摘要：The results of meat productivity of young cattle of beef breeds (Auliekol, Kazakh Whitehead, Galloway, Hereford) depending on the breed, sex, and age (young bulls, steers-calves, heifers, first-calf cows, adult cattle-cows, bulls, calves) grown in the Western Region of the Republic of Kazakhstan during winter, turning winter (pre-spring), early spring and spring periods are given. The animals were divided into three groups according to their breed and growing conditions. The highest slaughter yield among adult animals was found in the cow of the Auliekol breed-63,7% with a pre-slaughter weight of 532.8 kg； the lowest yield was in the cow of the Hereford breed - 53,6% with a pre-slaughter weight of 410.0 kg. Studies of young animals showed that the highest and the lowest values were 61.3% in a bull of the Auliekol breed with a pre-slaughter weight of 460.1 kg and 50.8% in a bull of the Hereford breed with a pre-slaughter weight of 372.3 kg, respectively. The proportion of muscle, fat, connective, and bone tissue in the slaughter process is determined. The muscle tissue of the animals of higher fatness in the I and II groups consists of 56.6-57.3% of carcass weight, fat-15.7-16.1%, and connective, bone and cartilage-26.9-27.2%. The muscle tissue of the animals of I and II groups of average fatness amounts to 59.7-60.2% of carcass weight, fat-9.8-10.3%, connective, bone and cartilage-29.8-30.1%, the muscle tissue of the animals of III group of average fatness amounts to 58.4% of carcass weight, fat-10.2%, connective, bone, and cartilage-31.4%. The amino acid content of cattle cuts of different breeds is almost identical in proline-0.68-0.7%, serine - 0.76-0.79%, alanine - 1.09-1.13%, tyrosine - 0.63-0.66%； but there are also significant differences, such as arginine-from 0.65 to 1.27%, lysine-from 0.86 to 1.66% and leucine-from 0.87 to 1.56%. The highest total amino acid content is 13.59% and the lowest is 9.26%. As a result, the food and biological quality of beef depending on breed, age, living conditions, pre-slaughter housing, slaughtering, and production processes.
