Document Type : Research Paper
Authors
1 Assistant Professor of Department of Animal Nutrition and Physiology, Animal Science Research Institute (ASRI)
2 Assistant Professor of Department of Animal Breeding and Genetic, Animal Science Research Institute (ASRI)
Abstract
This study was carried out by using two hundred ewes (2-4 years old) as pure breeding (Zel × Zel) and crossbreeding (Chal × Zel). In each treatment, 30 male and 30 female lambs were fattened in a feedlot experiment for three periods; 75, 100 and 125 days. At the end of each period, 10 lambs of each treatment were slaughter and carcasses analysis was down. The lean meat percentage and bone percentage in each feedlot periods was not affected by genetic composition and lamb gender (P< 0.05), but carcass fat percent in feedlot periods were significantly (P<0.05) lower in Zel male and crossbred female lambs. Weight of crossbred lambs at the weaning and finishing were 22 and 26 percent heavier than the purebred lambs, respectively. In this study, under industrial breeding conditions, ewes produced 5382 kg live weight lambs in pure breeding system (with 165 percent increase) and 6774 kg live weight lambs, under crossbreeding system (with a 234 percent increase). Consequently, breeding of purebred or crossbred Zel lambs which fattened in an intensive feedlot condition would be economically beneficial to farmers.
Keywords
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