Gut microbiota not only participate in the digestion and absorption of exogenous nutrients but also regulate protein synthesis and degradation, energy metabolism, and inflammatory responses through the synthesis of metabolites such as short-chain fatty acids and bile acids, thereby being deeply involved in muscle metabolic processes. Based on these findings, scholars have proposed a bidirectional communication mechanism known as the gut-muscle axis. In recent years, with the rapid increase in livestock and poultry production efficiency, muscle metabolic disorders in livestock and poultry have occurred frequently and are closely associated with gut microbiota dysbiosis and its metabolite-mediated inflammatory activation and intestinal barrier damage. This review systematically summarizes the mechanisms by which gut microbiota affect muscle metabolic abnormalities in livestock and poultry via the gut-muscle axis, with emphasis on the processes by which gut microbial metabolites affect meat quality by regulating immune pathways and intestinal barrier functions. Combined with specific cases, such as wooden breast meat and white striping meat, it analyzes the role of the gut-muscle axis in the progression of metabolic abnormalities. Furthermore, the species-specific regulatory characteristics of the gut-muscle axis in pigs, poultry, and ruminants are summarized, alongside its application strategies in livestock and poultry production. This review aims to deepen the understanding of the role played by gut microbiota in muscle metabolic abnormalities, providing a reference for improving muscle health and enhancing meat yield and meat quality via the gut-muscle axis.

[Objective] To analyze the nutritional composition, anti-nutritional factors and related indicators of five unconventional feed ingredients from Moyu and Hotan Counties in Xinjiang, providing a reference for the development, promotion and application of local feed resources in animal husbandry. [Methods] A total of 50 kg each of five unconventional feed ingredients-grape pomace, pomegranate peel, reed, cottonseed, and wheat straw-were collected from Moyu and Hotan Counties in the Hotan region of Xinjiang. Moisture, nutritional composition, minerals, mycotoxins, and anti-nutritional factors were determined in these five unconventional feed ingredients to comprehensively evaluate their utilization value. [Results] Under natural air-drying conditions, the moisture content of the five unconventional ingredients was generally low, mostly ranging from 6% to 10%. The crude protein content of cottonseed （30.06%） was significantly higher than that of grape pomace （9.79%）, pomegranate peel （3.15%）, reed （3.66%）, and wheat straw （3.77%）. The crude fiber, neutral detergent fiber, and acid detergent fiber contents of reed were 32.44%, 67.94%, and 48.89%, respectively, all significantly higher （P<0.05） than those of grape pomace, pomegranate peel, and cottonseed. The crude fiber, neutral detergent fiber, and acid detergent fiber contents of wheat straw were 36.76%, 73.23%, and 50.84%, respectively, all significantly higher （P<0.05） than those of grape pomace, pomegranate peel, and cottonseed, with no significant differences from those of reed. The total sugar content of pomegranate peel （47.75%） was significantly higher （P<0.05） than that of grape pomace, reed, cottonseed, and wheat straw. The calcium content of grape pomace was significantly higher （P<0.05） than that of the other four ingredients, while the phosphorus content of cottonseed was significantly higher （P<0.05） than that of the other four ingredients. Except for pomegranate peel, the toxin contents （AFB₁, ZEN, DON） in the other four ingredients met the feed hygiene standards. The gossypol content in cottonseed complied with the feed hygiene standards. According to the Tables of Feed Composition and Nutritional Value in China （35th Edition）, the crude protein content of cottonseed is close to that of soybean meal, the crude fiber contents of reed and wheat straw are relatively high, and the crude protein content of grape pomace is close to that of maize. [Conclusion] The five unconventional feed ingredients can be precisely utilized according to differences in their nutritional composition. Cottonseed can serve as a protein supplement ingredient, partially replacing soybean meal in diet formulations; reed and wheat straw can be used as roughage ingredients to regulate dietary fiber levels; grape pomace can function as an auxiliary energy and protein supplement ingredient, replacing part of maize silage （at maturity）; pomegranate peel requires resolution of toxin and anti-nutritional factor issues and can only be used in small amounts as a functional additive, not as a primary ingredient.

