1 to 4 of the experiment, compared with the ozone group, the average daily gain in the sorbic acid group was significantly increased (P<0.05), and the feed to gain ratio was significantly decreased (P<0.05). 2) The liver index in the sorbic acid group was significantly higher than that in the ozone group (P<0.05). 3) Compared with the control group, the serum alanine aminotransferase activity in the ozone group was significantly increased (P<0.05), while the serum immunoglobulin M content was significantly decreased (P<0.05). 4) Compared with the control group, the villus height of duodenum in the sorbic acid group was significantly increased (P<0.05), while that in the ozone group was significantly decreased (P<0.05). Meanwhile, compared with the ozone group, the villus height to crypt depth ratio of duodenum in the sorbic acid group and the control group were significantly increased (P<0.05), and the crypt depth of jejunum in the sorbic acid group was significantly decreased (P<0.05). 5) The ileal amylase activity in the ozone group was significantly higher than that in the control group and the sorbic acid group (P<0.05), and the ileal trypsin activity was significantly higher than that in the sorbic acid group (P<0.05); the ileal lipase activity in the sorbic acid group was significantly higher than that in the control group and the ozone group (P<0.05). 6) The mRNA relative expression levels of Claudin-2 and tumor necrosis factor-α (TNF-α) in ileum in the ozone group were significantly lower than those in the control group (P<0.05), and the mRNA relative expression levels of Occludin, Claudin-2, zonula occludens-1 (ZO-1), zonula occludens-2 (ZO-2), interleukin-1β (IL-1β) and TNF-α in ileum were significantly lower than those in the sorbic acid group (P<0.05). In conclusion, the drinking water disinfected with ozone may affect the immune function and intestinal health of laying hens during the brooding period in a certain extent; the drinking water disinfected with sorbic acid can enhance the growth performance of chicks in the early stage of brooding and improve intestinal health; both ozone and sorbic acid for drinking water disinfection can enhance the digestive enzyme activity in ileum.

The purpose of this experiment was to investigate the contents of calcium and phosphorus in corn from different producing areas and the apparent metabolic rates and true utilization rates of calcium and phosphorus in laying hens during the peak period of laying. The apparent metabolic rates and true utilization rates of calcium and phosphorus in laying hens were determined by using 10 kinds of corn from Heilongjiang, Hebei, Jilin, Inner Mongolia, Henan, Shandong, Anhui, Beijing and Yunnan. Ninety-six 35-week-old healthy Roman grey laying hens with similar body weight were randomly divided into ten semi-pure corn diet groups, one calcium-free diet group and one phosphorus-free diet group, with 8 replicates in each group and 1 chicken in each replicate. The pre-test period was 3 days and the test period was 4 days. The total fecal collection method was used to collect excreta, and the apparent metabolic rate/value of calcium and phosphorus and the true utilization rate/value of calcium and phosphorus were measured and calculated. Based on the physical characteristics and chemical composition, the prediction equations of the apparent metabolic rate/value and true utilization rate/value of calcium and phosphorus in laying hens during the peak laying period were constructed. The results showed as follows: 1) the content of calcium in 10 kinds of maize ranged from 0.01% to 0.13%, with an average of 0.05% and a coefficient of variation of 78.75%; the content of total phosphorus ranged from 0.18% to 0.31%, with an average of 0.26% and a coefficient of variation of 15.00%. The content of phytate phosphorus (PP) ranged from 0.08% to 0.16%, with an average of 0.13% and a coefficient of variation of 18.75%. From the perspective of producing areas, the content of calcium was higher in Linyi of Shandong, Zhuozhou of Hebei and Zhengzhou of Henan, while lower in Beijing, Anqing of Anhui. The content of phosphorus was the higher in Anqing of Anhui, Zhengzhou of Henan and Harbin of Heilongjiang, and the lower in Zhuozhou of Hebei and Bayannaoer of Inner Mongolia. The content of PP and the content of total phosphorus showed the same trend. 2)During the peak laying period, the calcium true utilization value of laying hens on 10 kinds of corn was 0.07 to 0.91 g/kg, with an average value of 0.36 g/kg. The true utilization rate of calcium was 67.42% to 78.75%. The true utilization rate of 10 kinds of corn phosphorus in laying hens was 0.73 to 1.58 g/kg, with an average of 1.18 g/kg, and the true utilization rate was 40.22% to 63.13%. 3) Taking the physical and chemical properties and nutritional components of corn as predictors, the prediction equation of the true utilization rate of calcium and phosphorus in corn by laying hens at the peak of laying was Ca_TUR=67.16+1.881 total phosphorus (TP)-0.089 bulk density (BD)-0.432 crude ash (Ash) and P_TUR=40.48+1.542 crude protein (CP)+0.229 acid detergent fiber (ADF)-0.279 PP. Considering that the percentage cannot be accurate to the decimal point, and the true utilization value was used as a variable to predict the dynamic equation, it was Ca_TUV=0.162+0.113TP-0.025 5BD and P_TUV=0.207+0.64CP+0.204 neutral detergent fiber (NDF)-0.221Ash. In summary, the contents of calcium and phosphorus in corn from different producing areas are quite different, and their utilization rates are also quite different; during the peak laying period, the true utilization value of calcium in corn is 0.07 to 0.91 g/kg, and the true utilization value of phosphorus is 0.73 to 1.58 g/kg. The TP, Ash content and BD in corn can be used as predictors of calcium apparent metabolic rate and true utilization rate, while the contents of CP, NDF, Ash, ADF and PP can be used as predictors of phosphorus apparent metabolic rate and true utilization rate. The determination coefficients of the prediction equations of calcium apparent metabolic rate and calcium true utilization rate are 0.624 and 0.933, respectively, and the determination coefficients of the prediction equations of phosphorus apparent metabolic rate and phosphorus true utilization rate are 0.737 and 0.952, respectively.

This experiment aimed to compare and study the effects of supplementation of solid essential oil (SEO) in diet or liquid essential oil (LEO) in drinking water, as well as their combination, on performance, egg quality and body health of laying hens in the later laying stage, in order to determine the feeding effects of using them alone and in combination on laying hens. A total of 560 57-week-old Roman pink laying hens were selected and randomly divided into 4 groups according to the principle of consistent laying rate, with 7 replicates in each group and 20 hens in each replicate. The control group was fed the basal diet, the SEO group was fed the basal diet+100 g/t SEO, the LEO group was fed the basal diet and 250 mL/t LEO was added to the drinking water (fed for 4 days every 2 weeks), and the SEO+LEO group was fed the basal diet+100 g/t SEO and 250 mL/t LEO was added to the drinking water (fed for 4 days every 2 weeks). The pre-experiment lasted for 2 weeks and the formal experiment lasted for 16 weeks. The results showed as follows: 1) compared with the control group, the combination of SEO and LEO significantly increased the laying rate from weeks 1 to 16 (P<0.05), while the single supplementation of SEO or LEO and both significantly increased the laying rate from weeks 9 to 12 and 13 to 16 (P<0.05); the supplementation of LEO significantly reduced the feed to egg ratio from weeks 9 to 12 (P<0.05), the supplementation of SEO significantly reduced the feed to egg ratio from weeks 13 to 16 (P<0.05), and the combination of SEO and LEO significantly reduced the feed to egg ratio from weeks 9 to 12 and 13 to 16 (P<0.05). 2) Compared with the control group, the supplementation of SEO significantly increased the eggshell ratio in week 4 (P<0.05), and the combination of SEO and LEO significantly increased the eggshell thickness in week 4 (P<0.05). 3) Compared with the control group, the supplementation of SEO significantly increased the total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) activity in serum (P<0.05), significantly increased the T-AOC and activities of catalase (CAT) and T-SOD in ovary (P<0.05), and significantly reduced the malondialdehyde (MDA) content in serum (P<0.05); the supplementation of LEO or its combination with SEO significantly increased the T-AOC and T-SOD activity in serum, liver and ovary (P<0.05), significantly increased the CAT activity in jejunum (P<0.05), and significantly reduced the MDA content in serum, liver and ovary (P<0.05). 4) Compared with the control group, the supplementation of LEO or its combination with SEO significantly increased the Claudin-1 mRNA relative expression level in jejunum (P<0.05), and significantly decreased the mRNA relative expression levels of interleukin-1β (IL-1β) and Toll-like receptor 4 (TLR4) in jejunum (P<0.05). In conclusion, the supplementation SEO in diet or LEO in drinking water, as well as their combination, can enhance the antioxidant capacity, improve the intestinal barrier function, and inhibit the intestinal inflammation, thereby increasing the laying rate of laying hens in the later laying stage and reducing the feed to egg ratio. Moreover, it has a time-dependent effect, and the combination of the two has a better effect.

This experiment was conducted to study the effects of Monascus pigments (MP) on laying and hatching performance, egg quality, nutrient utilization and blood biochemical indicators of Guizhou yellow-feather breeders. A total of 564 Guizhou yellow-feather breeders aged 200 days were randomly divided into 3 groups with 4 replicates in each group and 47 hens in each replicate, including 4 cocks and 43 hens. Breeders in control group were fed a basal diet, and those in MP200 and MP400 group fed experimental diets which were supplemented with 200 and 400 mg/kg MP, respectively. The trial included a 1-week pre-experimental period and an 8-week formal experimental period. The results showed as follows: 1) compared with the control group, diet supplemented with 400 mg/kg MP did not significantly affect the average daily feed intake (ADFI) of breeders (P>0.05). However, it significantly improved the laying rate and feed/egg ratio (P<0.05), significantly increased the fertilization rate and hatchability (P<0.05), and significantly reduced the embryo mortality (P<0.05). 2) Dietary supplemented with different levels of MP had no significant effects on egg quality indexes such as yolk ratio, yolk color, albumen height, Haugh unit, egg shape index, eggshell strength, and eggshell thickness, etc. (P>0.05). 3) Compared with the control group, diet supplemented with 400 mg/kg MP significantly increased the apparent metabolizabilities of crude protein and calcium (P<0.05). 4) Compared with the control group, dietary supplemented with 400 mg/kg MP significantly reduced plasma triglyceride, total cholesterol, uric acid, and low-density lipoprotein cholesterol contents (P<0.05), while significantly increased plasma high-density lipoprotein cholesterol content (P<0.05). It also significantly decreased serum immunoglobulin A content (P<0.05). Furthermore, dietary supplemented with 400 mg/kg MP significantly enhanced the activities of serum glutathione peroxidase and superoxide dismutase (P<0.05), and significantly reduced the contents of serum reactive oxygen species, malondialdehyde, and tumor necrosis factor-α (P<0.05). In conclusion, dietary supplemented with 400 mg/kg MP can enhance immunity, antioxidant capacity, and anti-inflammatory ability of Guizhou yellow-feather breeders, also can promote the utilization of dietary nutrients, thereby improving laying and hatching performance.

This experiment aimed to investigate the effects of different levels of Sanghuang extract on the growth performance, slaughter performance, meat quality, muscle texture characteristics, serum immune, and antioxidant indexes of white-feather broilers, and to compare them with the effects of the same levels of hawthorn leaf extract and velvet antler extract. A total of 72 healthy 21-day-old 817 white-feather broiler male chicks with no significant difference (P>0.05) in initial body weight were randomly divided into 6 groups, with 3 replicates per group and 4 chicks per replicate. The control group was fed a basal diet, and the experimental groups were supplemented with 100, 200, and 400 mg/kg of Sanghuang extract, 400 mg/kg of hawthorn leaf extract, and 400 mg/kg of velvet antler extract, respectively. The experimental period lasted for 21 days. The results showed as follows: 1) compared with the control group, the feed-to-gain ratio was significantly reduced in all Sanghuang extract groups, and the hawthorn leaf group had a significantly lower feed-to-gain ratio than both Sanghuang 3 and velvet antler groups (P<0.05). 2) The muscle brightness (L^*) value was significantly higher in the hawthorn leaf group compared with all Sanghuang extract groups (P<0.05). 3) Compared with the control group, the drip loss rate was significantly reduced in the Sanghuang 2 group (P<0.05). 4) Compared with the control group, the muscle fiber cross-sectional area was significantly decreased in Sanghuang 1 group (P<0.05), while it significantly increased in Sanghuang 3 group (P<0.05). The fiber diameter was significantly reduced in Sanghuang 1 and 2 groups (P<0.05), while it was significantly increased in Sanghuang 3 group (P<0.05). The hawthorn leaf group had significantly lower fiber diameter and cross-sectional area compared with both Sanghuang 3 and velvet antler groups (P<0.05). 5) Compared with the control group, the contents of serum immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) were significantly increased in all Sanghuang extract groups (P<0.05). The serum content of interleukin-4 (IL-4) was significantly higher in Sanghuang 2 and 3 groups (P<0.05), while the serum content of interleukin-6 (IL-6) was significantly lower in Sanghuang 2 and 3 groups (P<0.05). The serum content of interleukin-1β (IL-1β) was significantly lower in the Sanghuang 3 group (P<0.05). The serum contents of IgA, IgM, IgG, and IL-4 in the Sanghuang 3 group were significantly lower than those in the hawthorn leaf group (P<0.05), but there were no significant differences in serum immune indexes compared with the velvet antler group (P>0.05). 6) Compared with the control group, serum superoxide dismutase (SOD) activity was significantly increased in all Sanghuang extract groups (P<0.05), and the total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), and catalase (CAT) activities were significantly increased in Sanghuang 2 and 3 groups (P<0.05). The malondialdehyde (MDA) content in serum was significantly reduced in Sanghuang 1 and 3 groups (P<0.05). The antioxidant effect in the hawthorn leaf group was more significant than in Sanghuang 3 group (P<0.05), and there were no significant differences in serum antioxidant indexes between the velvet antler and control groups (P>0.05). In conclusion, dietary supplementation with an appropriate level of Sanghuang extract can reduce the feed-to-gain ratio in white-feather broilers, enhance immune function and antioxidant capacity, and improve muscle texture characteristics. Compared with other novel green additives, it shows comparable immunomodulatory effects. Under the conditions of this experiment, the optimal supplementation level of Sanghuang extract in the diets of white-feather broilers is 200 mg/kg.

