The efficiency of using simmental x holstein hybrids of various types of body composition

Abstract

In crossbred cows, three exterior and body composition types are distinguished: dense shallow, dense medium, and dense broad. Cows of broad type were superior to their peers of shallow type in height at the withers by 3.98 cm, by chest depth by 3.33 cm, by chest width by 8.25 cm, by chest girth by 5.5 cm, and by the slope body length by 5.37 cm. Cows of the medium type take an intermediate position. The share of the cows of the broad type is 67.5 %, they have a broader body, have an advantage in the indices of the breast width (5.5 – 9.2 %, P ≤ 0.001), and pelvic-thoracic width (7.2 – 13.1 %, P ≤ 0.001), but are inferior in the index of leg length (0.6 – 0.9 %). During the first lactation, heifers of shallow type gave 5,353 kg of milk, which was more by 500 – 539 kg than from heifers of the medium and broad types (P ≥ 0.99). In terms of the live weight, the calves obtained from the mothers of the broad type are superior to their peers at birth by 1.6 – 2.5 kg; at the age of three months, the difference between the groups of animals reached 8.0 – 13.0 kg (P ≤ 0.01, P ≤ 0.001); at the age of six months —15.0 – 25.0 kg (P ≤ 0.001); at the age of nine-months — 17.0 – 28.0 kg (P ≤ 0.001); at the age of twelve months — 25.0 – 44.0 kg (P ≤ 0.001); at the age of fifteen months — 25.0 – 46.0 kg (P ≤ 0.001); and at the age of eighteen months — 30.0 – 52.0 kg (P ≤ 0.001). By the weight of hot carcass, calves of the broad type were superior to their peers of the shallow type by 38.9 kg (P ≤ 0.01), and to those of the medium type — by 23 kg (P ≤ 0.05). The yield of boneless meat per 1 kg of bones in the calves of the shallow type was 3.87 kg, of the medium type — 4.10 kg, and of the broad type — 4.22 kg (P ≤ 0.05). The coefficient of feed protein and energy conversion to the dietary protein in the edible part of the carcass was higher in the calves of the broad type, which was due to the more intensive accumulation of muscle and adipose tissues in their organisms.