No abstract

The paper presents the results of a study on the effect of probiotic feed additive “Amilotsin” on the productivity of pregnant ewes and castrate rams. The ewes who received the optimal level of Probiotic feed additive (PFA) “Amilotsin” in the diet throughout the entire experiment were significantly superior in their live weight to their analogues. Animals of the second group at the end of the experiment had a live weight higher by 3.4% than in the first and by 2.4% compared to the third group. The highest average daily gains during the study period were in ewes of the second group, then in animals of the third group. Castrate rams of the first experimental group treated with the composition of the basic diet of the feed additive “Amilotsin” in the amount of 0.38 and 0.19 g/kg of live weight per day during the entire experimental period had an average and absolute live weight higher than the control group, the second and the third experimental groups.

To increase the production of mutton, it is necessary to improve the genetic resources of sheep with precocity and high meat productivity. In this regard, the meat breed Dorper has gained its popularity, which has good meat qualities. The aim of this paper is to study the hematological parameters in the blood of the Kalmyk fat-tailed breed and hybrids (1/2 Kalmyk fat-tailed × ½ dorper). The work was carried out in LLC “Agrofirma Aduchi”, the Republic of Kalmykia in 2017. It is established that hybrids have a high content of hemoglobin, leukocytes, erythrocytes in the blood, which indicates the activation of redox processes in the body, and confirms their higher growth rates during cultivation. The content of total protein in the blood serum increased with age and was within the physiological norm. At 4 months of age, in the serum of lambs of group II, there was more total protein by 4.86 g/l (7.39%) (P > 0.95), and at 8 months of age – by 5.16 g/l (7.74%) (P > 0.99), than in peers of the control group. Crossbred calves were significantly superior to purebred animals also in blood serum, albumin, activity of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase. The activation of metabolic processes in the body of local sheep contributed to a high energy of growth in comparison with purebred peers of Kalmyk fat-tailed breed.

The successful development of the world sheep breeding is due to its meat productivity. In this regard, dorper meat breed gained its popularity, which has good meat qualities. The aim of the paper was to study the histological structure of the longissimus muscle of back of young rams of Kalmyk fat-tailed breeds and hybrids (1/2 Kalmyk fat-tailed + ½ dorper), as well as to establish a correlation between histological indicators of muscle tissue and slaughter and meat qualities. The work was carried out in LLC “Agrofirma Aduchi”, Republic of Kalmykia in 2016-2017. It was found that the muscle tissue of crossbred young rams was characterized by a large number of muscle fibers per unit area, a smaller diameter of muscle fiber, a higher rating of “marbling”. The content of connective tissue was greater in purebred rams than in crossbred ones. The area of the “muscle eye” was larger in crossbred animals of the second group. In the animals of Kalmyk fat-tailed breed, the coefficient of variation in the number of muscle fibers per mm2 was high and made up of 7.36% for the overall assessment of “marbling” to 10.59%, the content of connective tissue – 5.94%, which is higher compared to crossbred animals. Muscle tissue of crossbreed young rams is characterized by significantly more muscle fibers per unit area, smaller diameter of muscle fiber, and a higher rating of “marbling”.

The aim of the study is to analyze the commodity properties of sheepskin and the histostructure of the skin of rams of Kalmyk fat tail breed and crossbreeds (1/2 Kalmyk fat tail × 1/2 Dorper). The uterus of group I was covered with sheep of the Kalmyk fat tail breed, and the ewes of group II with sheep of the Dorper breed (experimental group). The study revealed, the mass of paired sheepskins of young group I was greater than that of peers of group II by 1.0 kg or 34.5 % (P> 0.999). A large live weight affected the large area of the skin of the second group of young animals, and the length of the hair of the experimental group, which turned out to be shorter, affected the smaller weight of the sheepskin. Pets have the best quality indicators of sheepskin and the best histological structure of the skin. Cross-breed animals have 14.52 % of more elastic, stronger and less thick skin, due to a greater epidermis thickness of 27.7 % and a denser reticular layer of 13.7 %. Wool cover (the ratio of primary follicle on the secondary) in cross-breeding sheep is 10.47 % thicker, compared to peers of white color, which corresponds to the technological requirements for the production of high-quality sheepskins.