[Objective] To investigate the effects of replacing a portion of conventional soybean meal and wheat bran with fermented soybean meal in the basal diet on the production performance, egg quality, and health status of Hy-Line Brown laying hens during the late laying period, providing a basis for the rational application of fermented soybean meal in the diets of aging hens. [Methods] A total of 480 Hy-Line Brown laying hens aged 65 weeks old were selected and randomly assigned to two groups, with four replicates per group and 60 hens per replicate. The control group was fed a basal diet, while the experimental group received a diet where 5% fermented soybean meal replaced a portion of the conventional soybean meal and wheat bran under the condition of equal dietary nutritional levels. The pre-trial period lasted for 1 week, and the formal trial lasted 8 weeks. During the formal trial period, daily records were kept of the number of eggs laid, qualified egg weight, total feed intake, and mortality and culling number, and production performance indices, such as laying rate and average egg weight, were calculated. At the end of the trial, multiple egg quality indices were measured; blood samples were collected to determine lipid metabolism and antioxidant-related indices; organs were weighed to calculate visceral organ indices; and an economic benefit analysis was conducted based on market prices of materials. [Results] Compared with the control group, the experimental group showed significantly lower laying rates and average daily feed intake （P<0.05）, while the feed-to-egg ratio and mortality/culling rate exhibited a downward trend without significant differences （P>0.05）. The eggshell color L* and b* values were significantly increased （P<0.05）, with no significant differences observed in other egg quality parameters （P>0.05）. The net profit per hen increased by 0.12 RMB, indicating improved economic benefits. No significant differences were found in visceral organ indices, ovary weight, graded follicle weight, or the number of graded follicles and small yellow follicles （P>0.05）. Serum triglyceride （TG） levels significantly decreased （P<0.05）, whereas total cholesterol （T-CHO）, low-density lipoprotein cholesterol （LDL-C）, and high-density lipoprotein cholesterol （HDL-C） showed no significant differences （P>0.05）. Serum total antioxidant capacity （T-AOC） was significantly increased （P<0.05）, while catalase （CAT）, superoxide dismutase （SOD） activities, and malondialdehyde （MDA） content exhibited no significant differences （P>0.05）. [Conclusion] Under equal dietary nutrient levels, replacing a portion of soybean meal and wheat bran with 5% fermented soybean meal can improve lipid metabolism and antioxidant capacity, optimize eggshell color, and enhance economic benefits for Hy-Line Brown laying hens during the late laying period, without adverse effects on visceral organ development. Fermented soybean meal can serve as an alternative ingredient to conventional soybean meal in the diets of Hy-Line Brown laying hens during the late laying period.

China has a large-scale poultry industry with substantial feed demand, and feed protein is mainly supplied by soybean meal. However, the shortage of domestic soybean resources and the high price of soybean meal have increased production costs and hindered the healthy development of the poultry industry. Rapeseed meal, a by-product of obtained after oil extraction from rapeseed, is rich in protein with a relatively balanced amino acid profile, and contains abundant mineral elements, making it a promising alternative to soybean meal. Nevertheless, rapeseed meal contains antinutritional factors such as glucosinolates, tannins, phytic acid, and sinapine, which reduce feed protein utilization efficiency in poultry and lead to impaired growth performance and reproductive capacity, thereby limiting the application of rapeseed meal in poultry production. To improve the utilization efficiency of rapeseed meal, antinutritional factors of rapeseed meal can be eliminated through physical, chemical, and microbial fermentation methods. This review summarizes the nutritional value of rapeseed meal, types of antinutritional factors, methods for elimination of antinutritional factors, and its application in poultry production, with the aim of the rational utilization of rapeseed meal, reduction of feed costs, and promotion of application of rapeseed meal in poultry production.

