Growth and development of limousine bulls of various genotypes in postnatal ontogenesis

The purpose of research is to study the growth and development of Limousin bulls of various geno-types in postnatal ontogenesis. Objectives: to study of weight growth, absolute, average daily gains in live weight and relative growth rate of young animals by age periods and for the entire period of growing and fattening; to study of the linear growth of bulls in postnatal ontogenesis based on the dynamics of body measurements and body composition indices. The objects of the study are bulls of the Limousin breed of various genotypes obtained from the mating of cows of French, Australian and local selection with bulls of local reproduction. The scientific and economic experiment was carried out in 2021–2022 at LLC Meat Union of Bashkir Producers, located in the Kuyurgazinsky District of the Republic of Bashkortostan. Indica-tors of live weight dynamics, live weight gain, relative growth rate, body measurements and body composi-tion indices in the age aspect were studied. Research of the weight growth of young animals of various genotypes made it possible to identify significant differences in terms of absolute and average daily gain in live weight for the entire period of growing and fattening between bulls of the 1st and 2nd experimental groups, respectively, by 32.5 kg and 59.7 g (in both cases – by 6.2 %). The highest values of measure-ments, indicating the formation of meat qualities and body shape, were noted in bulls of the 1st group compared with peers of the 2nd and 3rd experimental groups. Breeding animals for a long period under different housing and feeding technologies influences the characteristics of the growth and development of the descendants of local reproduction of Limousin breed cattle.