Evaluation of meat productivity of Holstein bull calves in conditions of the Lower Volga Region

Aim. To study the influence of linear affiliation on the meat productivity of Holstein gobies. Materials and Methods. The experimental part of the work was carried out in 2019-2020 on the territory of a dairy unit for milk production, “Donskoe” farm enterprise, LLC, Kalachevsky district, the Volgograd region. For the experiment, 3 groups of 10 heads were formed according to the principle of analogues of purebred Holstein bulls from three lines: Reflection Sovering, Vis Back Ideal, and Montvik Chieftain. During the scientific and economic experiment, the technology of keeping animals used in beef cattle breeding was used. Classical and modern zootechnical methods are used in the process of research. The obtained research materials were processed by the method of variation statistics, taking into account the reliability criterion according to the Student, using the Microsoft Excel software package. Results. Studies have established that in order to achieve the desired parameters of the live weight gain of bull calves, it is necessary to drink them with whole milk. During 2.5 months, the experimental animals consumed 198 liters of whole milk per head. To obtain high average daily gains in fat mass from the 6th day of life, starter feed and finely crushed grain were introduced into the diet of steers. The norms of nutrients were determined depending on the planned growth and live weight. The results of changes in absolute indicators of live weight of calves with age showed that calves belonging to the line of Reflection Sovering 198998, with intensive cultivation, grow much faster than their peers from other lines. The results of the control slaughter show that at the age of 13 months, it is possible to obtain sufficiently full-bodied carcasses from animals. The largest carcass weight was observed in the Reflection Sovering 198998 bull calves (240.5 kg), which is 7.7 and 19.1 kg or 3.2 and 8.2% more than in the peers from other groups. When deboning carcasses, it was found that the bulls of the Reflection Sovering 198998 line also exceeded the pulp mass by 4.0 and 14.9 kg or 2.04 and 7.59% (P ≥ 0.99), and the pulp yield by 0.7 and 0.8%. Thus, it is established that the belonging of bull calves to different lines is related to the change in the composition of the carcass, the ratio between muscle, bone and adipose tissue. Conclusion. Scientific and economic experience shows that high indicators of meat productivity can be obtained from German-bred Holstein steers of various linear varieties, which can serve as a necessary reserve for increasing the level of beef production.