This experiment was conducted to evaluate the effective energy values of cottonseed meal and cottonseed protein from different sources in yellow-feathered broilers and construct their prediction equations using chemical components, aiming to provide data references for the scientific utilization of cottonseed meal and cottonseed protein in feed. A total of 7 cottonseed meal and 4 cottonseed protein samples were collected in the experiment, and yellow-feathered broiler roosters were selected and two batches of metabolic experiments were conducted using true metabolizable energy (TME) combined with substitution method. The basal diet adopted a corn-soybean meal type diet, and the experiment diet was composed of cottonseed meal or cottonseed protein at a ratio of 20% replacing the basal diet and mixed with it. There were 10 replicates in each treatment, and 2 chickens in each replicate. The forced feeding amount for the metabolic experiment was 50 g, and the endogenous energy was evaluated by the fasting method. The fasting time and excrement collection time were both 48 hours, and the recovery period between the two batches was 14 days. The results showed as follows: 1) the average gross energy (GE) of 7 kinds of cottonseed meals and 4 kinds of cottonseed proteins was 18.38 MJ/kg. The average contents of dry matter (DM), crude protein (CP), ether extract (EE), crude fiber (CF), neutral detergent fiber (ADF), acid detergent fiber (ADF), crude ash (Ash) and total phosphorus (TP) were 96.83%, 60.16%, 1.64%, 4.28%, 13.50%, 5.20%, 7.41% and 0.83%, respectively, and the average content of free gossypol (FG) was 393.14 mg/kg. Among them, the coefficients of variation of EE, CF, NDF and FG contents were relatively high (>26%). 2) The average values of apparent metabolizable energy (AME), nitrogen-corrected apparent metabolizable energy (AMEn), TME and nitrogen-corrected true metabolizable energy (TMEn) of 7 kinds of cottonseed meals and 4 kinds of cottonseed proteins in yellow-feathered broilers were 12.37, 12.12, 13.60 and 12.43 MJ/kg; the average values of AME, AMEn, TME and TMEn of 7 kinds of cottonseed meals were 11.69, 11.65, 13.22 and 12.13 MJ/kg; and the average values of AME, AMEn, TME and TMEn of 4 kinds of cottonseed proteins were 13.81, 13.41, 14.99 and 13.69 MJ/kg, respectively. 3) The prediction equations for AME, AMEn, TME and TMEn of cottonseed meal and cottonseed protein were established by stepwise regression method as follows: AME=59.183 6-2.691 2EE-2.261 0GE+0.322 3NDF-0.787 3ADF [coefficient of determination (R²)=0.508, P<0.05]; AMEn=16.356 9-2.874 7EE+0.188 0NDF-0.563 2ADF (R²=0.458, P<0.05); TME=18.996 0-2.964 5EE-0.286 8CF-0.141 9ADF (R²=0.499, P<0.05); TMEn=59.402 3-2.330 7EE-2.305 8GE+0.347 6NDF-0.787 0ADF (R²=0.467, P<0.05). In conclusion, this experiment provides basic data for the utilization of cottonseed meal and cottonseed protein in feed. However, the common chemical components of cottonseed meal and cottonseed protein from different sources vary greatly, and it is necessary to continuously increase the sample size of cottonseed meal and cottonseed protein to improve the accuracy of the effective energy value prediction equation.

This study aimed to systematically evaluate the effects of different replacement ratios and different indicator methods on the determination results of effective energy values of soybean meal in broilers, in order to identify suitable replacement ratio and indicator method. In the experiment, ninety-six 7-day-old Arbor Acres (AA) broiler roosters were selected and randomly divided into 4 groups with 6 replicates each and 4 chickens in each replicate. Simultaneously, forty-eight 21-day-old AA broiler roosters were selected and randomly divided into 4 groups with 6 replicates each and 2 chickens in each replicate. All of them were set up with a basal diet group (SM0 group) and three soybean meal replacement ratio groups where the basal diet was replaced by soybean meal at the ratio of 10% (SM10), 20% (SM20) and 30% (SM30). All diets were supplemented with 0.4% titanium dioxide (TiO₂) as an exogenous indicator. An open-circuit respiratory calorimetry device was used to measure oxygen (O₂) and carbon dioxide (CO₂) data in the test broilers from 11 to 14 days of age and from 25 to 28 days of age. Concurrently, a metabolism trial was conducted to determine the available energy values of soybean meal using total excreta collection method (as the control), endogenous indicator method [acid-insoluble ash (AIA) method] method, and exogenous indicator method (TiO₂ method). The results showed as follows: 1) comparison of different replacement ratios, the feed-to-gain ratio of broilers from 25 to 28 days of age in the SM10 group was significantly lower than that in the SM0 and SM20 groups (P<0.05), and the nitrogen utilization rate was significantly higher than that in the SM20 and SM30 groups (P<0.05); for broilers aged 11 to 14 days, the apparent metabolic rates of gross energy (GE) and crude protein (CP) of soybean meal in the SM10 group were significantly higher than those in the SM20 and SM30 groups (P<0.05). Concurrently, for broilers aged 25 to 28 days, the apparent metabolic rates of GE and ether extract (EE) of soybean meal in the SM10 group were significantly higher than that in the SM30 group (P<0.05). During both the 11 to 14 days of age and 25 to 28 days of age, the apparent metabolizable energy (AME), net energy (NE) values, and energy conversion efficiency (AME/GE, NE/AME) of soybean meal in the SM10 group were significantly higher than those in the SM30 group (P<0.05). 2) Comparison of different indicator methods with the total excreta collection method, the apparent metabolic rates of GE, CP and EE, AME and NE values of soybean meal in SM10, SM20 and SM30 groups measured by AIA method were significantly higher than those of total excreta collection method and TiO₂ method (P<0.05); the results of the TiO₂ method did not differ significantly from those of total excreta collection method (P>0.05). In conclusion, when determining the effective energy values of soybean meal for broilers, using different replacement ratios will result in differences in the outcomes. Based on the assessment of nitrogen utilization rate and growth performance, a replacement ratio of 10% is recommended. Regarding the indicator application, the results obtained by the TiO₂ method do not differ significantly from those of the total excreta collection method, and TiO₂ can be used as an ideal indicator for determining the available energy values of soybean meal in broilers.

This experiment aimed to investigate the effects of adding different doses of zinc in the forms of zinc sulfate (ZS) and coated zinc sulfate (CZS) to the diet on the growth performance, zinc content in tissues and blood, alkaline phosphatase (AKP) activity in blood, and intestinal microbiota of broilers. The experiment used a 2×2 factorial design, with the two factors being zinc adding form (ZS or CZS) and zinc adding dose (36 or 54 mg/kg). A total of four dietary groups were formed: 36 mg/kg ZS group, 54 mg/kg ZS group, 36 mg/kg CZS group, and 54 mg/kg CZS group. Each group consisted of six replicates, with 20 one-day-old male Ross 308 broiler chicks assigned to each replicate. The trial lasted for 49 days, comprising a 7-day adaptation period (1 to 7 days of age) followed by a 42-day experimental period (8 to 49 days of age). The experimental period was further divided into two phases: 8 to 28 days of age and 29 to 49 days of age. All birds were slaughtered for sample collection at 49 days of age. The results showed as follows: 1) compared with ZS, dietary supplementation with CZS extremely significantly or significantly reduced the feed to gain ratio (F/G) of broilers aged 29 to 49 days (P<0.01) and 8 to 49 days (P<0.05); 2) dietary supplementation with CZS, as opposed to ZS, significantly increased both the blood zinc content and serum AKP activity of broilers (P<0.05); 3) dietary supplementation with 36 mg/kg zinc resulted in a significantly higher Simpson index of intestinal microbiota compared with the 54 mg/kg zinc (P<0.05). Under the conditions of this experiment, adding zinc in the form of CZS at a dose of 36 mg/kg can increase the feed conversion efficiency, enhance the blood zinc content and AKP activity, and improve intestinal microbial diversity of broilers.

This experiment was conducted to study the effects of dietary Astragalus polysaccharides (APS) on growth performance in broilers using a Meta-analysis. This study retrieved 25 eligible articles and 5 832 research subjects from domestic and international databases spanning January 2000 to February 2025, and the Meta-analysis was conducted using the online tool SPSSAU. The heterogeneity testing for growth performance indicators in included studies was performed based on the statistics (I²), while publication bias was assessed through Egger’s test. Due to significant heterogeneity across all analyzed indicators, a random effects model was applied for continuous data analysis. Subgroup analysis based on APS supplemental levels was to investigate the effect of different supplemental levels of APS on the growth performance of broilers at different stages. The results showed that during 1 to 21 days of age, the APS significantly increased the average daily gain (ADG) [standardized mean difference (SMD)=1.163, 95% confidence interval (CI): (0.355, 1.970)]; during 22 to 42 days of age, the APS significantly increased the ADG [SMD=1.148, 95%CI: (0.432, 1.864)], and significantly decreased the F/G[SMD=-0.498, 95%CI: (-0.955, -0.042)]; during 22 to 42 days of age, the APS significantly increased the ADG[SMD=1.148, 95%CI: (0.432, 1.864)]. The subgroup analysis results showed that the high supplemental level APS significantly increased the ADG during 1 to 21 days of age [SMD=1.322, 95%CI: (0.012, 2.633)]; the low supplemental level APS significantly increased the ADG during 22 to 42 days of age [SMD=1.052, 95%CI: (0.030, 2.074)], and significantly decreased the F/G [SMD=-0.553, 95%CI: (-0.995, -0.110)]; the high supplemental level [SMD=1.187, 95%CI: (0.536, 1.838)] and low supplemental level APS [SMD=0.669, 95%CI: (0.206, 1.131)] significantly increased the ADG during 1 to 42 days of age, and the high supplemental level APS significantly decreased the F/G [SMD=-0.725, 95%CI: (-1.299, -0.151)]. In conclusion, the high supplemental level APS has positive effect on ADG of broilers during 1 to 21 days of age, the low supplemental level APS has positive effect on ADG and F/G of broilers during 22 to 42 days of age.

This experiment was conducted to investigate the differences in ultrastructure between green-shelled and white-shelled eggs of Longyan Shanma ducks and analyze the correlation between eggshell ultrastructure and eggshell strength. A total of 200 green-shelled and 200 white-shelled eggs laid by 300-day-old Longyan Shanma ducks were selected to measure eggshell quality traits. Additionally, 12 eggshells from each group were observed for ultrastructural characteristics, and the mastoid gap and effective thickness were calculated. Results showed as follows: 1) the green-shelled eggs exhibited significantly higher egg weight and eggshell strength compared with the white-shelled eggs (P<0.05). 2) In terms of ultrastructure, the green-shelled eggshells displayed a smoother inner surface with densely and orderly distributed fibers, clear primary and secondary branches, and a three-dimensional fiber network structure. The outer surface was dense and flat, with fewer and shallower cracks, as well as fewer and smaller pores. The cross-section was generally flat, with compact fibers, smaller mastoid cones, tightly arranged mastoid units with minimal gaps, and a close connection between the mastoid layer and the shell membrane layer, resulting in an overall dense structure. Notably, the mastoid gap of green-shelled eggshells was significantly smaller than that of white-shelled eggshells (P<0.05), while the effective thickness was significantly larger (P<0.05). 3) For both green-shelled and white-shelled eggshells, the mastoid gap was significantly negatively correlated with eggshell strength (r=-0.781, r=-0.657, respectively; P<0.05), whereas the effective thickness was significantly positively correlated with eggshell strength (r=0.848, r=0.708, respectively; P<0.05). Additionally, the mastoid gap was significantly negatively correlated with the effective thickness (r=-0.593, r=-0.515, respectively; P<0.05). In conclusion, there are significant differences in the ultrastructure between the eggshells of green-shelled eggs and white-shelled eggs with similar thicknesses. The density of the eggshell ultrastructure plays an important role in eggshell strength, among which papillary gap and effective thickness are key factors affecting eggshell strength.

