Abstract
The study of milk productivity of local breeds of cattle (Alatau, Aulieata, Red Steppe) revealed an increase in milk yield with increasing lactation period, with a stable average daily milk yield. Monitoring showed that the productivity of cows increases with the age of the animals. Evaluation of milk quality (fat and protein content, somatic cells) confirmed the stability of characteristics and satisfactory udder condition. Studies were conducted in the farm partnership "Khilnichenko and K" of Zhetisu region for the Alatau breed, in the farms "Yesbol" and "Zhantai" of Aktobe region for the Red Steppe breed, and in the farms "Umrali Ata" and "Uzbekova" of Turkestan region for the Aulieata breed. The obtained data showed that the milk yield of cows of the Alatau breed increases with age and lactation, reaching 5769.6 kg on the third and older lactations, with an average milk yield on herd 5537.8 kg. Fat and protein content in the milk of the Alatau breed remained consistently high (3.88% and 3.29%, respectively). The average milk yield of the Aulieata breed was 4006.6-4296.6 kg, with a fat content of 3.88-3.91% and protein content of 3.22-3.25%. The Red Steppe breed showed lower milk yields (2985.3-3201.4 kg), but stable milk quality parameters (fat - 3.61-3.84%, protein - 3.10%). The level of somatic cells in all breeds was within normal limits, indicating satisfactory udder health. Analysis of spermograms of bulls-producers of domestic (Alatau, Aulieata, Red Steppe) and foreign (Angler, Schwyz, Zebu) selection confirmed high indicators of sperm viability (more than 64%) and sperm survival (more than 40 hours), which indicates their high reproductive efficiency for breeding programs of return crossbreeding. The study confirms the strategic importance of conservation and rational use of genetic resources of local breeds for sustainable livestock breeding and adaptation to changing conditions, offering science-based approaches to breeding and management of the gene pool of cattle in Kazakhstan.