Rajab M H, Cartwright T C, Dahm P F, Figueiredo E A
Department of Statistics, Texas A&M University, College Station 77843.
J Anim Sci. 1992 Nov;70(11):3351-9. doi: 10.2527/1992.70113351x.
The performance of three hair sheep breeds (Brazilian Somali, Morada Nova, and Santa Ines) was evaluated in the production environment of northeastern Brazil. Data from a total of 524 lambs sired by 21 rams and out of 190 ewes were analyzed. These data were collected from 1980 to 1983 at Sobral, Brazil from an experiment designed to compare performance of the three breeds. The traits included weights of lambs at birth, weaning, 8 mo, 10 mo, and yearling ages and ewe characters of weight at lambing (EWT), total lamb weight born (LWB), total lamb weight weaned (LWW), and prolificacy rate (PR). Differences (P < .01) among breeds were found for all characters. The Brazilian Somali, the smallest and slowest-gaining breed, was less sensitive to yearly variation than were the other breeds. The Santa Ines, the largest and fastest-gaining breed, was superior in LWB and LWW per ewe lambing. Averaged over the 4-yr period, the Morada Nova had the highest PR (1.82), and the Brazilian Somali and Santa Ines had similar PR (1.39 and 1.31, respectively). Environmental effects on PR due to yearly rainfall quantity and distribution pattern influenced lamb growth up to weaning and ewe reproduction performance. Breed x year (P < .05) interaction effects on PR were largely attributable to the Somali breed's exhibiting higher PR than the Santa Ines and Morada Nova breeds during the relatively wet years of 1981 and 1982.
在巴西东北部的生产环境中，对三个毛用绵羊品种（巴西索马里羊、莫拉达诺瓦羊和圣伊内斯羊）的生产性能进行了评估。分析了来自21只公羊和190只母羊所产的总共524只羔羊的数据。这些数据是1980年至1983年在巴西索布拉尔通过一项旨在比较这三个品种性能的实验收集的。所测定的性状包括羔羊出生、断奶、8月龄、10月龄和周岁时的体重，以及母羊产羔时的体重（EWT）、产羔总重（LWB）、断奶总重（LWW）和繁殖率（PR）。发现所有性状在品种间均存在差异（P < 0.01）。巴西索马里羊是最小且生长最慢的品种，与其他品种相比，对年度变化的敏感性较低。圣伊内斯羊是最大且生长最快的品种，每只产羔母羊的LWB和LWW表现最优。在4年期间平均来看，莫拉达诺瓦羊的PR最高（1.82），巴西索马里羊和圣伊内斯羊的PR相近（分别为1.39和1.31）。由于年降雨量和分布模式导致的环境对PR的影响，会影响羔羊断奶前的生长和母羊的繁殖性能。品种×年份（P < 0.05）对PR的交互作用主要归因于在1981年和1982年相对湿润的年份里，索马里羊的PR高于圣伊内斯羊和莫拉达诺瓦羊。
