Mussabekov Aidos - Kazakh Agro Technical University S. Seifullin, Astana, Akmola Region, Kazakhstan.
Shamshidin Aljan - Republican Center of Livestock Breeding JSC ASIL TYLІK. Akmola Region, Kazakhstan.
Alshinbaev Orynbasar - South Kazakhstan State University M. Auezov, South-Kazakhstan Region, Kazakhstan.

The results obtained in the study age dynamics of indicators of sperm production of breeding bulls of black-motley and hill breeds indicate on the Republican Center of livestock breeding JSC ASIL TYLІK Akmola Province, Kazakhstan indicate that the quantity of the received sperm production changes by years of their use. Special differences of age dynamics between breeds it isn t observed

Bull, Sperm production, Age