Influence of genotype and season on the sperm production of beef cattle-producing bulls in Kazakhstan

In this paper, we aimed to study the influence of genotype and season on sperm production in beef cattle sires in Kazakhstan. Based on the results obtained over five years of using beef cattle sires, it can be considered that the spring and summer periods have a significant impact on Kazakh Whiteheaded sires; the winter and summer periods affect Aberdeen-Angus sires, and the spring period affects Hereford sires. Other seasons mainly had a positive influence on sperm production indicators, and if there were any changes, they were not significant. The highest concentration in the ejaculate was observed in Kazakh Whiteheaded sires during the winter-autumn period, amounting to 0.82 billion/ml; in Aberdeen-Angus sires during the spring-autumn period, it was 0.72-0.72 billion/ml; and in Hereford sires during the autumn period, it was 0.82 billion/ml. Autumn had a positive influence on all genotypes.