Consumption and use of the main nutrients of the ration when crossbreeding cattle of Kazakh White-headed and Hereford breeds

Abstract

Crossbreeding in cattle contributes to the production of crossbred young animals, which due to enriched heredity have the potential for intensive growth and achieving a high level of beef productivity. The purpose of the work was to study the infl uence of crossbreeding of cattle of Kazakh White-headed and Hereford breeds on the efficiency of consumption and use of the main nutrients of the ration by steers, heifers and castrated steers. For the experiment, 3 groups of heifers and 6 groups of steers of the following genotypes have been formed: the 1st Kazakh White-headed, the 2nd – 1/2 Hereford×1/2 Kazakh White-headed, the 3rd – 3/4 Kazakh White-headed×3/4 Hereford. At the age of 3 months half of the steers were castrated. It has been found that purebred animals were inferior to crossbreds from the crossbreeding of cattle of Kazakh White-headed and Hereford breeds. For example, during the rearing period, purebred animals of Kazakh White-headed breed consumed 2638,8– 3272,1 feed units and 2674,8–3549,2 EFU, crossbreds of the genotype 1/2 Hereford×1/2 Kazakh White–headed – 2811,6–3389,2 feed units and 2836,4–3640,1 EFU, crossbreds of the genotype 3/4 Kazakh White-headed×3/4 Hereford – 2749,2–3332,1 feed units and 2764,3–3332,0 EFU, metabolic energy, respectively, by genotypes – 26 748,1–35 492,1 MJ, 28 364,2 – 36 401,2 MJ and 27 643,1–35 941,9 MJ, digestible protein – 246,0–344,2 kg, 296,1–356,9 kg and 289,2–350,5 kg, crude protein-350,9–451,4 kg, 365,2–466,8 kg and 362,1–460,5 kg. The crossbreeding of cattle of Kazakh White-headed and Hereford breeds had a certain influence on the studied indicators. Thus, the best indicators of the efficiency of consumption and use of the main nutrients of the ration among steers, heifers and castrated steers were distinguished by half-blood crossbreds. At the same time, the largest amount of consumption of all nutrients in the ration was distinguished by steers, the smallest – heifers, castrated steers occupied an intermediate position.