the Importance of the Feeding Levels and Adequacy on the Meat Quality and Productivity Performance of Cross-Bred Bulls

The study aimed to determine the effect of the level and adequacy of feeding on the dynamics of live weight and meat productivity of Simmental x Holstein bulls with a close blood relationship (87.5%) for the Holstein breed. Three groups of bulls with 87.5% Holstein heredity in the genotype were formed, out of which two groups were experimental and one group served as a control group. The bulls of the control group received a diet compiled according to detailed standards, and their analogs from the experimental groups had a diet exceeding the norm by 10 and 20%, respectively. During the entire growing period, the bulls of the 1st experimental group consumed 3,564 energetic feed units (EFU) and 362.5 kg of digestible protein (DP); the 2nd experimental group consumed 3,875 EFU and 394.3 kg DP; and the control group consumed 3,245 EFU and 329.9 kg DP, respectively. In terms of carcass yield, bulls of the first and second experimental groups outperformed the ones from the control group by 2.41% and 3.92%. With an increase in the level of feeding in experimental bulls, fat deposition accelerated; thus, the meat of bulls of the experimental groups contained 2.13% and 2.54% more fat than in animals of the control group. At the same time, the protein content in the meat of experimental bulls decreased by 0.15 and 0.22% in comparison with the control group. The energy value of 1 kg of meat of experimental bulls was higher by 0.77-0.90 MJ. It can be concluded that a possible increase in the meat productivity of bulls-crossbreeds of the Holstein breed with a close blood relationship and the determination of planned indicators of animal growth should be taken into account when developing breeding programs.