[Objective] To investigate the effects of a tea polyphenol-taurine compound additive on the growth performance, rumen fermentation parameters, serum biochemical indices, and antioxidant capacity of beef cattle, providing a reference for the application of novel green feed additives in beef cattle production. [Methods] A total of 120 healthy Simmental crossbred beef cattle aged 12 months with similar body weights were selected and randomly assigned to four groups using a completely randomized design, with 3 replicates per group and 10 cattle per replicate. The control group （CON） was fed a basal diet, while experimental groups Ⅰ, Ⅱ, and Ⅲ were fed the basal diet supplemented with 200, 400, and 600 mg/kg of the tea polyphenol-taurine compound additive （at a 1∶1 ratio of tea polyphenol to taurine）, respectively. The trial consisted of a 15-day pre-trial period and a 60-day formal trial period. Initial body weight of the formal trial period was measured at the end of the pre-trial period, and daily feed intake was recorded throughout the formal trial period. At the end of the formal trial, final body weight of the formal trial period was measured; rumen fluid was collected to determine rumen fermentation parameters; and serum was collected to analyze biochemical and antioxidant indices. [Results] Regarding growth performance, compared with the CON group, the average daily gain of cattle in experimental groups Ⅱ and Ⅲ increased significantly （P<0.05）, while the feed-to-gain ratio （F/G） decreased significantly （P<0.05）; no significant differences were observed in all indicators in experimental group I （P>0.05）, compared with the CON group. For rumen fermentation parameters, compared with the CON group, experimental groups Ⅱ and Ⅲ showed significantly higher the contents of acetate, propionate, butyrate, and total volatile fatty acids in the rumen （P<0.05）, while ammonia nitrogen content decreased significantly （P<0.05）, with experimental group Ⅱ showing superior effects to experimental group Ⅲ. In terms of serum biochemical indices, the contents of total protein and albumin in serum exhibited an initial increase followed by a decrease as the additive dosage increased, with experimental group Ⅱ being significantly higher than the other groups （P<0.05） and urea nitrogen content decreased significantly （P<0.05）. Regarding serum antioxidant capacity, compared with the CON group and experimental group Ⅰ, experimental groups Ⅱ and Ⅲ showed significantly increased activities of superoxide dismutase and glutathione peroxidase in serum, and increased total antioxidant capacity in serum （P<0.05）, while malondialdehyde content decreased significantly （P<0.05）; all antioxidant indices in experimental group Ⅱ were superior to those in experimental groups Ⅰ and Ⅲ. [Conclusion] Under the conditions of this experiment, supplementing the basal diet with 400 mg/kg of the tea polyphenol-taurine compound additive （1∶1 ratio） can significantly improve the growth performance of beef cattle, optimize rumen fermentation patterns, and enhance serum biochemical profiles and antioxidant capacity, serving as an efficient and green feed additive suitable for beef cattle production.

[Objective] To investigate the effects of Astragalus membranaceus stem and leaf powder and Codonopsis pilosula stem and leaf powder, as feed additives, on growth performance, antioxidant capacity, and serum biochemical indices in chicks. [Methods] Forty healthy 1-day-old Sanhuang chicks were selected and randomly divided into four groups. The control group （Group A） received a basal diet, while the experimental groups （Groups B, C, and D） were fed the basal diet supplemented with 1% A. membranaceus stem and leaf powder+1% C. pilosula stem and leaf powder, 2% A. membranaceus stem and leaf powder+1% C. pilosula stem and leaf powder, and 3% A. membranaceus stem and leaf powder+1% C. pilosula stem and leaf powder, respectively （all addition ratios were calculated as mass percentages of the basal diet）. The trial lasted 18 days and was divided into two phases （days 1-9 and days 10-18）. Growth performance indicators, serum antioxidant parameters, and biochemical indices were measured and analyzed across groups. [Results] The final body weight and average daily gain of chicks in all experimental groups were significantly higher （P<0.05） than those in the control group, while the feed-gain ratio was significantly lower （P<0.05）; among them, Group C （supplemented with 2% A. membranaceus stem and leaf powder+1% C. pilosula stem and leaf powder） exhibited the most significant growth-promoting effect. Regarding antioxidant capacity, compared to the control group, only Group D （3% A. membranaceus stem and leaf powder+1% C. pilosula stem and leaf powder） showed a significant increase in serum total superoxide dismutase （T-SOD） activity （P<0.05）; no significant differences （P>0.05） were observed in total antioxidant capacity （T-AOC） or malondialdehyde （MDA） content between Groups B, C, D and the control group, although a beneficial trend of improvement was evident overall. Serum biochemical indices detection revealed significant inter-group differences only in urea nitrogen content: compared with Group A, serum urea nitrogen concentrations in Groups B, C, and D showed a decreasing trend, with those in Groups B and D being significantly lower than that in Group A （P<0.05）, suggesting that supplementation with A. membranaceus and C. pilosula stem and leaf powders may enhance protein metabolic efficiency in chicks. No significant differences （P>0.05） were found among groups in total protein, albumin, globulin, albumin-to-globulin ratio, creatinine, or glucose levels. [Conclusion] The results demonstrate that A. membranaceus stem and leaf powder ; C. pilosula stem and leaf powder can effectively promote growth, improve feed conversion efficiency, and enhance antioxidant function in chicks, with the optimal effect achieved at a supplementation level of 2% A. membranaceus stem and leaf powder+1% C. pilosula stem and leaf powder in the basal diet.

