1Centro Regional de Investigaciones INIA Tamel Aike,Instituto de Investigaciones Agropecuarias,Casilla de Correos 296,Coyhaique,Región de Aysen,Chile.
2Department of Agriculture, Environment and Rural Affairs,Room 650 A Dundonald House,Upper Newtonards Road,Belfast BT4 3SB,UK.
Animal. 2019 Jan;13(1):213-220. doi: 10.1017/S1751731118000848. Epub 2018 Apr 30.
A low finishing weight and poor carcass characteristics are major causes of lower incomes in extensive sheep flocks; however, the use of terminal sire crossbreeding would improve lamb performance and carcass traits under these conditions. The aim of this study was to evaluate sire breed effects on the performance of lambs born to Corriedale ewes in extensive sheep systems in Western Patagonia. A total of 10 Corriedale, 10 Dorset, nine Suffolk and seven Texel sires, 16 of which were under a genetic recorded scheme and 20 selected from flocks not participating in genetic improvement programmes, were used across six commercial farms for 2 successive years. Data were collected from 685 lambs of the four resulting genotypes. Overall, Corriedale lambs were 0.47 kg lighter at birth than crossbred lambs (P0.05). Carcass conformation was higher in Texel sired lambs compared with Corriedale lambs (P<0.05), with Dorset and Suffolk sired lambs being intermediate. Crossbred lambs showed a greater (P<0.001) eye muscle than Corriedale. Commercial cuts were affected by sire breed, as a result of the Corriedale lambs being smaller and having lighter carcass than crossbred lambs. Significant improvement in lamb weights at weaning and carcass traits could be expected when using a terminal sire on Corriedale ewes in Western Patagonia. However, no advantages were detected with the use of recorded sires under these production systems.
低屠宰体重和较差的胴体特征是粗放型绵羊群体收入较低的主要原因；然而，在这种条件下，使用终端父本杂交可以提高羔羊的性能和胴体特征。本研究旨在评估父本品种对在巴塔哥尼亚西部广泛的绵羊系统中生产的考力代母羊所产羔羊的性能的影响。在连续两年的 6 个商业农场中，使用了总共 10 只考力代、10 只 Dorset、9 只萨福克和 7 只特克赛尔公羊，其中 16 只为遗传记录计划下的公羊，20 只为未参与遗传改良计划的羊群中选出的公羊。从四个由此产生的基因型的 685 只羔羊中收集数据。总体而言，考力代羔羊的初生重比杂交羔羊轻 0.47 公斤（P0.05）。与考力代羔羊相比，特克赛尔公羊所产羔羊的胴体结构更高（P<0.05），而 Dorset 和萨福克公羊所产羔羊则处于中间水平。杂交羔羊的眼肌面积比考力代羔羊更大（P<0.001）。由于考力代羔羊比杂交羔羊小，胴体轻，商业性切块受到父本品种的影响。在巴塔哥尼亚西部，使用终端父本配种考力代母羊，可以预期羔羊断奶体重和胴体特征得到显著改善。然而，在这些生产系统下，使用记录的公羊并没有发现优势。
