MEAT PRODUCTION AND GROWTH OF INTERNAL ORGANS AND ADIPOSE TISSUE IN BULLS, OBTAINED FROM THE SELECTION OF THEIR PARENTS ACCORDING TO THE INDEX OF SIMILARITY OF SYSTEM B ANTIGENS OF BLOOD GROUPS

Abstract

During reproductive crossing, the genetic diversity of animals increases and the problem of consolidating livestock by type and productivity arises. Blood group antigens are one of the factors that indicate genetic variability, so they can be used as markers when selecting parent pairs. The purpose of this study was to analyse the meat productivity, development of internal organs and accumulation of adipose tissue in 18-month-old bulls derived from different selection of their parents according to the index of antigenic similarity (ras) of the B system of blood groups at the first stages of a complex reproductive cross between Simmental and grey Ukrainian cattle with breeders of Charolais and Kian breeds. According to the value of ras, the bulls were divided into two groups. In the first – from a homogeneous selection of parents (over 0.268; n=9); in the second – from heterogeneous (ras up to 0.267; n=7). After slaughtering the bulls, the meat productivity, mass, and output of the head, liver, lungs, and other organs and glands of internal secretion were determined. Intermuscular, interstitial, perirenal, pregastric, intestinal, and pericardial fat were separated and weighed. With homogeneous selection of parents, their sons, in comparison with their peers from heterogeneous mating, show a tendency to increase the content of muscles (by 4.2%), fat tissue in carcasses (by 12.4%), including between muscles (by 1.1 points). There is 11.6% less pulp per kilogram of bones, 17.2% worse muscle tissue index, 7.8% less absolute weight of liver, 10.0% of kidney, 27.8% of heart, head – by 2.0% and lungs – by 11.6%. In bulls, from the heterogeneous selection of parents with ras to 0.267, there is 7.2% more fat tissue in the body, including internal fat tissue by 7.8%, the relative mass of bones is 0.8 points higher. The practical use of homogeneous selection according to antigens of blood groups of crossbreed parents allows improving the morphological composition of the carcasses of their offspring. Heterogeneous selection promotes better development of internal organs, which are less valuable slaughter products