Reproductive traits of young bulls and heifers of the Aberdeen Angus breed

Abstract

The article presents materials on the reproductive ability of servicing bulls and first-calf heifers of the Aberdeen Angus breed of American selective breeding. The objects of the research were 4 bulls of the Aberdeen Angus breed of American selective breeding. The breeding stock was young heifers of the Aberdeen Angus breed of American selective breeding at the age of 16-18 months in number of 100 head, which were bred on the “Reina-Kench” breeding farm in the Ak-Suu District, Issyk-Kul Region. A cow in heat was
identified by its behavior (“standing reflex”), changing in the external genitalia and flux. Heat detectors were also used. The scrotal circumference of young bulls in our studies averaged 33.4 cm, which corresponds to the standards of the Aberdeen Angus cattle breed. The fertilizing ability of Aberdeen Angus bulls between the groups had insignificant differences and was in the range of 88-96%. The lowest rate for the servicing bull was in group III, the fertilizing ability of which was 88%. Matrix A502 bull had the highest rate of 96% or it was 8% more
than the bull of the group III Cavalry A861. In the process of adaptation to the new conditions of keeping and feeding, there were several abortions in the herd. Thus, one abortion occurred in groups I, II, and two abortions occurred in groups III and IV. There were also stillborn
calves in the amount of 1 head in group I and 1 head in group III. Therefore, as a result of calving, 23 head of alive calves were obtained in groups I and IV for each, in group II – 24 head and in group III – 22 head. Matrix A502 bull had good rates. In the conditions of the Eastern part of the Issyk-Kul Region, the Aberdeen Angus breeds of American selective breeding had good adaptive and reproductive abilities.