This study aimed to investigate the effects of dietary oil source and supplemental level on growth performance, slaughter performance, meat quality and fatty acid composition of meat ducks. The experiment adopted a 2×3 two factor completely randomized design, the dietary oil sources were duck oil and soybean oil, and the oil supplemental levels were 3%, 6% and 9%, respectively. Two hundred and forty 1-day-old Cherry Valley meat ducks were randomly divided into 6 groups with 5 replicates per group and 8 ducks per replicate. The experimental period lasted for 42 days. The results showed as follows: 1) for the oil source, compared with the soybean oil, the duck oil significantly decreased the feed to gain ratio (F/G) during 1 to 14 days of age (P<0.05). For the oil supplemental level, the average daily gain (ADG) and average daily feed intake (ADFI) during 1 to 42 days of age of 6% and 9% oil supplemental levels were significantly higher than those of 3% oil supplemental level (P<0.05). 2) For the oil source, compared with the soybean oil, the duck oil significantly increased the abdominal fat rate and breast muscle rate (P<0.05), and significantly decreased the leg muscle rate (P<0.05). For the oil supplemental level, the abdominal fat rate of 6% and 9% oil supplemental levels was significantly higher than that of 3% oil supplemental level (P<0.05), and the liver weight rate was significantly lower than that of 3% oil supplemental level (P<0.05). 3) For the oil source, compared with the soybean oil, the duck oil significantly decreased the lightness (L^*) value and shear force in breast muscle (P<0.05). For the oil supplemental level, the breast muscle intramuscular fat content was significantly increased with the oil supplemental level increased (P<0.05). 4) For the oil source, compared with the soybean oil, the duck oil significantly increased the contents of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) in breast muscle (P<0.05), and significantly decreased the contents of polyunsaturated fatty acids (PUFA), n-3 PUFA, and n-6 PUFA in breast muscle (P<0.05). For the oil supplemental level, the breast muscle SFA content of 6% oil supplemental level was significantly lower than that of 3% oil supplemental level (P<0.05), and the contents of PUFA and n-6 PUFA in breast muscle of 6% and 9% oil supplemental levels were significantly higher than those of 3% oil supplemental level (P<0.05). In conclusion, the dietary appropriate oil supplemental level for meat ducks is 6%. The oil source can change the meat quality and fatty acid composition, the duck oil promotes the enrichment of SFA and MUFA, improves intramuscular fat content and tenderness, while the soybean oil promotes the enrichment of PUFA.

This experiment was conducted to study the effects of Pennisetum giganteum silage on growth performance, nutrient apparent digestibility and serum biochemical indices of beef cattle. Forty-two Holstein bulls in good health, aged from 6 to 8 months and weighing (226.5±4.5) kg were selected and divided into 2 groups according to the completely randomized experimental design, with 3 replicates in each group and 7 cattle in each replicate. The control group was fed a basal diet, and the experimental group was fed the equal energy and equal nitrogen experimental diet which use the Pennisetum giganteum silage replacing whole corn silage in the basal diet. The pre-experimental period lasted for 10 days, and the experimental period lasted for 60 days. The results showed as follows: 1) compared with the control group, the average daily gain during 31 to 60 days of the experimental group was significantly decreased (P<0.05), and the average daily gain during 1 to 60 days was trend to significantly decreased (P=0.091); the dry matter intake during 31 to 60 days and 1 to 60 days of the experimental group was significantly increased (P<0.01); the feed to gain ratio during 1 to 30 days, 31 to 60 days and 1 to 60 days of the experimental group was significantly increased (P<0.01). 2) Compared with the control group, the apparent digestibility of neutral detergent fiber, acidic detergent fiber and calcium of the experimental group was significantly increased (P<0.01), the phosphorus apparent digestibility was significantly decreased (P<0.01), and the dry matter apparent digestibility was trend to significantly increased (P=0.052). 3) Compared with the control group, the serum urea nitrogen content of the experimental group was significantly increased (P<0.05). There were no significant differences in glucose, total protein, albumin, triglycerides, total cholesterol, immunoglobulin G, immunoglobulin A and immunoglobulin M contents and alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase activities in serum between 2 groups (P>0.10). In conclusion, the Pennisetum giganteum silage replacing whole corn silage has no significant effects on the body weight and weight gain rate of beef cattle, can improve the apparent digestibility of neutral detergent fiber, acidic detergent fiber, calcium and phosphorus, and has no significant effects on serum biochemical indices. It can be used as the main source of roughage for beef cattle.

This study aimed to comprehensively analyze the meat quality and metabolomics of fattening Angus cattle, in order to reveal the potential mechanism of Allium mongolicum Regel powder improving beef quality. Twelve healthy (14±2)-month-old Angus female cattle with body weight of (271.17±17.60) kg were selected and randomly divided into 2 groups with 3 replicates per group and 2 cattle per replicate. The control group (group C) was fed a basal diet, and the experimental group (group H) was fed the basal diet supplemented with 20 g/d Allium mongolicum Regel powder. The pre-experimental period lasted for 15 days, and the experimental period lasted for 120 days. The results showed as follows: 1) compared with group C, the longissimus dorsi shear force of group H was extremely significantly decreased (P<0.01), the malondialdehyde content was significantly decreased (P<0.05), and the total antioxidant activity was extremely significantly increased (P<0.01). 2) The metabolomic analysis identified 31 differential metabolites, 6 differential metabolic pathways related to meat quality regulation (cAMP signaling pathway, ABC transporters, biosynthesis of unsaturated fatty acids, AMPK signaling pathway, alanine, aspartate and glutamate metabolism, FoxO signaling pathway), among which 6 key differential metabolites (acetylcholine, deoxyuridine, γ-linolenic acid, fructose-6-phosphate, N-acetylaspartylglutamate and adenosine monophosphate) elative contents were extremely significant change (P<0.01). In conclusion, dietary 20 g/d Allium mongolicum Regel powder can improve the longissimus dorsi total antioxidant capacity of Angus cattle, while reduce the shear force and malondialdehyde content. The Allium mongolicum Regel powder regulates metabolic pathways such as cAMP signaling pathway, ABC transporters and biosynthesis of unsaturated fatty acids et al, affecting the expression of 6 key differential metabolites such as acetylcholine, deoxyuridine and γ-linolenic acid et al, revealing that the Allium mongolicum Regel powder can improve the meat quality of Angus cattle by regulating muscle metabolic pathways.

This experiment was conducted to investigate the effects of coated guanidinoacetic acid (GAA) on the growth performance, rumen microbiota and meat quality of Holstein steers. Thirty-two healthy 8-month-old Holstein steers with the body weight of (299.78±23.45) kg were randomly allocated to four group (eight steers per group) according to initial body weight and assigned to four diets: a basal diet without coated GAA (control group) and the basal diet supplemented with 0.04%, 0.08% or 0.12% coated GAA on the dry matter basis. After a 14-day adaptation period, the trial period lasted for 300 days. The results showed as follows: 1) compared with the control group, dietary supplementation with 0.04%, 0.08% and 0.12% coated GAA showed no significant effects on the growth performance indexes of Holstein steers (P>0.05). As the supplemental level of coated GAA increasing, the relative abundances of the Fibrobacterota and the Fibrobacter in the rumen microbiota significantly decreased (P<0.05). In contrast, the relative abundances of Synergistota, Actinobacteriota, Rikenellaceae_RC9_gut_group exhibited quadratic changes of first increasing and then decreasing with increasing coated GAA supplemental level (P<0.05). Compared with the control group, dietary supplementation with 0.04%, 0.08% and 0.12% coated GAA significantly reduced the relative abundance of Fibrobacterota (P<0.05), and significantly elevated the relative abundances of Synergistota and Ruminococcaceae_NK4A214_group (P<0.05). 3) Compared with the control group, dietary supplementation with 0.08% and 0.12% coated GAA significantly increased plasma glucose content (P<0.05) without significantly affecting other plasma biochemical indexes (P>0.05). 4) Dietary supplementation with varying levels of coated GAA had no significant effects on carcass weight, slaughter percentage, and viscera indexes (P>0.05). However, the spleen index exhibited a quadratic change of decreasing initially and then increasing with increasing dietary coated GAA supplemental level (P<0.05). 5) Meat redness (a^*) and yellowness (b^*) values increased linearly (P<0.05) and water loss rate decreased linearly (P<0.05) as coated GAA supplemental level increasing; specifically, dietary supplementation with 0.04% and 0.12% coated GAA significantly improved the a^* and b^* values, and dietary supplementation with 0.08% and 0.12% coated GAA significantly reduced the water loss rate compared with the control group (P<0.05). In conclusion, although coated GAA does not enhance the growth performance, it can modulate the rumen microbiota structure and improve the meat quality of Holstein steers. Under the conditions of this experiment, dietary supplementation with 0.08% coated GAA can yield the optimal results.

This experiment was conducted to investigate the effects of rumen-protected guanidinoacetic acid (RPGAA) on growth performance, nutrient apparent digestibilities and rumen microbiota of yaks. Thirty healthy 4-year-old yaks with similar body weight were randomly divided into 3 groups with 10 replicates in each group and 1 yak in each replicate. Yaks in the control group were fed a basal diet, while others in the low-dose group (group L) and high-dose group (group H) were fed the basal diet supplemented with 600 and 1 200 mg/kg RPGAA, respectively. The pre-experiment lasted for 15 days, and the experiment lasted for 120 days. The results showed as follows: 1) compared with the control group, the average daily gain (ADG) of group H was significantly increased (P<0.05), and the feed to gain ratio (F/G) of group L and group H was significantly decreased (P<0.05). 2) There were no significant differences in the apparent digestibilities of crude protein (CP), organic matter (OM), ether extract (EE), neutral detergent fiber (NDF) and acid detergent fiber (ADF) among the groups (P>0.05). 3) At the phylum level, compared with the control group, the rumen Bacteroidota relative abundance of group L was significantly increased (P<0.05), and the Actinobacteriot and Synergistota relative abundances were significantly decreased (P<0.05); the rumen Candidatus_Thermoplasmatota relative abundance of group L and group H was significantly decreased (P<0.05). 4) At the genus level, compared with the control group, the rumen Mogibacterium and Eubacterium relative abundances of group L were significantly decreased (P<0.05), and the Lentimicrobium and Candidatus_Sulfidibacterium relative abundances were significantly increased (P<0.05); the rumen Alistipes relative abundance of group H was significantly decreased (P<0.05). 5) In the functional analysis of carbohydrate-active enzymes (CAZy), compared with the control group, the carbohydrate-binding modules (CBM) family and glycoside hydrolases (GH) family relative abundances of group L were significantly decreased (P<0.05), and the glycosyl transferases (GT) family relative abundance was significantly increased (P<0.05); the carbohydrate esterases (CE) family relative abundance of group L and group H was significantly decreased (P<0.05). In conclusion, dietary supplemented with RPGAA can improve the ADG and reduced the F/G of yaks, and the RPGAA can enhances fiber degradation capacity and suppresses energy loss by modulating rumen microbial ecology.

This study aimed to investigate the effects of a composite microecological ammonia-assimilating bacterial agent on the milk production performance, serum biochemical indicators, and rumen microbial flora of lactating dairy cows. Seventy-two lactating dairy cows were selected and randomly divided into four groups (18 cows per group) based on parity (2nd parity), lactation days [(90.0±2.0) d], and milk yield [(47.3±0.9) kg/d]. The control group was fed a basal diet, while the experimental groups were supplemented with 100, 200, and 300 mL/d of composite microecological ammonia-assimilating bacterial agent (along with 20 g of microbial fermentation metabolite powder), respectively. The trial period lasted for three months. The results showed as follows: 1) compared with the control group, supplementing 100 mL/d of composite microecological ammonia-assimilating bacterial agent increased the average daily milk yield of dairy cows, and supplementing 300 mL/d of complex microecological ammonia-assimilating bacterial agent increased the milk protein percentage (P<0.05). 2) Compared with the control group, supplementing 200 and 300 mL/d of the composite microecological ammonia-assimilating bacterial agent significantly decreased the serum malondialdehyde (MDA) content (P<0.05) and enhanced the antioxidant capacity of dairy cows. 3) Compared with the control group, supplementing 100 and 300 mL/d of the composite microecological ammonia-assimilating bacterial agent significantly increased the rumen propionic acid content in dairy cows (P<0.05). Meanwhile, the composition of the rumen content microbial community at the phylum level was basically similar among all groups, mainly consisting of Firmicutes and Bacteroidetes. However, there were still uniqueness in the composition and proportion of different microbial groups among the groups. In terms of microbial functions, supplementing 100 and 200 mL/d of the composite microecological ammonia-assimilating bacterial agent significantly increased the mean abundance of the lysosome pathway (P<0.05), while supplementing 300 mL/d of the agent significantly enhanced multiple metabolic pathways such as penicillin and cephalosporin biosynthesis, and chlorocyclohexane and chlorobenzene degradation (P<0.05). This indicates that a high dose can regulate the functional activity of microorganisms more extensively. In conclusion, it can be concluded that the composite microecological ammonium assimilation agent significantly improves the milk production performance of lactating dairy cows, increasing daily milk yield and milk protein content. It also enhances the antioxidant capacity of dairy cows, improves rumen fermentation and microbial community structure, and maintains rumen internal environmental homeostasis.

