This review describes the prevalence and accumulation of key chemical micro- and macroelements (CE) (including co-accumulation) in animal organs and tissues. Clinical differential diagnostic criteria for immune-mediated paraneoplastic ophthalmopathy in domestic animals are established and substantiated. Scientific data demonstrates a direct correlation between the concentration of copper, iron, zinc, cadmium, and lead in the coat and the development of cancer. The authors conducted a comprehensive analysis and diagnosed "malignant neoplasms" in dogs associated with high levels (twofold or more) of not only toxic CEs like cadmium, but also important CEs like zinc, copper, and iron in the fur. Based on our research, a diagnostic method for associated ophthalmological and oncological pathologies was developed using "CE centile scales" based on the results of corresponding animal fur monitoring. This method holds great promise not only for assessing and predicting the development of these diseases but also for their correction using special CE-optimized diets for animal feeding. A major advantage of the authors' proposed method is its non-invasive sampling and the relative simplicity of preparation and analysis, which is extremely important for conducting "regular screening examinations" of animals.

This article presents a comprehensive analysis of modern genomic technologies and genetic evaluation methods used in chicken breeding, aimed at improving productivity, product quality, and disease resistance. The key economically useful traits (egg production, egg weight and its components), their polygenic nature and heritability were described. The article substantiates the transition from phenotypic selection to precision selection based on genotype using integrative approaches. Particular attention was given to the methods of breeding value assessment (BLUP), the use of genome-wide association analysis (GWAS), region of homozygous analysis (ROH), and identification of quantitative trait loci (QTL), the use of resource populations (F2). The integration of transcriptomic, metabolomic, and epigenetic data to identify genetic markers and candidate genes associated with target traits and the use of CRISPR technologies for functional validation were also considered. In the context of the genetic architecture of traits, candidate genes regulating egg production (MSX2, CNNM2), egg weight (IGF1, BMP15), yolk quality (ZAR1, STARD13), protein quality (CISD1, OVAL) and shell strength (PIK3C2G, BMP2) were characterized. The described research forms the basis for the development of DNA panels, specialized bioinformatics analysis methods, and other innovative tools that contribute to the sustainable development of egg poultry farming, increasing the competitiveness of the industry, and ensuring food security.

Modern research on the genetic diversity of domestic hens (Gallus gallus domesticus) is key to understanding the processes of domestication and selection in poultry breeds for preserving the genetic diversity of the species. The review examined modern molecular approaches to study domestication and selective breeding of chickens based on the analysis of genetic diversity using anonymous and microsatellite markers, as well as the variability of single nucleotide polymorphisms in nuclear and mitochondrial genome. Special attention is given to the application of molecular-genetic approaches used to identify population structure and to address the level of intraspecific variability in chickens of different breeds. In addition, this review summarizes modern methods for statistical processing of bioinformatic data, such as the runs of homozygosity (ROH), cluster analysis (Admixture), Principal Component Analysis (PCA) and phylogenetic tree construction and other methods of analysis of single nucleotide polymorphisms (SNP) for biodiversity assessment. Knowledge of the genetic diversity and characteristics of the chicken genome obtained through these approaches will optimize breeding programs and create the base for a strategy to conserve unique poultry genetic resources.

This review examines immunological infertility in cattle, a specific type of reproductive disorder in which the immune system perceives gametes or other components of the reproductive system as foreign and produces antibodies against them. Key areas of modern research in reproductive immunology include the impact of immune disorders on fertility, the mechanisms underlying the immune response against gametes, and the development of diagnostic methods for these conditions and their causes. Immunological infertility is characterized by the production of specific antisperm antibodies (ASA), which impair sperm function. This is due to the disruption of biological barriers, primarily the blood-testis barrier (BTB) in males. This leads to contact between the immune system and gamete antigens, which are normally found in an immunologically privileged environment, triggering a humoral and cellular immune response. The development of pathology in males is caused by microtrauma, genital inflammation, infections, and overheating. In females, the following factors are likely to occur: impaired natural immune tolerance in the reproductive tract, inflammatory diseases, genetic predisposition, hormonal imbalances, oxidative stress, micronutrient deficiencies, and so on. This review demonstrates that immunological infertility primarily occurs at the intersection of dysfunctions of the immune and reproductive systems. The materials presented in this review will help specialists in the field of bovine reproduction more thoroughly address the problems of infertility and infertility.

Ketosis, acidosis and mastitis in cows often occur in a subclinical form without visible signs of inflammation, and therefore changes in biochemical and hematological parameters can help diagnose them in a timely manner. The presence of various forms of ketosis in dairy cows may be indicated by changes in nitrogen metabolism, manifested in an increase in total protein levels due to the globulin fraction along with hypoalbuminemia and a decrease in urea concentration. Disorders of carbohydrate-lipid metabolism have been reported, namely an increase in triglycerides, HDL, and a decrease in cholesterol and glucose. Changes in mineral metabolism are mainly due to a decrease in the level of calcium, phosphorus, magnesium and alkaline reserve, hormonal and antioxidant status of the body. In case of acidosis in dairy cows, negative changes in the antioxidant status occur, expressed in a decrease in the activity of antioxidant defense enzymes (catalase, superoxide dismutase) and an increase in the level of MDA. An increase in blood triglycerides and ketone bodies has been reported. Data on an increase in the activity of ALT AST LDH, lipase, and lactate levels are presented. With acidosis, hypoalbuminemia and hypocalcemia are observed along with an increase in phosphorus. The main changes in mastitis relate to clinical blood parameters characterized by an increase in the number of white blood cells, a decrease in red blood cells and hemoglobin. It is necessary to further expand and study the hormonal and antioxidant parameters of blood in metabolic disorders in the body, the relationship of biochemical, including antioxidant, markers of blood and milk composition.