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 purpose of the study was to assess the efficiency of crossing the ewes of Kalmyk fat tailed breed with the rams of the Dorper breed to create a new genotype of the purebred sheep, as well as to assess the productive qualities and interior features of the first generation cross breed during intensive feeding in the conditions of the arid zone of Kalmykia. It was established that the crossbred rams have the best feed-efficiency by the body weight gain. In two months of feeding they consumed less dry matter per 1 kg of the body weight gain than the purebred animals by 2.11 kg, energetic feed unit (EFU) – by 2.17, exchange energy – by 21.67 MJ, crude protein – by 354.26 g. The cross breed of the experimental group showed a significantly higher content of total protein, alkaline phosphatase, AST and ALT enzymes transamination in the blood and serum during all periods of the study indicating the activation of redox processes in animals. The crossbred rams significantly surpassed their purebred herdmates in terms of preslaughter body weight by 11.07 kg, chilled carcass weight – by 5.37 kg, slaughter weight – by 5.18 kg, boneless meat weight in carcass – by 4.86 kg, loin eye area – by 3.54 cm2.

проспект Городовикова, 5, г. Элиста, Республика Калмыкия, 358011 2 Кафедра морфологии животных и ветсанэкспертизы Российский университет дружбы народов ул. Микулухо-Маклая, 8/2, Москва, Россия, 117198 В статье приводятся результаты исследований по изучению влияния различных доз нанопро-дукта «M-Feed» на гематологические показатели и динамику живой массы баранчиков калмыцкой породы по возрастам. Авторами установлено, что при практически одинаковой постановочной живой массе баранчики из второй опытной группы, получавших «M-Feed» дозировки 5 г на го-лову в сутки, к концу опыта имели живую массу на 6,26 кг больше, чем у контрольных аналогов, на 4,1 кг, чем из первой опытной группы, и на 2,84 кг из третьей группы. За период опыта баранчики из второй опытной группы давали абсолютного прироста 39,57 кг, что выше, чем у контрольных, на 6,06 кг, аналогов из первой опытной группы -на 4,43 кг и из третьей -на 2,51 кг. В крови растущих баранчиков калмыцкой курдючной породы опытных групп, получавших различные дозировки кормовой добавки «M-Feed», наблюдается некоторое увеличение количества эритроцитов и гемоглобина. Так, содержание эритроцитов в крови баранчиков из контрольной группы было на 1,2% и 0,8% меньшим, чем у аналогов, из первой опытной группы, на 12,14 и 10,8%, из второй группы на 3,2 и 2,7% чем из третьей опытной группы.Ключевые слова: кормовая добавка «M-Feed», прирост, живая масса, энергия роста, гемато-логические показатели, возраст, обмен веществ.Продуктивность, рост, развитие овец и количество получаемого приплода во многом обуславливается условиями кормления, в особенности в молодом воз-расте [1][2][3][4]. Качественное кормление молодняка оказывает прямое воздействие на формирование конституции, помогая созданию животных желательного типа.В последние годы в животноводстве начали широко использовать высоко-эффективный нанопродукт «M-Feed».Анализ литературных и компьютерных источников показывает, что кормовая добавка оказывает положительное действие на продуктивность и резистентность животных. Однако до настоящего времени наука и передовая практика не распо-

The purpose of this work was to determine the efficiency of using crossbred rams(? Kalmyk fat-tailed + ? Dorper) for crossing with Stavropol breed ewes in order to obtain lamb meat. In order to carry out the research and production experiment, two groups of Stavropol breed ewes with 40 heads in each group were formed according to the paired comparison method. In late October – early November 2019, ewes from group 1 were inseminated with the sperm of Stavropol breed rams and ewes from group 2 were inseminated with the sperm of crossbred rams (? Kalmyk fat-tailed + ? Dorper). It was found that the conception rate of ewes from the 2nd experimental group was 2.5% higher than in the control group. 44 lambs were obtained from the ewes of the 2nd experimental group, which was 4 heads or 10% more than from the 1st control group. Crossbred lambshave increased growth and they are significantly superior to purebred herdmates of Stavropol breed in live weight at the age of five months by 3.3 kg (P> 0.999), at the age of six months by 4.2 kg (P> 0.999), and at the age of seven months by 5.1 kg (P> 0.999). The study of exterior traits indicates that crossbred animals have higher indices of format, chest, blockiness and massiveness, while purebred animals of Stavropol breed are distinguished by higher indices of long legs and overgrowth.

The article presents the study of polymorphism of the CAST and GH genes, which determine the features of the manifestation of the productive and biological characteristics of sheep with ½ Kalmyk + ½ Dorper blood system. Calpastatin gene polymorphism represented by alleles M and N, whose frequency was 0,65 and 0,35; genotypes MM, MN – 30 and 70% accordingly. The desired NN genotype has not been identified. A relatively uniform incidence of allele N (0,35) CAST gene and B (0,40) GH was established, what contributed to an almost equal distribution of allele frequencies М (0,65) and А (0,60) genes of calpastatin and somatotropin accordingly. The frequency of heterozygous genotypes occurrence by CAST gene composed 0,7. By GH gene the following distribution of genotype frequencies is observed. Frequency of occurrence homozygous АА and heterozygous AB genotypes was equal to and is 0,4, wherein the frequency of occurrence advised homozygous ВВ genotype was 0,2. Among the animals studied, sheep with a complex genotype are most common CASTMN GHAB (40 %). The amount of percent CASTMM GHAA and CASTMN GHAA is in 22,2%. 10% is for genotypes CASTMM GHBB and CASTMN GHBB.