Domestic sheep (Ovis aries) is one of the first domesticated livestock species, which, following human migrations, spread to most countries around the world. The modern sheep gene pool is represented by a vast variety of breeds, differing in wool type (fine wool, semi-fine wool, semi coarse wool, and coarse wool) and tail type (short/long, fat/thin). DNA microarrays have revolutionized the area of genomic research of domestic sheep and their wild relatives, allowing the identification of signatures of selection that shaped the genomes of existing breeds. Certain signatures of selection have been identified in most breeds and contain so called selection hotspots"— genomic regions containing genes primarily associated with growth and development, body size, and coat color. Candidate genes involved in the formation of adaptations are identified in genomic regions that underlie selection pressure in local breeds living in extreme conditions. This review summarizes the results of studies examining the origins of local sheep breeds in relation to the global gene pool, represented by whole genome SNP genotypes from publicly available databases. A brief description of the main modern bioinformatics approaches used to search for signatures of selection is provided. Key candidates associated with economically significant traits, disease resistance, adaptive qualities, and phenotypic characteristics are listed. Assessing genomic diversity in sheep populations is important not only for generating new knowledge on their origins but also for developing approaches for preserving valuable genotypes.

Modern animal husbandry faces the challenge of finding effective and safe alternatives to feed antibiotics due to the global spread of antimicrobial resistance. Probiotics based on spore-forming bacteria, particularly Heyndrickxia coagulans (formerly Bacillus coagulans), represent one of the most promising solutions. This microorganism uniquely combines the technological advantages of bacilli (thermostability, resistance to gastric acid and bile salts) with metabolic properties characteristic of lactobacilli (homofermentative production of L-lactic acid). This review summarizes and systematizes current data on the taxonomy, biological characteristics, genomic features, and mechanisms of probiotic action of H. coagulans. Key aspects of its positive effects are discussed in detail: modulation of intestinal microbiota (increasing beneficial genera such as Lactobacillus, Bifidobacterium, and butyrate producers), strengthening of the intestinal barrier via upregulation of tight junction proteins and mucin production, immunomodulation through cytokine balance regulation and interaction with TLR receptors, antagonism against pathogens including Escherichia coli, Salmonella spp., and Clostridium perfringens, antioxidant activity, and improvement of feed digestibility through secretion of hydrolytic enzymes. The results of using various strains of H. coagulans in poultry farming (broilers, laying hens, quails), pig husbandry (weaned piglets), cattle farming (calves, yaks), and aquaculture are analyzed, demonstrating increased productivity, improved feed conversion, enhanced survival rates, and greater disease resistance. Special attention is paid to safety issues, including GRAS/QPS status, absence of pathogenicity genes and transmissible antibiotic resistance genes confirmed by genomic analysis. Emerging applications of the probiotic, including oral health (reduction of Streptococcus mutans) and correction of metabolic disorders, are considered. The prospects for using H. coagulans in synbiotic formulations and as part of antibiotic reduction strategies in animal production are discussed.

This review analyzes the factors influencing the effectiveness of using donors for oocyte retrieval via ultrasound-guided ovarian follicle aspiration — Ovum Pick-Up (OPU), in cattle. The introduction highlights the gradual shift from in vivo embryo production to the production of embryos obtained in vitro from oocytes retrieved via OPU. This makes it crucial to address the challenge of increasing the quantity and quality of oocytes obtained from female donors. The research material consisted of scientific and informational sources available in Russian and international databases (E-Library, Wiley, Elsevier, ResearchGate, PubMed), as well as statistical and analytical data from the Data Collection Committee of the International Embryo Technology Society (IETS) (https://www.iets.org/Committees/Data-Retrieval-Committee). A total of 151 primary sources were selected for this review. A brief analysis of the current state of research on the characteristics of the estrous cycle in female cattle was conducted. Methods that help improve OPU outcomes in cows are described. These include: selecting optimal technical parameters for the procedure, performing OPU at a specific stage of follicular development, stimulating follicular growth and maturation using gonadotropins, and using biomarkers to select the best donor cows. The authors’ own research contributions to addressing the scientific problem are highlighted.

Milk, a vital source of nutrition, contains well-known proteins, minerals, vitamins, and lesser-known signaling molecules in the form of short non-coding RNAs, both free and contained in exosomes. The composition of the exosomal load is dynamic and depends on the physiological state of the organism, including the stage of lactation and mammary gland health. This review focuses on key epigenetic components such as milk microRNAs contained in exosomes. This review examines the role of milk exosomal microRNAs as a genetic marker of productivity and health in dairy cattle. It addresses the formation of exosomes and the mechanism of exosomal cargo sorting, focusing on the stages of microRNA biosynthesis in mammals and the mechanism of their influence on the genome as the main epigenetic post-transcription factor. Studies on the profile of milk microRNAs depending on the stage of lactation and mammary gland health in cattle are described. The presented data will be useful for understanding the organization, regulation and epigenetics of microRNAs in ruminant milk and opens up opportunities for the development of new diagnostic and selection tools in animal husbandry.

Broiler meat occupies a special place in the human diet due to the combination of high nutritional value and dietary properties: it is distinguished by easily digestible complete protein, low fat and cholesterol content. In broiler muscle tissue, macro- and microelements are presented both in the composition of metalloenzymes and metalloproteins, and in the form of free ions, which ensures water-salt balance, participation in energy metabolism and antioxidant protection. Sodium/potassium maintain the Na⁺/K⁺-ATPase gradient; magnesium is involved in more than 300 enzymatic reactions as a Mg-ATP cofactor; phosphorus is essential for energy metabolism; iron (60-70% heme) dominates in myoglobin, providing oxygen storage; copper is a part of Cu/Zn-SOD and ceruloplasmin; zinc is associated with MT proteins; chromium enhances insulin sensitivity; Manganese is a cofactor for manganese superoxide dismutase. The physiological significance of these elements makes it advisable to quantify them in broiler meat to assess the human daily intake requirements. The aim of this study was to analyze the macro- and micronutrients of broiler meat and summarize their role in human nutrition. The results demonstrate a rich mineral profile with essential elements. A 300 g serving per day fully covers the requirements for phosphorus, potassium, iron, zinc, copper, selenium, and chromium, helping to prevent anemia and immunodeficiency, while magnesium, sodium, and calcium require dietary supplementation.