5-hydroxytryptamine (5-HT), also known as serotonin, is a neurotransmitter closely related to aggression, tryptophan (Trp) is the only precursor for 5-HT synthesis, its cerebral bioavailability in brain is influenced by multiple factors, including the ratio of Trp to other large neutral amino acids, competitive metabolic shunting through Trp pathways and blood-brain barrier transport mechanisms. Dietary Trp supplementation can promote the synthesis of 5-HT in the central nervous system, helps alleviate anxiety and impulsive behaviors, thereby reduce the aggression propensity of canine. This article reviews the research advances on the role of Trp in regulating aggressive behavior in dogs and its potential mechanisms in mechanistic actions and across blood-brain barrier transport, in order to provide references for nutritional intervention in canine behavioral regulation and commercial canine diet formula design.

Leymus chinensis is the main feed for herbivorous animals such as cattle and sheep, with rich nutrient content, and serves as a key forage for livestock fattening in summer and autumn. Silage is one of the important methods for the efficient preservation and utilization of Leymus chinensis, which can achieve maximum nutrient retention through anaerobic fermentation while improving its palatability and nutritional value. Currently, relevant research on Leymus chinensis silage mainly focuses on modulation technologies such as cutting length, moisture content, compaction density, harvest time and mixed silage, as well as the application of silage additives and the dynamic changes of microbial community structure. Based on this, this review summarizes the influencing factors of Leymus chinensis silage quality and discusses future research directions, aiming to provide references for optimizing Leymus chinensis silage technology and improving feed utilization efficiency.

Polyunsaturated fatty acids (PUFAs) are involved in key physiological processes of dairy cows, such as lipid metabolism, phospholipid composition of biological membranes, reproduction, immune function and synthesis of bioactive substances. In intensive farming, enhancing the immune function of dairy cows is important for fighting off pathogens and boosting products quality. More and more studies have shown that PUFAs play a key role in regulating the immune function of dairy cows. In this paper, the effects of PUFAs supplementation in diets on the regulation of dairy cows’ immune function in the latest researches are reviewed. We focus on the effects of n-3 and n-6 PUFAs on immune function and performance of dairy cows, balance of n-3 and n-6 PUFAs in the diets, and the molecular mechanisms of PUFAs. The aim is to deepen the understanding of the nutritional roles of PUFAs in the immune system, to come up with nutritional strategies that boost the immune function of dairy cows, and to provide a solid foundation for improving health and performance of dairy cows.

Lactobacillus reuteri is widely colonized in the mammal intestines, breast milk and natural environment. As one of the most extensively studied probiotics, it exerts broad application prospects in the field of animal health due to its unique biological characteristics. Recent studies have confirmed its diverse functional characteristics in piglet production, including growth performance elevation and intestinal health improvement. However, there is currently a lack of systematic comparison of the effects of different strains, dosages, and addition methods of Lactobacillus reuteri. The research on its action targets and mechanisms, as well as the safety research on long-term use, remains insufficiently in-depth. This paper systematically reviewed the latest research progress on Lactobacillus reuteri in enhancing piglet growth performance, regulating intestinal health, and modulating immunity, aiming to provide valuable references for developing new probiotic formulations and innovative ideas for achieving green farming.

Salmonella is an important pathogen that threatens the health and breeding efficiency of broiler chickens. Its infection can cause high mortality, growth inhibition and internal organ damage in broiler chickens, and threaten the safety of human food sources through meat and egg products. Salmonella destroys the intestinal barrier function and induces systemic inflammatory response through intestinal colonization, invasion and immune escape mediated by virulence factors, which endangers the health of broilers, resulting in damage to growth performance and even death. Green intervention strategies based on nutritional regulation have become a research hotspot. By adjusting the level of dietary nutrients and adding bioactive ingredients, they can target and regulate the balance of intestinal microecology, enhance the mucosal immune barrier, inhibit the adhesion of pathogenic bacteria, and alleviate the inflammatory response, thereby reducing the risk of infection. This paper systematically reviewed the pathogenic mechanism and nutritional prevention and control strategies of Salmonella infection in broilers, aiming to provide theoretical basis and practical guidance for the prevention and control of Salmonella infection in broilers.

Milk fat is a key nutritional component of milk, primarily existing in the form of triglycerides and rich in fat-soluble vitamins such as vitamins A, D, E and K. It imparts milk with its characteristic flavor and high energy density, while its content and fatty acid composition determine both the nutritional value of milk and the processing properties of dairy products. Milk fat percentage in dairy cows is influenced by multiple overlapping factors including breed, genetic traits, nutrition, environment and health status, with complex interactions among these factors. This paper reviews recent research advances in the regulation of milk fat percentage through genetic basis and feeding management, aiming to provide theoretical references for improving milk fat content and dairy quality.

Conjugated linoleic acid (CLA), the signature bioactive lipid of ruminant-derived foods, exerts hypolipemic, anti-inflammatory, anti-carcinogenic and immunomodulatory bioactivities, and has consequently become a central theme in contemporary ruminant nutrition and functional-food research. This review dissects the two dominant CLA biogenetic routes in ruminants-ruminal microbial biohydrogenation of linoleic acid and endogenous Δ9-desaturase-catalyzed desaturation of trans-vaccenic acid-and delineates the complementary catabolic fluxes governed by incomplete ruminal hydrogenation and hepatic β-oxidation. From a nutritional-modulation perspective, we critically evaluate evidence-based strategies-dietary formulation refinement, functional additive deployment and targeted rumen microbiome intervention-that suppress CLA catabolism while channeling metabolic flux toward its efficient enrichment in milk and muscle. The mechanistic insights and translational outcomes synthesized herein provide an integrated theoretical framework and practical roadmap for enhancing the functional value of ruminant edible products via precision nutrition.

Copper is one of the essential trace nutrients for aquatic animals, serving as a key component of various enzymes and proteins within cells. It plays a crucial role in the growth, immunity and antioxidant capacity, as well as respiratory physiological functions of aquatic animals. Feed is one of the primary source for aquatic animals to obtain copper. Therefore, considering the species-specific characteristics and the requirements of different growth stages, selecting appropriate copper source feed additives is of great significance for ensuring the healthy growth of aquatic animals and improving aquaculture efficiency. This paper systematically reviews the three major types of copper-based feed additives and their characteristics, explains the physiological functions of copper in aquatic animals, as well as its absorption, metabolism and transport mechanisms, and the relationship between copper and respiration-related enzymes and genes, and reviews the research progress in the application of copper-based additives in aquatic animals. On this basis, the main problems existing in the current research and application of copper-based feed additives are further summarized, and the future research trends are prospected, aiming to provide a scientific basis for the scientific, efficient and green application of copper-based additives in aquaculture and promote the sustainable development of the aquaculture industry.

Scenedesmus sp., a photosynthetic microalgae with heterotrophic potentiality, exhibits a rapid growth rate, high nutritional value, and strong stress tolerance. It shows great promise for applications in livestock wastewater treatment and as a novel feed resource. However, its complex cultivation modes and high harvesting costs hinder widespread adoption in livestock production. This paper systematically reviews the different cultivation strategies for Scenedesmus sp., outlines the main limiting factors for growth, and provides a comparative analysis of mainstream harvesting methods. Furthermore, it summarizes the latest research progress in utilizing Scenedesmus sp. for wastewater treatment and feed resource development. The aim is to provide theoretical and technical insights to support the scaling up of Scenedesmus sp. production and its scientific utilization in the livestock industry.

Curcumin is a natural polyphenol extracted from the rhizome of turmeric. Due to its multiple biological functions, including anti-inflammatory, antioxidant, and anti-stress effects, it has shown great potential as an alternative to antibiotics in animal production. Recent studies have demonstrated that curcumin plays an important role in regulating bile acid metabolism, which is closely related to lipid digestion, gut-liver homeostasis, and animal health. This review summarizes the current research progress on curcumin’s effects on bile acid synthesis, transport, reabsorption, and the formation of secondary bile acids, aiming to provide a theoretical basis for further understanding the mechanism by which curcumin regulates bile acid metabolism in animals and for its development as a novel green feed additive to improve animal health.

Guanidinoacetic acid is the sole precursor for creatine synthesis and possesses multiple biological functions, including antioxidation, regulation of energy metabolism, promotion of muscle fiber development and insulin hormone release, as well as improvement of animal growth performance. This article systematically expounds the physicochemical properties, in vivo synthesis and metabolic pathways, as well as the biological functions of guanidinoacetic acid. It reviews the effects of guanidinoacetic acid on improving meat quality in pig, poultry and ruminant production and deeply explores its mechanism of action, with the aim of providing theoretical references for the application of guanidinoacetic acid in meat quality regulation in livestock and poultry production.

Diarrhea is a common gastrointestinal disease in young animals, which leads to decreased performance and causes significant economic losses to the livestock industry. Conventional antibiotic treatments for the prevention of diarrhea face challenges of drug resistance and residue risks, prompting the urgent need to develop green and efficient antibiotic alternatives. Resveratrol, as a natural plant extract, possesses various biological functions including antioxidant and anti-inflammatory activities, as well as the ability to modulate gut microbiota. This review systematically summarizes the regulatory effects of resveratrol on diarrhea in young animals and its underlying molecular mechanisms, with a focus on elucidating its roles in promoting intestinal development, protecting intestinal barrier integrity, enhancing immune function, and modulating gut microbiota. The findings aim to provide a theoretical basis for the scientific application of resveratrol in livestock production.

As a rich agricultural by-product in China, straw is one of the key nutritional sources for ruminants to maintain basic nutritional needs. However, cellulose and lignin in the cell wall of straw form a dense structure mediated by hemicellulose, seriously hinder the effective contact between rumen microorganisms and cellulose and degradation, resulting in low digestion and utilization rate of animals, which has become a key bottleneck restricting the high-value utilization of straw resources. At present, the biodegradation method shows great application potential due to its low energy consumption, low pollution and green sustainability. The rumen of ruminants is composed of complex microbial communities such as bacteria, fungi and protozoa, through a variety of synergistic effects, it can effectively deconstruct stubborn lignocellulose and convert it into soluble sugar to provide main energy for the host. Previous studies have confirmed that targeted optimization of the structure and function of rumen microbial communities through exogenous regulatory measures such as probiotics, enzymes and plant extracts is an effective way to enhance their lignocellulose degradation ability. In this paper, the structural characteristics of cellulose and lignin in straw and the anti-degradation barrier formed by lignin were systematically reviewed. The molecular mechanism and synergistic interaction of rumen bacteria, fungi and protozoa were analyzed, and the mechanism of related regulation strategies in improving the degradation efficiency of straw cellulose was summarized. The aim is to provide a theoretical basis for further understanding the specific molecular mechanism of rumen microbial degradation of lignocellulose, and to provide a reference for the development of efficient straw bioconversion technology, the promotion of high-value utilization of straw resources and the sustainable development of animal husbandry.

In recent years, the scale of livestock and poultry breeding in China has expanded rapidly, leading to an increasingly prominent shortage of feed resources. Although the output of agricultural by-products in China is substantial, their direct application in animal diets remains limited. Through the inoculation and fermentation of filamentous fungi, certain agricultural by-products can be transformed into biological feed with enhanced nutritional value and improved palatability. This paper aims to review the characteristics and metabolites of filamentous fungi during the bioconversion of agricultural by-products including straw, distillers’ grains and pomaces, and oilseed meal, as well as their application effects in the production of poultry, pigs and ruminants, so as to provide a reference for the extensive application of agricultural by-products in the livestock and poultry breeding industry.

This experiment was conducted to explore the effects of dietary lysine level on the growth performance, serum biochemical and antioxidant indices, and fecal microbiota of commercial Rongchang pigs. A total of 75 “Rongchang×Landrace×Yorkshire” hybrid pigs with good health and similar body weight of (14.81±0.03) kg were selected and randomly divided into 5 groups, with 5 replicates in each group and 3 pigs in each replicate. The experiment was divided into two phases, and five dietary standardized ileal digestible lysine (SID Lys) levels were set in each phase. Among them, the dietary SID Lys levels in the 15 to 30 kg phase were 0.83%, 0.91%, 0.99%, 1.07% and 1.15%, and in the 30 to 60 kg phase were 0.51%, 0.57%, 0.63%, 0.69% and 0.75%, respectively. The experiment lasted for 63 days. The results showed as follows: 1) in the 15 to 30 kg phase, the feed to gain ratio in 0.99% SID Lys group was the lowest, which was significantly lower than that in 0.83% and 1.07% SID Lys groups (P<0.05); in the 30 to 60 kg phase, the average daily weight gain in 0.63% SID Lys group was the highest, which was significantly higher than that in 0.75% SID Lys group (P<0.05). 2) At 30 kg, the serum alkaline phosphatase activity in 0.91% SID Lys group was significantly higher than that in 0.83% and 1.07% SID Lys groups (P<0.05); at 60 kg, the serum alanine aminotransferase activity and urea nitrogen content in 0.75% SID Lys group were significantly higher than those in 0.57%, 0.63% and 0.69% SID Lys groups (P<0.05). 3) The dietary SID Lys level had no significant effect on the serum antioxidant indices (P>0.05). 4) The dietary SID Lys level had no significant effect on the α diversity of fecal microbiota (P>0.05); the results of principal coordinate analysis (PCoA) indicated that there were significant differences in the β diversity of fecal microbiota among the groups (P<0.05). At 30 kg, compared with 1.15% SID Lys group, the fecal Firmicutes relative abundance in 0.83% and 0.99% SID Lys groups was significantly increased (P<0.05), while the fecal Bacteroidota relative abundance was significantly decreased (P<0.05); the fecal Prevotellaceae_NK3B31_group relative abundance in 1.15% SID Lys group was significantly higher than that in the other groups (P<0.05). At 60 kg, there was no significant difference in the relative abundances of the main phyla and genera of fecal microbiota among the groups (P>0.05). To sum up, the dietary SID Lys level can change the fecal microbiota of commercial Rongchang pigs. Based on the evaluation index of growth performance, the appropriate dietary SID Lys level for commercial Rongchang pigs in the 15 to 30 kg phase is 0.99%, and that in the 30 to 60 kg phase is 0.63%.

This experiment was conducted to investigate the effects of enzyme-hydrolyzed soybean meal replacing soybean meal in diet on growth performance, nutrient apparent digestibility, immune function and intestinal health of nursery pigs. Sixty-four “Duroc×Landrace×Yorkshire” nursery pigs with a body weight of (11.75±0.22) kg and age of (41±1) days were selected and randomly divided into two groups with 8 replicates in each group and 4 pigs in each replicate. They were fed diets formulated with common soybean meal (SBM group) and enzyme-hydrolyzed soybean meal (ESBM group), respectively. The experiment lasted for 28 days. The results showed as follows: 1) compared with SBM group, the feed to gain ratio from days 15 to 28 and the whole phase of the experiment in ESBM group was significantly decreased (P<0.05), while the apparent digestibilities of crude protein, ether extract, gross energy, total amino acids and 17 kinds of amino acids were significantly increased (P<0.05). 2) Compared with SBM group, the plasma immunoglobulin G content in ESBM group was significantly increased (P<0.05), and the plasma pig acute phase protein content was significantly decreased (P<0.05). 3) Compared with SBM group, the mRNA relative expression levels of tumor necrosis factor receptor-associated factor 6 (TRAF6) and interleukin-1β (IL-1β) in ileum in ESBM group were significantly decreased (P<0.05). 4) Compared with SBM group, at phylum level, the Firmicutes relative abundance in colon in ESBM group was significantly increased (P<0.05), while the relative abundances of Patescibacteria and Spirochaetota in colon were significantly decreased (P<0.05); at genus level, the relative abundances of Lactobacillus and Streptococcus in colon in ESBM group were significantly increased (P<0.05). In addition, ESBM group was significantly enriched with bacteria such as Prevotella, Alloprevotella and Ruminococcus in colon (P<0.05), which regulated intestinal energy supply and produced short-chain fatty acids. Meanwhile, compared with SBM group, the contents of butyrate and isobutyrate in colon in ESBM group were significantly increased (P<0.05). In conclusion, the enzyme-hydrolyzed soybean meal can promote the growth and development of nursery pigs, increase the nutrient apparent digestibility, enhance the immune function, enrich the beneficial bacteria in intestine, increase the production of short-chain fatty acids, and promote intestinal health.

