EFFICIENCY OF BIOCONVERSION OF NUTRIENTS AND FEED ENERGY INTO MEAT PRODUCTS BY SHEEP OF DIFFERENT GENOTYPES

Abstract

The purpose of the study is to determine the influence of the genotype of rams on the efficiency of transformation of protein and energy of the feed ration by purebred young animals of the Romanov breed (Group I), its crosses with the Edilbaevskaya breed of the first generation 1/2 Romanovskaya × 1/2 Edilbay (II group) and the second generation 1/4 Romanovskaya × 1/4 Edilbay – ( Group III) in food protein and energy of meat products. Crossbreeds of groups II and III were distinguished by less crude protein consumption per 1 kg of live weight gain than peers of group I – by 15.9 (1.62 %) and 33.5 g (3.48 %) and energy by 3.64 (4.23 %) and 4.89 mJ (5.77 %). An advantage was noted for crosses of groups II and III in terms of the weight of edible parts of the carcass, which amounted to 5.05 (36.89 %) and 6.79 kg (49.60 %). Purebred rams of group I were inferior to crossbred young animals of groups II and III in terms of protein content in the edible part of the carcass by 0.86 (31.62 %) and 1.15 kg (42.28 %), respectively, extractable fat – by 0.82 (66.13 %) and 1.25 kg (100.8 %), energy – by 46.54 (49.01 %) and 68.30 mJ (71.93 %). All this determined the advantage of crossbred rams of groups II and III in terms of the yield of nutrients, edible parts of the carcass and energy per 1 kg of pre-slaughter live weight. For protein, this advantage was 2.49 (3.53 %) and 4.32 g (6.12 %), extractable fat – 9.86 (30.65 %) and 16.01 g (49.77 %), energy – 0.59 (23.98 %) and 0.70 mJ (28.45 %). The advantage of crossbred young animals of groups II and III in terms of the protein bioconversion coefficient was established, which was 0.26 and 0.65 % for protein, 0.21 and 0.40 % for energy, respectively. The leading position in all indicators was noted for crossbreeds of the second generation of group III.