This experiment aimed to investigate the effects of epigallocatechin gallate (EGCG) on growth performance, slaughter performance, antioxidant capacity and meat quality of Hu sheep. Fifty-four healthy 4-month-old Hu sheep with similar body weight [(23.50±3.65) kg] were randomly divided into 3 groups with 18 replicates per group and 1 sheep per replicate. The control group (group CON) was fed a basal diet, and the experimental groups were fed the basal diets supplemented with 300 (group L) and 1 000 mg/(sheep·d) (group H) EGCG, respectively. The pre-experimental period lasted for 10 days, and the experimental period lasted for 90 days. The results showed as follows: 1) there were no significant differences in growth performance and slaughter performance among all groups (P>0.05). 2) The longissimus dorsi cooking loss of group L was significantly lower than that of group CON and group H (P<0.01), and the longissimus dorsi meat color brightness and yellowing values of group H were significantly higher than those of group CON (P<0.05). 3) The activities of total superoxide dismutase and glutathione peroxidase in serum of group L were significantly higher than those of group CON (P<0.05), and the serum malondialdehyde content was significantly lower than that of group CON (P<0.05). The longissimus dorsi glutathione peroxidase activity of group L was significantly higher than that of group CON and group H (P<0.05), and the longissimus dorsi malondialdehyde content was significantly lower than that of group CON and group H (P<0.05). 4) The contents of pentadecenoic acid and γ-linolenic acid in longissimus dorsi of group H were significantly higher than those of group CON (P<0.05), and the contents of heptadecanoic acid and stearic acid in longissimus dorsi of group L were significantly lower than those of group CON (P<0.05). The contents of cysteine and methionine in longissimus dorsi of group H were significantly higher than those of group CON (P<0.05), and the longissimus dorsi alanine content of group H was significantly lower than that of group CON (P<0.05). In summary, dietary EGCG can improve the meat quality, antioxidant capacity and muscle fatty acid and amino acid composition of Hu sheep.

This experiment aimed to investigate the effects of coated Bacillus subtilis on the growth performance, serum biochemical indexes, rumen fermentation, and gas emissions of goats. Fifty castrated male Liuyang black goats in the late fattening stage, with similar body conditions, body weights [(18.21±2.02) kg], genetic backgrounds, and good health, were selected. These goats were randomly divided into five groups: the CON group (control group, basal diet), the C1 group (basal diet+0.5 g/kg of coated Bacillus subtilis), the C2 group (basal diet+1.0 g/kg of coated Bacillus subtilis), the NC1 group (basal diet+0.5 g/kg of uncoated Bacillus subtilis), and the NC2 group (basal diet+1.0 g/kg of uncoated Bacillus subtilis). Each group had five replicates, with two goats in each replicate. The pre-experimental period lasted for 15 days, and the formal experimental period lasted for 60 days. The results showed as follows: 1) compared with the CON group, the apparent digestibility of acid detergent fiber (ADF) was significantly increased in the C1 and C2 groups (P<0.05). 2) Compared with the CON group, the serum glucose (GLU) content and total antioxidant capacity (T-AOC) in the C1 and C2 groups were significantly increased (P<0.05), and the serum malondialdehyde (MDA) content in the C1, C2, NC1, and NC2 groups was significantly decreased (P<0.05). Compared with the uncoated treatment, the coated treatment significantly increased the serum creatinine (CRE) and MDA contents (P<0.05). 3) Compared with the CON group, the rumen microbial protein (MCP) and propionate contents in the C1 and C2 groups were significantly increased (P<0.05), while the acetate:propionate in the C1 and C2 groups was significantly decreased (P<0.05). At the same time, the ammonia nitrogen (NH₃-N) content in the C2 and NC2 groups was significantly increased (P<0.05). Compared with the untreated treatment, the treated treatment significantly increased the MCP and propionate contents in the rumen fluid (P<0.05), significantly decreased the isovalerate, valerate contents and acetate:propionate (P<0.05); the interaction analysis indicated that there was a significant interaction effect between the treatment and the dose in terms of pH, acetate and isovalerate contents (P<0.05). 4) Compared with the CON group, the ammonia (NH₃) emissions in the C1 and C2 groups were significantly reduced (P<0.05). Compared with the untreated treatment, the treated group significantly decreased the NH₃ emissions (P<0.05). In conclusion, adding coated Bacillus subtilis to the diet can effectively improve the rumen fermentation pattern of goats, enhance nutrient digestibility, and reduce NH₃ emissions, indicating a promising application prospect.

The aim of this experiment was to study the effects of Tribulus terrestris by-products on the growth performance, digestive metabolism, slaughter performance and meat quality of Tan sheep. Sixty-eight healthy three-month-old male Tan lambs with similar body weight [(24.68±0.90) kg] were selected and randomly divided into four groups, with 17 lambs in each group. They were raised in individual pens. Tribulus terrestris by-products were added 0, 5%, 10% and 15% to the diets of control group, trial group Ⅰ, trial group Ⅱ, and trial group Ⅲ, respectively. The experiment included a 10-day adaptation period followed by a 60-day formal trial period. The results were as follows: 1) the final weight of the trial group Ⅰ was extremely significantly higher than that of the other three groups (P<0.01). Furthermore, both weight gain profit and net profit of trial group Ⅰ were higher than those of the other three groups. 2) The apparent digestibility of dry matter, neutral detergent fiber and crude protein in the trial group Ⅲ was extremely significantly lower than in the other three groups (P<0.01). 3) Compared with the control group, the digestible nitrogen and retention nitrogen in the trial group Ⅰ were extremely significantly increased (P<0.01). Compared with both the control group and trial group Ⅰ, the fecal nitrogen and total nitrogen excretion in the trial group Ⅱ and trial group Ⅲ were extremely significantly increased (P<0.01), while their nitrogen digestibility and nitrogen utilization rate were extremely significantly decreased (P<0.01). 4) The live weight at slaughter in the trial group Ⅰ was extremely significantly higher than that in the control group (P<0.01). 5) The shear force of muscle in the trial group Ⅲ was significantly increased compared with the control group (P<0.05). Meanwhile, the redness (a^*) value of muscle in the trial group Ⅲ was significantly lower than that in both trial group Ⅰ and trial group Ⅱ (P<0.05). 6) No significant differences were observed among the groups for the muscle moisture, crude protein, crude ash, and ether extract contents in Tan sheep (P>0.05). Based on the comprehensive findings, the supplementation of 5% Tribulus terrestris by-products in the diet can enhance the digestible nitrogen, retention nitrogen, live weight at slaughter, and economic benefits of Tan sheep, and it does not have a negative effect on growth performance and meat quality of Tan sheep.

This study aimed to investigate the effects of dietary supplementation with steam-explosion and fermentation corn stalk on growth performance, apparent digestibility of nutrients, slaughter performance, serum biochemical parameters, and plasma metabolome in Xing’an Duo lambs. Forty-four healthy 3-month-old male Xing’an Duo lambs with similar initial body weight [(25.68±4.78) kg] were randomly assigned to 4 groups with 11 replicates per group, and one lamb per replicate. Group A (control) was fed diet with corn stalk as the roughage source. Group B was fed diet with steam-exploded and fermented corn stalk as the roughage source. Group C was fed diet with steam-exploded corn stalk as the roughage source. Group D was fed diet with yellow silage of corn stalk as the roughage source. The experiment lasted 85 days, including a 10-day adaptation period and a 75-day formal trial. The results showed as follows: 1) scanning electron microscopy observation revealed that, compared with the control group, the fibrous structures of corn stalks in groups B, C, and D were disrupted, with the smooth cell wall surfaces showing tearing and delamination. 2) For growth performance, compared with the control group, the average daily gain (ADG) of lambs in groups B, C, and D was significantly higher (P<0.05). 3) For apparent digestibility of nutrients, the apparent digestibility of crude protein (CP) was extremely significant difference among all groups (P<0.01), with group B was extremely significantly higher than the other three groups (P<0.01). Compared with the control group, the apparent digestibility of crude ash in groups C and D was significantly higher (P<0.05); and the apparent digestibility of neutral detergent fiber (NDF) in groups B and C was significantly higher (P<0.05), while no significant difference was observed in group D (P>0.05). 4) For slaughter performance, compared with the control group, the GR value in groups B, C and D was significantly higher (P<0.05). The dressing percentage in groups B and C was extremely significantly higher than that in group A (P<0.01), with no significant difference between groups B and C (P>0.05). The dressing percentage was not significantly different between groups D and A (P>0.05). 5) For serum biochemical indicators, serum glucose content in group B was significantly higher than that in groups A and D (P<0.05). The serum urea nitrogen and creatinine contents in groups B and C were extremely significantly lower than those in group A (P<0.01), with no significant difference between groups B and C (P>0.05) or between groups A and D (P>0.05). 6) Plasma metabolome analysis based on KEGG enrichment showed that differential metabolites between groups A and B were significantly enriched in vitamin digestion and absorption pathway; between groups B and C in the renin-angiotensin system pathway; and between groups B and D in riboflavin metabolism and glycolysis/gluconeogenesis pathways. In conclusion, steam-explosion and fermentation treatments can disrupt the fibrous structure of corn stalk; feeding with steam-exploded and fermented corn stalk can regulate plasma metabolite profiles and energy metabolism-related signaling pathways in Xing’an Duo lambs, thereby improving the apparent digestibility of crude protein and neutral detergent fiber, enhancing average daily gain and dressing percentage.

This experiment was conducted to investigate the effects of diets with different nutrient levels on performance, serum biochemical indexes, rumen microflora of lactating female goats and growth performance of lambs in Shaanbei white cashmere goats, aiming to determine the optimal dietary nutrient level for mother-offspring integrated feeding of this breed. A total of 32 lactating Shaanbei white cashmere goats with consistent genetic background, good body condition, similar body weight [(43.40±1.28) kg] and aged 2-3 years were selected and randomly divided into 4 groups with 8 replicates per group and 1 goat per replicate. The control group (CON group) was fed a basal diet, while the low nutrient level group (LEL group), medium nutrient level group (MEL group) and high nutrient level group (HEL group) were fed diets with energy and protein levels being 0.88, 1.12 and 1.24 times those of the basal diet, respectively. The experiment started on the day of parturition and lasted for 90 days. The results showed as follows: 1) the final body weight of female goats in the HEL group was significantly higher than that in the LEL group (P<0.05), and the body weight gain was significantly higher than that in the LEL group and CON group (P<0.05); the first postpartum estrus time of female goats in the MEL group and HEL group was significantly shorter than that in the LEL group and CON group (P<0.05); the weaning age of lambs in the MEL group was extremely significantly lower than that in the other 3 groups (P<0.01), and the average daily gain was extremely significantly higher than that in the other 3 groups (P<0.01). 2) On the 60th day postpartum, the serum glucose (GLU) content in the LEL group was significantly lower than that in the MEL group and HEL group (P<0.05), while the serum triglyceride (TG) content was significantly higher than that in the MEL group and HEL group (P<0.05). 3) On the 60th day postpartum, the milk protein rate in the MEL group and HEL group was significantly higher than that in the LEL group and CON group (P<0.05). 4) The rumen microbial ACE index in the LEL group was significantly lower than that in the MEL group (P<0.05). At phylum level, the relative abundance of Bacillota in rumen of the LEL group was significantly lower than that in the MEL group and HEL group (P<0.05), the relative abundance of Bacteroidota was significantly higher than that in the CON group and MEL group (P<0.05), and extremely significantly higher than that in the HEL group (P<0.01); the relative abundance of Spirochaetota in rumen of the HEL group was significantly lower than that in the LEL group and CON group (P<0.05). At genus level, the relative abundance of Selenomonas in rumen of the LEL group was significantly lower than that in the MEL group (P<0.05), the relative abundance of Bacteroides was extremely significantly higher than that in the MEL group and HEL group (P<0.01), and the relative abundance of Fibrobacter in rumen of the CON group was significantly higher than that in the MEL group and HEL group (P<0.05). At species level, the relative abundance of Methanobrevibacter_millerae in rumen of the HEL group was significantly higher than that in the LEL group and MEL group (P<0.05). 5) With the increase of dietary nutrient level, the enrichment degree of insulin resistance and central carbon metabolism in cancer pathways showed an upward trend; the relative abundance of glycoside hydrolase (GH) 13 showed an upward trend, while the relative abundances of GH6, GH92, GH53, GH51, carbohydrate-binding module (CBM) 32, CBM6, CBM72 and CBM35 showed a downward trend. In conclusion, the optimal dietary nutritent level for mother-offspring integrated feeding of Shaanbei white cashmere goats is the medium level, specifically with a metabolizable energy level of 8.96 MJ/kg and a crude protein level of 9.51%.