[Objective] To investigate the effects of ensiled rice straw on growth performance, economic benefits, fecal odor substances, and intestinal microecology of growing-finishing pigs. [Methods] Twelve Jinhua pigs were selected at each of three weight grades with initial body weights of （29.88±3.45） kg （L）, （48.58±6.51） kg （M）, and （63.08±5.22） kg （H）, respectively. Each grade was randomly divided into three treatments: positive control group, negative control group and experimental group, with 4 pigs per treatment and 1 pig per replicate. The positive control group was fed complete feed, the negative control group was fed 97% complete feed + 3% dry rice straw powder, and the experimental group was fed 95% complete feed + 5% ensiled rice straw powder. The pre-feeding period lasted 7 d. The formal experiment lasted 31 d for the L and M grades, and 60 d for the H grade. At the end of the experiment, growth performance indicators and fecal odor substances contents were determined, economic benefits were calculated and analyzed, and intestinal microecological structure was detected. [Results] ①During the 31-day experimental period, there were no significant differences in final body weight and average daily gain among all treatments in the L, M and H grades （P>0.05）; during the 60-day experimental period in the H grade, the difference in average daily gain among treatments tended to be significant （P=0.072）, and the average daily gain of the experimental group was 4.66% and 17.62% higher than that of the positive and negative control groups, respectively. ②Numerically, in the L grade, the weight gain cost of the experimental group was higher than those of the positive and negative control groups, and the weight gain benefit and profit were lower than those of the positive and negative control groups. In the M and H grades, the weight gain costs of the experimental group were lower than those of the positive and negative control groups, and the weight gain benefits and profits were higher than those of the positive and negative control groups. ③In the H grade, the difference in fecal ammonia nitrogen content among treatments tended to be significant （P=0.087）. The ammonia nitrogen content in the experimental group was 23.85% lower than that in the positive control group and 10.63% higher than that in the negative control group. ④At the phylum level, the abundance of Desulfobacterota in feces differed significantly among treatments in the H grade （P<0.05）; the abundance in the experimental group was close to that in the positive control group and 0.28% lower than that in the negative control group; the abundance of Fibrobacterota tended to differ significantly （P=0.097）; the abundance in the experimental group was close to that in the positive control group and 0.59% lower than that in the negative control group. At the genus level, the abundance of Limosilactobacillus differed extremely significantly among treatments （P<0.01）; the abundance in the experimental group was close to that in the positive control group and 3.60% higher than that in the negative control group; the abundances of Lactobacillus and p-251-o5 tended to differ significantly （P=0.077 and P=0.061, respectively）; the abundance of Lactobacillus in the experimental group was 5.95% and 9.39% higher than those in the positive and negative control groups, respectively, and the abundance of p-251-o5 was 2.78% and 10.09% lower than those in the positive and negative control groups, respectively. [Conclusion] In summary, dietary supplementation with 5% ensiled rice straw in medium- and high-weight Jinhua growing-finishing pigs exerts no negative effects on growth performance, can reduce production cost, improve economic benefits, decrease the emission of fecal odor substances, increase the abundance of beneficial intestinal microbiota in feces, and improve the composition of intestinal microorganisms.

