Comparison of growth and carcass traits of Lori-Bakhtiari lambs and their crosses ‎with Romanov and Pakistani breeds

This study was conducted to investigate the performance of growth and carcass traits of Lori-Bakhtiari (L), Romanov×Lori-Bakhtiari (F1RL), Pakistani×Lori-Bakhtiari (F1PL), (Pakistani×Lori-Bakhtiari)×(Romanov×Lori-Bakhtiari) (¼P¼R½L) and (Romanov×Lori-Bakhtiari)×(Romanov×Lori-Bakhtiari) (F2RL) crossbred lambs. Carcass characteristics of Lori-Bakhtiari (n=50), F1RL (n=41) and F2RL (n=20) crossbred lambs. Lambs were weaned at the age of 90 ± 5 days. Lambs were slaughtered at six month of age. Birth weight in Lori-Bakhtiari (5.12 kg) was significantly (P<0.05) higher than in Romanov (4.81 kg) and Pakistani (4.57 kg) crossbred. Weaning weight and body weight in six months were significantly higher (P<0.05) in Romanov × Lori-Bakhtiari crossbred lambs (30.96 and 42.75, respectively) than in Lori-Bakhtiari (28.81 and 41.69, respectively) and others genetic compositions. F1RL and F2RL crossbred lambs for lean percentage were significantly (P<0.05) higher than in Lori-Bakhtiari lambs in constant age (59.57, 60.57 and 50.03, repectively) and in constant weight (60.99, 59.24 and 49.56, repectively). Weight and percentage of total fat of carcass in Lori-Bakhtiari lambs (7.56 kg, 31.57% in constant age 6.65 kg, 30.46% in constant weight, repectively) were significantly (P<0.05) higher than of F1RL (4.25 kg, 20.91% and 4.30 kg, 20.08%, repectively) and F2RL (2.95 kg, 17.97% and 5.12 kg, 22.46%, repectively) lambs. In conclusion, crossbreeding between Romanov and Lori-Bakhtiari (F1) improves body weight at weaning and at six months of age, and carcass composition.