The experiment was conducted to evaluate the effects of dietary supplementation with mixed extracts of Lonicera flos and Scutellaria baicalensis (LSE) on reproductive performance, serum indices, colostrum quality and placental function of sows. A total of 1 255 sows with similar parity (2 to 4 parities), genetic background and body condition were randomly allocated into 2 groups, in which the control group (CON group) received a basal diet, and the experimental group (LSE group) received the basal diet supplemented with 150 mg/kg LSE during gestation and 500 mg/kg LSE during lactation. Supplementation began at breeding and continued until weaning. The results showed as follows, compared with CON group: 1) dietary LSE supplementation significantly reduced the numbers of stillbirths and mummy fetuses (P<0.05), and significantly increased the average daily feed intake (ADFI) of sows as well as the average daily gain (ADG) and average weaning weight of piglets (P<0.05); 2) dietary LSE supplementation significantly decreased the serum malondialdehyde content on day 110 of gestation (P<0.05), significantly increased the serum catalase activity on day 14 of lactation (P<0.05), significantly reduced the serum interleukin-2 content on day 70 of gestation and serum interleukin-6 content on day 14 of lactation, and significantly elevated the serum immunoglobulin G content on day 110 of gestation (P<0.05); 3) dietary LSE supplementation significantly increased the contents of fat, protein and true protein in colostrum, and significantly increased the contents of free amino acids such as histidine, isoleucine, methionine, phenylalanine and serine in colostrum (P<0.05); 4) dietary LSE supplementation significantly increased the mRNA relative expression levels of placental function-related genes such as superoxide dismutase 2 (SOD2), vascular endothelial growth factor-A (VEGF-A), solute carrier family 1 member 4 (SLC1A4), solute carrier family 7 member 1 (SLC7A1), and 4F2 heavy chain protein (4F2HC) (P<0.05). In conclusion, under the large-scale pig farming production model, dietary LSE supplementation can improve the serum antioxidant and immune status of sows, upregulate the expression of genes related to placental function, reduce the numbers of stillbirths and mummy fetuses, increase the ADFI and colostrum quality of sows during lactation, and enhance the ADG and average weaning weight of piglets.

This study aimed to analysis of structural diversity and interaction relationships of fecal bacterial and fungal communities of pregnant sows and lactating sows. Eighteen Large Yorkshire sows were selected, and the fresh fecal samples were collected during pregnancy and lactation periods, respectively. The metagenomic sequencing technology was used to analyze the changes of bacterial and fungal communities in feces, and analysis their interaction relationships. The results showed as follows: 1) the α diversity analysis revealed that the Richness, Simpson and Pielou indexes of bacteria and fungi in feces of lactating sows were significantly higher than those of pregnant sows (P<0.05); the β diversity analysis revealed that there was significant difference in distribution of fecal bacterial and fungal communities between pregnant sows and lactating sows (P<0.05). 2) At the phylum level, compared with pregnant sows, the relative abundances of Bacteroidota and Chytridiomycota in feces of lactating sows were increased, while the relative abundances of Spirochaetota and Basidiomycota were y decreased. At the genus level, compared with pregnant sows, the relative abundances of Prevotella, Faecousia, Globomyces and Neocallimastix in feces of lactating sows were increased, while the relative abundances of Treponema, Clostridium, Escherichia, Lactobacillus, Mucor and Astraeus were decreased. 3) The linear discriminant analysis effect size (LEfSe) analysis identified 9 significantly different bacteria and 21 significantly different and fungi in feces of pregnant and lactating sows. Among them, the relative abundances of Escherichia coli, Lactobacillus amylovorus, Mucor ambiguus and Aspergillus fumigatus et al in feces of pregnant sows were significantly higher than those of lactating sows (P<0.05), while the relative abundances of Neocallimastix californiae and Terrisporobacter glycolicus et al were significantly lower than those of lactating sows (P<0.05). 4) The correlation network analysis revealed that the interaction connectivity between bacteria and fungi of pregnant sows was higher, with more complex interaction relationships, and the core bacterium, Lactobacillus amylovorus, had significant interaction with multiple fungal nodes (P<0.05 or P<0.01). The interaction network of lactating sows was relatively simpler, with a reduction in the interaction partners of Lactobacillus amylovorus. In summary, the fecal bacterial and fungal structures of pregnant sows and lactating sows exhibit significant differences and potential interaction associations, providing new insights into exploring the adaptation mechanisms of gut microbiota during key physiological stages of sows.

This experiment was conducted to explore the effects of feeding low protein diet to sows during gestation on growth performance, immune function and antioxidant capacity of their offspring. Twenty-four “Landrace×Yorkshire” crossbred sows with similar body condition and parity (3 to 5 parities) were selected. After artificial insemination, they were randomly divided into 2 groups (12 sows in each group) at 30 days of gestation. During gestation, they were fed a normal protein diet (NP group, with crude protein content of 13.65%) and a low protein diet (LP group, with crude protein content of 11.30%), respectively. Sows were fed the same lactation diet during the lactation period. Piglets were weaned at 21 days of age, and two male castrated piglets with a body weight close to the average body weight of the litter were selected from each litter (a total of 48 piglets), with 8 replicates in each group and 3 piglets in each replicate. The offspring were fed the same diet during the nursery period and the growth period. The piglets were slaughtered and sampled 90 days after weaning. The results showed as follows: 1) compared with NP group, there was no significant difference in the growth performance of offspring in LP group (P>0.05). 2) Compared with NP group, the jejunal secretory immunoglobulin A (sIgA) content of offspring in LP group was significantly increased 90 days after weaning (P<0.05). 3) Compared with NP group, the valeric acid content in feces during the growth period in LP group was significantly decreased (P<0.05). 4) Compared with NP group, the mRNA relative expression levels of thymic interleukin-1β (IL-1β) and nuclear factor-κB (NF-κB) during the growth period in LP group were significantly increased (P<0.05); there was no significant difference in the weight of spleen (P>0.05), while the mRNA relative expression levels of interleukin-6 (IL-6) and interleukin-10 (IL-10) in spleen were significantly increased (P<0.05). 5) Compared with NP group, the mRNA relative expression levels and enzyme activities of catalase (CAT) and superoxide dismutase (SOD) in spleen and thymus during the growth period in LP group were significantly increased (P<0.05), the mRNA relative expression levels of endoplasmic reticulum stress marker genes glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) in spleen were significantly decreased (P<0.05), and the malondialdehyde content in spleen was significantly decreased (P<0.05). In conclusion, appropriately reducing the dietary protein level of sows during gestation has no significant effect on the growth performance of offspring, but it can increase the jejunal sIgA content of offspring during the growth period, enhance the antioxidant capacity and immune function of thymus and spleen.

This experiment was conducted to explore the effects of dietary lactoferrin peptide (LFP) supplementation on growth performance, nutrient apparent digestibility, immune function and intestinal health of weaned piglets. Eighty “Duroc×Landrace×Yorkshire” three-way hybrid weaned piglets [(24±2) days old, (7.36±0.14) kg, castrated boars] were selected and randomly divided into 2 groups, with 8 replicates in each group and 5 pigs in each replicate. The control group (CON group) was fed a basal diet, while the LFP group was fed the basal diet supplemented with 500 mg/kg LFP. The experiment lasted for 35 days. The results showed as follows, compared with CON group: 1) the average daily feed intake in LFP group was significantly increased in week 3 of the experiment (P<0.05), the average daily gain in week 4 (P=0.073) and the whole phase (P=0.055) showed an increasing trend, and the feed to gain ratio tended to be decreased in week 2 (P=0.070); 2) the apparent digestibilities of gross energy, crude protein, total amino acids, dry matter and each amino acid in LFP group were all significantly increased (P<0.05); 3) the proportion of T helper cell 1 in blood in LFP group was significantly increased (P<0.05), and the contents of pig major acute-phase protein and tumor necrosis factor-α (TNF-α) in plasma were significantly decreased (P<0.05); 4) the ratio of ileal villus height to crypt depth in LFP group showed an increasing trend (P=0.074), and the TNF-α mRNA relative expression level in ileum was significantly decreased (P<0.05); 5) the [Eubacterium] coprostanoligenes group relative abundance in colon in LFP group was significantly increased (P<0.05). In conclusion, dietary LFP supplementation shows a trend of improving the growth performance of weaned piglets, which is related to its ability to increase the nutrient apparent digestibility, regulate the intestinal microbiota structure, and enhance the immune function.

This experiment was conducted to investigate the effects of dietary supplementation with Clostridium butyricum on semen quality and fecal microbial composition of Duroc boars. Twenty adult Duroc boars with similar body weights [(133.53±5.00) kg] and good body condition were randomly divided into 4 groups with 5 boars per group, and reared individually in stalls. The control group was fed a basal diet, while the experimental groups were fed the basal diets supplemented with 50, 100 and 200 mg/kg of Clostridium butyricum (freeze-dried powder, viable count≥1.0×10⁹ CFU/g), respectively. The pre-experiment period lasted for 7 days, and the formal experiment period lasted for 60 days. The results showed as follows: 1) compared with the control group, dietary supplementation with 200 mg/kg Clostridium butyricum significantly increased the ejaculatory duration time, sperm motility, sperm linear motion ability, and Grade A+B sperm proportion of Duroc boars by 63%, 14%, 29% and 33%, respectively (P<0.05), and significantly decreased the ejaculatory response time by 57% (P<0.05); the sperm plasma membrane integrity rate was significantly increased by 12% (P<0.05), and the sperm mitochondrial membrane potential was significantly increased by 9% (P<0.05); the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and lactate dehydrogenase (LDH) in seminal plasma were significantly increased by 33%, 20% and 56%, respectively (P<0.05), and the contents of fructose and adenosine triphosphate (ATP) were significantly increased by 6% and 46%, respectively (P<0.05). 2) Fecal microbial analysis results showed that compared with the control group, dietary supplementation with 200 mg/kg Clostridium butyricum significantly increased the relative abundances of Spirochaetota, Oscillospiraceae, Lachnospiraceae and UCG-002 in feces (P<0.05), and significantly decreased the relative abundances of Desulfobacterota, Streptococcaceae, Peptostreptococcaceae, and Clostridium_sensu_stricto_1 in feces (P<0.05). 3) Metabolomics results showed that compared with the control group, dietary supplementation with 200 mg/kg Clostridium butyricum significantly increased the contents of isocitric acid and β-D-fucose in seminal plasma (P<0.05), and significantly increased the content of tartaric acid (P<0.05) and significantly decreased the content of hyocholic acid (P<0.05) in feces. In conclusion, dietary supplementation with 200 mg/kg Clostridium butyricum can alter the intestinal flora structure and regulate seminal plasma metabolites of Duroc boars, thereby improving their semen quality.

This experiment was conducted to investigate the effects of metabolizable energy (ME) intake on digestive tract development and cecal microbiota of laying hens during 7 to 15 weeks of age. A total of 540 six-week-old Hy-Line brown laying hens were randomly divided into 3 groups with 6 replicates in each group and 30 hens in each replicate. During 7 to 15 weeks of age, the laying hens in 3 groups were fed the experimental diets which the ME levels were 12.34 (control group), 11.11 (90% ME group) and 9.87 MJ/kg (80% ME group) and the other nutrient levels were same. The laying hens in control group were fed freely, and the hens in experimental group were fed a fixed amount of diet according to the feed intake of the hens in control group. The experiment lasted for 9 weeks. The results showed as follows: 1) with the ME intake decreased, the average daily gain of laying hens during 7 to 15 weeks of age, and the body weight, body weight coefficient of variation and body slope length of laying hens at 15 weeks of age were linearly decreased (P<0.05). 2) With the ME intake decreased, the relative thickness of gizzard, the relative length of duodenum, jejunum and ileum, and the relative weight of gizzard, duodenum and jejunum of laying hens at 15 weeks of age were linearly increased (P<0.05). 3) With the ME intake decreased, the villus height and villus-crypt ratio of laying hens at 15 weeks of age were linearly increased (P<0.05), and the crypt depth was linearly decreased (P<0.05). 4) The relative abundances of Fusobacteriota, Halobacterota and Proteobacteria in cecum of 90% ME group were significantly lower than those of the control group (P<0.05 or P<0.01). The relative abundances of Euryarchaeota, Desulfobacterota, Fusobacteriota and Proteobacteria in cecum of 80% ME group were significantly lower than those of the control group (P<0.05 or P<0.01), and the relative abundance of Halobacterota in cecum was significantly higher than that of the control group (P<0.05). 5) The microbiota functional prediction revealed that the cecal microbiota in 80% ME group was significantly enriched in the glycolysis, citric acid cycle, pyruvate metabolism, aspartate and glutamate metabolism and purine metabolism, which were the free energy yielding substance metabolism pathways. In conclusion, reducing the ME intake of laying hens during 7 to 15 weeks of age to 90% or 80% can improve the uniformity of laying hens at 15 weeks of age, promote the intestinal development, improve the intestinal tissue morphology, reduce the relative abundances of harmful bacteria such as Desulfobacterota, Fusobacteriota and Proteobacteria in cecum, increase the relative abundance of beneficial bacteria such as Halobacterota in cecum, and the microbial biological function significantly enrich in the metabolic pathways that produce free energy.

This experiment was conducted to explore the effects of dietary mixed Chinese herbs on performance, egg quality and oviduct health of laying hens. Using a single-factor completely randomized experimental design, 480 Lohmann Pink laying hens of 45-week-old with a laying rate of (95.10±3.61)% were selected and randomly divided into 6 groups, with 8 replicates in each group and 10 hens in each replicate. The control group (CON group) was fed with a corn-soybean meal type basal diet, and the experimental groups were fed with the basal diets supplemented with 1 000 mg/kg mixed Chinese herbs with different compatibility proportions, in which the dandelion∶mugwort leaf∶Hedyotis diffusa∶motherwort∶honeysuckle were 1∶1∶1∶1∶1 (MCH1 group), 6∶1∶1∶1∶1 (MCH2 group), 1∶6∶1∶1∶1 (MCH3 group), 1∶1∶6∶1∶1 (MCH4 group), and 1∶1∶1∶6∶1 (MCH5 group), respectively. The experiment lasted for 8 weeks after a one-week adaptation. The results showed as follows: 1) compared with CON group, the average daily feed intake in MCH5 group from weeks 5 to 8 was significantly decreased (P<0.05); there were no significant differences in the other performance indices among the groups (P>0.05). 2) Compared with CON group, the eggshell strength, eggshell redness (a^*) value and albumen height in MCH1 group were significantly increased in week 4 (P<0.05), and the eggshell strength in MCH5 group was significantly increased in week 4 (P<0.05). 3) Compared with CON group, dietary mixed Chinese herbs significantly increased the serum estradiol content (P<0.05); the contents of serum interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in MCH3 group were significantly decreased (P<0.05). 4) Compared with CON group, dietary mixed Chinese herbs significantly increased the superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC) in liver (P<0.05), and significantly reduced the malondialdehyde (MDA) content in liver (P<0.05). 5) Compared with CON group, the TNF-α content in magnum of oviduct in experimental groups was significantly decreased (P<0.05); the contents of IL-1β and TNF-α in isthmus in MCH2 group were significantly decreased (P<0.05); the IL-6 content in uterus in MCH1 group, MCH2 group, MCH3 group and MCH4 group was significantly decreased (P<0.05); the contents of IL-1β and IL-6 in magnum, IL-1β in isthmus as well as TNF-α in uterus in MCH3 group were significantly decreased (P<0.05). 6) Compared with CON group, the activities of SOD and catalase (CAT) in isthmus of oviduct in experimental groups were significantly increased (P<0.05), which was the highest in MCH3 group; the MDA content in uterus in MCH1 group, MCH3 group and MCH4 group was significantly decreased (P<0.05), which was the lowest in MCH3 group; the CAT activity in uterus in experimental groups was significantly increased (P<0.05). In conclusion, an appropriate compatibility proportion of 1 000 mg/kg dietary mixed Chinese herbs can enhance the antioxidant capacity, reduce the inflammatory response, and maintain the oviduct health of laying hens. Among them, the MCH3 group with mugwort leaf as the main component has a better effect.

