<b>РЕЗУЛЬТАТЫ ОЦЕНКИ БЫЧКОВ АУЛИЕКОЛЬСКОЙ ПОРОДЫ ПО СОБСТВЕННОЙ ПРОДУКТИВНОСТИ В ТОО «АГРОФИРМА КАРКЫН»     RESULTS OF EVALUATION OF AULIEKOL BREED BULLS BY THEIR OWN PRODUCTIVITY AT AGROFIRMA KARKYN LLP</b>, <b>RESULTS OF EVALUATION OF AULIEKOL BREED BULLS BY THEIR OWN PRODUCTIVITY AT AGROFIRMA KARKYN LLP</b>

<jats:p>Evaluating bulls for their own productivity through a comprehensive study of their performance indicators to identify the best individuals by genotype is essential for breeding high-quality bulls and subsequently using them in selective breeding to increase beef production. This article presents the results of testing Auliekol bulls for their own productivity, bred at Karkyn Agrofirma LLC, across different lines. It was found that bulls belonging to the Budilnik 825 line exhibited better growth rates and feed efficiency. Thus, per 1 kg of gain they spent 0.33-0.40 ECU less compared to the descendants of bulls belonging to the Zenit-Chubatogo 1165 and Zenit 1060 lines. The results of the study of the live weight dynamics during the growth period indicate that the higher live weight at the age of 12 months was in the first group (Budilnik 825 line) and amounted to 358.1 kg, which is 6.4% and 5.5% more than in the second (Zenit-Chubatogo 1165 line) and third (Zenit 1060 line) groups, respectively. In the period of 8-12 months, the bulls of the first group had an advantage in absolute live weight gain over their peers of the second and third groups by 9.3 kg or 9.6% at P ≤ 0.05 and by 10.0 kg or 10.3% at P ≤ 0.05, respectively. The average daily live weight gain corresponded to the absolute weight gain dynamics, and in the 8-12 month and 12-15 month age periods, Budilnik 825 line bulls had a reliable advantage over their peers of the Zenit Chubaty and Zenit 1060 lines by 78 g or 10.6% at P≤0.05 and 83 g or 10.2% at P≤0.05; by 121 g or 10.3% at P≤0.01 and 112 g or 9.5% at P≤0.05, respectively. Under identical feeding and housing conditions, the genetic potential of the line was manifested differently in the bulls of the experimental groups. Therefore, testing the bulls for their own productivity made it possible to identify a line of breeding bulls that consistently transmit hereditary traits to their offspring, which will accelerate the results of the breeding work carried out on the farm and improve the economically useful traits of the animals.</jats:p>