Improving the Technology for Assessing the Semen of Beige Karakul Sheep

Abstract

The article presents the research results on the effective use of seed products from breeding rams in reproduction for the conservation and targeted propagation of genetic resources of Karakul sheep of rare beige color, which are on the verge of extinction. Selected freshly obtained ejaculates from 6 beige rams of the Karakul breed in the amount of 32 samples, meeting the requirements of the sperm production standard for sheep, were studied by the speed of sperm movement and the frequency of occurrence of the acrosomal area of sperm. It was established that the seed production of producers in terms of the speed of sperm cell movement ranged from 80-169 µm/s and the area of the acrosome in the head of the sperm ranged from 40-86%. Various parameters for their integration have been determined and various gradations of parameters have been developed, which are divided into 9 groups with the functional characteristics of sperm products. Testing samples of freshly obtained sperm in artificial insemination of sheep showed that among all groups, the most effective was the semen produced by rams that have a VAP movement speed of at least 110 μm/sec and a sperm acrosomal area of at least 60%, ensuring the fertility of ewes up to 100%, which is higher in compared to the traditional assessment method by 22%. During cryopreservation of freshly obtained semen, in all 9 groups of frozen-thawed semen, the speed of sperm cell movement decreases by 30.7-97.4 μm/sec and the area of the acrosome in the head of the sperm decreases by 9.2-36.7% and is, respectively, within 49, 62-68.67 µm/sec and 17.4-65.0% and significantly affects the fertility of ewes. The developed method for selecting ram sperm with new morphological parameters and the speed of sperm cell movement in the ejaculate increases the genetic progress of beige color reproduction in Karakul sheep populations from 12.0-22.0%. The data presented in the article on the morphological structure of sperm, their motility, and their fertilizing ability indicate their great importance in the reproduction of especially valuable beige-colored genotypes in astrakhan sheep breeding.