This study aimed to investigate the effects of partially replacing soybean meal with red yeast rice distillers’ grains on the laying performance, hatching performance, nutrient digestion and utilization, and blood biochemical indices of Guizhou yellow chickens, and to evaluate the nutritional value and safety of red yeast rice distillers’ grains. A total of 576 healthy Guizhou yellow chickens aged 29 weeks with similar body weight were selected and randomly divided into 4 groups, with 4 replicates per group and 36 chickens per replicate (34 hens+2 roosters). Chickens in the CON, D5, D10 and D15 groups were fed experimental diets containing 0 (control), 5%, 10%, and 15% red yeast rice distillers’ grains as a partial substitute for soybean meal, respectively. The experiment included a 1-week adaptation period followed by an 8-week formal trial period. The results showed as follows: 1) the supplemental level of red yeast rice distillers’ grains had no significant effects on the laying rate, average daily feed intake and feed-to-egg ratio of Guizhou yellow chickens (P>0.05), but showed an increasing trend in average egg weight (P=0.006). 2) Compared with the CON group, dietary supplementation with 5% to 15% red yeast rice distillers’ grains significantly increased the fertility rate and hatchability of Guizhou yellow chickens (P<0.05). 3) Compared with the CON group, dietary supplementation with 5% to 15% red yeast rice distillers’ grains significantly improved the yolk ratio of Guizhou yellow chickens at both the 4th and 8th weeks of the trial (P<0.05); when the red yeast rice distillers’ grains supplemental level reached 15%, it significantly enhanced yolk color at the 4th week (P<0.05). In addition, dietary supplementation with 5% red yeast rice distillers’ grains significantly increased eggshell strength at the 4th and 8th week (P<0.05). 4) The activities of glutathione peroxidase and superoxide dismutase in the serum of Guizhou yellow chickens showed an extremely significant linear increase with the increase of red yeast rice distillers’ grains supplemental level (P<0.01), while the content of malondialdehyde in plasma showed an extremely significant linear decrease (P<0.01). Similarly, the contents of immunoglobulin Y and immunoglobulin A in serum also exhibited an extremely significant linear decline with the increase of red yeast rice distillers’ grains supplemental level (P<0.01). The contents of interleukin-1β, tumor necrosis factor-α and interleukin-6 in serum followed an extremely significant quadratic curve (P<0.01), initially decreasing and then increasing as the red yeast rice distillers’ grains supplemental level increasing. With the increase of red yeast rice distillers’ grains supplemental level, the content of uric acid in plasma displayed an extremely significant quadratic trend (P<0.01), first decreasing and then increasing, whereas the content of triglycerides in plasma showed an extremely significant linear decrease (P<0.01). Furthermore, compared with the CON group, dietary supplementation with 5% to 10% red yeast rice distillers’ grains significantly increased the activity of aspartate aminotransferase in serum (P<0.05). 5) The apparent metabolizabilities of dry matter, gross energy, crude protein and calcium in the diets by Guizhou yellow chickens showed an extremely significant linear increase with the increase of red yeast rice distillers’ grains supplemental level (P<0.01). The apparent metabolizabilities of dry matter, gross energy, crude protein, ether extract, calcium and phosphorus in red yeast rice distillers’ grains for Guizhou yellow chickens were 83.22%, 88.26%, 59.81%, 88.24%, 41.69% and 45.44%, respectively. In conclusion, dietary supplementation with 5% to 10% red yeast rice distillers’ grains as a partial replacement for soybean meal can improve nutrient digestion and utilization, enhance antioxidant capacity, increase hatchability and egg quality, and alleviate inflammatory responses in Guizhou yellow chickens. However, it may also cause certain adverse effects on the liver function and humoral immunity.

This experiment aimed to determine the optimal dietary methionine level in low-protein diet of medium-growing yellow-feathered broilers aged from 1 to 30 days by investigating the effects of corn-miscellaneous meal diets supplemented with different methionine levels on their growth performance, carcass quality, serum indices and methionine metabolism. A total of 720 one-day-old female medium-growing yellow-feathered broiler chicks (Mahuang breed) were randomly allocated into 6 groups with 6 replicates per group and 20 chicks in each replicate. Chicks in control group (NP group) received a diet with crude protein (CP) and amino acid levels meeting the nutrient requirements for medium-growing yellow-feathered broilers aged from 1 to 30 days. The other five groups were the low-protein low-methionine group (LP-Met group), low-protein normal-methionine group (LP group), low-protein high-methionine group 1 (LP+Met1 group), low-protein high-methionine group 2 (LP+Met2 group), and low-protein high-methionine group 3 (LP+Met3 group). Chicks in these five groups were fed low-protein diets with a CP level approximately 2 percentage points lower than that of the NP group [CP level of (19.80±0.07)%], and with dietary methionine levels of 0.37%, 0.45%, 0.54%, 0.63%, and 0.72%, respectively. Other nutrient levels were kept constant. The trial lasted for 30 days. The results showed as follows: 1) compared with NP group, yellow-feathered broilers in LP group showed no significant differences in growth performance, serum immunoglobulin contents, antioxidant indices, free methionine content, or the relative mRNA expression levels of key hepatic methionine metabolism enzymes (P>0.05); LP group had a significantly lower thigh muscle percentage and a significantly higher abdominal fat percentage (P<0.05). 2) The methionine level in low-protein diet significantly affected average daily feed intake and feed-to-gain ratio (F/G) (P<0.05). The F/G showed significant linear and quadratic responses to increasing dietary methionine levels (P<0.05). Using a single-slope broken-line regression analysis with F/G as the evaluation criterion, the optimal dietary methionine level was determined to be 0.55%. 3) The methionine level in the low-protein diet significantly influenced serum immunoglobulin G content, total antioxidant capacity, and glutathione peroxidase activity (P<0.05). Serum free methionine content tended to increase linearly with rising dietary methionine levels (P=0.088). Furthermore, dietary methionine level significantly affected the relative mRNA expression of hepatic glycine N-methyltransferase, S-adenosylhomocysteine hydrolase, methionine synthase, and adenosine deaminase (P<0.05). In conclusion, supplementing an appropriate level of methionine in the low-protein diet for medium-growing yellow-feathered broilers (female Mahuang breed) aged 1 to 30 days can improve growth performance, enhance systemic antioxidant capacity, regulate hepatic methionine metabolism, and optimize methyl-group metabolism and balance. Based on F/G, the optimal dietary methionine level in a corn-miscellaneous meal-based low-protein diet [CP level of (19.80±0.07)%] for these broilers is 0.55%.

This experiment aimed to investigate the effects of dietary short-chain fatty acids mixture on growth performance, nutrient apparent metabolic rates and intestinal function of broilers. A total of 192 healthy 22-day-old Shenzhe 901 broilers were randomly assigned to 4 groups with 6 replicates per group and 8 broilers per replicate. The control group (CON group) was fed a basal diet, and the experimental groups were fed basal diets supplemented with different concentrations (acetic acid 6.14 mmol/L, propionic acid 1.31 mmol/L and butyric acid 1.67 mmol/L, SCFA1 group; acetic acid 12.28 mmol/L, propionic acid 2.62 mmol/L and butyric acid 3.35 mmol/L, SCFA2 group; acetic acid 18.42 mmol/L, propionic acid 3.93 mmol/L and butyric acid 5.02 mmol/L, SCFA3 group) short-chain fatty acids mixture based on the body weight of broilers×15 mL/kg. The experiment lasted for 21 days. The results showed as follows: 1) there were no significant differences in growth performance and organ indices of broilers among all groups (P>0.05), but the feed to gain ratio (F/G) of SCFA1 group was lower than that of SCFA2 group and SCFA3 group. 2) The ether extract apparent metabolic rate of SCFA1 group and SCFA2 group was significantly higher than that of CON group (P<0.05), and the crude protein apparent metabolic rate was significantly higher than that of SCFA3 group (P<0.05). 3) Compared with the CON group, the jejunal mucosa maltase activity of SCFA1 group was significantly increased (P<0.05), the jejunal mucosa lipase activity was trend to increase (P=0.062), and the mRNA relative expression levels of sodium-glucose cotransporter 1 (SGLT1), glucose transporter 2 (GLUT2), oligopeptide transporter 1 (PepT1) and neutral amino acid transporter 1 (B⁰AT1) in jejunal mucosa were significantly up-regulated (P<0.05). 4) Compared with the CON group, the jejunal mucosa malondialdehyde content of SCFA1 group was significantly decreased (P<0.05), the jejunal mucosa superoxide dismutase activity was trend to increase (P=0.067), and the mRNA relative expression levels of glutathione peroxidase (GSH-Px), Kelch-like ECH-associated protein 1 (Keap1) and nuclear factor erythroid 2-related factor 2 (Nrf2) in jejunal mucosa were significantly up-regulated (P<0.05). 5) Compared with the CON group, the Bacteroidetes relative abundance and Bacteroidetes/Firmicutes ratio in cecum were increased, the contents of acetic acid, butyric acid and total short-chain fatty acids in cecum were significantly increased (P<0.05), and the content of isovaleric acid in cecum was significantly decreased (P<0.05). In conclusion, dietary supplementation of short-chain fatty acids mixture (acetic acid 6.14 mmol/L, propionic acid 1.31 mmol/L and butyric acid 1.67 mmol/L) can enhance nutrient absorption by improving jejunal digestive enzyme activities and up-regulating the mRNA relative expression levels of nutrient transporter related gene, and can enhance intestinal function by increasing antioxidant enzyme activities, up-regulating the mRNA relative expression levels of antioxidant related genes, and improving cecal butyric acid content, thereby promoting the growth of broilers.

This experiment was conducted to investigate the effects of different dietary supplementation levels of fucoidan (FUC) on growth performance, immune function, intestinal barrier function and cecal microbiota of broilers. A total of 320 one-day-old male Arbor Acres (AA) broilers with similar body weight were randomly divided into 4 groups, with 8 replicates in each group and 10 chickens in each replicate. The control group was fed a basal diet, while the experimental groups were fed the basal diets supplemented with 125, 250 and 500 mg/kg FUC, respectively. The experiment lasted for 42 days. The results showed as follows: 1) compared with the control group, dietary supplementation of 250 mg/kg FUC significantly increased the final body weight and average daily gain of broilers (P<0.05), and dietary supplementation of 125 and 250 mg/kg FUC significantly reduced the feed to gain ratio (P<0.05). 2) Compared with the control group, dietary supplementation of 250 mg/kg FUC tended to increase the thymus index (P=0.074). 3) Compared with the control group, dietary supplementation of 125 and 250 mg/kg FUC significantly decreased the serum D-lactate content (P<0.05), and significantly increased the serum interleukin-10 content (P<0.05). 4) Compared with the control group, dietary supplementation of 250 and 500 mg/kg FUC significantly upregulated the jejunal zonula occludens-1 (ZO-1) mRNA relative expression level (P<0.05), and dietary supplementation of 250 mg/kg FUC significantly downregulated the jejunal interleukin-1β (IL-1β) mRNA relative expression level (P<0.05). 5) Compared with the control group, dietary supplementation of 250 mg/kg FUC significantly increased the contents of acetate and butyrate in cecum (P<0.05), whereas dietary supplementation of 500 mg/kg FUC significantly improved the butyrate content in cecum only (P<0.05). 6) Compared with the control group, dietary supplementation of 125 and 250 mg/kg FUC significantly increased the Fournierella relative abundance in cecum (P<0.05), and dietary supplementation of 250 and 500 mg/kg FUC significantly decreased the Campylobacter relative abundance in cecum (P<0.05). In conclusion, dietary supplementation of 250 mg/kg FUC can effectively improve the intestinal health through multiple pathways such as regulating the cecal microbiota composition of broilers, enhancing intestinal barrier function, reducing local inflammatory responses, and promoting the production of short-chain fatty acids, thereby enhancing their growth performance.

This experiment was conducted to investigate the effects of dietary supplementation with different levels of lysozyme on growth performance, immune function, antioxidant capacity, intestinal short-chain fatty acids contents and microbial flora of yellow-feathered broilers. A total of 450 healthy 1-day-old yellow-feathered broilers with an initial average body weight of approximately 31.7 g were randomly divided into 3 groups with 10 replicates per group and 15 broilers per replicate. Broilers in the control group (CON group) were fed a basal diet, while those in the experimental groups were fed the basal diets supplemented with 250 (LZ250 group) and 500 mg/kg (LZ500 group) lysozyme (enzyme activity: 100 000 U/g), respectively. The experimental period lasted for 56 days. The results showed as follows: 1) compared with the CON group, the feed-to-gain ratio in the LZ500 group was significantly decreased (P<0.05). 2) Compared with the CON group, the serum contents of immunoglobulin A (IgA), immunoglobulin M (IgM) and immunoglobulin Y (IgY) in the LZ250 and LZ500 groups were significantly increased (P<0.05), and the serum content of tumor necrosis factor-α (TNF-α) was significantly decreased (P<0.05); the serum contents of interleukin-1β (IL-1β) and interleukin-6 (IL-6) in the LZ500 group were significantly decreased (P<0.05), while the serum content of interleukin-10 (IL-10) was significantly increased (P<0.05). 3) Compared with the CON group, the serum glutathione peroxidase (GPx) activity in the LZ250 and LZ500 groups was significantly increased (P<0.05), and the serum malondialdehyde (MDA) content was significantly decreased (P<0.05); the serum superoxide dismutase (SOD) activity in the LZ500 group was significantly increased (P<0.05). 4) Compared with the CON group, the cecal contents of propionic acid, butyric acid and isobutyric acid in the LZ500 group were significantly increased (P<0.05). 5) Compared with the CON group, the relative abundance of Streptococcus in cecum of the LZ250 and LZ500 groups was significantly increased (P<0.05), while the relative abundance of Butyricimonas in cecum was significantly decreased (P<0.05); the relative abundance of Turicibacter in cecum of the LZ500 group was significantly increased (P<0.05). In conclusion, dietary supplementation with 500 mg/kg lysozyme can significantly improve the growth performance, immune function and antioxidant capacity of yellow-feathered broilers, increase the contents of SCFAs in cecum, and alter the cecal microbial composition.

This experiment was conducted to investigate the effects of stevia chlorogenic acid in diets on growth and development, meat quality, antioxidant capacity and intestinal morphology of yellow-feathered broilers under heat stress. A total of 180 one-day-old male rapidly yellow-feathered broilers were randomly divided into 3 groups with 6 replicates in each group and 10 birds in each replicate. The control group (CON group) and heat stress group (HS group) were fed a basal diet, and the heat stress+stevia chlorogenic acid group (SCGA group) was fed the basal diet supplemented with 100 mg/kg stevia chlorogenic acid. When broilers were feeding to 39 days of age, pre-feeding 7 days, the CON group was maintained at room temperature, while the HS group and SCGA group underwent a 14 days cyclic heat stress treatment. The results showed as follows: 1) compared with the CON group, the final body weight, average daily gain (ADG), average daily feed intake (ADFI), bursa of Fabricius index and spleen index of the HS group were significantly decreased (P<0.05), the rectal temperature on days 4, 7, 10 and 14 of heat stress treatment were significantly increased (P<0.05), the redness value and 24 h pH of breast muscle and serum glucose (GLU) content were significantly decreased (P<0.05), the breast muscle lightness value and serum aspartate aminotransferase (AST) activity were significantly increased (P<0.05), the liver total cholesterol (TC) and total antioxidant capacity (T-AOC) were significantly increased (P<0.05), the ileal length and jejunal and ileal villus height and villus height to crypt depth ratio (V/C) were significantly decreased (P<0.05), and the jejunal and ileal crypt depth were significantly increased (P<0.05). 2) Compared with the HS group, the rectal temperature on days 10 and 14 of heat stress treatment and breast muscle 24 h pH of the SCGA group were significantly decreased (P<0.05), the breast muscle redness value and liver index were significantly increased (P<0.05), the serum T-AOC was significantly decreased (P<0.05), the liver T-AOC and serum malondialdehyde (MDA) content were significantly increased (P<0.05), the ileal crypt depth was significantly decreased (P<0.05), and the ileal length, jejunal villus height and ileal V/C were significantly increased (P<0.05). In conclusion, dietary supplemented with stevia chlorogenic acid can improve the meat quality and liver development and antioxidant capacity, and alleviate the heat stress-induced intestinal morphological damage of yellow-feathered broilers.

