This article aims to elucidate how single-cell omics technologies advance livestock research and provides a systematic review of the construction process， current applications， and major challenges of single-cell transcriptomic databases in domestic animals. It seeks to offer data references and analytical frameworks for researchers， thereby promoting deeper application of this technology in livestock studies. This review conducted a comprehensive review and integrated analysis of existing single-cell transcriptomic database resources for livestock， summarizing their construction methodologies and application pathways， while also discussing current technical bottlenecks. The review demonstrates that single-cell transcriptomics offers novel perspectives and abundant data resources for elucidating mechanisms of livestock diseases， molecular breeding， and health management， while also revealing significant challenges in areas such as data integration and annotation standardization. Future efforts should focus on constructing high-quality databases， developing analysis algorithms tailored to livestock species， and promoting multi-omics integration to fully leverage the potential of single-cell technologies in the development of animal husbandry.

During the estrous cycle of mammals， a large number of follicles are recruited. Typically， only one follicle is selected for dominance and ovulation in monotocous （single-offspring） species per cycle， while only a few follicles are selected for dominance in polytocous （multiple-offspring） species. The vast majority of the remaining follicles undergo atresia. In recent years， significant progress has been made in research focusing on follicular dominance selection， although the underlying mechanisms have not yet been fully elucidated. Insulin-like growth factor 1 （IGF-1） has been demonstrated to play a crucial role in follicular development. This review summarizes the roles and mechanisms of IGF-1 in mammalian follicular development， focusing on its involvement in dominant follicle selection， promotion of follicular growth and development， inhibition of granulosa cell apoptosis， and maintenance of normal reproductive performance in female mammals.

Fucoidan is a water-soluble polysaccharide derived from brown algae， which possess anti-inflammatory， antioxidant， antiviral， and immunomodulatory function， and also has a protective effect on the intestinal barrier. It has shown promise as a novel additive in animal production. This article reviews the structure， extraction methods， physiological functions， factors affecting biological activity， protective effects on the intestinal barrier， and applications in poultry and livestock production of fucoidan.

Salmonella is a common foodborne pathogen worldwide. With the promotion and use of antibiotics， more and more Salmonella produce or acquire antibiotic resistance genes （ARG） through vertical transmission and horizontal gene transfer （HGT）， causing widespread dissemination of antibiotic resistance. In the process of horizontal gene transfer， ARGs are mainly carried by mobile genetic elements （MGEs）， which are important mediators of HGT and can facilitate the spread of ARGs. Among them， MGEs mainly include plasmids， integrons and conjugative elements， transposons， insertion sequences， and phages， etc. MGE-associated transfer mechanisms， accessory gene compositions， and relationships between ARG dissemination and animal sources and geographic environments vary. The aim of this review is to outline the HGT mechanism of ARG in Salmonella， the different MGE-mediated HGT mechanisms and the influencing factors of HGT occurrence and development， which is of great significance for the in-depth investigation of the HGT mechanism of drug resistance in Salmonella.

This study aimed to systematically evaluate the population genetic characteristics of Hetao Big-ear pigs using genomic approaches， providing scientific basis for the conservation of their germplasm resources. Based on 50K SNP chip data， Using software such as plink （v1.90）， GCTA （v1.93）， and MEGAX （v10.0） for analysis， PCA， genetic distance， kinship relationship， inbreeding coefficient， and phylogenetic tree information were obtained. Multi-dimensional analysis methods were used to detect 78 Hetao Big-ear pigs. Population structure analysis revealed that the population could be divided into 4 subgroups， with an average genetic distance of 0.793， and 6 sire lineages forming the foundation of its pedigree. Analysis of genomic runs of homozygosity （ROH） detected a total of 2 601 segments， with individuals carrying an average of 21 ROHs and an average length of 7.77 Mb. The population inbreeding coefficient （F_ROH ） was 0.13. Comprehensive analysis indicated that this population exhibits characteristics including a limited number of lineages， relatively few sire bloodlines， moderate kinship relationships， and low inbreeding levels. These findings at the genomic level provide important references for the population optimization and genetic improvement of Hetao Big-ear pigs.

The purpose of this study was to investigate the therapeutic effects of deer blood polypeptide （ARPBP） in the treatment of androgenic alopecia and to reveal underlying. By using ARPBP to treat testosterone （TES）-induced C57BL mouse alopecia model， HE staining， immunohistochemical staining qPCR and Western blot experiments were performed on the skin tissue of its back. Results showed that it significantly promoted hair regeneration， and the efficacy exhibited a concentration-dependent manner. Histological analysis showed that the skin thickness， follicle density and diameter in TES group were significantly reduced， which was consistent with the pathological characteristics of androgenic alopecia. After the treatment with ARPBP， the skin thickness and parameters of hair follicle shape in the low-dose ARPBP treatment group （15 mg·mL^-1） recovered nearly to the physiological level， and the hair density and area of hair coverage were better than those of the high-dose treatment group （75 mg·mL^-1）， indicating that the low-dose ARPBP group could reverse the testosterone induced hair follicle miniaturization more effectively. Immunohistochemical results showed that low-dose （15 mg·mL^-1） ARPBP significantly up-regulated the expression of follicle proliferation markers KI67 and PCNA， and enhanced the nuclear localization signal of upstream factor LEF in Wnt/β-catenin pathway. Western blot analysis further confirmed that low-dose ARPBP significantly reversed the inhibitory effect of androgen on LEF1 protein expression， and inhibited the activation of androgen on BMP4 signaling pathway. This study revealed the effective dose-dependent effect of ARPBP in the treatment of androgen alopecia. The mechanism underlying these achieved results could be via promoting the transition of androgen-induced hair follicles from resting period to growth period by activating LEF1-Wnt/β-catenin signaling pathway and inhibiting BMP signaling pathway， thus promoting hair regeneration. We believe our study has laid the foundation for the development of precision medicine strategies based on natural peptides.

