کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5796210 | 1110689 | 2013 | 6 صفحه PDF | دانلود رایگان |
Genotype effects on lamb carcass traits were investigated in a 4-year study aimed at assessing potential benefits from introducing meat breeds into the wool-oriented extensive sheep systems of northeastern Patagonia, Argentina. Five ram [Corriedale: CO; Border Leicester: BL; Ãle de France: IF; Texel: TX; and synthetic CRIII (25% Merino, 37.5% IF, 37.5% TX)] and 5 dam (CO; synthetic CRIII; BLCO: BLÂ ÃÂ CO; IFCO: IFÂ ÃÂ CO; and TXCO: TXÂ ÃÂ CO) genotypes were represented in the study. Data were collected from 436 male lambs of 9 genotypes (COÂ ÃÂ CO, BLÂ ÃÂ CO, IFÂ ÃÂ CO, TXÂ ÃÂ CO, CRIIIÂ ÃÂ CO, CRIIIÂ ÃÂ BLCO, CRIIIÂ ÃÂ IFCO, CRIIIÂ ÃÂ TXCO, and CRIIIÂ ÃÂ CRIII). Hot carcass weights and dressing yields were determined after slaughtering. Carcasses were given conformation and subcutaneous fat scores using the EUROP system [scale varying from E (best) to P (poorest) for conformation, and from 1 (lean) to 5 (overfat) for subcutaneous fat]. Linear measurements of carcass length and width were recorded and carcass compactness indices were calculated from those. Purebred CO acted as a standard for comparisons. On a constant liveweight basis, genotypes CRIIIÂ ÃÂ IFCO and CRIIIÂ ÃÂ CRIII presented higher (PÂ <Â 0.05) carcass weight and dressing yield than COÂ ÃÂ CO and BLÂ ÃÂ CO. Crossbred and synthetic genotypes showed higher (PÂ <Â 0.05) carcass width than COÂ ÃÂ CO. With the exception of BLÂ ÃÂ CO the remaining genotypes showed higher (PÂ <Â 0.05) carcass width/length ratio than COÂ ÃÂ CO. The probability that carcasses of crossbred and synthetic lambs presented better conformation than COÂ ÃÂ CO was higher than 84%. Carcasses of CRIIIÂ ÃÂ IFCO lambs were given the best conformation scores. The probability that BLÂ ÃÂ CO carcasses presented higher subcutaneous fat than the remaining genotypes exceeded 79%. Our results indicate significant improvements in carcass conformation arising from crossing. Sheep farmers in extensive systems could take advantage of the higher fatness of BL crossbred lambs to produce light carcasses with adequate fat cover, a crucial industry requirement. Terminal crossbreeding with Ãle de France, Texel, and CRIII rams could be implemented to improve carcass conformation thus matching market demand for heavy carcasses with limited fat content. Second cross schemes did not improve carcass commercial traits over the best terminal cross or the synthetic CRIII breed.
Journal: Small Ruminant Research - Volume 109, Issue 1, January 2013, Pages 9-14