The world production of sheep milk has more than doubled in the last 50 years. However, sheep milk and sheep milk products have not yet become a traditional consumer product in Russia. One of the main reasons for this is the lack of specialised dairy breeds of sheep and insufficient use of modern breeding methods, including marker‑assisted selection. The article considers the main candidate genes of sheep dairy productivity, shows their influence on milk yield, fat and protein content, resistance to mastitis.

The article presents the results of genotyping of sheep of the Manych Merino breed. The specificity of the allele spectrum of the GH (growth hormone) gene controlling growth and development, as well as influencing the meat productivity of sheep, was revealed, expressed in different frequency of occurrence of both alleles and genotypes. The connection of allelic variants of the GH gene with growth indicators and exterior parameters has been established.

The article presents the results of studying the features of mineral metabolism in the body of purebred Romanov sheep (group I), its crossbreeds of the first generation with Edilbai – ½ Romanov × ½ Edilbai (group II) and the second generation – ¼ Romanov × ¾ Edilbai (group III). It was found that due to the effect of crossing, crossbred sheep of groups II and III outperformed purebred peers of group I in terms of calcium and phosphorus intake with feed by 3.93‑20.39% and 12.23‑14.63%, their deposition in the body – by 15.30‑25.07% and 16.20‑17.88%, the value of the utilization factor from the accepted – by 0.38‑1.92% and 1.56‑4.57%.

The article considers some indicators of resistance of sheep kept in different biochemical zones of Donbass.

The article presents data on the study of the quality of goat’s milk, as well as goat cheese made from it. To achieve these goals, 4 samples of cheese were produced – a control and 3 prototypes with vegetable fillers in various quantities. It is shown that vegetable fillers favorably influenced the qualitative composition of cheeses.

The article presents the results of experimental studies to study the effect of feeding probiotic feed additives Kluver Pro and BeneFIT Basic on milk productivity, composition and technological properties of milk from Saanen goats. It has been established that feeding probiotics Kluver Pro and BeneFIT Basic as part of the diets of lactating goats of the Saanen breed helps to increase milk yield by 9,5‑4,4% (p≤0,001), the mass fraction of fat in milk – by 0,73% (p≤0,05) and 0,11%, mass fraction of protein in milk – by 0,25% (p≤0,05) and 0,19%, as well as milk clotting time – by 7,3% and 5,4% (p≤0,001) and the formation of a denser rennet curd, which is a desirable property in the production of fermented milk products and cheese making.

The article presents data on the study of milk productivity, qualitative composition and properties of milk of goats of local and Czech breeds. Goat milk of the compared groups of animals has high organoleptic, physicochemical and technological properties and meet the requirements of GOST 32940‑2014 “Raw goat milk. Technical conditions”.

The material on the study of the digestibility of nutrients in the diets of purebred and crossbred Romanov sheep from birth to 9 months of age is presented. It was found that according to these indicators, the Ile de France × Romanov sheep had the best results compared with purebred Romanov sheep in the same age periods.

The authors of the presented article studied the influence of prebiotic feed additives that can stimulate the course of metabolic processes, strengthening the immune status of the body and, as a result, have a positive effect on increasing the efficiency of lamb production.

It has been proven that the inclusion of feed additives at a dose of 0.6 and 0.5% of the concentrate weight makes it possible to increase the live weight of rams of experimental groups at the age of 4 months by 3.05 (P<0.05) and 3.50 kg (P<0.01), at 7 months of age – by 3.65 kg (P<0.01) and 4.15 kg (P<0.01) relative to the control. The studied prebiotic additives significantly influenced the increase in metabolic processes in the body of animals, the production of specific enzymes in the gastrointestinal tract, increasing the absorption of nutrients and stimulating the bioconversion of feed protein into meat products, activating hematological parameters, strengthening the immunological status.

The article found that the biological usefulness of wheat grain seedlings as feed increases significantly compared to whole grain. The expenditure and revenue parts of the organization of the farm for 30 dairy goats, including the rearing of young animals, have been studied.

The article presents the results of a zootechnical analysis of soybean waste (straw and forage waste), used as the main diet for sheep during the active feeding period. It was concluded on the basis of clinical and biochemical parameters of blood that there was an increase in the level of protein metabolism in experimental animals.

The paper evaluates the efficiency of hemp and flax cakes in the diet of dairy goats against the background of inclusion of enzymatic probiotic substance, in the conditions of the Southern Urals. Additional inclusion of probiotic preparation Cellobacterin+ promoted a significant increase in digestibility of crude fiber (by 4.9‑5.5%), crude protein (by 3.3‑4.1%), crude fat (by 3.8‑5.1%), as well as an increase in average daily milk yield by 2.1‑4.7% (p≤0.05).

In the process of studying the feeding of the developed “protected” form of betaine to sheep, a positive effect was determined with respect to metabolic processes in the body of lambs of the transition period. The use of betaine supplements in a “protected” form contributed to the improvement of fat and protein metabolism, functional liver function.