This study was conducted to investigate the effects of mulberry leaf polysaccharide (MLP) supplementation in high starch diet on growth performance, antioxidant capacity, glucose and lipid metabolism, and intestinal microbiota of largemouth bass (Micropterus salmoides). A total of 270 largemouth bass with an initial weight of (35.34±0.52) g were randomly divided into three groups as low starch group (CK group, 7.58% starch in diet), high starch group (HD group, 12.68% starch in diet), and high starch supplemented with MLP group (MLP group, 12.68% starch supplemented with 0.6% MLP in diet), with 3 replicates per group and 30 fish per replicate, and fed for 60 d. The results showed as follows: 1) compared to the HD group, the MLP group showed a significant increase in weight gain rate and condition factor (P<0.05), and a significant decrease in viscerosomatic index, hepatosomatic index, and feed coefficient (P<0.05). 2) Compared to the HD group, the MLP group exhibited a significant decrease in serum alanine aminotransferase and aspartate aminotransferase activities, liver malondialdehyde content, and the mRNA relative expression levels of liver interleukin-8, nuclear factor-κB, and tumor necrosis factor-α (P<0.05); a significant increase in liver total superoxide dismutase and glutathione peroxidase activities, and the mRNA relative expression levels of interleukin-10 and transforming growth factor-β (P<0.05). 3) Compared to the HD group, the MLP group showed a significant decrease in serum triglyceride (TG) and glucose contents, liver TG and glycogen contents, and the mRNA relative expression levels of liver diacylglycerol acyltransferase, fatty acid synthase, and acetyl-CoA carboxylase (P<0.05); a significant increase in the mRNA relative expression levels of liver phosphofructokinase, glucokinase, carnitine palmitoyltransferase 1, and peroxisome proliferator-activated receptor α (P<0.05). 4) Compared to the HD group, the MLP group exhibited a significant increase in intestinal muscle layer thickness and propionic acid content (P<0.05), and an upward trend in the Shannon index, Simpson index, and the relative abundances of Bacteriodota, Firmicutes, and Lactobacillus in the intestinal microbiota (P>0.05). In summary, the high starch diet supplemented with MLP can enhance the growth performance, antioxidant capacity, intestinal microbiota diversity, and beneficial bacterial relative abundance of Micropterus salmoides. It also alleviates the liver inflammation and promotes the glucose and lipid metabolism by accelerating carbohydrate and fatty acid oxidation and inhibiting insulin resistance.

This experiment aimed to investigate the effects of fava bean addition levels in diets on the growth performance, muscle texture characteristics, and nutritional components of Salmo trutta fario. Four experimental diets were formulated, containing 0, 12.5%, 25.0%, and 37.5% fava beans (named D1, D2, D3, and D4, respectively). A total of 960 Salmo trutta fario with an initial body weight of (206.08±1.62) g were randomly divided into 4 groups, each fed one of the four experimental diets with 3 replicates per group and 80 fish per replicate, and the trial lasted for 90 days. The results showed that compared with the D1 group, the condition factor of the D3 group was significantly increased (P<0.05), and the muscle hardness, elasticity, chewiness, and shear force were also significantly improved (P<0.05); meanwhile, the contents of essential amino acids, non-essential amino acids, umami amino acids, and total amino acids in muscles decreased without significant difference (P>0.05), while the eicosapentaenoic acid content in muscles was significantly increased (P<0.05). In the D4 group, indicators like muscle hardness, elasticity, chewiness, and shear force slightly increased but with no significant differences (P>0.05). In conclusion, adding 25.0% fava beans to the diet significantly improve muscle texture and nutritional components of Salmo trutta fario while maintaining its growth performance, with minimal effects on amino acid and fatty acid contents.

This experiment aimed to investigate the effects of dietary supplementation of fermented black soldier fly (Hermetia illucens L.) on hepatic histoarchitecture, antioxidant indexes, and intestinal non-specific immune enzyme activities, antioxidant indexes, tight junction protein gene expression, and microbiota composition of channel catfish (Ictalurus punctatus). Based on a conventional diet formulation, four isonitrogenous and isolipidic experimental diets were prepared by adding 0 (G0), 2% (G2), 4% (G4), and 8% (G8) of fresh fermented black soldier fly larvae, respectively. A total of 480 channel catfish with an initial body weight of (2.75±0.01) g were selected and randomly divided into 4 groups (with 3 replicates per group and 40 fish per replicate). These groups were fed the corresponding four experimental diets for a 56-day feeding trial. The results showed as follows: 1) histological examination showed no pathological liver damage, with hepatocytes exhibiting regular arrangement, distinct nucleocytoplasmic boundaries, and no vacuolization or inflammatory infiltration was observed. 2) Compared with the control group (G0 group), hepatic total antioxidant capacity (T-AOC) and catalase (CAT) activity in the G2 and G4 groups were significantly increased (P<0.05), hepatic total superoxide dismutase (T-SOD) activity in the G4 group was significantly elevated (P<0.05), while hepatic protein carbonyl (PrC) content in the G2, G4 and G8 groups was significantly decreased (P<0.05). 3) Intestinal alkaline phosphatase (AKP) activity in the G2 group and acid phosphatase (ACP) activity in the G4 group were significantly higher than those in the control group (P<0.05); compared with the control group, intestinal CAT activity was significantly increased in the G2 group (P<0.05), while intestinal malondialdehyde (MDA) content was significantly reduced in the G2, G4, and G8 groups (P<0.05). 4) The relative expression levels of zonula occludens-1 (ZO-1) and claudin-2 (Claudin-2) genes in the G2 group were significantly upregulated compared with the control group (P<0.05). 5) The α and β diversity of intestinal microbiota in channel catfish among all groups showed no significant changes (P>0.05). In intestinal microbiota, G2 group showed increased Firmicutes relative abundance and G8 group displayed decreased Proteobacteria with elevated Fusobacteria (mainly Cetobacterium) relative abundance. In conclusion, dietary supplementation with 2% to 4% fresh fermented black soldier fly can improve hepatic antioxidant capacity, enhance intestinal mechanical barrier and immune barrier functions, and improve the intestinal microbiota structure of channel catfish.

This experiment was conducted to investigate the effects of the fat soluble extract of Angelica sinensis (FSE) on the growth performance, body composition, nutrient metabolism, and antioxidant capacity of Jian carp (Cyprinus carpio var. Jian), aiming to provide a basis for developing FSE as a lipid-lowering feed additive for fish. A total of 420 juvenile Jian carp with an average body weight of (12.89±0.05) g were randomly divided into 7 groups, with 3 replicates in each group and 20 carp in each replicate. The blank group was fed a basal diet, while the other 6 groups were fed experimental diets supplemented with FSE at 0.2%, 0.4%, 0.8%, 1.2%, 1.6%, and 2.0%, respectively. The feeding trial lasted for 15 days. The results showed that compared with the blank group, when dietary FSE supplementation level was 0.2% to 2.0%, weight gain, specific growth rate, feed efficiency, lipid productive value, malondialdehyde (MDA) content in the hepatopancreas, plasma glutamate-pyruvate transaminase (GPT) activity and high-density lipoprotein cholesterol content significantly decreased (P<0.05); the body protein content, anti-superoxide anion (ASA) activity in the hepatopancreas, creatine kinase activity in muscle, glutamate-oxaloacetate transaminase (GOT) and superoxide dismutase (SOD) activities in the gills, as well as Na⁺/K⁺-ATPase (NKA) and lactate dehydrogenase (LDH) activities in erythrocytes were significantly increased (P<0.05). Meanwhile, dietary FSE at the supplementation levels of 0.8% to 1.6%, 0.4% to 2.0%, 0.4% to 2.0%, 1.6%, 0.8% to 2.0%, 0.8% to 2.0%, and 1.2% to 2.0% significantly reduced the condition factor (CF), body lipid content, ammonia excretion rate (AER), plasma GOT activity, total amino acid content, hydrogen peroxide (H₂O₂) content in muscle, and MDA content in the gills (P<0.05), respectively. Furthermore, dietary FSE at supplementation levels of 0.8% to 2.0%, 0.4% to 2.0%, 0.4% to 2.0%, 0.2% to 0.8%, 0.8% to 2.0%, 1.6%, 0.4% to 0.8%, 1.6% to 2.0%, 0.8% to 2.0%, 0.2% to 1.2%, 0.4% to 0.8%, 0.4% to 2.0%, 0.8% to 2.0%, 1.6% to 2.0%, 0.4% to 1.2%, and 1.6% to 2.0% significantly increased protein productive value (PPV), oxygen consumption rate (OCR), O∶N ratio, plasma low-density lipoprotein cholesterol content, GOT, LDH and SOD activities in the hepatopancreas, GPT, LDH, and catalase activities in muscle, NKA and anti-hydroxyl radical (AHR) activities in the gills, as well as GOT, GPT and glutathione peroxidase (GPx) activities and glutathione (GSH) content in erythrocytes (P<0.05), respectively. These findings indicate that under the experimental conditions, dietary FSE can reduce the body lipid content and increase body protein content by enhancing the catabolism of lipids and carbohydrates, ATP consumption, and protein synthesis. Concurrently, it improves the Jian carp’s antioxidant capacity by increasing the activities of enzymatic antioxidants and the contents of non-enzymatic antioxidants, thereby inhibiting the generation of reactive oxygen species and lipid oxidation in tissues and organs. Broken-line regression analysis based on CF and PPV indicated that the appropriate dietary FSE supplementation levels are 1.16% and 1.24%, respectively. In conclusion, FSE can reduce body fat deposition and enhance protein deposition in Jian carp by improving nutrient metabolism and antioxidant capacity. Keywords: fat soluble extract of Angelica sinensis; Jian carp; growth performance; body composition; metabolism; antioxidant

This experiment was conducted to investigate the regulatory effects of glycyrrhiza extract on intestinal microbiota disorders in rabbits induced by long-term zearalenone (ZEN) intake. One hundred and twenty 35-day-old Ira meat rabbits were randomly divided into 4 groups with 30 rabbits per group (half male and half female). The control group (group C) was fed a basal diet, the zearalenone group (group Z) was fed a basal diet+5.0 mg/kg ZEN, the glycyrrhiza extract group (group G) was fed a basal diet+0.4 g/kg glycyrrhiza extract, and glycyrrhiza extract+zearalenone group (group GZ) was fed a basal diet+5.0 mg/kg ZEN+0.4 g/kg glycyrrhiza extract. The pre-experimental period lasted for 3 days, and the experimental period lasted for 42 days. The results showed that the total operational taxonomic units (OTU) number of group Z decreased from day 14 to day 28, increased on day 42, and the proportion of unique OTU increased to 55.1%; the Firmicutes relative abundance on day 14 was lower, while the Bacteroidetes and Proteobacteria relative abundances were higher; the Ruminococcus relative abundance on day 42 reduced to 5.0%. The total OTU number of group G reached peak on day 28, the Verrucomicrobia and Akkermansia relative abundances reached peak on day 42, and the Ruminococcus relative abundance reached peak on day 28. The total OTU number of group GZ increased on day 42; the Firmicutes relative abundance reached peak on day 42, while others were lower; the Bacteroides relative abundance reached peak on day 14. In conclusion, ZEN inhibits the proliferation of Firmicutes and fiber degrading bacteria, promotes the proliferation of pathogenic bacteria, and long-term intake can lead to the formation of tolerant communities and functional disorders; adding glycyrrhiza extract in diet can effectively increase the relative abundance of anti-inflammatory bacteria (Bacteroidetes) and fiber-degrading bacteria (Ruminococcus) in the short term, alleviating the inhibitory effect of ZEN, but long-term intake carries the risk of microbial community simplification.

This experiment was conducted to investigate the effects of diet supplemented with glycerol monolaurate (GML) on growth performance, apparent nutrient digestibility, serum biochemical indices and immune function of growing male minks. A total of 96 red-eyed white male minks aged approximately 80 days were randomly divided into 6 groups, with 8 replicates per group and 2 minks per replicate. The control group was fed a basal diet, while the experimental groups were fed the basal diets supplemented with 300, 600, 900, 1 200 and 1 500 mg/kg GML, respectively. The experimental period lasted for 8 weeks, which was divided into period Ⅰ (weeks 1 to 4) and period Ⅱ (weeks 5 to 8). The results showed as follows: 1) compared with the control group, the 1 200 mg/kg GML group had significantly higher final body weight (FBW) and average daily gain (ADG) in period Ⅰ, FBW in period Ⅱ as well as ADG during the whole experimental period and fresh pelt length (P<0.05), the 900 mg/kg GML group had significantly higher ADG during the whole experimental period (P<0.05). 2) Compared with the control group, the 900 and 1 200 mg/kg GML groups had significantly higher apparent digestibility of dry matter and crude protein in period Ⅰ and apparent digestibility of ether extract and crude protein in period Ⅱ (P<0.05), the 600 mg/kg GML group had significantly higher apparent digestibility of crude protein in period Ⅰ (P<0.05). 3) Compared with the control group, the 1 200 mg/kg GML group had significantly higher serum albumin (ALB) content, globulin (GLB) content and alkaline phosphatase (ALP) activity (P<0.05), the 900 mg/kg GML group had significantly higher serum GLB content and ALP activity (P<0.05). 4) Compared with the control group, the 1 200 mg/kg GML group had significantly higher serum immunoglobulin G (IgG) content and immunoglobulin M (IgM) content (P<0.05), the 900 mg/kg GML group had significantly higher serum IgM content (P<0.05). In conclusion, diet supplemented with appropriate amount of GML can improve the growth performance, apparent nutrient digestibility and immune function of growing male minks. Considering comprehensively, it is recommended that the dietary GML supplemental level for growing male minks is 900 mg/kg.