This experiment was conducted to investigate the effects of compound Chinese herbal medicine on growth performance, slaughter performance, immune organ indexes, serum biochemical indexes, jejunal morphology and cecal microbiota structure of broilers. A total of 240 one-day-old Arbor Acres (AA) broilers were selected and randomly divided into 4 groups, with 6 replicates per group and 10 chickens per replicate. The control group was fed a basal diet, while the experimental groups were supplemented with 1%, 2% and 4% compound Chinese herbal medicine in the basal diet, respectively. The trial lasted for 42 days. The results showed as follows: 1) compared with the control group, diet supplemented with 2% compound Chinese herbal medicine significantly reduced the average feed intake and feed-to-gain ratio at the 1 to 21 days of age (P<0.05). 2) Compared with the control group, diet supplemented with 2% compound Chinese herbal medicine significantly increased the dressing percentage, semi-eviscerated percentage and eviscerated percentage (P<0.05), while significantly reduced the abdominal fat percentage (P<0.05). 3) Compared with the control group, diet supplemented with 2% compound Chinese herbal medicine significantly increased the thymus index (P<0.05), while diet supplemented with 1% compound Chinese herbal medicine significantly increased the bursa of Fabricius index (P<0.05). 4) Compared with the control group, diet supplemented with 2% compound Chinese herbal medicine significantly increased the serum total protein and globulin contents (P<0.05), while significantly reduced the serum total cholesterol content and aspartate aminotransferase activity (P<0.05). Meanwhile, diet supplemented with 4% compound Chinese herbal medicine significantly increased the serum albumin content (P<0.05), and significantly decreased the serum uric acid content compared with the control group (P<0.05). 5) Compared with the control group, diet supplemented with 2% compound Chinese herbal medicine significantly increased the jejunal villus height to crypt depth ratio (P<0.05); furthermore, it significantly reduced the relative abundance of Alistipes in the cecal microbiota (P<0.05). In conclusion, diet supplemented with 2% compound Chinese herbal medicine can promote growth, enhance immune function, and improve intestinal health of broilers.

This experiment was conducted to investigate the effects of Phellodendron amurense extract in different dosage forms on growth performance, antioxidant indicators, cytokines, ileum morphological structure and cecal microbiota of broilers coinfected with Eimeria and Clostridium perfringens, so as to clarify their efficacy against broiler necrotic enteritis. A total of 120 healthy 1-day-old Arbor Acres broilers with similar body weight were randomly divided into 5 groups: control group (C group), challenge group (CI group), Phellodendron amurense extract treatment group (CIP group), enteric-coated sustained-release Phellodendron amurense extract treatment group (CIESP group) and antibiotic treatment group (CIA group). Each group had 6 replicates with 4 chicks per replicate. The experimental period was 20 days, including a 3-day pre-test period and a 17-day formal test period [divided into a challenge phase (4 to 9 days of age) and a treatment phase (10 to 20 days of age)]. During the challenge period, except for the C group, the broilers in all other groups were gavaged daily with 1 mL of Eimeria tenella oocyst suspension (33 000 sporocysts/mL) from 4 to 6 days of age, and then with 1 mL of Clostridium perfringens CP4 bacterial suspension (1×10⁹ CFU/mL) from 7 to 9 days of age. The broilers in the C group were gavaged daily with 1 mL of normal saline. All groups were fed a basal diet from 1 to 9 days of age. From 10 to 20 days of age, C and CI groups continued with the basal diet; CIP group was fed the basal diet+0.1 g/kg Phellodendron amurense extract; CIESP group was fed the basal diet+40 g/kg enteric-coated sustained-release Phellodendron amurense extract; CIA group was fed the basal diet+4 g/kg enramycin premix. The results showed as follows: 1) the feed-to-gain ratio (F/G) from 4 to 21 days of age in the CIP group was significantly higher than that in the C and CIESP groups (P<0.05). At the end of the experiment, the survival rate of CI group was 67%, while the survival rates of CIP and CIESP groups (75%) were higher than that of CI group but lower than that of CIA group (83%). 2) The malondialdehyde (MDA) content in serum and ileum in the CI group was significantly higher than that in the C group (P<0.05). The MDA content in serum, jejunum and ileum in the CIP, CIESP and CIA groups was significantly lower than that in the CI group (P<0.05). The total superoxide dismutase (T-SOD) activity in ileum in the CIESP group was extremely significantly higher than that in the CI group (P<0.01), and the glutathione peroxidase (GSH-Px) activity in serum, ileum and cecum was significantly higher than that in the CI group (P<0.05). The T-SOD activity in ileum in the CIA group was extremely significantly higher than that in the CI group (P<0.01). 3) The interleukin-6 (IL-6) content in ileum and cecum and the tumor necrosis factor-α (TNF-α) content in serum in the CI group were extremely significantly higher than those in the C group (P<0.01). Compared with the CI group, the IL-6 and TNF-α contents in serum, as well as the IL-6 content in ileum and cecum, were extremely significantly decreased in the CIP, CIESP and CIA groups (P<0.01); the TNF-α content in ileum was extremely significantly decreased (P<0.01), and the TNF-α content in cecum was significantly decreased (P<0.05) in the CIESP and CIA groups; the TNF-α content in jejunum was extremely significantly decreased in the CIA group (P<0.01). The contents of IL-6 and TNF-α in serum and ileum in the CIESP group were extremely significantly lower than those in the CIP group (P<0.01). 4) The ileal crypt depth (CD) in the CIESP group was significantly lower than that in the C group (P<0.05). The ileal villus height (VH) and CD in the CIA group were significantly lower than those in the C and CIP groups (P<0.05). 5) There was no significant difference in cecal microbiota Alpha diversity among all groups (P>0.05). The relative abundance of cecal Actinobacteria in the CIA group was extremely significantly higher than that in the other 4 groups (P<0.01). The relative abundance of cecal Ruminococcaceae_Ruminococcus in the CIESP group was significantly higher than that in the C, CI and CIP groups (P<0.05). The relative abundance of cecal Butyricicoccus in the CIP and CIESP groups was significantly higher than that in the C group (P<0.05). In conclusion, the enteric-coated sustained-release Phellodendron amurense extract can effectively reduce the increase in pro-inflammatory factor contents induced by coinfection with Eimeria and Clostridium perfringens, repair the damaged ileal tissue morphology, improve the antioxidant capacity, and alter the cecal microbiota structure of broilers.

This study aimed to compare differences in liver and abdominal fat phenotypes, as well as transcriptomic expression profiles, between low and high residual feed intake (RFI) fast-growing meat ducks, to investigate the mechanism underlying the negative regulation of RFI on abdominal fat deposition. A candidate population of 200 male fast-growing meat ducks was used. Ducks were housed in individual cages from 15 to 35 days of age, and individual RFI values were calculated. After ranking by RFI from high to low, the 10 individuals with the highest RFI were selected to form the high-RFI group (H-RFI group), and the 10 individuals with the lowest RFI were selected to form the low-RFI group (L-RFI group). The selected individuals were fasted for 12 h. After measuring the 35-day-old body weight, they were slaughtered. Liver weight and abdominal fat weight were measured, and the liver index and abdominal fat index were calculated. From each group, liver and abdominal fat tissues were collected from four ducks, total RNA was extracted, libraries were constructed, and transcriptome sequencing was performed. DESeq2 software was used to identify differentially expressed genes (DEGs) in liver and abdominal fat tissues between the two groups. The clusterProfiler package was employed for KEGG pathway enrichment analysis of DEGs and GSEA-KEGG pathway enrichment analysis of all genes to screen for pathways and candidate genes related to abdominal fat deposition. The results showed as follows: 1) no significant differences were observed in body weight at 35 days of age, liver weight, and liver index between the L-RFI and H-RFI groups (P>0.05). However, abdominal fat weight and abdominal fat index were extremely significantly lower in the L-RFI group compared with the H-RFI group (P<0.01). 2) Using the H-RFI group as the control, 24 up-regulated and 22 down-regulated DEGs were identified in the liver, while 49 up-regulated and 39 down-regulated DEGs were identified in the abdominal fat. No common DEGs were shared between the liver and abdominal fat. 3) KEGG pathway enrichment analysis revealed three significantly enriched pathways in the liver: transcriptional misregulation in cancer, protein processing in endoplasmic reticulum, and extracellular matrix (ECM)-receptor interaction, and two significantly enriched pathways in the abdominal fat: peroxisome proliferator-activated receptor (PPAR) signaling pathway and ECM-receptor interaction. Key candidate genes involved included high mobility group AT-hook 2 (HMGA2), nuclear factor-κB inhibitor zeta (NFKBIZ), zinc finger and BTB domain containing 16 (ZBTB16), growth arrest and DNA damage inducible gene 45 gamma (GADD45G), retinoid X receptor gamma (RXRG), lipoprotein lipase (LPL), stearoyl-CoA desaturase (SCD), glucokinase (GK), apolipoprotein C3 (APOC3), heat shock protein family A member 5 (HSPA5), thrombospondin 1 (THBS1), and thrombospondin 2 (THBS2). In conclusion, these results indicate that differences in fat deposition may be a key factor contributing to variation in RFI among individuals of fast-growing meat ducks. Gene functional enrichment analysis suggests that the transcriptional misregulation in cancer, protein processing in endoplasmic reticulum, PPAR signaling, and ECM-receptor interaction pathways may play important roles in regulating abdominal fat deposition in meat ducks. This study provides a theoretical foundation for breeding strategies aimed at reducing abdominal fat rate and improving feed utilization efficiency in meat ducks through negative selection for RFI.

This experiment aimed to investigate the effects of supplementing an enzyme blend to diets with different barley supplementation levels, based on the enzyme hydrolysate gross energy (EHGE) system, on the growth performance, slaughter performance and intestinal health of Cherry Valley meat-type ducks. A total of 992 one-day-old male Cherry Valley ducklings with an initial body weight of (53.44±0.47) g were randomly assigned to 4 groups with 4 replicates per group, and 62 ducks per replicate. A 2×2 factorial randomized design was used, with dietary barley supplementation levels at 20% and 40%, and enzyme blend supplementation levels at 0 and 0.5 g/kg. Group T1 received a 20% barley diet without the enzyme blend, group T2 received a 40% barley diet without the enzyme blend, group T3 received a 20% barley diet+0.5 g/kg enzyme blend, and group T4 received a 40% barley diet+0.5 g/kg enzyme blend. The trial lasted for 37 days. The results showed as follows: 1) regarding growth performance, compared with the 20% barley diet, the 40% barley diet significantly increased the feed-to-gain ratio (F/G) during 16 to 37 and 1 to 37 days of age (P<0.05), and significantly decreased the fattening index during the same periods (P<0.05). Compared with no enzyme supplementation, adding 0.5 g/kg of the enzyme blend to the barley-based diets significantly increased the average daily gain (ADG) and fattening index during 1 to 15, 16 to 37 and 1 to 37 days of age, as well as body weight at 15 and 37 days of age (P<0.05), while significantly reducing F/G during these periods (P<0.05). 2) For slaughter performance, the 40% barley diet significantly increased the relative weight of abdominal fat compared to the 20% barley diet (P<0.05). 3) Intestinal development results indicated that the 40% barley diet significantly increased the relative weight of jejunum (P<0.05). Enzyme blend supplementation significantly reduced both the relative weight and the weight per unit length of duodenum (P<0.05). 4) Analysis of cecal microbiota structure and function revealed that both barley supplementation level and enzyme blend supplementation level significantly affected the Chao1, Observed species, Shannon and Simpson indices of the cecal microbiota (P<0.05). At the phylum level, the 40% barley diet significantly increased the relative abundance of Actinobacteria (P<0.05). Enzyme blend supplementation significantly increased the relative abundance of Actinobacteria and decreased that of Firmicutes (P<0.05). At the genus level, enzyme blend supplementation significantly reduced the relative abundance of Bacteroides while increased that of Prevotella (P<0.05). In conclusion, supplementing an enzyme blend to high-level (40%) barley-based diets can effectively improve the growth performance of meat-type ducks and reshape their intestinal microbiota structure.

This study aimed to investigate the caging stress on structure, composition and short chain fatty acid (SCFA) producing capacity of jejunal and cecal bacterial community in Shaoxing ducks. Two hundred 168-day-old Shaoxing ducks were floor-reared and then placed in cages for 14 days. At days 0 (before caging, while still floor-reared), 1, 3, 7 and 14 after caging, ten ducks were randomly selected at each time point for weighing, slaughtering, and collecting eggs and jejunal and cecal contents samples for further analysis. The results showed as follows: compared with the before caging, the egg production rate of Shaoxing ducks dropped to 29.27% (vs. 76.50% before caging) on day 3 post-caging, and eggshell strength decreased significantly (P<0.05). In comparison with before caging, distinct differences in the structure of jejunal and cecal bacterial community were observed on days 1 and 3 post-caging. In the jejunum, the relative abundances of Bacteroidota and Muribaculum increased, while the relative abundances of Campylobacterota and Helicobacter decreased. In the cecum, the relative abundances of Firmicutes, Actinobacteriota, Faecalibacterium and Slackia increased, whereas the relative abundances of Proteobacteria and Bacteroides decreased. The SCFA quantification results showed that, compared with the before caging, the propionate content in the jejunal contents was significantly decreased on day 1 post-caging (P<0.05), the acetate and isovalerate contents in the jejunal contents were significantly decreased on day 3 post-caging (P<0.05), and the acetate content in the jejunal contents was reduced significantly on day 7 post-caging (P<0.05). In the cecal contents, the contents of acetate, propionate, butyrate and valerate were all significantly decreased on days 1, 3, and 7 post-caging compared with before caging (P<0.05). On day 14 post-caging, egg production, eggshell strength, jejunal and cecal bacterial community structure, and SCFA producing capacity returned to before caging levels. In conclusion, ephemeral caging stress can reduce egg production rate and egg quality in Shaoxing ducks, and it also can alter the structure, composition and SCFA producing capacity of the jejunal and cecal bacterial community. However, these indicators gradually recover to the before caging levels on day 14 post-caging.

This experiment was conducted to investigate the effects of adding different levels of sweet sorghum silage on growth performance, antioxidant capacity, slaughter performance, meat quality and intestinal health of geese from 28 to 70 days of age. A total of 180 male geese at 28 days of age were randomly allotted to 5 groups with 6 replicates per group and 6 goslings per replicate. Geese in the control group were fed a basal diet containing 0 sweet sorghum silage, and the others in the experimental groups were fed diets containing 4%, 8%, 12% and 16% sweet sorghum silage, respectively. The experiment lasted for 42 days. The results showed as follows: 1) from 28 to 49 days of age, compared with the control group, diets adding sweet sorghum silage significantly decreased average daily gain of geese (P<0.05), increased feed/gain (P<0.05). From 28 to 70 days of age, compared with the control group, diets adding 8%, 12% and 16% sweet sorghum silage significantly increased average daily feed intake and feed/gain (P<0.05), and had no significant effects on body weight at 70 days of age and average daily gain (P>0.05). Compared with the control group, diets adding 16% sweet sorghum silage increased feed cost per kg gain throughout the experimental period (P>0.05). 2) Diets adding sweet sorghum silage had no significant effects on plasma biochemical indexes of geese at the age of 70 days (P>0.05). Compared with the control group, diets adding 12% and 16% sweet sorghum silage increased plasma activity of glutathione peroxidase of geese at the age of 70 days (P>0.05), and had no significant effect on other antioxidant indicators in plasma (P>0.05). 3) Diets adding sweet sorghum silage had no significant effects on carcass trait and meat quality in breast muscle of geese at the age of 70 days (P>0.05). 4) Compared with the control group, diets adding 16% sweet sorghum silage significantly increased duodenal villus height of geese at the age of 70 days (P<0.05); diets adding sweet sorghum silage had no significant effects on other indicators of small intestinal morphology development (P>0.05); compared with the control group, diets adding 4%, 12% and 16% sweet sorghum silage significantly decreased duodenal mucosal trypsin of geese at the age of 70 days (P<0.05); diets adding sweet sorghum silage had no significant effects on other digestive enzyme activities in duodenal mucosal of geese at the age of 70 days (P>0.05). In conclusion, under the conditions of this experiment, dietary adding sweet sorghum silage can increase average daily feed intake, feed/gain, and feed cost per kg gain of geese, and increase antioxidant capacity and duodenal morphology development in geese. Based on feed cost per kg gain, the upper critical dietary addition of sweet sorghum silage is 12% in geese from 28 to 70 days of age.

This study aimed to investigate the effects of the supplementation of multiple plant extracts on performance, apparent nutrient digestibility, serum immune indicators and intestinal fermentation in mid-lactation Holstein dairy cows. A total of thirty cows [with milk yield (39.34±4.05) kg/d, (127.80±14.79) days in milk, (2.57±1.20) parities] were randomly divided into two groups (15 cows per group). Cows in the control group (CON group) were supplied with a basal diet containing 17.76% crude protein, while cows in the supplemented group (HAF group) received the same basal diet supplemented with 6 g/(head·day) multiple plant extracts. The experimental period lasted for 55 days, including a 10-day adaptation period and a 45-day trial period. Results showed as follows: 1) the milk yield, 4% fat-corrected milk yield, and energy-corrected milk yield in the HAF group were significantly higher than those in the CON group (P<0.05), while there were no significant differences in dry matter intake, milk protein percentage, milk fat percentage, or milk lactose percentage between HAF group and CON group (P>0.05). 2) Compared with the CON group, the apparent digestibility of dry matter, crude protein, crude fat, and neutral detergent fiber in the HAF group was significantly increased (P<0.05), but there was no significant difference in the apparent digestibility of acid detergent fiber (P>0.05). 3) Compared with the CON group, the serum contents of inflammatory factors interleukin-6 (IL-6) and haptoglobin (HP) in the HAF group were significantly decreased (P<0.05), while the serum contents of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-10 (IL-10), and serum amyloid A (SAA) showed no significant differences (P>0.05). 4) Compared with the CON group, the fecal isobutyrate content in the HAF group was significantly increased (P<0.05), and the contents of other volatile fatty acids remained unchanged (P>0.05). In conclusion, dietary supplementation of multiple plant extracts to mid-lactation Holstein dairy cows can maintain stable milk yield, significantly improve the apparent digestibility of nutrients, and enhance the body’s immune level.