[Objective] To investigate the effects of graded replacement of the diet of fermented sauce-flavor distillers' grains and grain distillers′ syrup with liquid feeding on the growth performance, carcass traits, and meat quality of Duroc×Landrace×Yorkshire finishing pigs, aiming to provide data support and practical strategies for their efficient and safe application in pig production. [Methods] A total of 80 healthy Duroc×Landrace×Yorkshire barrows were randomly assigned to two groups, with four replicates per group （four independent feeding units） and ten pigs per replicate. The trial period was 77 day and was divided into two stages: early stage （days 1-49） and late stage （days 50-77） with graded replacement feeding. The control group was fed a basal diet throughout both stages; the experimental group received a diet in which 6% fermented sauce-flavor distillers′ grains+6% grain distillers′ syrup replaced the basal diet in equal amounts in the early stage, and 9% fermented sauce-flavor distillers′ grains+8% grain distillers′ syrup replaced the basal diet in the late stage. A liquid feeding system was utilized throughout the trial. At the end of the trial, growth performance indicators, carcass trait indicators, organ indices, and meat quality indicators of Duroc×Landrace×Yorkshire finishing pigs were measured. [Results] Compared with the control group, the experimental group showed a significant increase in the average daily gain （P<0.05） and an extremely significant decrease in the feed-to-gain ratio （P<0.01） during the overall period; the fat percentage in the experimental group increased significantly （P<0.05）, the lean meat percentage decreased significantly （P<0.05）, and the loin eye area decreased extremely significantly （P<0.01）, while no significant differences were observed in other carcass traits （P>0.05）; no significant differences were detected in organ indices or meat quality （P>0.05）. [Conclusion] Under the conditions of this experiment, replacing the basal diet with graded proportions of fermented sauce-flavor distillers′ grains and grain distillers′ syrup had no negative effects on the growth performance, carcass traits, organ indices, or meat quality of Duroc×Landrace×Yorkshire finishing pigs, and improved the growth performance of finishing pigs. However, attention should be paid to the decrease in lean meat percentage.

[Objective] To systematically investigate the effects of three different rearing patterns-grazing, semi-confinement, and total confinement-on the growth performance, slaughter performance, meat quality, rumen fermentation parameters, and rumen microbial community of Sonid lambs, providing a reference for optimizing efficient and healthy rearing models for Sonid sheep. [Methods] A total of 60 healthy 3-month-old Sonid lambs were selected and were randomly assigned to three groups: a grazing group （FM）, a semi-confinement group （BS）, and a confinement group （SS）, with 20 lambs per group. The FM group grazed freely without supplementation; the BS group received concentrate supplementation on the basis of daytime free grazing, with 0.3 kg/d of concentrate supplement per lamb in the first week, followed by a weekly increase of 50 g per lamb; the SS group was fed a total mixed ration ad libitum under total confinement conditions. The trial consisted of a 14-day pre-trial and a 60-day formal trial. Growth performance was measured at the beginning and end of the trial. After the trial, 5 lambs were randomly selected from each group to determine slaughter performance, organ indices, meat quality, rumen fermentation parameters, and rumen microbial community. [Results] Regarding growth and slaughter performance, the final body weight, average daily gain, carcass weight, and dressing percentage of the BS and SS groups were extremely significantly higher than those of the FM group （P<0.01）; the final body weight of the SS group was significantly higher than that of the BS group （P<0.05）. For organ indices, the heart index in the BS group and the liver index in the SS group were significantly lower than those in the FM group （P<0.05）. In terms of meat quality, the crude fat content in the SS group was significantly higher than those in the FM group （P<0.05）. For rumen fermentation, compared with the FM group, the pH in the BS and SS groups decreased significantly （P<0.05）, while the ammonia nitrogen content increased significantly （P<0.05）. Microbial community analysis showed that the Shannon index of α-diversity in the FM group was extremely significantly higher than in the BS and SS groups （P<0.01）, and the Chao1 index was significantly higher than in the BS group （P<0.05） and extremely significantly higher than in the SS group （P<0.01）. The relative abundances of Succinivibrio and Succiniclasticum in the SS group increased extremely significantly （P<0.01）. [Conclusion] Under the experimental conditions, compared with traditional grazing, both semi-confinement and total confinement models significantly improved the growth performance, slaughter performance, and rumen fermentation function of Sonid lambs, and significantly altered the rumen microbial community structure. Among them, the total confinement model was most effective in promoting weight gain with no negative impact on the primary edible quality of the mutton. Therefore, total confinement is recommended as an efficient rearing model for Sonid sheep.