This study was conducted to investigate the effects of adding Lactobacillus reuteri postbiotics (LRP) to the basal diet on the growth performance, nutrient apparent digestibility, and serum immune, antioxidant and biochemical indexes of growing female minks. Eighty-eight healthy 12-week-old red-eyed white female minks with similar body weight were randomly divided into four groups, with 11 replicates per group and two minks per replicate. The LRP addition levels in diets were 0 (control group), 0.05% (0.05%LRP group), 0.10% (0.10%LRP group), and 0.15% (0.15%LRP group), respectively. The pre-experimental period lasted for 1 week, and the formal experimental period lasted for 8 weeks. The digestion trial was conducted in the 7th week of the formal experiment. The results showed as follows: 1) compared with the control group, the body weight at the end of weeks 4 and 8, as well as the average daily gain (ADG) during weeks 1 to 4, 5 to 8, and 1 to 8, in both the 0.10%LRP group and 0.15%LRP group were significantly increased (P<0.05); furthermore, the feed-to-gain ratio (F/G) during weeks 1 to 4 and 1 to 8 in the 0.10%LRP group, and during weeks 1 to 4 in the 0.15%LRP group was significantly decreased (P<0.05). 2) Compared with the control group, the 0.10%LRP group and 0.15%LRP group showed a significant increase in the apparent digestibility of dry matter and crude protein (P<0.05). 3) Compared with the control group, 0.10%LRP group exhibited a significant increase in serum immunoglobulin A (IgA) and immunoglobulin M (IgM) contents (P<0.05), while the 0.15%LRP group showed significantly higher serum IgA and complement 4 (C4) contents (P<0.05). 4) Compared with the control group, the content of serum malondialdehyde in the 0.05%LRP group and 0.10%LRP group was significantly decreased (P<0.05), and the serum total antioxidant capacity in the 0.10%LRP group was significantly increased (P<0.05). 5) Compared with the control group, the 0.10%LRP group exhibited a significant elevation in serum albumin, globulin and total protein contents (P<0.05), while the 0.15%LRP group showed a significant increase in serum globulin and total protein contents (P<0.05). In summary, Lactobacillus reuteri postbiotics has probiotic effects, it can enhance the dietary nutrient digestion, improve the immune and antioxidant capacities of growing female minks, thereby enhancing their growth performance. The opium addition level of Lactobacillus reuteri postbiotics is 0.10%.

The aim of this experiment was to investigate the resveratrol-mediated nuclear factor E2-related factor 2 (Nrf2) signaling pathway to alleviate heat stress-induced oxidative damage in skeletal muscle cells. Thoracic muscles of 11-day-old broiler chicken embryos were selected for isolation and culture of primary skeletal muscle cells. Skeletal muscle cells were treated with different temperatures (37.0, 39.5, 42.0, 44.5, and 47.0 ℃) and different concentrations of resveratrol (0, 12.5, 25.0, 50.0, and 100.0 μmol/L) to screen the temperatures of heat stress and treatment concentrations of resveratrol. Skeletal muscle cells were randomly assigned to the following treatments: control (cultured at 39.5 ℃ for 24 h), resveratrol treatment (treated with 25.0 μmol/L resveratrol at 39.5 ℃ for 24 h), heat stress treatment (cultured at 39.5 ℃ for 23 h, followed by transfer to 44.5 ℃ for 1 h heat stress) and resveratrol+heat stress treatment (cells cultured at 39.5 ℃ with 25.0 μmol/L resveratrol for 23 h, followed by continued heat stress at 44.5 ℃ for 1 h). Subsequently, skeletal muscle cells were treated with the Nrf2 activator t-BHQ (50.0 μmol/L) or the inhibitor ML385 (5.0 μmol/L) for 24 h (39.5 ℃), or pretreated for 23 h (39.5 ℃) followed by combined treatment with heat stress (44.5 ℃) for 1 h, and cell samples were collected to detect intracellular antioxidant enzyme activities, malondialdehyde (MDA), protein carbonyls (PC), and reactive oxygen species (ROS) contents, as well as the expression of genes and proteins related to the Nrf2 signaling pathway. The results showed as follows: 1) compared with 37.0 ℃, 39.5 ℃ significantly increased the viability of skeletal muscle cells (P<0.05); compared with 39.5 ℃, 44.5 ℃ heat stress treatment significantly decreased the viability, glutathione (GSH) content, total superoxide dismutase (T-SOD) activity, and total antioxidant capacity (T-AOC) of skeletal muscle cells (P<0.05), and significantly increased the MDA, ROS and PC contents (P<0.05). 2) Compared with 0 μmol/L resveratrol, 25.0 μmol/L resveratrol significantly decreased the content of MDA, ROS and PC in skeletal muscle cells (P<0.05), and significantly increased the content of GSH, the activities of T-SOD and catalase (CAT), as well as the Nrf2, heme oxygenase-1 (HO-1), quinone oxidoreductase 1 (NQO1) and superoxide dismutase 2 (SOD2) mRNA relative expression levels (P<0.05). 3) Compared with the control treatment, heat stress significantly increased the contents of MDA, ROS, and PC in skeletal muscle cells (P<0.05), and significantly decreased cell viability as well as T-AOC, T-SOD, and CAT activities as well as the expression levels of Nrf2 nucleoprotein (nucl-Nrf2), Nrf2, HO-1, and NQO1 protein (P<0.05); compared with heat stress treatment, the addition of 25.0 μmol/L resveratrol significantly decreased the contents of MDA, ROS and PC in skeletal muscle cells (P<0.05), and significantly increased T-AOC and CAT activity, as well as the expression levels of nucl-Nrf2, Nrf2, HO-1, and NQO1 protein (P<0.05). 4) Compared with heat stress treatment, the combination of heat stress and t-BHQ treatment significantly decreased the contents of MDA, ROS and PC in skeletal muscle cells (P<0.05), and significantly increased T-AOC and the activities of T-SOD and CAT, as well as the expression levels of nucl-Nrf2, Nrf2, HO-1 and NQO1 protein (P<0.05). 5) Compared with heat stress treatment, the combined treatment of ML385, resveratrol and heat stress significantly increased the contents of MDA, ROS and PC in skeletal muscle cells (P<0.05), and significantly decreased T-AOC and the activities of T-SOD and CAT as well as the expression levels of nucl-Nrf2, Nrf2, HO-1 and NQO1 protein (P<0.05). In summary, resveratrol can alleviate heat stress-induced oxidative damage in skeletal muscle cells, and its mechanism of action is related to the activation of the Nrf2 signaling pathway.

This experiment was conducted to investigate the effects of Pueraria lobata polysaccharides (PLP) on immune function and spleen gene expression of broilers. A total of 336 one-day-old Arbor Acres (AA) broilers with an initial body weight of (42.31±0.94) g were randomly divided into 4 groups, with 6 replicates per group and 14 broilers per replicate. The control group (NC-A group) was fed a basal diet, while the experimental groups were fed basal diets supplemented with 100 (PLP-L group), 200 (PLP-M group) and 400 mg/kg (PLP-H group) PLP, respectively. The experiment lasted for 35 days. The immune organ indices and tissue morphology, peripheral blood lymphocyte proliferation activity, serum immunoglobulin and cytokine contents of broilers were determined at 7, 14, 21, 28 and 35 days of age. Additionally, spleen tissues of broilers at 28 days of age were collected for transcriptome sequencing and comparative analysis. The results showed as follows: 1) compared with the NC-A group, the thymus index of the PLP-L group was significantly increased at 28 and 35 days of age (P<0.05); the PLP-M group showed significant increases in the thymus index from 21 to 35 days of age (P<0.05), the bursa of Fabricius index at 21 and 28 days of age (P<0.05) and the spleen index at 28 days of age (P<0.05); the PLP-H group showed significant increases in the thymus index from 21 to 35 days of age (P<0.05) and the spleen index at 7 and 28 days of age (P<0.05). 2) Compared with the NC-A group, the peripheral blood T cell stimulation index (SI) was significantly increased in the PLP-M and PLP-H groups at 7, 28 and 35 days of age (P<0.05), and the peripheral blood B cell SI was significantly increased from 7 to 35 days of age (P<0.05). 3) Compared with the NC-A group, the serum immunoglobulin G (IgG) content was significantly increased in the PLP-M and PLP-H groups at 21 and 28 days of age (P<0.05). 4) Compared with the NC-A group, the serum interleukin-2 (IL-2) content was significantly increased in the PLP-M group from 14 to 28 days of age (P<0.05), and the serum interleukin-4 (IL-4) and interferon-γ (IFN-γ) contents were significantly higher from 14 to 35 days of age (P<0.05). 5) Transcriptome analysis of the spleen at 28 days of age revealed 672 differentially expressed genes (DEGs) in the PLP-M group compared with the NC-A group, including 388 up-regulated and 284 down-regulated genes. GO functional enrichment analysis indicated that these DEGs were mainly involved in immune cell recognition, signal transduction, activation, and effector processes. KEGG pathway analysis further showed that DEGs were significantly enriched in cytokine-cytokine receptor interaction, interleukin-17 signaling pathway, Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway, intestinal immunoglobulin A (IgA)-related immune network, and Toll-like receptor signaling pathway (P<0.05). In conclusion, dietary supplementation with 200 and 400 mg/kg PLP can promote the maturation of immune organs and immune cells, enhance immunoglobulin secretion, and improve immune function of broilers, with 200 mg/kg being the optimal dose. The mechanism involves PLP enhancing splenic immune response in broilers by regulating a hierarchical network consisting of Toll-like receptors, nuclear factor-κB, cytokine network and JAK-STAT signaling pathway.

This study aimed to establish an in vitro heat stress model of bovine mammary epithelial cells (BMECs) by simulating a high-temperature environment, and to investigate the changes in various indicators in BMECs under defined conditions of heat stress. The experiment included one control group (CON group) and three heat stress groups. BMECs in the CON group were maintained at 37 ℃, while those in the three heat stress groups were exposed to 41 (HS1 group), 42 (HS2 group), and 43 ℃ (HS3 group), respectively. At 1, 3, 6 and 12 h post-treatment, cell viability, reactive oxygen species (ROS) level, and cell morphology were examined to screen for the optimal treatment temperature and time. Based on the screened optimal temperature and time conditions, further measurements of intracellular indicators were performed. The results showed that compared with the CON group, the cell viability of the HS1 group was significantly increased at 1 h of treatment (P<0.05), but there was no significant difference between the two groups as time increased (P>0.05); there was no significant difference in cell viability between HS2 group and CON at all treatment time (P>0.05); with the increase of treatment time, the cell viability of HS3 group showed a downward trend, and it dropped below the critical value of 80% at 6 h of treatment (P<0.05). The intracellular ROS level in both the HS2 group and HS3 group was significantly higher than those in the CON group after more than 3 h of treatment (P<0.05), with the greatest difference observed between the HS3 group and CON group. Examination of cell morphology revealed that in the HS3 group, treated for 3 to 6 h, the cell density decreased obviously, the number of cells gradually reduced, and intercellular spaces increased. Based on the above results, 43 ℃ treatment for 6 h was selected as the BMECs in vitro heat stress modeling condition. Compared with CON, heat stress treatment (43 ℃ treatment for 6 h) significantly decreased the activities of antioxidant enzymes such as total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) and copper and zinc superoxide dismutase (CuZn-SOD) (P<0.05), and significantly increased the content of malondialdehyde (MDA) in cells (P<0.05); furthermore, it significantly increased the contents of heat shock protein (HSP) 70 and HSP90 (P<0.05), and also significantly upregulated the mRNA relative expression levels of heat stress-related genes HSPA6, HSPA1A, HSPAA1 and HSPA8 in cells (P<0.05). This study systematically evaluates the response of BMECs to temperature and time changes, and successfully establishes an in vitro heat stress model of BMECs by treating them at 43 ℃ for 6 h. This modeling condition effectively induces typical oxidative stress phenotypes of BMECs, including inhibition of antioxidant enzyme activities, accumulation of lipid peroxidation products, and dynamic imbalance of ROS.

This study aimed to establish a method for the isolation, culture and identification of donkey mammary epithelial cells (DMECs), providing a cellular model for donkey mammary gland-related research. Primary cells were isolated from donkey mammary tissue using collagenase Ⅳ, purified by differential digestion method, and identified through morphological observation, specific gene detection, and immunofluorescence labeling. The results showed that DMECs isolated and cultured using enzymatic digestion method exhibited a polygonal or ovoid morphology and were arranged in a pavement stone pattern. The purified DMECs had a typical “S”-shaped growth cycle. Agarose gel electrophoresis demonstrated that the cultured DMECs could express the specific gene cytokeratin 18 (CK18). The immunofluorescence results showed a positive expression of CK18 in the DMECs. This study successfully established an isolation, culture and identification system for DMECs, which can provide crucial cellular materials for in-depth research on the physiological functions and lactation mechanisms of the donkey mammary gland.