This experiment aimed to investigate the effects of dietary rumen-protected docosahexaenoic acid (DHA) on performance, serum immune, inflammatory and antioxidant indices, and hindgut microbiota in dairy cows. Using a single-factor completely randomized design, 120 early-lactation Holstein cows with similar parity (2 to 3 parities), milk yield [(32.71±0.35) kg], and days in milk [(43.31±0.98) d] were randomly assigned to three groups of 40 cows each. The control (CON) group received a basal diet, while experimental groups 1 (T1) and experimental groups 2 (T2) were supplemented with 10 and 20 g/(cow·d) of rumen-protected DHA, respectively. The trial lasted 90 days. The day before experiment was set as “day 0”, and the initial index determination was completed on that day. The results showed as followed: 1) on day 0, days 1 to 30, days 31 to 60, days 61 to 90, and the overall 1 to 90 days, no significant changes were observed in dry matter intake (DMI) or average milk yield among the CON, T1, and T2 groups (P>0.05). Milk fat, milk protein, and lactose percentages on days 0, 30, 60, and 90 also were not different significantly (P>0.05). 2) On day 60, serum contents of immunoglobulin A (IgA), immunoglobulin M (IgM) and immunoglobulin G (IgG) were significantly higher in the T1 and T2 groups compared with the CON group (P<0.05). Serum contents of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were significantly lower (P<0.05), while serum interleukin-10 (IL-10) content was significantly higher (P<0.05) in the T1 and T2 groups. Moreover, serum malondialdehyde (MDA) content was significantly reduced (P<0.05), whereas total antioxidant capacity (T-AOC) and the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were significantly increased (P<0.05) in the T1 and T2 groups. 3) On day 0, the Chao 1 index of the hindgut microbiota was significantly lower in the T2 group than in the CON group (P<0.05); on day 90, it was significantly lower in both T1 and T2 groups compared with the CON group (P<0.05). At the phylum level, the relative abundance of Actinobacteriota in the T2 group was significantly higher than that in the CON and T1 groups on day 90 (P<0.05). At the genus level, the relative abundance of Monoglobus in the T1 group was significantly lower than that in the CON group on day 0 (P<0.05), while the relative abundance of Bifidobacterium in the T2 group was significantly higher than that in the CON and T1 groups on day 90 (P<0.05). In conclusion, dietary supplementation with 10 and 20 g/(cow·d) of rumen-protected DHA does not negatively affect production performance in dairy cows, effectively reduces systemic inflammation, and enhances immune function and antioxidant capacity. Furthermore, supplementation with 20 g/(cow·d) of rumen-protected DHA can modulate the structure of the hindgut microbiota, thereby further improving cow health status.

This experiment was conducted to investigate the effects of dietary supplementation of α-amylase (AM) or in combination with polysaccharide cinnamaldehyde (PC) on growth performance, meat quality, serum biochemical indices and nutrient apparent digestibility of Holstein steers. Twenty-one 16-month-old Holstein steers with a body weight of (614.28±42.61) kg were selected and randomly divided into 3 groups, with 7 replicates in each group and 1 cattle in each replicate. The control group (CK group) was fed a basal diet, the AM group was fed the basal diet+0.6 g/kg dry matter (DM) AM, and the APC group was fed the basal diet+0.6 g/kg DM AM+1 g/kg DM PC. The experiment lasted for 75 days, including a 15-day pre-experiment and a 60-day formal experiment. The results showed as follows: 1) there were no significant differences in growth performance and slaughter performance among the groups (P>0.05). Compared with the CK group, the marbling score in the AM group and the APC group showed an increasing trend (P=0.068). 2) Compared with the CK group, the cooking loss of longissimus muscle in the AM group was significantly reduced (P<0.05); the redness (a^*) and yellowness (b^*) values of longissimus muscle in the APC group were significantly increased (P<0.05), and the contents of intramuscular fat (IMF) and collagen in longissimus muscle were significantly increased (P<0.05). 3) Compared with the CK group, the serum creatinine content in the APC group was extremely significantly increased (P<0.01), and the serum albumin content showed an increasing trend (P=0.075). 4) Compared with the CK group, the DM apparent digestibility in the AM group was extremely significantly increased (P<0.01), and the apparent digestibilities of crude protein (CP) and neutral detergent fiber (NDF) were significantly increased (P<0.05); the NDF apparent digestibility in the APC group was significantly increased (P<0.05). In conclusion, dietary supplementation of AM or in combination with PC for Holstein steers in later fattening stage have no significant effects on growth performance and slaughter performance; dietary supplementation of AM can increase the apparent digestibilities of DM, CP and NDF, and reduce the cooking loss of longissimus muscle; the combined dietary supplementation of AM and PC can improve the meat color, increase the contents of IMF and collagen in longissimus muscle, and enhance the NDF apparent digestibility.

This experiment aimed to investigate the effects of low-protein diet supplemented with slow-release urea on the growth performance, serum biochemical indices, rumen fermentation parameters and microflora of beef cattle. Eighteen Simmental crossbred bulls with similar body weight [(521.86±22.86) kg] and in good health were selected and randomly divided into 3 groups, with 6 replicates in each group and 1 bull per replicate. The control group (CON group) was fed a basal diet with a protein level of 12.50%, the low-protein group (LP group) received a low-protein diet with the protein level reduced to 9.50%, and the slow-release urea group (SRU group) was fed a diet formulated based on the LP group diet, where 0.6% slow-release urea was used to iso-nitrogenously replace part of the feed ingredients, restoring the protein level to 12.50%, which was consistent with the CON group diet. The experiment included a 15-day adaptation period followed by a 35-day experimental period. The results showed as follows: 1) there were no significant difference in the average daily gain, dry matter intake, and feed-to-gain ratio of beef cattle among the groups (P>0.05). 2) The content of serum urea nitrogen in the LP group was significantly lower than that in the CON and SRU groups (P<0.05). 3) Regarding rumen fermentation parameters, the ammonia nitrogen (NH₃-N) content in the SRU group was significantly higher than that in the CON and LP groups (P<0.05); the proportion of butyrate in the SRU group was significantly higher than that in the LP group (P<0.05); the microbial protein (MCP) content and the proportion of isobutyrate in the LP group were significantly lower than those in the CON and SRU groups (P<0.05). 4) There were no significant differences in rumen microbial diversity among the groups (P>0.05). At the phylum level, Bacillota and Bacteroidetes were the dominant phyla across all groups, the relative abundance of Patescibacteria was significantly higher in the LP group than in the CON and SRU groups (P<0.05). At the genus level, dominant genera of all groups were Xylanobacter, Rikenellaceae_RC9_gut_group and norank_f__F082, the relative abundance of NK4A214_group in the LP group was significantly lower than that in the CON and SRU groups (P<0.05), and the relative abundance of Lachnospiraceae_NK3A20_group in the CON group was significantly higher than that in the LP and SRU groups (P<0.05). Correlation analysis revealed that the relative abundance of the Lachnospiraceae_NK3A20_group in the rumen showed an extremely significant positive correlation with MCP content (r=0.611, P=0.007), and showed a significant positive correlation with the proportion of isobutyrate (r=0.520, P=0.027). In conclusion, under the conditions of this experiment, reducing dietary protein level altered the relative abundance of certain rumen bacteria in beef cattle, leading to decreased serum UN content and reduced rumen NH₃-N and MCP contents, as well as changes in the proportions of butyrate and isobutyrate. Supplementation with slow-release urea can ameliorate these effects without negatively impacting the health and growth performance of beef cattle.

This experiment aimed to investigate the effects of dietary different starch levels on growth performance and fecal microbiota structure of yaks. Thirty healthy 3-year-old male yaks with similar body weight [(138±12) kg] were randomly divided into 3 groups with 10 yaks in each group. The dietary starch levels of 3 groups were 24% (LL group), 27% (ML group) and 30% (HL group), respectively. The pre-experimental period lasted for 10 days, and the experimental period lasted for 60 days. The results showed as follows: 1) there were no significant differences in the final body weight and average daily gain of yaks among all groups (P>0.05), but the final body weight and average daily gain of ML group were the highest. 2) The Chao1 index, Observed_features index, Shannon index and Simpson index of LL group were extremely significantly higher than those of ML group and HL group (P<0.01). 3) At the phylum level, the relative abundances of Firmicutes and Bacteroidota in feces of ML group were the highest, which were 63.76% and 32.04%, respectively; the fecal Firmicutes relative abundance of ML group was significantly higher than that of HL group (P<0.05), and the fecal Proteobacteria relative abundance of HL group was extremely significantly higher than of LL group and ML group (P<0.01). At the genus level, the fecal UCG-005 relative abundance of ML group was the highest, which was 31.75%; the fecal UCG-005 relative abundances of LL group and HL group were 28.83% and 7.91%, respectively; the fecal potential pathogens such as Escherichia_Shigella relative abundance of HL group was higher. In conclusion, the dietary starch level influences the fecal microbiota diversity of yak by regulating the gut microbiota structure. Compare with the 24% and 30% starch levels, the 27% starch level is conducive to improving the growth performance of yaks, and the fecal microbiota diversity of yaks is moderate, with a higher relative abundance of beneficial bacteria, and no pathogenic bacteria present, making it more suitable for the intestinal tract of yaks.

This experiment was conducted to investigate the effects of dextran and polyglutamic acid on rumen fermentation parameters, microbial flora and metabolome of perinatal dairy goats. Eighteen healthy primiparous Saanen dairy goats in late pregnancy with similar body weight [(40.00±1.73) kg] were randomly divided into 3 groups (6 goats per group): a high-dose group (HI group), a low-dose group (LO group) and a control group (CON group). Goats in the HI group were orally administered with 3 g dextran+20 g polyglutamic acid per day, those in the LO group were orally administered with 1.5 g dextran+10 g polyglutamic acid per day, and those in the CON group were orally administered with the same volume of normal saline per day. The continuous oral administration lasted for 42 days (21 days before parturition and 21 days after parturition). Rumen fluid samples were collected on day 1 and day 21 postpartum for the determination of rumen fermentation parameters, microbial flora and metabolome. The results showed as follows: 1) on day 21 postpartum, the valeric acid content in rumen fluid of the LO group and HI group was significantly higher than that of the CON group (P<0.05), the butyric acid content tended to be higher than that of the CON group (P=0.057), and the ammonia nitrogen content tended to be lower than that of the CON group (P=0.073). On day 21 postpartum, there were no significant differences in all rumen fermentation parameters among the three groups (P>0.05). 2) On day 21 postpartum, the α diversity indexes of rumen microbiota (except Goods_coverage index) in the HI group were higher than those in the CON group and LO group, but the differences were not significant (P>0.05). On day 21 postpartum, the proportion and abundance of Prevotella in rumen of the HI group were higher than those in the CON group and LO group. The two significantly different microbial predictive functions with the highest enrichment degree in the HI group were RNA polymerase and biosynthesis of unsaturated fatty acids. On day 21 postpartum, the differential microorganisms between the HI group and CON group showed significant differences in the functions of Staphylococcus aureus infection and ECM-receptor interaction (P<0.05). 3) On day 21 postpartum, compared with the CON group, the significantly up-regulated differential metabolites in rumen fluid of the HI group included 4,4'-diaminodibutylamine classified as heterocyclic compounds, pyridoxamine-5'-phosphate classified as organic acids and their derivatives, and L-methionine sulfoxide classified as amino acids and their metabolites (P<0.05); the significantly down-regulated differential metabolites included 4-(3-methylbutoxy) aniline hydrochloride classified as benzene and its derivatives, trans-2-hexenal dimethyl acetal, and Trp-Ile classified as amino acids and their metabolites (P<0.05). The metabolic pathways with high significant differences between the two groups were cysteine and methionine metabolism and inflammatory mediator regulation of TRP channels. In conclusion, oral administration of dextran and polyglutamic acid can promote the rumen fermentation function, increase the proportion and abundance of rumen dominant microbiota, and improve the abundance of energy-supplying nutrient metabolites in the rumen of perinatal dairy goats.

This experiment was conducted to investigate the effects of dietary chromium supplementation on antioxidant capacity, immune function and milk composition in late-gestation does, so as to determine the appropriate dietary chromium supplementation level for pregnant does. Forty multiparous Lezhi black goats at (90±4) days of gestation with similar body weight [(52.36±8.24) kg] and body condition were selected and randomly divided into 4 groups with 10 replicates (pens) per group and 1 doe per replicate. The control group was fed a basal diet, and the experimental groups were supplemented with 0.4, 1.2 and 2.0 mg/d chromium (in the form of chromium propionate) on the basis of the basal diet, respectively. The experiment lasted for 81 days from day 90 of gestation to day 21 of lactation, including a 7-day pre-experimental period. Blood samples of does were collected on day 120 of gestation, and milk samples were collected on day 1 (colostrum), day 3, day 7, day 14 and day 21 of lactation. The results showed as follows: 1) dietary chromium supplementation significantly reduced the mortality rate of kids born to does during 1 to 7 days of age and 1 to 21 days of age (P<0.05), and tended to reduce the mortality rate of kids during 1 to 14 days of age (P=0.074 5), and no dead individuals were found in the group supplemented with 1.2 mg/d chromium. 2) Dietary supplementation with different levels of chromium had no significant effects on the serum superoxide dismutase, glutathione peroxidase activities, glucose, urea nitrogen and immunoglobulin A contents of does (P>0.05); the serum malondialdehyde content had linear and quadratic effects with the increase of dietary chromium supplementation level (P<0.05), compared with the control group, the serum malondialdehyde content in the group supplemented with 1.2 mg/d chromium had no significant change (P>0.05), while that in the group supplemented with 2.0 mg/d chromium was significantly increased (P<0.05); the serum total protein, immunoglobulin G and immunoglobulin M contents increased linearly with the increase of dietary chromium supplementation level (P<0.05), and the serum immunoglobulin G and immunoglobulin M contents in the groups supplemented with 1.2 and 2.0 mg/d chromium were significantly higher than those in the control group (P<0.05). 3) The colostrum milk fat content of does increased linearly with the increase of dietary chromium supplementation level (P<0.05), and the colostrum milk fat contents in the groups supplemented with 1.2 and 2.0 mg/d chromium were significantly higher than that in the control group (P<0.05). It can be concluded that under the conditions of this experiment, the appropriate dietary chromium supplementation level for late-gestation does is 1.2 mg/d; this supplementation level can significantly improve the immune function of does and effectively increase the colostrum milk fat content.