Selection signature analysis, as a core analytical approach in population genomics, can identify genomic regions subjected to positive, negative, and balancing selection during long-term natural selection and artificial breeding, providing molecular evidence to elucidate the mechanisms of adaptive evolution and the genetic basis of key traits in animals. This review systematically summarizes the research progress on selection signatures related to important economic and phenotypic traits in domestic horses during domestication and artificial breeding, covering core breeding traits such as body size, athletic performance, and coat color, and also summarizes the characteristics of selection signatures associated with pathological traits retained due to linkage drag. By summarizing the application of selection signature detection techniques and candidate gene screening strategies across diverse horse populations, this review elucidates the pivotal role of this method in revealing population genetic structure, domestication-adaptation mechanisms, and the molecular regulatory mechanisms of economic traits. Finally, in combination with the trends of multi-omics integration and technological development, the review discusses the application prospects of selection signature analysis in equine genomics research, breed improvement, and genetic resource conservation, providing a reference for future molecular breeding and evolutionary studies of domestic horses.

[Objective] To investigate the effects of exogenous ascorbate （AsA） priming on the seed germination of Bothriochloa ischaemum under NaCl stress.[Methods] Seeds of B. ischaemum were used as experimental materials. Priming treatments were conducted using AsA solutions at concentrations of 0.1, 0.2, 0.3, 0.4, and 0.5 mmol/L for durations of 0 （CK, a blank control without priming under direct salt stress）, 3, 6, 9, and 12 h. Germination tests were subsequently performed in a NaCl solution with an Na⁺ concentration of 30 mmol/L. Seed germination percentage, germination index, mean germination time, seedling vigor index, radicle length, and plumule length were measured and analyzed. [Results] Under fixed treatment durations, the comparison of different AsA concentrations at the same time revealed that the germination percentage, germination index, seedling vigor index, radicle length, and plumule length of B. ischaemum seeds exhibited a continuous downward trend as AsA concentration increased; at a priming concentration of 0.1 mmol/L, both seed germination percentage and seedling vigor index were higher than those of other concentration groups at the same time; mean germination time was significantly （P<0.05） lower only in the 3 h treatment group at 0.2 mmol/L AsA compared to other concentration groups, with no significant differences （P>0.05） observed among other groups. Under fixed treatment concentrations, the comparison among different priming durations at the same concentration showed that at an AsA concentration of 0.1 mmol/L, the germination percentage and seedling vigor index were significantly （P<0.05） higher than those of CK after 9-12 h of priming, while radicle and plumule lengths were significantly （P<0.05） higher than those of CK after 12 h of priming; no significant differences （P>0.05） were found in mean germination time across these groups; at AsA concentrations of 0.2 and 0.3 mmol/L, the germination percentage, germination index, and seedling vigor index showed a trend of initially decreasing and then increasing; at AsA concentrations of 0.4 and 0.5 mmol/L, the seedling vigor index was significantly （P<0.05） lower than those of CK as priming time extended, and differences in germination percentage, mean germination time, radicle length, and plumule length were not significant （P>0.05）. Membership function analysis indicated that the comprehensive evaluation values of B. ischaemum seeds ranked among the highest at an AsA concentration of 0.1 mmol/L, identifying it as the optimal concentration for priming against NaCl stress; at this concentration, 12 h of priming ranked first in comprehensive evaluation. [Conclusion] Under NaCl stress with an Na⁺ concentration of 30 mmol/L, priming with 0.1 mmol/L AsA solution for 12 h is most favorable for the seed germination of B. ischaemum.

In the context of Chinese-style modernization, the green and low-carbon transformation of animal husbandry has become a core element of sustainable agricultural economic development and ecological civilization construction. This study provides a deep analysis of the theoretical logic and implementation pathways of the green and low-carbon transformation of animal husbandry, and systematically articulates its practical foundation across economic, technological, and environmental dimensions, including key factors such as industrial scale expansion, growing market demand, breakthroughs in green and low-carbon technologies, policy support, and the elevation of social awareness. The study identifies core tasks in the transformation process, including optimizing the utilization of feed resources, accelerating the transformation and application of green technological achievements, and focusing on the market demand for green products. Feasible implementation pathways are proposed in terms of deepening technological innovation, constructing full-chain green production processes, and improving environmental policy systems. Through multi-dimensional theoretical analysis and practical exploration, this study clarifies the theoretical logic of the green and low-carbon transformation of animal husbandry in the process of Chinese-style modernization and suggests feasible implementation pathways, aiming to provide a reference for safeguarding the comprehensive production capacity of animal husbandry, reducing environmental impacts, promoting harmony between humanity and nature, and driving the high-quality development of the industry.

