Meat productivity of beef steers of different genotypes in Saryesik-Atyrau desert conditions.

Significant climatic changes, driven by an increase in average annual temperature and a decrease in precipitation, have led to extreme conditions for animal husbandry, including beef cattle breeding. Therefore, the aim of the study was to evaluate the meat productivity of Aberdeen-Angus, Hereford, and Kazakh white-headed breeds raised in the climatic conditions of farms in the Saryesik-Atyrau desert region of the Republic of Kazakhstan. Quantitative productivity characteristics were assessed through controlled slaughtering of nine animals (three from each breed), with an initial weight of 400 kg ± 10 kg. Qualitative indicators of meat raw material were determined using arbitration methods. Morphometric analysis of carcass weight indices revealed the influence of dimensional differences inherent to the different genotypes. The maximum carcass measurements and post-slaughter weight were observed in Hereford bulls, while Aberdeen bulls had the smallest measurements (P < 0.05). The Kazakh white-headed breed exhibited intermediate values compared to the specialized meat breeds. The quality indicators of meat raw material were more significantly influenced by breed characteristics. Thus, meat from Hereford and Kazakh white-headed breeds showed higher (P < 0.05) protein content (17.1-18.2%) compared to Aberdeen, in which fatty tissue predominated (17.9%), compared to 12-14% in the other breeds. This higher fat content in Aberdeen meat was associated with a greater energy value, by 1287-1789 kJ per kilogram of meat, while the protein content was higher in Hereford meat. In conclusion, the genetically determined qualitative and quantitative characteristics of meat productivity are preserved even under extreme desert conditions. Given the similar indicators of meat productivity across these breeds under temperature stress, it is possible to select livestock for fattening based on the target parameters of meat raw material.