This experiment was conducted to study the effects of different iron sources on blood physiological indexes, iron apparent digestibility and iron absorption rates of mice, to compare the iron absorption rates of different iron sources in intestine of mice. Thirty-two healthy four-week-old male ICR mice were randomly divided into 4 groups with 4 replicates per group and 2 mice per replicate. The control group (CON group) was fed a low-iron diet (iron content was 16 mg/kg), and the experimental groups were fed low-iron diets supplemented with 100 mg/kg (all calculated based on iron content) ferrous sulfate monohydrate (FeSO₄ group), cassava polysaccharide iron (Dt Fe group) and iron dextran (Dex Fe group), respectively. The experimental period lasted for 14 days. The results showed as follows: 1) compared with the CON group, the red blood cell (RBC) number and hemoglobin (HGB) content in blood of Dt Fe group and Dex Fe group were significantly increased (P<0.05). 2) Compared with the CON group, the fecal iron content of FeSO₄ group, Dt Fe group and Dex Fe group was significantly increased (P<0.05), and the serum iron content of Dt Fe group and Dex Fe group was significantly increased (P<0.05). Compared with the FeSO₄ group, the fecal iron content of Dt Fe group and Dex Fe group was significantly decreased (P<0.05), and the iron apparent digestibility was significantly increased (P<0.05). 3) Compared with the FeSO₄ group, the iron absorption rate in duodenum of Dt Fe group and Dex Fe group was significantly increased (P<0.05). 4) The correlation analysis results showed that there was a significant positive correlation between iron absorption rate in duodenum and iron absorption rate in jejunum of FeSO₄ group [correlation coefficient (r)=0.964, P<0.05], and there was a significant negative correlation between iron absorption rate in duodenum and iron absorption rate in jejunum of Dt Fe group (r=-0.988, P<0.05). In summary, dietary cassava polysaccharide iron and iron dextran can increase the RBC number and HGB content in blood, iron apparent digestibility, intestinal iron absorption rates of mice, and maintain the intestinal integrity.

This study aimed to establish prediction models for conventional nutritional components in natural mixed forage from Altay region of Xinjiang, China, by using near-infrared spectroscopy (NIRS). A total of 120 natural mixed forage samples were collected from natural pasturelands in Xinjiang’s Altay Region. Through randomized allocation, a total of 100 samples were randomly selected as the calibration set, with the remaining 20 samples serving as the validation set. The prediction models for dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE), crude protein (CP), crude ash (Ash), calcium (Ca), and phosphorus (P) were developed and cross-validated using the measured values and NIRS data from the calibration set. The effectiveness of these established prediction models was then evaluated using the validation set. The results showed that, among the established NIRS prediction models, the prediction coefficient of determination (RSQ_P) for DM and CP contents in natural mixed forage were 0.91 and 0.92, respectively, the external validation relative analysis errors (RPD) were 3.30 and 3.23, respectively, both exceeding the threshold of 3.0. These results indicated a successful calibration performance and demonstrated that the models were suitable for precise predictions. For NDF and ADF contents in natural mixed forage, the RSQ_P were 0.83 and 0.85, respectively, and the RPD were 2.40 and 2.58, respectively. The calibration performance is considered good, supporting the model’s applicability for accurate predictions. In contrast, the RSQ_P for EE, Ash, Ca, and P contents in natural mixed forage ranged from 0.08 to 0.38, and the RPD ranged from 0.95 to 1.21, all of which were below 2.5. The calibration performance for these nutritional components was unsatisfactory and thus not suitable for practical application. In conclusion, the NIRS prediction models for the DM, NDF, ADF and CP contents in the natural mixed forage are preliminarily established in this experiment, which can be applied to practical production.

This study aimed to investigate the effects of dietary Caragana korshinskii Kom. on rumen fermentation characteristics and microbial community structure in vitro. The proportion of whole plant corn silage and Caragana korshinskii Kom. in roughage were 100∶0 (CK0 group), 75∶25 (CK25 group), 50∶50 (CK50 group), 25∶75 (CK75 group) and 0∶100 (CK100 group), respectively, then make a total mixed ratio with the concentrate to roughage of 40∶60, each group had 3 repelicates, donducted the in vitro simulated rumen fermentation experiments. The results showed that the Caragana korshinskii Kom. supplemental proportion significantly affected the gas production (GP), in vitro dry matter degradation rate (IVDMD) and contents of ammonia nitrogen (NH₃-N), butyric acid (BA), valeric acid (VA) (P<0.05). The principal coordinate analysis (PCoA) revealed there were significant differences in microbial community structure among all groups (P=0.004), the Caragana korshinskii Kom. supplemental proportion significantly affected the relative abundances of probable_genus_10 and Saccharofermentans (P<0.05), and the relative abundance of Bacteroidetes and Rikenellaceae_RC9_gut_group of CK25 group were the highest. The linear discriminant analysis effect size (LefSe) analysis identified 21 differential microbial communities (P<0.05), and the Spearman correlation analysis revealed an extremely significant positive correlation between GP and Saccharofermentans (r=0.77, P<0.01). In conclusion, dietary Caragana korshinskii Kom. can affect the rumen fermentation performance, and increase the richness and stability of rumen microorganisms. The recommended Caragana korshinskii Kom. supplemental proportion is 25% when the ratio of concentrate to roughage in the diet is 40∶60.

This experiment aimed to investigate the effects of co-pretreatment with urea and corn steep liquor on in vitro degradability, cellulase activities and rumen microbial attachment of corn stover. A total of 20 kg corn stover was cut into 1 to 2 cm segments, and then randomly divided into 4 groups: control group (CON group: no additives), 3% urea group (UC group: supplemented with urea at 3% of corn stover dry matter), 5% corn steep liquor group (CCL group: supplemented with corn steep liquor at 5% of corn stover dry matter), and 3% urea+5% corn steep liquor group (UCC group: supplemented with both urea at 3% and corn steep liquor at 5% of corn stover dry matter). Each group had 5 replicates, with 1 kg of corn stover per replicate. Each replicate of corn stover was vacuum-sealed in a respiration-fermentation bag and fermented at room temperature. After 56 days, the samples were collected as fermentation substrates for a 72 h in vitro fermentation experiment to determine the in vitro degradability, analyze the cellulase activities in the fermentation broth, and assess the microbial diversity attached to the residue. The results showed as follows: 1) at both 24 and 72 h of in vitro fermentation, the UCC group showed significantly higher in vitro dry matter degradability (IVDMD), in vitro neutral detergent fiber degradability (IVNDFD), and in vitro acid detergent fiber degradability (IVADFD) compared with the CON group (P<0.05). 2) Compared with the CON group, the filter paper enzyme (FPA) activity in the 72 h fermentation broth of the UCC group was significantly increased(P<0.05). 3) At the family level, the dominant bacterial families in all groups were Prevotellaceae and Lachnospiraceae. Compared with the CON group, the UCC group had an increased relative abundance of Lachnospiraceae, but decreased relative abundances of Prevotellaceae and Ruminococcaceae. At the genus level, the dominant bacterial genera in all groups were Xylanibacter and Succiniclasticum. Compared with the CON group, the UCC group showed increased relative abundances of Succiniclasticum and [Ruminococcus]_gauvreauii_group, while the relative abundances of Xylanibacter and Ruminococcus were decreased. 4) LEfSe analysis showed that Saccharofermentans was significantly enriched in the CON group(P<0.05), Treponema was significantly enriched in the UC group (P=0.016), Ruminococcus was significantly enriched in the CCL group (P<0.05), and Syntrophococcus, Shuttleworthia, Eubacterium_ruminantium_group, Olsenella, Oribacterium and Eubacterium_cellulosolvens_group were significantly enriched in UCC group (P<0.05). 5) Correlation analysis showed that IVDMD_{72 h}, IVNDFD_{72 h} and IVADFD_{72 h} were significantly or extremely significantly positively correlated with the relative abundances of Eubacterium_ruminantium_group, Shuttleworthia, Eubacterium_cellulosolvens_group, Olsenella, and Syntrophococcus (P<0.05 or P<0.01), and extremely significantly negatively correlated with the relative abundance of Saccharofermentans (P<0.001). In conclusion, these results indicate that 3% urea combined with 5% corn steep liquor pretreatment can effectively enhance the in vitro degradability of corn stover, stimulate the FAP activity, and promote the attachment of fiber-degrading bacteria.

This study aimed to investigate the effects of different fermentation treatments of cottonseed meal on nutrient contents, in vitro rumen fermentation parameters and microbial flora. A mixture of cottonseed meal and beet pulp with a ratio of 8∶2 on dry matter basis was used as the fermentation substrate, set up the raw material group, control group (without starter culture), protease group (added with 0.8 g/kg protease), microbe group (added with 0.3 g/kg Bacillus subtilis+1.5 g/kg Saccharomyces cerevisiae+0.3 g/kg Enterococcus faecalis), and bacteria-enzyme synergy group (added with 0.8 g/kg protease+0.3 g/kg Bacillus subtilis+1.5 g/kg Saccharomyces cerevisiae+0.3 g/kg Enterococcus faecalis), and each group contained 6 replicates. The conventional nutrient, free gossypol (FG), acid-soluble protein (ASP) contents were determined, and the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) test and rumen in vitro fermentation test were carried out. The results showed as follows: 1) the FG content of protease group, microbe group and bacteria-enzyme synergy group was significantly lower than that of the control group (P<0.05), and the ASP content of bacteria-enzyme synergy group was significantly higher than that of the control group (P<0.05). 2) The protein molecular weight of protease group and bacteria-enzyme synergy group was mainly concentrated at about 13 ku. 3) The dry matter digestibility (DMD) and contents of ammonia nitrogen (NH₃-N), acetate, isobutyrate, butyrate, isovalerate, valerate and total volatile fatty acids (TVFA) in rumen fluid of protease group and bacteria-enzyme synergy group were significantly higher than those of the control group (P<0.05). 4) At the phylum level, the relative abundances of Desulfobacterota and Synergistota of bacteria-enzyme synergy group were significantly higher than those of the control group (P<0.05), and the Bacteroidota relative abundance was significantly lower than that of the control group (P<0.05). At the genus level, the Succinivibrionaceae_UCG-001 relative abundance of bacteria-enzyme synergy group was significantly lower than that of the control group (P<0.05), and the relative abundances of UCG-002 and Erysipelotrichaceae_UCG-009 were significantly higher than those of the control group (P<0.05). 5) The relative abundances of NK4A214_group, Succiniclasticum, UCG-002 and Erysipelotrichaceae_UCG-009 had significant or extremely significant positive correlations with TVFA content (P<0.05 or P<0.01). In conclusion, the treatments of protease, microbe and bacteria-enzyme synergy can reduce the FG content in cottonseed meal; the bacteria-enzyme synergy treatment has the best effects on improving DMD and contents of ASP, NH₃-N, volatile fatty acids and other aspects of cottonseed meal, and has a positive effect on the structure of rumen microbiota.

Fermentation process is one of the important factors affecting the quality of yeast cultures and their effects, and this experiment was designed to investigate the effects of different fermentation processes on the quality of yeast cultures and the fermentation parameters and nutrient degradation rates in rumen of beef cattle in vitro. A single factor experimental design was used in this experiment, which was divided into four groups according to the fermentation process as the control group (CON group, mixed feed without bacteria), the accumulation fermentation group (AF group, accumulation fermentation in fermentation tank), the bag fermentation group (BF group, anaerobic fermentation in fermentation bag), and the two-stage fermentation group (TF group, accumulation fermentation followed by bag fermentation), and the samples were collected after 72 h fermentation to determine the nutritional active substance contents, physicochemical indices, and quantity of probiotics; and the fermentation parameters and nutrient degradation rates were determined using rumen fermentation technology in vitro. The results showed as follows: 1) compared with CON group, the nutrient active substance contents in yeast cultures in the three experimental groups were significantly increased (P<0.05). Meanwhile, the mannan content in TF group was significantly higher than that in BF group (P<0.05), and the taurine content was significantly higher than that in AF group and BF group (P<0.05). The arachidonic acid content in AF group was the highest, which was significantly higher than that in the other experimental groups (P<0.05). 2) Compared with CON group, the contents of trichloroacetic acid-soluble protein and total organic acids in the three experimental groups were significantly increased (P<0.05), and the pH was significantly decreased (P<0.05). Meanwhile, the crude protein content in TF group was significantly higher than that in the other groups (P<0.05). 3) Compared with CON group, the quantity of probiotics in each experimental group was significantly increased (P<0.05). Meanwhile, the quantity of Kluyveromyces marxianus XR4 in AF group and TF group was significantly higher than that in BF group (P<0.05). 4) The in vitro dry matter degradation rate, in vitro acid detergent fiber degradation rate, in vitro fermentation gas production, as well as the contents of ammonia nitrogen and total volatile fatty acids in TF group were significantly higher than those in BF group (P<0.05), and the bacterial protein content was significantly higher than that in AF group (P<0.05). In conclusion, the yeast cultures prepared by the two-stage fermentation process are of superior quality to those prepared by the accumulation fermentation and bag fermentation processes, and the two-stage fermentation process is more suitable for the production of yeast cultures.