Streptococcus suis is a critical zoonotic pathogen capable of causing meningitis, septicemia, and sudden death in pigs, resulting in substantial economic losses. Furthermore, it can be transmitted to humans through contact, leading to fatal diseases. In recent years, the misuse of antibiotics has led to the widespread emergence of multi-drug resistant strains, significantly diminishing the efficacy of traditional antimicrobial therapies. Phage endolysins, as cell wall hydrolases encoded by bacteriophages, can specifically degrade the bacterial cell wall and exhibit advantages such as high bactericidal efficiency, low propensity to induce resistance, and minimal disruption to microbial communities, making them promising candidates as antibiotic alternatives. This review systematically summarizes the fundamental characteristics, mechanisms of action, cloning and expression, and production processes of phage endolysins, describes the pathogenic characteristics and the limitations of current prevention and control measures of S. suis, summarizes the research progress on phage endolysins against S. suis in terms of the in vitro antibacterial activity and in vivo animal studies, discusses potential challenges and corresponding strategies in practical applications related to delivery, immunogenicity, production and regulation, and outlines future research directions, including engineering modification, development of combination therapies, and clinical translation, with the aim of providing novel solutions to address S. suis infections and antibiotic resistance challenges.

Subclinical ketosis （SCK） is a common metabolic disorder in high-yielding dairy cows during the periparturient period. It is characterized by elevated blood β-hydroxybutyrate （BHBA） levels and decreased blood glucose concentrations, presenting no apparent clinical symptoms but posing insidious detrimental effects. The occurrence of SCK is associated with physiological metabolic changes and feeding management during the periparturient period. SCK can trigger hepatic glucose and lipid metabolism disorders, impair dairy cow health, and reduce production performance, leading to significant economic losses in the livestock industry. Recent studies have indicated that SCK interferes with key processes of hepatic glucose metabolism and disrupts the balance between lipid synthesis and lipolysis. Through multiple signaling pathways, including peroxisome proliferator-activated receptors （PPARs）, nuclear factor-κB （NF-κB）, mechanistic target of rapamycin complex 1/2 （mTORC1/2）, and phosphatidylinositol 3-kinase/protein kinase B （PI₃K/Akt）, as well as key genes such as forkhead box O1 （FOXO1）, SCK regulates transcriptional networks and the activities of key metabolic enzymes, thereby exacerbating insulin resistance （IR）, hepatic steatosis, and oxidative stress. This review systematically summarizes the definitional characteristics and etiologies of SCK, and the effects of SCK on glucose and lipid metabolism and the associated molecular regulatory mechanisms, with the aim of providing a basis for reducing SCK incidence, optimizing farm management, and improving the production performance of dairy cows.

[Objective] To address the issues of high invasiveness, low efficiency, and susceptibility of chips to frequency interference in traditional individual horse identification methods, an open-set individual horse face recognition method based on multi-scale feature fusion was explored. [Methods] Selecting MobileFaceNet as the backbone network, a lightweight horse face recognition network, HorseFaceNet, was designed by incorporating an Enhanced Bidirectional Feature Pyramid Network （EnhancedBiFPN） module to achieve multi-scale feature fusion. Using a self-built Ili horse facial image dataset, training was conducted on the training set with partial classes selected via five independent random resamplings. Testing was performed on a test set containing all classes, followed by calculation of the mean recognition accuracy. [Results] To verify the robustness and generalization ability of the model in open-set scenarios, the proposed HorseFaceNet was systematically evaluated under training settings with different proportions of known classes. Experimental results demonstrated that the model achieved a mean accuracy of 98.28% when the training set included 70% of known classes. When the proportion of known classes decreased to 50%, the mean accuracy reached 97.28%. Even with only 30% of known classes used for training, the model maintained a mean accuracy of 95.52%. With a parameter size of only 1.72 M, the proposed HorseFaceNet reduced the number of parameters by approximately 0.39 M （about 18.5%） compared to the original MobileFaceNet, while improving the recognition accuracy by 3.09 percentage points in an open-set recognition scenario with 50% of classes participating in training. [Conclusion] These results fully indicate that the HorseFaceNet model possesses excellent recognition performance and strong generalization ability even under conditions of limited samples from known classes. The model balances model lightweight with improved recognition performance, making it of wide application value for intelligent horse farm management and other practical scenarios.