This study aimed to investigate the energy and protein requirements of Tan sheep breed rams at different periods. Thirty-two 1.5-year-old Tan breed rams with similar body weight and good condition were selected and randomly divided into the energy group [initial body weight was (56.15±2.12) kg] and the protein group [initial body weight was (48.53±2.50) kg]. Each group was further divided into 4 groups, with 4 replicates in each group and 1 sheep in each replicate. The experimental sheep in the energy groups were fed with diets with digestible energy (DE) levels of 8.50 (group Ⅰ), 10.00 (group Ⅱ), 11.50 (group Ⅲ) and 13.00 MJ/kg (group Ⅳ), respectively, and the crude protein (CP) content in diets was 9.10%. The experimental sheep in the protein groups were fed with diets with CP contents of 6.99% (group Ⅰ), 8.25% (group Ⅱ), 9.49% (group Ⅲ) and 10.79% (group Ⅳ), respectively, and the dietary DE level was 9.0 MJ/kg. The experiment lasted for 120 days, and was divided into three periods as the mating preparation period (50 days), the mating period (40 days), and the mating recovery period (30 days). The digestion and metabolism experiment was conducted in the last 10 days of each period. The former 30 days of the mating period were divided into three phases (F₁, F₂ and F₃ phases) with different frequencies of sperm collection. The results showed as follows: 1) with the increase of dietary DE level and CP content, the average daily gain (ADG) of experimental sheep was significantly increased (P<0.05). With the increase of sperm collection frequency, the ADG was decreased, showing a negative growth. 2) With the increase of dietary DE level, the serum glucose content of experimental sheep was significantly increased in each mating phase (P<0.05), the serum urea nitrogen (Urea) content was significantly decreased at each mating phase and mating recovery period (P<0.05), the serum triglyceride (TG) content was significantly increased in the mating F₂ phase (P<0.05), and the serum contents of TG and total cholesterol were significantly increased in the mating F₃ phase (P<0.05). With the increase of dietary CP content, the serum Urea content of experimental sheep was significantly increased at each period (P<0.05). 3) The semen quality of experimental sheep in energy group Ⅱ was relatively high. With the increase of dietary CP content, the ejaculation volume, sperm density and effective sperm count were significantly increased (P<0.05). With the increase of sperm collection frequency, the semen quality was significantly decreased (P<0.05), and the serum testosterone content was significantly decreased (P<0.05). 4) The dietary energy and protein requirements of Tan sheep breed rams at different periods were as follows. The mating preparation period: DE (MJ/d) =0.557W^0.75+0.071ADG (R²=0.802, P<0.01) (W^0.75 was metabolic body weight, the same as below), metabolic energy (ME, MJ/d)=0.450W^0.75+0.061ADG (R²=0.799, P<0.01); CP (g/d) =5.52W^0.75+0.366ADG (R²=0.998, P<0.01), digestible crude protein (DCP, g/d)=2.95W^0.75+0.310ADG (R²=0.983, P<0.01). The mating period: DE (MJ/d)=0.557W^0.75+0.928 3n (n was the number of sperm collection, the same as below), ME (MJ/d)=0.450W^0.75+0.765 6n; CP (g/d)=5.52W^0.75+68.97n, DCP=2.95W^0.75+47.84n. The mating recovery period: DE (MJ/d)=0.444W^0.75+0.046ADG (R²=0.890, P<0.01), ME (MJ/d)=0.359W^0.75+0.039ADG (R²=0.891, P<0.01); CP (g/d)=5.55W^0.75+0.604ADG (R²=0.972, P<0.01), DCP (g/d)=2.37W^0.75+0.506ADG (R²=0.974, P<0.01). In conclusion, it is recommended that the DE requirement for Tan sheep breed rams is 11.40 MJ/d and the CP requirement is 171.12 g/d.

This study aimed to investigate the effects of dietary excessively high or low fat levels on growth performance and intestinal health of largemouth bass (Micropterus salmoides). A total of 270 largemouth bass with an average initial body weight of (2.68±0.01) g were selected and randomly divided into 3 groups with 3 replicates per group and 30 fish per replicate. The dietary fat levels of the control group, low-fat group and high-fat group were 10%, 4% and 18%, respectively. The experiment lasted for 8 weeks. The results showed that compared with the control group, dietary excessively high or low fat levels affected the growth performance of largemouth bass, which showed the weight gain rate and specific growth rate were significantly decreased (P<0.05), and the feed conversion ratio was significantly increased (P<0.05); weakened the intestinal antioxidant capacity, which showed the intestinal malondialdehyde content was significantly increased (P<0.05), and the intestinal superoxide dismutase and catalase activities were significantly decreased (P<0.05); induced the intestinal inflammation, which showed the gene relative expression levels of interleukin-1β (IL-1β), interleukin-8 (IL-8) and transforming growth factor-β (TGF-β) in intestine were significantly up-regulated (P<0.05); aggravated the intestinal apoptosis, which showed the gene relative expression levels of cysteinyl aspartate proteinase 3 (Caspase3) and cysteinyl aspartate proteinase 9 (Caspase9) in intestine were significantly up-regulated (P<0.05); reduced the intestinal microbiota α diversity and changed its composition, which showed the relative abundances of Firmicutes and Mycoplasma in intestine were significantly increased (P<0.05), and the relative abundances of Cyanobacteria and Actinobacteriota in intestine were significantly decreased (P<0.05). In conclusion, dietary excessively high or low fat levels have negative effects on the growth performance and intestinal health of largemouth bass.

This experiment was conducted to study the effects of dietary Zanthoxylum bungeanum seeds supplemental level on growth performance, slaughtering performance, serum biochemical indicators, muscle quality and antioxidant capacity of meat rabbits, and so as to provide a theoretical reference for the use of Zanthoxylum bungeanum seeds in rabbit production. A total of 256 Taishan white rabbits at 35 days of age were randomly divided into 4 groups with 8 replicates per group and 8 rabbits per replicate. Rabbits in 4 group were fed experimental diets which supplemented with 0 (control), 2%, 4% and 6% Zanthoxylum bungeanum seeds powder, respectively. The pre-experimental period lasted for 7 days, and the experimental period lasted for 42 days. The results showed as follows: 1) the average daily feed intake of 6% addition group was significantly lower than that of control group, 2% addition group and 4% addition group (P<0.05), and the feed to gain ratio of 2% addition group and 6% addition group was significantly lower than that of the control group (P<0.05). 2) The liver index of 6% addition group was significantly lower than that of control group, 2% addition group and 4% addition group (P<0.05), and the kidney index of 6% addition group was significantly higher than that of control group, 2% addition group and 4% addition group (P<0.05). 3) The contents of total protein and albumin in serum of 2% addition group, 4% addition group and 6% addition group were significantly lower than those of the control group (P<0.05), the serum globulin content of 4% addition group was significantly lower than that of control group, 2% addition group and 6% addition group (P<0.05), and the serum albumin/globulin of 4% addition group was significantly higher than that of control group, 2% addition group and 6% addition group (P<0.05). 4) The muscle redness value of 4% addition group was significantly higher than that of the control group (P<0.05), and the muscle brightness value of 4% addition group and 6% addition group was significantly lower than that of the control group (P<0.05). 5) The contents of dry matter, ether extract and organic matter in muscle of 2% addition group, 4% addition group and 6% addition group were significantly higher than those of the control group (P<0.05), and the muscle crude protein content of 4% addition group and 6% addition group was significantly higher than that of the control group (P<0.05). 6) The total antioxidant capacity and activities of superoxide dismutase and catalase in muscle of 2% addition group, 4% addition group and 6% addition group were significantly higher than those of the control group (P<0.05), the muscle malondialdehyde content of 2% addition group, 4% addition group and 6% addition group was significantly lower than that of the control group (P<0.05), and the muscle glutathione peroxidase activity of 2% addition group and 4% addition group was significantly higher than that of the control group (P<0.05). In conclusion, dietary Zanthoxylum bungeanum seeds can improve the growth performance of meat rabbits, improve the muscle color, increase the muscle nutritional value, improve the muscle antioxidant capacity, and the appropriate supplemental level of Zanthoxylum bungeanum seeds is 2% to 4%.

This study aimed to investigate the alleviating effects of taurine (TAU) on deoxynivalenol (DON)-induced ileal injury in weaned piglets and to elucidate its potential underlying mechanisms. A total of 18 healthy weaned piglets at 21 days of age with similar body weight were randomly assigned into three groups as BD group (fed basal diet), DON group (fed 3 mg/kg DON-contaminated diet), and DON+TAU group (fed 3 mg/kg DON-contaminated diet+3 000 mg/kg TAU) with 6 replicates in each group and 1 pig in each replicate, and fed for 24 days. The results showed as follows: 1) compared with BD group, DON exposure significantly decreased the ileal villus height and villus height to crypt depth ratio (P<0.05), significantly increased the crypt depth (P<0.05), significantly decreased the goblet cell number (P<0.05), and significantly reduced the mucin 2 (MUC2) mRNA relative expression level and relative fluorescence intensity, as well as downregulating both the mRNA and protein relative expression levels of tight junction proteins [zonula occludens 2 (ZO2), occludin (OCLN) and claudin 1 (CLDN1)] (P<0.05). DON significantly elevated the 8-hydroxydeoxyguanosine (8-OHdG) and malonaldehyde (MDA) contents, while significantly reduced the activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) as well as glutathione (GSH) content, and significantly decreased the mRNA relative expression levels of antioxidant-related genes such as nuclear factor E2-related factor 2 (Nrf2), heme oxygenase 1 (HO1), superoxide dismutase 1 (SOD1) and superoxide dismutase 2 (SOD2) (P<0.05). Moreover, DON significantly increased the contents of pro-inflammatory cytokines [interleukin-1β (IL-1β), interleukin-6 (IL-6) and interleukin-8 (IL-8)] and cell apoptosis rate (P<0.05), significantly suppressed B-cell lymphoma 2 (BCL2) expression and upregulated B-cell lymphoma 2-associated X protein (BAX), cytochrome C (CYCS), Caspase 9 (CASP9), Caspase 3 (CASP3) and apoptosis inducing factor mitochondria associated 1 (AIFM1) expression (P<0.05), and significantly increased the protein relative expression levels of BAX, cleaved CASP3 and AIFM1 (P<0.05). In addition, DON disrupted mitochondrial structure, significantly reduced the activities of mitochondrial respiratory chain complexes Ⅰ, Ⅱ and Ⅳ, as well as ATP content and mitochondrial DNA (mtDNA) relative copy number (P<0.05), and induced the mitochondrial quality control imbalance [significant downregulation of expression of peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α), nuclear respiratory factor 1 (NRF1), transcription factor A, mitochondrial (TFAM), and mitofusin 2 (MFN2) (P<0.05), and significant upregulation of expression of dynamin-related protein 1 (DRP1), fission, mitochondrial 1 (FIS1), PTEN induced kinase 1 (PINK1), Parkin RBR E3 ubiquitin protein ligase (PRKN) and microtubule associated protein 1 light chain 3β (LC3B) (P<0.05)]. 2) Compared with DON group, TAU treatment significantly alleviated the injury of morphological structure of ileal tissues and the down-regulation of barrier function-related indices (P<0.05), significantly reduced the MDA content (P<0.05), significantly increased the T-SOD activity (P<0.05), and significantly upregulated antioxidant-related gene expression (P<0.05). TAU also significantly reduced the contents of IL-1β and IL-8 as well as cell apoptosis rate (P<0.05), significantly reversed the abnormal expression of apoptosis-related genes and proteins (P<0.05), restored mitochondrial structure, significantly enhanced the activities of mitochondrial respiratory chain complexes Ⅰ, Ⅱ, Ⅲ and Ⅳ, as well as ATP content and mtDNA relative copy number (P<0.05), and significantly improved the mitochondrial quality control process (P<0.05) and maintained its functional homeostasis. In conclusion, dietary supplementation of TAU can alleviate DON-induced ileal injury in weaned piglets, potentially by regulating mitochondrial quality control to maintain mitochondrial functional homeostasis, reducing oxidative stress, inflammation and apoptosis, as well as improving barrier function.

This study aimed to investigate the alleviating effect of Pleurotus ostreatus polysaccharides (POP) on aflatoxin B₁ (AFB₁)-induced oxidative damage in porcine intestinal epithelial cells (IPEC-J2 cells). First, the working concentrations of POP and AFB₁, as well as the pretreatment time of POP, were determined using the CCK-8 kit. Subsequently, IPEC-J2 cells were divided into four groups (with three replicates per group): 1) Control group, no treatment; 2) AFB₁ group, treated with 16 μmol/L AFB₁ for 24 h; 3) POP+AFB₁ group, pretreated with 0.25 mg/mL POP for 24 h, followed by co-treatment with 16 μmol/L AFB₁ for another 24 h; 4) POP group, treated with 0.25 mg/mL POP for 24 h. After treatment, cells were collected to measure reactive oxygen species (ROS) relative content, mitochondrial membrane potential, ATP relative level, antioxidant enzyme activities, and the relative expression levels of apoptosis-related proteins and mitochondrial dynamics-related proteins. The results showed that: 1) treatment of IPEC-J2 cells with 16 μmol/L AFB₁ for 24 h successfully established an oxidative damage model; pretreatment with 0.25 mg/mL POP for 24 h extremely significantly increased cell viability (P<0.01). 2) Compared with the Control group, the AFB₁ group showed an extremely significant increase in ROS relative content (P<0.01), an extremely significant decrease in mitochondrial membrane potential and ATP relative level (P<0.01), an extremely significant reduction in the relative expression level of mitofusin 1 (MFN1) (P<0.01), a significant reduction in the relative expression level of mitofusin 2 (MFN2) (P<0.05), an extremely significant decrease in the relative expression level of the anti-apoptotic protein B-cell lymphoma-2 (Bcl-2) (P<0.01), a significant decrease in the Bcl-2/Bcl-2-associated X protein (Bax) ratio (P<0.05), and an extremely significant reduction in the activities of the antioxidant enzymes glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) (P<0.01). In contrast, pretreatment with 0.25 mg/mL POP for 24 h reversed all the above changes. In conclusion, POP alleviates AFB₁-induced oxidative damage in porcine intestinal epithelial cells by restoring mitochondrial function and maintaining mitochondrial dynamics homeostasis.

This experiment aimed to investigate the effects of dietary coconut oil supplementation on lipopolysaccharide (LPS)-induced muscle injury and cyclic GMP-AMP synthase (cGAS)-stimulator of interferon gene (STING) signaling pathway in piglets. A total of twenty-four 28-day-old “Duroc×Landrace×Yorkshire” weaned piglets were randomly allocated to four groups with six replicates per group and one piglet per replicate. A 2×2 factorial design was adopted, with the main factors being dietary treatment (supplemented with 3% soybean oil or 3% coconut oil) and LPS treatment (injected with LPS or saline). On day 28 of the trial, piglets were intraperitoneally injected with 100 μg/kg BW LPS or an equal volume of saline, and samples were collected after slaughter 4 hours later. The results showed as follows: 1) coconut oil significantly reduced the serum total protein (TP) content under LPS challenge (P<0.05), and alleviated the LPS-induced decrease in serum glucose (GLU) content (P>0.05). 2) Coconut oil significantly exacerbated the LPS-induced increase in the mRNA relative expression level of interleukin-6 (IL-6) in muscle (P<0.05), and significantly inhibited the LPS-induced increase in the mRNA relative expression level of interleukin-10 (IL-10) in muscle (P<0.05). 3) Coconut oil significantly reduced the muscle malondialdehyde (MDA) content (P<0.05) and significantly alleviated the LPS-induced increase in muscle total antioxidant capacity (T-AOC) (P<0.05). 4) Coconut oil significantly increased the mRNA relative expression level of forkhead box protein O1 (FOXO1) in muscle (P<0.05), and significantly increased the relative mRNA expression of both FOXO1 and forkhead box protein O4 (FOXO4) in muscle under LPS challenge (P<0.05). 5) Coconut oil significantly increased the mRNA relative expression level of 2',5'-oligoadenylate synthetase 2 (OAS2) in muscle (P<0.05), and significantly exacerbated the LPS-induced increase in the mRNA relative expression level of STING in muscle (P<0.05). Based on the above results, it can be concluded that replacing an equal amount of soybean oil with coconut oil in the diet promotes the activation of the cGAS-STING signaling pathway, and exacerbates LPS-induced muscle inflammation and protein degradation in piglets.

This study aimed to investigate the effects of arginine (Arg) on proliferation and milk fat fatty acid synthesis of bovine mammary epithelial cells (BMECs) through G protein-coupled receptor family C, group 6 and subtype A (GPRC6A)/protein kinase B (Akt)-mammalian target of rapamycin (mTOR) signaling pathway, and systematically evaluate its regulatory effects and molecular mechanisms on the proliferation activity, apoptosis level and milk fat synthesis ability of BMECs. Using BMECs as a model, the cell proliferation was assessed by CCK-8, and the expression of proteins related to proliferation, apoptosis and fatty acid synthesis was detected by Western blot. The cells were treated with the Akt inhibitor (AKT-IN-1), mTOR inhibitor (rapamycin), AMP-activated protein kinase (AMPK) activator (EX229) and GPRC6A mall interfering RNA (siRNA), to verify the signaling pathway dependency of Arg’s effects. The results showed that 1.00 μmol/L Arg significantly promoted BMECs proliferation (P<0.05), significant or extremely significant up-regulated the protein expression levels of proliferation marker proteins such as proliferating cell nuclear antigen (PCNA), cyclin D1 (Cyclin D1) and B-cell lymphoma 2 (BCL2) (P<0.05 or P<0.01), and significant or extremely significant down-regulated the protein expression levels of pro-apoptotic proteins such as BCL2 associated X protein (BAX), cysteine aspartic acid specific protease-3 (Caspase-3) and cysteine aspartic acid specific protease-9 (Caspase-9) (P<0.05 or P<0.01). Arg activated GPRC6A and its downstream Akt-mTOR signaling pathway, and the proliferative and anti-apoptotic effects were reversed by GPRC6A siRNA or Akt/mTOR inhibitors. In addition, 1.00 μmol/L Arg significant or extremely significant up-regulated the protein expression levels of fatty acid synthesis-related proteins such as peroxisome proliferator-activated receptor gamma (PPARγ), sterol regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FASN) and stearoyl-CoA desaturase 1 (SCD1) (P<0.05 or P<0.01), and the AMPK activation or GPRC6A siRNA could blocked the fatty acid synthesis-promoting effect of Arg. Collectively, the Arg promotes BMECs proliferation and inhibits apoptosis via the GPRC6A receptor mediated activation of the Akt-mTOR signaling pathway, and enhances the milk fat fatty acid synthesis through the GPRC6A/AMPK axis, providing a theoretical basis for targeted regulation of milk component synthesis.

