INFLUENCE OF GENOTYPE AND TECHNOLOGY OF GROWING ON GROWTH, DEVELOPMENT AND PRODUCTIVE QUALITY OF CALFS

Abstract

The meat productivity of animals of a particular breed is due to morphological and physiological characteristics that are formed and developed under the influence of heredity and environmental conditions (feeding and maintenance) during the rearing period. In the process of growth and development of animals, significant quantitative and qualitative changes occur, associated with an increase in weight and changes in the morphological composition of the carcass. When studying the influence of breed on the productive qualities of black-and-white bulls and aberdeen angus x black-and-white hybrids raised according to the technology of dairy cattle breeding, it was found that the advantage in live weight of aberdeen angus x black-and-white hybrids at the age of 2 months. on the6 kg or 8,3% (P<0,05) and at 3 months. - on the 7 kg or 7,3% (P<0,05). Average daily gains in live weight for the entire period of the experiment from birth to 6-6,5 months. were practically the same - 766 and 755 g. Heterosis in terms of growth intensity in crossbred gobies did not appear. The mass of paired carcasses of aberdeen angus gobies x black-and-white hybrids was on 11,9 kg or 15,9% (P<0,05) higher than among peers of the black-and-white breed, as well as the slaughter yield - by 7,8% (P<0,001), which amounted to 52,5% versus 44,7%. In calves of the control group and aberdeen angus x black-and-white hybrids, the flesh of the carcass (trimmed meat) is about 78%. According to the coefficient of meat content (yield of pulp on1 kg bones), no practical differences have been established, and in terms of fat and protein, in the average sample of meat, black-and-white bulls surpass their peers by 0,3 and 0,4%, respectively. According to the chemical composition of the longest muscle of the back, purebred bulls at the age of 6-6,5 months, compared to hybrid young animals, are distinguished by an increased fat content - by 0,6%.