AGE AND GENOTYPICAL CHARACTERISTICS OF REPRODUCTIVE QUALITIES OF STUD LINES OF KAZAKH WHITE-HEAD CATTLE
The peculiarities of sexual reflexes and quality indices of sperm production in Kazakh White-Head sires and steers of different stud lines in breeding herds of leading farms of West Kazakhstan region have been studied. The farms are located in the zone of arid steppes with sharply continental climate. The sheep’s fescue-wheat grass-kolyn vegetation prevails on the pasture. It has been found that the reproductive qualities of Kazakh-White-Head sires and steers were characterized by rather high indices. In terms of sexual reflexes, the age differences were insignificant, the interlinear differences were more noticeable, which should be taken into account when selecting sires for free mating or “stripping”. By the indices of semen quality, the more preferable ones were distinguished, which were represented by the Mialan-13851 stud lines progeny. In general, the quality indices of sperm production of sires and steers fully met the requirements of being used for the herd reproduction