This study was conducted to investigate the promoting effects of selenium (Se) on the synthesis of sphingosine-1-phosphate (S1P) and its mediated antioxidant and anti-inflammatory responses in peripheral blood mononuclear cells (PBMCs) of donkey, and to screen for the appropriate doses of Se or S1P. Two experiments were employed a single-factor completely randomized experimental design, adding different doses of Se [0, 0.2, 0.5, 1.0, 2.0 and 5.0 nmol/L, which were named as SE0 (control), SE0.2, SE0.5, SE1.0, SE2.0 and SE5.0 groups, with eight replicates per group] or different doses of S1P [0, 0.1, 0.2, 0.5, 1.0 and 2.0 nmol/L, which were named as SP0 (control), SP0.1, SP0.2, SP0.5, SP1.0 and SP2.0 groups, with eight replicates per group] in PBMCs. The results showed as follows: 1) compared with SE0 group, the cell viability and activities of catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) and contents of S1P and interleukin (IL)-2 in PBMCs of SE0.5 and SE1.0 groups were significantly increased (P<0.05), and the contents of IL-4, IL-6 and lipopolysaccharide (LPS) were significantly decreased (P<0.05); the mRNA relative expression levels of sphingosine-1-phosphate receptor 2 (S1PR2), acid ceramidase 1 (ASAH1) and sphingosine kinase 2 (SPHK2) in PBMCs of SE0.5 and SE1.0 groups were significantly increased (P<0.05); the mRNA relative expression levels of IL-2 and IL-10 in PBMCs of SE1.0 group were significantly increased (P<0.05), and the IL-6 mRNA relative expression level was significantly decreased (P<0.05). 2) Compared with SP0 group, the activities of CAT and SOD and contents of IL-2 and IL-6 in PBMCs of SP0.2 and SP0.5 groups were significantly increased (P<0.05), and the content of malondialdehyde (MDA) and activities of inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS) were significantly decreased (P<0.05); the mRNA relative expression levels of S1PR2, ASAH1, SPHK2 and IL-10 in PBMCs of SP0.2 group were significantly increased (P<0.05); the mRNA relative expression levels of GPx1 and IL-2 in PBMCs of SP0.2 and SP0.5 groups were significantly increased (P<0.05), and the mRNA relative expression levels of tumor necrosis factor-α (TNF-α) and IL-6 were significantly decreased (P<0.05). In summary, both Se and S1P can promote the antioxidant level and anti-inflammatory response in PBMCs of donkey, enhance the cell vitality, and Se can increase the S1P content and the mRNA relative expression levels of S1P synthesis-related genes ASAH1 and SPHK2 and receptor gene S1PR2. It shows good effects when the addition doses of Se and S1P are 0.5, 1.0 nmol/L and 0.2, 0.5 nmol/L, respectively.

This study aimed to establish an in vitro isolation and culture method for equine cardiac fibroblasts and analyze their biological characteristics, thereby providing a critical cellular model for equine exercise physiology and cardiac remodeling research. Using fetal horse heart tissue aged 3 to 6 months as experimental material, cardiac fibroblasts were isolated via a combined digestion method with trypsin and type Ⅱ collagenase. Subsequently, morphological observation, immunofluorescence characterization, growth curve analysis, apoptosis detection, and chromosomal karyotype analysis were performed on the cells. The results showed as follows: 1) the combined digestion method with trypsin and type Ⅱ collagenase successfully isolated equine cardiac fibroblasts, which could be sub-cultured continuously. Even at passage 16, the equine cardiac fibroblasts retained typical fibroblast characteristics and maintained good viability. 2) Immunofluorescence staining confirmed that the cultured cells were equine cardiac fibroblasts. 3) The cell cryopreservation and thawing test indicated that cells from both passage 3 and passage 16 maintained a viability above 90% after cryopreservation and thawing. 4) Growth curve analysis demonstrated that the isolated equine cardiac fibroblasts grew stably and healthily under in vitro culture conditions, exhibiting strong proliferative capacity. 5) Analysis based on low apoptosis rates and normal karyotypes indicated the cells were currently in good condition. In summary, this study successfully isolated equine cardiac fibroblasts using a combined digestion method with trypsin and type Ⅱ collagenase. The obtained cells exhibit typical morphology, strong proliferative capacity, and maintain excellent viability after multiple passages and cryopreservation.

This study aimed to explore the potential of Sophora alopecuroides L. to alleviate heat stress in animals using network pharmacology and molecular docking technology. The potential effective active ingredients of Sophora alopecuroides L. were retrieved from the HERB database, and their putative targets were predicted using the SwissTargetPrediction database. A “Sophora alopecuroides L.-potential effective active ingredients-targets” network was constructed and visualized with Cytoscape 3.10.3. Heat stress-related targets were collected from the GeneCards, OMIM and TTD databases. The overlapping targets between the potential effective active ingredient action targets of Sophora alopecuroides L. and heat stress-related targets were identified via a Venn diagram generated on the MicroBioInfo platform. These overlapping targets were uploaded to the STRING database to construct a protein-protein interaction (PPI) network, which was further refined and visualized using Cytoscape 3.10.3. Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for the overlapping targets were performed using the DAVID database. Molecular docking between the top 5 core targets from the PPI network and the potential effective active ingredients of Sophora alopecuroides L. was conducted using PyMOL 3.1.5 and AutoDockTools 1.5.7. The results showed as follows: 1) Sophora alopecuroides L. mainly contains 10 potential effective active ingredients, including cytisine, matrine, sophocarpine, sophoramine, and sophoridine. 2) A total of 276 overlapping targets between the action targets of potential effective active ingredients in Sophora alopecuroides L. and the heat stress-related targets were found, primarily involving protein kinase B1 (AKT1), caspase 3 (CASP3), epidermal growth factor receptor (EGFR), heat shock protein 90 alpha family class A member 1 (HSP90AA1), and matrix metalloproteinase 9 (MMP9). 3) GO functional enrichment analysis yielded 618 entries (P<0.01), comprising 372 biological process (BP) related entries [e.g., positive regulation of mitogen-activated protein kinase (MAPK) cascade, chemical synaptic transmission, and adenylate cyclase-activating adrenergic receptor signaling pathway], 80 cellular component (CC) related entries (e.g., plasma membrane, synapse and cell surface), and 166 molecular function (MF) related entries (e.g., identical protein binding, protein kinase activity, and protein serine/threonine kinase activity). 4) KEGG pathway enrichment analysis revealed 148 entries (P<0.05), mainly including the phosphoinositide 3-kinase (PI3K)- protein kinase B (Akt), cyclic adenosine monophosphate (cAMP), and calcium signaling pathways. 5) Molecular docking confirmed stable binding between the top 5 core targets and the potential effective active ingredients of Sophora alopecuroides L. In conclusion, Sophora alopecuroides L. may alleviate heat stress through potential effective active ingredients such as sophocarpine, sophoramine, sophoridine, and matrine, acting on core targets like AKT1, CASP3, EGFR, HSP90AA1 and MMP9, and by modulating multiple signaling pathways including PI3K-Akt, cAMP, and calcium. This study provides a theoretical foundation for further investigation into the mechanism by which Sophora alopecuroides L. mitigates heat stress.

This study aimed to predict the mechanism by which rutin alleviates porcine intestinal damage using network pharmacology, molecular docking technology, and in vitro cell experiments, so as to provide insights for the application of rutin in livestock and poultry production. Targets of rutin were retrieved from the Traditional Chinese Medicine Systems Pharmacology (TCMSP), SwissTargetPrediction, TargetNet, SuperPred, and PharmMapper databases. Targets related to intestinal damage were collected from the GeneCards database. Overlapping targets were identified, and a protein-protein interaction (PPI) network for porcine intestinal damage was constructed using the STRING database. Core targets were screened with Cytoscape 3.8.0. Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed on the overlapping targets using the DAVID database. A rutin-intestinal damage target-signaling pathway network was built with Cytoscape 3.8.0. Molecular docking between rutin and the core targets was conducted using AutoDock Vina 1.2.5 and visualized with PyMOL 2.6. Finally, quantitative real-time PCR (RT-qPCR) was performed on intestinal porcine epithelial cell line J2 (IPEC-J2) for experimental validation. The results showed as follows: 1) a total of 357 action targets of rutin and 14 729 intestinal damage-related targets (after quality control) were obtained, with 182 overlapping targets. The PPI network consisted of 174 nodes and 140 edges, with an average node degree of 4.37. 2) The core targets identified were insulin (INS), heat shock protein 90 alpha family class A member 1 (HSP90AA1), hypoxia-inducible factor 1 alpha (HIF1A), Toll-like receptor 4 (TLR4), and estrogen receptor 1 (ESR1). Molecular docking confirmed stable binding between rutin and these core targets. 3) GO analysis yielded 170 biological processes (BP), 44 cellular components (CC), and 89 molecular functions (MF). KEGG enrichment analysis identified 97 signaling pathways. 4) In vitro experiments showed that, compared with the control group, rutin significantly increased the mRNA relative expression levels of HSP90AA1 and ESR1 (P<0.05) and significantly decreased the mRNA relative expression level of HIF1A (P<0.05), while no significant effects were observed on INS and TLR4 mRNA relative expression levels (P>0.05). In conclusion, rutin may alleviate porcine intestinal damage by interacting with core targets such as HSP90AA1, HIF1A, and ESR1, and cooperatively regulating key pathways including the C-type lectin receptor signaling pathway, HIF-1 signaling pathway, adipocytokine signaling pathway, and glucagon signaling pathway, thereby suppressing inflammation, enhancing cellular stress tolerance, and promoting tissue repair.

This experiment aimed to evaluate the effects of red corn and purple corn on gas production characteristics, rumen fermentation parameters and microbiota of meat sheep using the in vitro gas production technique. White corn [control group (CON group)], red corn (D1 group) and purple corn (D2 group) were used as fermentation substrates, respectively, and six healthy female Qianbei Ma goats were selected as rumen fluid donors for in vitro fermentation. The results showed as follows: 1) after 48 hours of in vitro fermentation, there was no significant difference in cumulative gas production among the three groups (P>0.05). However, the gas production kinetic parameters, including the rapidly degradable fraction gas production (a) and the potential gas production (a+b), were significantly higher in the D1 and D2 groups than in the CON group (P<0.05). 2) Compared with the CON group, the D1 and D2 groups exhibited significantly higher pH at 6, 12, and 24 hours of in vitro fermentation, as well as significantly increased the concentrations of ammonia nitrogen (NH₃-N), propionic acid, and total volatile fatty acids (TVFA) at 24 hours of in vitro fermentation (P<0.05). 3) After 24 hours of in vitro fermentation, the neutral detergent fiber degradation rate (NDFD) was significantly higher in the D1 and D2 groups than in the CON group (P<0.05). 4) After 24 hours of in vitro fermentation, at the phylum level, the relative abundances of Spirochaetota, Desulfobacterota, and Fibrobacterota were significantly higher in the D1 and D2 groups than in the CON group (P<0.05). At the genus level, the relative abundances of Rikenellaceae_RC9_gut_group and Succiniclasticum in the D1 and D2 groups were significantly higher than those in the CON group (P<0.05), whereas the relative abundance of Clostridium_sensu_stricto_1 was significantly lower than that in the CON group (P<0.05). 5) In the 24 hours in vitro fermentation broth, the concentration of NH₃-N showed a significantly positive correlation with the relative abundances of Bacteroidota and Eubacterium_ruminantium_group (P<0.05), while exhibited a significantly negative correlation with the relative abundance of Firmicutes (P<0.05). The TVFA concentration was significantly positively correlated with the relative abundances of Anaerovibrio, Succiniclasticum and Rikenellaceae_RC9_gut_group (P<0.05). In conclusion, under in vitro fermentation conditions, compared with white corn, red corn and purple corn can improve the gas production kinetic parameters, rumen fermentation parameters, nutrient degradation rates, and rumen microbiota of meat goats.

This study aimed to analysis the probiotic properties and whole-genomic of Bacillus subtilis DN3-1 isolated from Diannan small-ear pigs, to provide a theoretical basis for its development as a probiotic feed additive. In vitro assays were performed to evaluate the acid tolerance, bile salts tolerance, adhesion capacity, enzyme production activity, antioxidant activity, antimicrobial activity, hemolytic activity and biogenic amine synthesis capability of Bacillus subtilis DN3-1, and the whole-genome sequencing was conducted to explore the its probiotic mechanisms and safety basis molecular. The results showed that the Bacillus subtilis DN3-1 whole-genome size was 4 121 215 bp, with a GC content of 43.73%, encoding 4 069 genes. No known virulence factor genes were detected in Bacillus subtilis DN3-1, and it exhibited no hemolytic activity and lacked the ability to synthesize cadaverine, putrescine, and agmatine. The Bacillus subtilis DN3-1 demonstrated strong tolerance to acid and bile salts, high surface hydrophobicity and auto-aggregation capacity, significant antioxidant and antimicrobial activities, and produced protease, lipase, amylase and cellulase. Genomic analysis identified multiple genes encoding potential antimicrobial secondary metabolites, alongside genes associated with acid tolerance, bile salt tolerance, adhesion and antioxidant. Collectively, the Bacillus subtilis DN3-1 is a promising candidate probiotic strain with significant potential for application as a microbial feed additive.

This experiment was conducted to investigate the effects of four functional probiotics isolated from the rumen of dairy cows (Pediococcus acidilactici, Bacillus subtilis, Bacillus amyloliquefaciens and Enterococcus faecalis) on rumen volatile fatty acids (VFAs) synthesis and epithelial absorption of dairy cows in vitro. Firstly, a dual-layer in vitro culture model of rumen epithelial tissue was established and validated. On this basis, rumen fluid and rumen epithelial tissue were collected from three healthy Holstein cows and randomly divided into five groups (a control group and four probiotic test groups) with three replicates per group. The control group was supplemented with 5 mL of distilled water in the upper layer of the culture system, and each test group was supplemented with 5 mL of corresponding probiotic bacterial suspension at a concentration of 1×10⁹ CFU/mL, including Pediococcus acidilactici, Bacillus subtilis, Bacillus amyloliquefaciens and Enterococcus faecalis respectively. After anaerobic culture at 39 ℃ for 24 h, the concentration of VFAs was determined, and the expression of proteins and genes related to VFAs absorption in rumen epithelial tissue was detected. The results showed as follows: 1) the rumen epithelial tissue could maintain viability and structural integrity for up to 36 h in the dual-layer in vitro culture model established in this experiment. 2) Compared with the control group, inoculation with the four probiotics extremely significantly increased the concentrations of acetate and total volatile fatty acids in the fermentation broth (P<0.01). 3) Compared with the control group, the protein relative expression levels of proton-coupled amino acid transporter 1 (PAT1) and anion exchanger 2 (AE2) in rumen epithelium were extremely significantly increased (P<0.01), the protein relative expression level of monocarboxylate transporter 1 (MCT1) was significantly increased (P<0.05), and the gene relative expression levels of sodium-hydrogen exchanger 3 (NHE3) and sodium-hydrogen exchanger 4 (NHE4) were significantly increased (P<0.05) in the Bacillus amyloliquefaciens group; in the Pediococcus acidilactici group, the protein relative expression levels of MCT1 and PAT1 in rumen epithelium were extremely significantly increased (P<0.01), the protein relative expression levels of down-regulated in adenoma (DRA) and AE2 were significantly increased (P<0.05), the gene relative expression level of sodium-hydrogen exchanger 1 (NHE1) was extremely significantly increased (P<0.01), and the gene relative expression levels of NHE3 and NHE4 were significantly increased (P<0.05); in the Bacillus subtilis group, the protein relative expression levels of PAT1 and AE2 in rumen epithelium were extremely significantly increased (P<0.01); in the Enterococcus faecalis group, the protein relative expression level of PAT1 in rumen epithelium was significantly increased (P<0.05). In conclusion, this study confirmed that the in vitro culture model of rumen epithelial tissue is suitable for the study of probiotic functions, and the rumen-derived Pediococcus acidilactici, Bacillus subtilis, Bacillus amyloliquefaciens and Enterococcus faecalis can promote rumen VFAs synthesis and enhance the VFAs absorption function of rumen epithelium.

