Fattening of bulls of Aberdeen-Angus Kalmyk and Charolais breeds in conditions of environmentally safe feeding and keeping

In a scientific and economic experiment on bulls of the Aberdeen-Angus, Kalmyk and Charolais breeds of pasture fattening in the foothill raw material zone of the Labinsk district of the Krasnodar region, the productivity, interior, quality and safety of meat raw materials were studied in a comparative aspect. At the fattening complex of the agricultural company, six-month-old bulls of Aberdeen-Angus, Kalmyk and Charolais breeds were formed into three groups by age according to the principle of analogues (n=12), which were raised from birth using the technology of specialized beef cattle breeding. The first group - Aberdeen-Angus bulls, the second - Kalmyk bulls and the third - Charolais bulls, which had a live weight at the beginning of fattening 189.5 ± 13.8; 175.5±11.5 and 177.1±7.6 kg, respectively. The results of the slaughter of bulls of three breeds revealed a direct relationship between pre-slaughter live weight and slaughter indicators. The pre-slaughter weight of Charolais bulls and, to a lesser extent, Aberdeen-Angus bulls was significantly higher than the mass of Kalmyk bulls. The difference between the slaughter rates of the three breeds of beef bulls is significant in terms of such indicators as slaughter yield, boneless beef yield with the advantage of carcass morphology of Charolais bulls. The slaughter yield was higher in bulls of the Charolais breed compared to groups 1 and 2 by at least 3.2 % and amounted to 69.5 %. In the study of the chemical composition of muscle tissue, a reliably maximum proportion of protein and a minimum proportion of fat in the longissimus muscle of carcasses of Charolais bulls were determined, which amounted to 21.7 and 7.6 %, respectively. A direct positive relationship was determined between meat productivity and the mass fraction of protein in the muscles of bulls of three breeds with such interior indicators as the mass fraction of total protein, protein index. The results of the research allowed to conclude that the biological status of animals has a significant impact on meat productivity, technological properties and the biological value of meat raw materials necessary for the production of baby and functional nutrition.