This experiment aimed to investigate the rumen degradation characteristics of tea residues, as well as the dynamic changes in surface cellulase activity and rumen microorganisms in Mindong goats. A single-factor experimental design was adopted, and four 14-month-old male Mindong goats with similar body weight and rumen fistulas were selected as experimental animals. The nylon bag method was used to determine the nutrient components, dynamic degradation rates of tea residues, and changes in surface-attached cellulase activity and microorganisms during degradation at 4, 8, 12, 24, 36, 48, and 72 h. The results showed as follows: 1) the contents of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and hemicellulose (HC) in tea residues were 80.42%, 27.56%, 45.54%, 25.10%, and 20.53%, respectively. 2) The effective degradation rates of DM, CP, NDF, and ADF of tea residues in the rumen were 42.27%, 43.87%, 31.49%, and 30.08%, respectively. Fermentation time significantly affected the degradation rates of nutrients in tea residues in the rumen. Among them, the degradation rates of DM, NDF, and ADF increased slowly from 4 to 8 h, increased significantly from 12 to 36 h (P<0.05), and the growth trend gradually flattened from 36 to 72 h; the CP degradation rate increased significantly from 4 to 36 h (P<0.05) and reached 60.34% at 72 h. 3) Fermentation time effectively increased rumen cellulase activity. Specifically, the activity of β-glucosidase (β-GC) attached to the surface of tea residues was significantly enhanced from 4 to 36 h (P<0.05); the activity of endo-β-1,4-glucanase (EG) at 12 h was significantly lower than that at other time points (P<0.05), and the activity at 72 h was significantly lower than that at 24 h (P<0.05); the activity of exo-β-1,4-glucanase (CBH) gradually increased from 4 to 36 h, and the activity at 72 h was significantly lower than that at 36 h (P<0.05); the activity of neutral xylanase (NEX) gradually increased from 4 to 24 h, with significant differences among different time points (P<0.05), and the activity at 72 h was significantly lower than that at 36 h (P<0.05). 4) The results of α and β diversity showed that tea leaves residues had a certain impact on the richness, diversity, and composition of rumen microorganisms at different fermentation time. At the phylum level, the dominant bacteria were Bacteroidetes and Firmicutes. At the genus level, Prevotella was the main dominant genus at all fermentation times. The relative abundance of Treponema increased significantly at 12 h (P<0.05); the relative abundance of Muribaculum increased at 72 h, which was significantly higher than that at other fermentation time (P<0.05); the relative abundance of [Eubacterium]_coprostanoligenes_group was the lowest at 12 h, which was significantly lower than that at 72 h (P<0.05). In conclusion, tea residues have good rumen degradation performance, with excellent DM and CP degradation. During the degradation process, they do not disrupt the dynamic balance of rumen microorganisms. Therefore, tea residues are a potential roughage resource.

This experiment was conducted to investigate the effects of different urea and glucose addition ratios on Miscanthus lutarioriparius-Phragmites australis mixed silage quality. Whole-plant Miscanthus lutarioriparius and Phragmites australis at the leaf-expansion stage from the east Dongting lake area were used as silage raw materials. A 5×4 two-factor experimental design was adopted, with 5 urea addition ratios [0 (U0), 0.5% (U0.5), 1.0% (U1), 1.5% (U1.5), 2.0% (U2.0)] and 4 glucose addition ratios [0 (G0), 2% (G2), 4% (G4), 6% (G6)], all calculated based on the fresh weight of the silage raw materials. A total of 20 treatments were set up, with 3 replicates per treatment. After 45 days of silage fermentation, the fermentation quality, nutrient quality and aerobic stability were determined. Based on the grey relational analysis to rank the comprehensive quality of silages from the 20 treatments, the top 2 optimal treatments were selected for further analysis, including Cornell Net Carbohydrate and Protein System (CNCPS) fractionation, in vitro digestibility determination and roughage grading evaluation. The results showed as follows: 1) the addition ratios of urea and glucose had significant effects on all silage quality indices (P<0.05), and their interaction had significant effects on all indices except water-soluble carbohydrate (WSC) content (P<0.05). 2) At a glucose addition ratio of 0, with the urea addition ratio increasing, the acetic acid content showed an initial increase followed by a decrease, propionic acid content showed an increasing trend and butyric acid content showed a decreasing trend; crude protein (CP), ether extract (EE) and starch contents showed decreasing trends, while neutral detergent fiber (NDF) and acid detergent lignin (ADL) contents showed increasing trends. At glucose addition ratios of 2%, 4% and 6%, with the urea addition ratio increasing, the lactic acid content showed an increasing trend, while NDF, acid detergent fiber (ADF) and ADL contents showed decreasing trends. 3) Under the same urea addition ratio, with the glucose addition ratio increasing, lactic acid content showed an increasing trend, while pH, ammonia nitrogen (NH₃-N) and propionic acid contents showed decreasing trends; NDF, ADF and ADL contents exhibited decreasing trends. 4) Grey relational analysis showed that the top two treatments in terms of comprehensive silage quality were U2.0G4 and U1.5G4. 5) CNCPS analysis revealed that compared with the U0G0 treatment, the U2.0G4 and U1.5G4 treatments significantly decreased the content of bound protein (PC) (P<0.05), and significantly increased the contents of non-protein nitrogen (PA), rapidly degradable carbohydrates (CA), undegradable carbohydrates (CC) and non-structural carbohydrates (NSC) (P<0.05); the contents of true protein (PB) and carbohydrates (CHO) in the U1.5G4 treatment were significantly higher than those in the U2.0G4 treatment (P<0.05). 6) Compared with the U0G0 treatment, the U2.0G4 and U1.5G4 treatments significantly increased the in vitro dry matter digestibility (IVDMD), in vitro crude protein digestibility (IVCPD), in vitro neutral detergent fiber digestibility (IVNDFD) and in vitro acid detergent fiber digestibility (IVADFD) (P<0.05); both the U1.5G4 and U2.0G4 treatments were graded as first-class silage. In conclusion, the U1.5G4 treatment (adding 1.5% urea and 4% glucose) can improve the quality of Miscanthus lutarioriparius-Phragmites australis mixed silage, contribute to preserving more digestible CNCPS fractions, and effectively enhance the in vitro digestibility of the silage.

This experiment was conducted to study the nutritional (crude protein, crude fat, moisture, crude ash, salinity, amino acids and fatty acids) contents, freshness (histamine, volatile basic nitrogen contents and acid value), odor and flavor indices of 9 types of fish meal (F1 to F9), to analysis and evaluate of quality characteristics of 9 types of fish meal. The results showed that based on the physicochemical properties stipulated in the national standards, F1 met the criteria for second-grade red fish meal, F2, F3 and F4 met the criteria for first-grade red fish meal, F5 met the criteria for premium-grade red fish meal, F6, F7, and F8 met the criteria for regular red fish meal, and F9 met the criteria for fish frame meal. The odor and flavor of 9 types of fish meal analyzed through electronic nose and electronic tongue, the odor in F7 and F9 was obvious difference compared to other fish meal, and the flavor in F8 and F9 was obvious difference compared to other fish meal. The correlation analysis indicated there were strong positive correlations (r≥0.7) between crude protein and umami amino acid, volatile basic nitrogen and acid value, saltiness and acid value, umami and saltiness, W5S (sensitive to nitrogen oxides) and umami amino acid, and W5S (sensitive to nitrogen oxides) and W2S (sensitive to alcohols and certain aromatic compounds); there were strong negative correlations (r≤-0.7) between acidity and umami, saltiness, histamine and crude ash, bitterness and acid value. The above results provide more references for the screening of fish meal raw materials, quality testing and feed preparation.

This experiment aimed to isolate and screen lactic acid bacteria from the intestinal contents of chickens, study their in vitro biological characteristics, and explore their effects on growth and immune function of mice. The intestinal contents of healthy broilers were collected in the experiment. Through isolation, screening and identification, four strains (strains 10, 82, A7 and A62) with good bacteriostatic ability were obtained. Then, their biological characteristics were evaluated through experiments such as acid resistance, bile salt resistance, high temperature resistance, gastrointestinal fluid resistance and hydrophobicity. Finally, mice were used as experimental animals, and after 14 days of intragastric administration of bacterial liquid and 3 days of challenge experiment, the effects on growth and immune function of mice were studied. The results showed as follows: 1) 16S rRNA gene sequencing revealed that strain 10 was Lactobacillus gasseri, strain 82 was Lactobacillus agilis, strain A7 was Pediococcus pentosaceus, and strain A62 was Pediococcus acidilactici. 2) Strains A7 and A62 had better stress resistance, while strains 82 and A62 had higher surface hydrophobicity and automatic aggregation ability. 3) All four strains of lactic acid bacteria significantly increased the weight gain of mice (P<0.05); strains A7 and A62 significantly reduced the plasma tumor necrosis factor-α content in mice before challenge (P<0.05); and strain A7 significantly increased the plasma interleukin-10 content in mice after challenge (P<0.05). In conclusion, the Pediococcus pentosaceus A7 and Pediococcus acidilactici A62 obtained in this experiment possess excellent biological characteristics and immune-enhancing function, and can be used as candidate strains for chicken probiotics.

This study aims to screen high-efficiency desulfurization strains and to optimize their growth conditions, so as to provide bacterial resources for the reduction of hydrogen sulfide (H₂S) and thus reduce odor emissions in animal husbandry. Sheep feces was selected as the source for strain isolation. Through enrichment, separation, purification, and desulfurization capability assessment, high-efficiency desulfurization strains were screened. The strains were then identified based on morphological characteristics and 16S rRNA gene sequencing. Furthermore, the optimal growth conditions for the high-efficiency desulfurization strain were investigated under various parameters: pH (5.0, 6.0, 7.0, 8.0 and 9.0), carbon sources (glucose, sucrose, fructose, maltose and xylose), salinity (0, 0.5%, 1.0%, 1.5% and 2.0%), temperature (30, 33, 35, 38 and 40 ℃), and inoculum amount (1%, 5%, 10%, 15% and 20%). Additionally, the H₂S-removing effect of the high-efficiency desulfurization strain was verified in the experiment of manure’ primary fermentation by measuring the released amount and removal rate of H₂S. The results showed as follows: 1) a high-efficiency desulfurization strain of Bacillus cereus was isolated from sheep feces by isolation, identification, and H₂S-removing measurement, and its H₂S removal rate reached up to 77.57% at 48 h of cultivation. 2) The optimal growth conditions for this high-efficient desulfurization strain were pH 6.0, salinity of 1.5%, sucrose as carbon source, temperature of 30 ℃, and inoculation amount of 10%. 3) Validation results of the desulfurization effect showed that adding this high-efficient desulfurization strain to feces significantly reduced the average released amount of H₂S compared to the control group (P<0.05), with the highest H₂S removal rate reaching 78.6%. In conclusion, the Bacillus cereus isolated from sheep feces in this experiment demonstrates a high capability for H₂S removal and can be considered as a candidate strain for deodorizing bacterial agents.

This study aimed to screen and identify high-quality Bacillus strains derived from Kunming dogs to provide microbial resources and a theoretical foundation for the development of novel probiotic formulations for canines. Fresh fecal samples from the Langqing and Caohuang canine strains at the Kunming Police Dog Base of the Ministry of Public Security were collected, and bacterial strains were isolated and purified using TSB and TSA medium. Their simulated gastrointestinal tolerance, antibiotic susceptibility, antibacterial activity, intestinal adhesion capacity, and anti-inflammatory potential were evaluated to comprehensively assess their probiotic properties. Bacillus strains with favorable probiotic properties were identified by 16S rDNA sequencing, and the safety of the strain was evaluated through an acute oral toxicity test in mice. Twelve 6-week-old SPF-grade Kunming mice were selected, randomly divided into a control group and an experimental group according to the principle of half male and half female with similar body weights, 6 mice per group, housed in single cages. Mice in the control group were gavaged with 200 μL of normal saline daily, while those in the experimental group were gavaged with 200 μL of the screened strain E2 bacterial solution (2×10⁸ CFU/mL) once a day for 7 consecutive days to evaluate the safety of the strain. The results showed that a total of 23 Bacillus strains were isolated from the fresh feces of Kunming dogs. Through comprehensive evaluation of their simulated gastrointestinal tolerance, antibiotic susceptibility, and antibacterial activity, five strains (A3, B7, B10, E2 and E5) with probiotic potential were selected for evaluation of intestinal adhesion capacity and anti-inflammatory effects. Among them, strains B10 and E2 exhibited strong adhesion to HT-29 cells, and strain E2 significantly suppressed the expression of interleukin-8 (IL-8) gene in LPS-induced HT-29 cells (P<0.01). Phylogenetic analysis based on 16S rDNA sequences identified strain E2 as Bacillus velezensis. The strain E2 was selected for an acute oral toxicity test in mice. The results indicated that, compared with the control group, gavage of strain E2 had no significant negative effects on the average daily weight gain or average daily feed intake of the mice (P>0.05). Necropsy showed no pathological changes in mouse organs, no significant differences in organ indexes (P>0.05). Furthermore, the mucosal structures of the jejunum and ileum remained intact. In conclusion, Bacillus velezensis E2 demonstrates excellent probiotic properties and safety, providing a foundation for developing specialized microecological preparations for police dogs.