This experiment was conducted to investigate the effects of Jerusalem artichoke straw (JAS) and Jerusalem artichoke powder (JAP) on rumen fermentation parameters, enzyme activities and microbiota count of Shaanbei white cashmere goats in vitro. A rumen in vitro fermentation method was adopted and supplemented with 0 (control), 5%, 10%, 15% and 20% JAS, as well as 0 (control), 1%, 2%, 4%, 6%, 8% and 10% JAP in the fermentation substrates with a forage to concentrate ratio of 70∶30, respectively, and the in vitro fermentation lasted for 72 hours. The results showed as follows: 1) the 72-hour cumulative gas production, gas production of slow fermentation section (b) and potential gas production (a+b) in 15% JAS supplemental group were the highest, which were significantly higher than those in the other groups (P<0.05). The 72-hour cumulative gas production and potential gas production in 8% JAP supplemental group were the highest, which were significantly higher than those in the other groups except for the potential gas production in 10% JAP supplemental group (P<0.05). The methane content in 2% and 4% JAP supplemental groups was lower, which was significantly lower than that in the other groups (P<0.05). 2) The in vitro dry matter degradation rate and microbial protein content in 15% JAS supplemental group and 8% JAP supplemental group were significantly higher than those in the other groups (P<0.05); the pH in fermentation broth was linearly decreased with the increase of JAS and JAP supplemental level (P<0.05). 3) The contents of acetate, propionate and total volatile fatty acids in 15% JAS supplemental group were significantly higher than those in the other groups (P<0.05). The butyrate content in 15% and 20% JAS supplemental group was significantly higher than that in the other groups (P<0.05), while the acetate to propionate ratio was significantly lower than that in the other groups (P<0.05). The propionate content in 8% JAP supplemental group was the highest, and the propionate content in the control group was significantly lower than that in the other groups (P<0.05). The acetate to propionate ratio in 8% JAP supplemental group was significantly lower than that in the other groups (P<0.05). 4) Compared with the control group, the cellulase activity in each JAS supplemental group was significantly increased (P<0.05), the α-amylase activity in 2% to 10% JAP supplemental groups was significantly increased (P<0.05), and the trypsin activity in all JAS and JAP supplemental groups was significant decreased (P<0.05). 5) The results of comprehensive evaluation of effects of Jerusalem artichoke feed supplemental level on rumen in vitro fermentation showed that the multiple-factors associative effects index (MFAEI) of JAS was highest at 15% (0.390 8), and the MFAEI of JAP was highest at 8% (0.302 1). 6) Compared with the control group, the numbers of bacteria, fungi, protozoa, methanogens, Ruminococcus albus, Ruminococcus flavefaciens, Butyrivibrio fibrisolvens, Fibrobacter succinogenes, Ruminobacter amylophilus, Prevotella ruminicola and Bifidobacterium in 15% JAS supplemental group were all significantly increased (P<0.05), and the numbers of Butyrivibrio fibrisolvens, Ruminobacter amylophilus, Prevotella ruminicola, Lactobacillus and Bifidobacterium in 8% JAP supplemental group were all significantly increased (P<0.05). In conclusion, based on the results of rumen in vitro fermentation experiment, the appropriate supplemental levels of JAS and JAP in the diet for Shaanbei white cashmere goats are 15% and 8%, respectively.

This study investigated the effects of dietary supplementation with Schizochytrium powder (SH) and vitamin E (VE), either individually or in combination, on in vitro ruminal fermentation, nutrient degradability and fatty acid composition in cashmere goats. Rumen fluid was collected orally from three 1.0-1.5 year-old Albas white cashmere goats [body weight: (45±3) kg]. A 2×3 factorial completely randomized design was employed, with two levels of SH (0 and 1.5%, designated as SH0 and SH1.5, respectively) and three levels of VE (0, 250 and 500 IU/kg, designated as VE0, VE1 and VE2, respectively). This resulted in six treatments: SH0+VE0 (basal diet, no SH and VE), SH0+VE1 (basal diet+250 IU/kg VE), SH0+VE2 (basal diet+500 IU/kg VE), SH1.5+VE0 (basal diet+1.5% SH), SH1.5+VE1 (basal diet+1.5% SH+250 IU/kg VE), and SH1.5+VE2 (basal diet+1.5% SH+500 IU/kg VE). Each treatment had six replicates. The results showed as follows: compared with SH0, SH1.5 significantly increased gas production, the contents of bacterial crude protein (BCP), propionic acid, butyric acid, and isovaleric acid, as well as the degradation rates of crude protein (CP), ether extract (EE) and neutral detergent fiber (NDF) (P<0.05), while significantly decreasing the contents of ammonia nitrogen (NH₃-N) and acetic acid, and the acetic acid/propionic acid ratio (P<0.05). Compared with VE0, VE1 significantly improved the CP degradation rate (P<0.05). Among the multiple combination effect indices, SH1.5+VE0 showed the best performance, followed by SH1.5+VE1. Both SH1.5 and VE1,VE2 significantly increased the contents of C18∶3n3, C20∶5n3, C22∶6n3, polyunsaturated fatty acids (PUFA), n-3 PUFA, n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA), and the PUFA/saturated fatty acid (P/S) in the in vitro rumen fermentation fluid (P<0.05); SH1.5 also significantly increased the content of C18∶1n9c (P<0.05) and significantly decreased the content of C18∶0 and the n-6 PUFA/n-3 PUFA (P<0.05). There were significant interactive effects between SH and VE on the contents of C18∶3n3, C20∶5n3, C22∶6n3, PUFA, n-3 PUFA, n-3 LCPUFA and the P/S (P<0.05), with the combinations of SH1.5+VE1 and SH1.5+VE2 being more favorable. In conclusion, dietary supplementation of 1.5% SH can promote in vitro rumen fermentation and nutrient degradation in cashmere goats; both 1.5% SH alone and 250 or 500 IU/kg VE alone can improve the PUFA composition, increase the contents of C22∶6n3, C18∶3n3, C20∶5n3, and n-3 PUFA, and the combined supplementation of the two can further enhance the contents of the aforementioned fatty acids.

This experiment was conducted to explore the effects of different additives on the fermentation quality and in vitro rumen fermentation characteristics of rice straw microbial silage. In experiment 1, eight groups were set, among which the control group (CK group) was not added with any additives, and the experimental groups were added with molasses (M group), Bacillus megaterium (BM group), Lactobacillus acidophilus (LB group), molasses+Bacillus megaterium (MBM group), molasses+Lactobacillus acidophilus (MLB group), Bacillus megaterium+Lactobacillus acidophilus (BMLB group), and molasses+Bacillus megaterium+Lactobacillus acidophilus (MBMLB group), respectively, with three replicates in each group. After 45 days of microbial fermentation, the bags were opened for sampling to determine the nutrient contents and fermentation quality. In experiment 2, taking the unfermented rice straw raw materials as FS group, as well as CK group and BMLB group in experiment 1 were used for in vitro rumen fermentation, and the gas production, nutrient degradation rates and fermentation parameters were determined. The results showed as follows: 1) the dry matter (DM) content in rice straw microbial silage in LB group was the highest; the contents of crude protein (CP) and ether extract in BMLB group were higher, while the contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were lower. 2) The pH of rice straw microbial silage in BMLB group was the lowest, and the lactic acid content was the highest. 3) Compared with FS group, the gas production after in vitro rumen fermentation for 48 and 72 hours in BMLB group was significantly increased (P<0.05), and the degradation rates of DM, CP, NDF and ADF were also significantly increased (P<0.05). Meanwhile, the pH and acetate to propionate ratio during in vitro rumen fermentation in BMLB group were significantly decreased (P<0.05), while the contents of total volatile fatty acids, acetate, propionate and ammonia nitrogen were significantly increased (P<0.05). In conclusion, the combined supplementation of Bacillus megaterium and lactic acid bacteria can improve the nutritional value, fermentation quality and in vitro rumen fermentation efficiency of rice straw microbial silage.

This experiment aimed to explore the role of bacterium-enzyme synergy in pomegranate peel (PP) for improving corn silage. A total of 5 groups were set up in the experiment, namely: 1) corn silage group (control group, group C); 2) corn silage+6% PP group (group P); 3) corn silage+6% PP+1×10⁵ CFU/kg Lactobacillus buchneri 40788 group (group PL); 4) corn silage+6% PP+40 mg/kg glucose oxidase (GOD) group (group PM); 5) corn silage+6% PP+1×10⁵ CFU/kg Lactobacillus buchneri 40788+40 mg/kg GOD group (group PML). After 60 days of ensiling, the fermentation quality, antioxidant capacity, microbiota and metabolites were analyzed. The results showed as follows: 1) compared with group C, the PP treatment significantly reduced the contents of neutral detergent fiber (NDF), ammonia nitrogen (NH₃-N) and non-protein nitrogen (NPN) in corn silage by enriching beneficial bacteria such as Lactiplantibacillus and promoting the accumulation of antioxidant metabolites such as flavonoids. Meanwhile, the total antioxidant capacity (T-AOC), glutathione peroxidase activity, total phenol and total flavonoid contents, as well as the free radical scavenging activity of 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) were significantly increased (P<0.05). 2) Compared with the PP treatment, the PP+GOD treatment further increased the contents of total phenols and total flavonoids (P<0.05); the treatment with PP+Lactobacillus buchneri mainly significantly increased the acetic acid content (P<0.05); the treatment with PP+GOD+Lactobacillus buchneri not only significantly reduced the contents of NDF, NH₃-N and NPN (P<0.05), but also increased the acetic acid content, T-AOC and DPPH free radical scavenging activity (P<0.05). In conclusion, the synergistic treatment of PP and bacterium-enzyme enhances the nutritional and functional characteristics of corn silage through the regulation of “microorganisms-metabolites-fermentation quality”.

This experiment was conducted to investigate the effects of endogenous Pediococcus acidilactici and Enterococcus faecium isolated from the natural silage of Cyperus esculentus stems and leaves, as well as exogenous Lactiplantibacillus plantarum, on the silage quality of Cyperus esculentus stems and leaves. Five experimental groups were set up with 5 replicates per group and 10 silage bags prepared for each replicate: the control group (CK group) without lactic acid bacteria (LAB) inoculation, the Pediococcus acidilactici group (PA group) inoculated with 5×10⁷ CFU/g FM of Pediococcus acidilactici, the Enterococcus faecium group (EF group) inoculated with 5×10⁷ CFU/g FM of Enterococcus faecium, the Lactiplantibacillus plantarum group (LP group) inoculated with 5×10⁷ CFU/g FM of Lactiplantibacillus plantarum, and the Pediococcus acidilactici+Enterococcus faecium group (PE group) inoculated with 5×10⁷ CFU/g FM of Pediococcus acidilactici and Enterococcus faecium at a 1∶1 quantitative ratio. Samples were collected at 3, 7, 15, 30 and 60 days of fermentation to determine the silage quality. The results showed that: 1) at 60 day of fermentation, the contents of dry matter (DM) and water-soluble carbohydrate (WSC) in all LAB-inoculated groups were significantly higher than those in the CK group (P<0.05), with the PE group being the highest; the neutral detergent fiber (NDF) content in all LAB-inoculated groups was significantly lower than that in the CK group (P<0.05), with the PE group being the lowest; the crude protein (CP) content in the PE group was significantly higher than that in the PA group, LP group and CK group at 30 and 60 days of fermentation (P<0.05). 2) The pH of all LAB-inoculated groups was significantly lower than that of the CK group at 3, 7, 15, 30 and 60 days of fermentation (P<0.05), and the pH of the PE group reached the lowest level (4.87) at 60 days of fermentation; the ammonia nitrogen (NH₃-N) content in the PA group, EF group and PE group was significantly lower than that in the CK group at 60 days of fermentation (P<0.05); the contents of acetic acid and lactic acid in all LAB-inoculated groups were significantly higher than those in the CK group at 30 and 60 days of fermentation (P<0.05), with the PE group being the highest. 3) The number of LAB in all LAB-inoculated groups was significantly higher than that in the CK group at 3, 7, 15, 30 and 60 days of fermentation (P<0.05), with the PE group being the highest; the numbers of molds and aerobic bacteria in all LAB-inoculated groups were significantly lower than those in the CK group at 60 days of fermentation (P<0.05). 4) The aerobic stability time of all LAB-inoculated groups was significantly prolonged by 26 to 46 h compared with the CK group (P<0.05); the PE group had the longest aerobic stability time (119 h) and the highest 72 h in vitro cumulative gas production among all groups. In conclusion, the mixed inoculation of Pediococcus acidilactici and Enterococcus faecium has the best effect on improving the silage quality of Cyperus esculentus stems and leaves, which can effectively reduce the loss of nutritional components, promote high-quality fermentation and prolong the aerobic stability time.

This experiment aimed to optimize the conditions for cellulase production by Bacillus amyloliquefaciens through liquid-state fermentation and to apply the resulting enzyme in the extraction of alkaloids from Macleaya cordata. First, single-factor test and response surface methodology (RSM) were used to optimize the fermentation conditions for cellulase production by Bacillus amyloliquefaciens, with carboxymethyl cellulase (CMCase) activity as the response value. Subsequently, the fermentation broth obtained under the optimal conditions was applied to the extraction of alkaloids from Macleaya cordata, and the enzymatic hydrolysis temperature and time were further optimized. The results showed that the optimal fermentation conditions for cellulase production by Bacillus amyloliquefaciens were as follows: using alfalfa as the carbon source at an addition amount of 13 g/L, an inoculation volume of 8% (v/v), an initial pH of 6.5, and incubation at 37 ℃ with shaking at 180 r/min for 48 h. Under these conditions, the CMCase activity reached 168.24 U/mL. When the fermentation broth obtained under the optimal conditions was applied to the enzymatic extraction of alkaloids from Macleaya cordata, the highest extraction efficiency was achieved after 5 h of treatment at 37 ℃, yielding an alkaloid concentration of 139.09 μg/mL. These findings provide a reference for the optimization of fermentation conditions for cellulase production by Bacillus amyloliquefaciens and for the scale up production of alkaloids from Macleaya cordata.

This study analyzed the gut microbiota of captive folivorous and frugivorous primates to understand the characteristics of gut microbiota in non-human primates with different dietary patterns, and provide reference for the research on their nutrition and health. The second-generation high-throughput sequencing technology was used to analyze the 16S rDNA V3 to V4 regions of microorganisms in 30 fecal samples, which were collected from three species of folivorous primates [Trachypithecus francoisi (n=5), Rhinopithecus roxellana (n=5) and Colobus guereza (n=5)] and three species of frugivorous primates [Cercopithecus neglectus (n=5), Chlorocebus sabaeus (n=5) and Nomascus annamensis (n=5)] at the Hangzhou zoo. The results showed as follows: 1) gut microbiota of 17 phyla, 27 classes, 60 orders, 107 families, 294 genera and 609 species were detected in the 30 fecal samples. The dominant flora at the phylum level were Firmicutes, Bacteroidota and Spirochaetota. 2) The gut microbiota of frugivorous primates showed significantly higher α diversity than that of folivorous primates (P<0.05), and significant differences were observed in their β diversity (P<0.05). 3) Compared with frugivorous primates, the gut microbiota of folivorous primates was dominated by families such as Oscillospiraceae, Muribaculaceae and Christensenellaceae. The increased relative abundances of these bacteria was probably related to cellulose metabolism. The dominant families of gut microbiota in frugivorous primates included Prevotellaceae and Lactobacillaceae, and the relative increased abundances of these bacteria was probably associated with the metabolism of simple carbohydrates. 4) The PICRUSt2 functional prediction results showed that the gut microbiota of folivorous primates had significantly higher relative abundances in pathways such as biosynthesis of arginine, cysteine and methionine metabolism, and butanoate metabolism (P<0.05). In conclusion, dietary pattern probably has a significant impact on the gut microbiota of non-human primates, and the gut microbiota has evolved structures that are adapted to the host’s dietary pattern.