Yaks are well-adapted to the extreme environment of the Qinghai-Tibet Plateau， characterized by low temperatures， intense ultraviolet radiation， hypoxia， and nutritional stress， making them the dominant livestock species in high-altitude pastoral areas. Yak are multi-functional cattle breeds， possessing the performance of meat production， cashmere production， service use and milk production， however， their milk production performance has not undergone high-intensity breeding.Yaks have low milk yield but significantly higher milk fat， lactose and milk protein content.As the core organ for milk secretion， the development of yak mammary gland is regulated by complex network of genes， and the maintenance of its homeostasis and lactation is an intricate biological process of the organism， which relies on the coordinated functioning of multiple cells. With the development of omics technology and the deepening of functional genomics research，the core regulators of mammary gland development in human， mouse and common cow species have been analyzed， and the regulatory networks controlling key processes such as lactation and milk lipid secretion have been clarified. Although milk production is an economically important trait in yak， relatively few studies have been conducted on the regulatory network of mammary gland and lactation-regulating genes in yak.In this paper， the similarities and heterogeneity of yak mammary glands in terms of morphology， development， lactation mechanism， lactation performance and other aspects compared with mammary glands of other species were systematically summarized， and key scientific issues that need to be urgently addressed in yak-related aspects are presented with a view to providing important information for mammary gland biology research and identification of functional genes for milk production traits in yaks.

Breed identification is fundamental to livestock conservation and plays a vital role in genetic resource management， breed purity assessment， breeding strategy implementation， product traceability， supply chain optimization， and ensuring food and biosafety. This review summarizes both traditional and modern methods for breed identification of common livestock and poultry （pig， cattle， sheep， dog， chicken）， and systematically reviews recent advances in machine learning-based breed identification research.Traditional methods， such as morphological assessment and physicochemical indicator analysis in animals，are increasingly inadequate for large-scale breed identification due to their limited accuracy，operational complexity，and time-consuming nature. With advancements in intelligent animal husbandry and high-throughput omics technologies， machine learning-based approaches have gained wide application. This paper reviews major achievements in breed identification using machine learning， analyzes the strengths and limitations of various algorithms， and highlights challenges in practical use. It offers insights for future development and supports molecular breeding and precision livestock management.

Salmonella poses a significant threat as a foodborne pathogen impacting global public health and the poultry industry. The escalating challenge of antibiotic resistance has intensified the difficulties in its control and prevention. Bacteriophage （phage） therapy， characterized by its high host specificity and intrinsic self-replication capability， has emerged as a promising novel biocontrol strategy to replace or complement antibiotics. Currently， several phage-based products targeting Salmonella are commercially deployed in livestock farming and poultry product processing. Extensive research and field trials have demonstrated their efficacy in reducing Salmonella loads within live poultry， decreasing mortality rates， enhancing production performance， and significantly reducing Salmonella contamination on poultry meat and eggs. Despite the promising potential， further field trials within commercial farm environments and robust clinical studies are imperative to evaluate clinical efficacy comprehensively， optimize application protocols， and promote standardized implementation.

Antibiotics once played an essential role in the process of China’s livestock industry. With the continuous increase in people’s attention to food safety and ecological environment issues， the adverse effects of antibiotic abuse have gradually become prominent. China’s feed industry has ushered in an era of a complete ban on antibiotics， and the livestock industry is facing significant challenges. Probiotics， as feed additive with great potential， can affect the composition of the intestinal flora after being ingested by animals， improve the intestinal barrier and regulate the immune response， showing unique advantages and value. It is expected to replace antibiotics and play a role in the livestock industry. Enterococcus faecalis， as a member of the lactic acid bacteria group， can be used as a feed additive and has attracted much attention. Enterococcus faecalis has relatively strong resistance to the environment， and its biological characteristics determine whether it can reach the host’s intestinal tract with a certain number of viable bacteria， and then determine whether this bacterium can be widely used in the livestock industry. As an active microorganism beneficial to the host， Enterococcus faecalis can regulate the balance of the body’s intestinal flora， enhance the function of the intestinal epithelial barrier， promote the metabolism of nutrients， and enhance the body's immunity. There is an increasing number of studies on the impact of Enterococcus faecalis on livestock and poultry. It has shown positive effects such as improving production performance， reducing the incidence of diarrhea and mortality， and enhancing the immune system in various livestock and poultry， including pigs， cattle， sheep， and chickens. This bacterium can optimize the digestive function of livestock and poultry， improve feed efficiency， and thus increase the economic benefits of farms. Its application range in the livestock industry is also constantly expanding. This article focuses on Enterococcus faecalis， summarizes its application in livestock and poultry in recent years， and reviews its biological characteristics， mechanisms of action， applications in the livestock and poultry industry， and the existing problems of Enterococcus faecalis. The aim is to provide a new insights from previous research about this bacterium and its impact in the livestock and poultry industry.