Data on 298 lambs from 161 ewes of the Barbados Blackbelly breed from 1982 to 1985 at the Blenheim Sheep Station in Tobago were studied to determine the influence of lambing season-year, sex and type of birth on body weights of lambs at birth, at 56 days (weaning) and 6 months of age, preweaning daily gain and mortality. The effect of the lambing season-year on litter size (total number of lambs born, born alive and weaned per ewe lambing) and total lamb weight at weaning were examined. The flock averages for body weights of lambs at birth, at 56 days and 6 months of age, preweaning daily gain and mortality were 2.75, 10.8, 19.2, 0.152kg, and 18.3%, respectively. Averages for total number of lambs born, born alive and weaned were 1.92, 1.88, 1.51, respectively, and total lamb weight at weaning was 16.7kg. The lambing season-year effect was apparent for all traits studied except for litter size and lamb mortality. Sex of lamb was not a significant source of variation. Type of birth had significant effect on lamb growth traits and total lamb weight at weaning. Single born lambs were heavier than those born as twins or more. Ewes with triplets or more weaned 21kg lamb weight compared to 18 and 12kg for twins and singles, respectively. Lamb mortality was 27.8% for those with below average birth weight and 8.8% for those with above average birth weight (P<0.05).

中文翻译：

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西印度群岛多巴哥巴巴多斯黑腹羊的生产性能

研究了 1982 年至 1985 年在多巴哥 Blenheim 绵羊站来自 161 只巴巴多斯黑腹羊品种的 298 只羔羊的数据，以确定产羔季节年份、性别和出生类型对出生时羔羊体重的影响，56天数（断奶）和 6 个月大，断奶前日增重和死亡率。检查产羔季节年对产仔数（每头母羊产羔的产仔数、活产和断奶的羔羊总数）和断奶时羔羊总重的影响。羔羊出生时、56 日龄和 6 月龄、断奶前日增重和死亡率的羊群平均值分别为 2.75、10.8、19.2、0.152kg 和 18.3%。出生、出生和断奶的羔羊总数的平均值分别为1.92、1.88、1.51，断奶时羔羊总重为16.7kg。除了窝产仔数和羔羊死亡率外，所有研究性状的产羔季节年效应都很明显。羔羊的性别不是变异的重要来源。出生类型对羔羊生长性状和断奶时羔羊总重有显着影响。单胎羔羊比双胞胎或更多的羔羊重。三胞胎或更多的母羊断奶羔羊体重为 21 公斤，而双胞胎和单胎分别为 18 公斤和 12 公斤。出生体重低于平均水平的羔羊死亡率为27.8%，出生体重高于平均水平的羔羊死亡率为8.8%（P<0.05）。三胞胎或三胞胎以上的母羊断奶羔羊体重为 21 公斤，而双胞胎和单胎母羊分别为 18 公斤和 12 公斤。出生体重低于平均水平的羔羊死亡率为27.8%，出生体重高于平均水平的羔羊死亡率为8.8%（P<0.05）。三胞胎或更多的母羊断奶羔羊体重为 21 公斤，而双胞胎和单胎分别为 18 公斤和 12 公斤。出生体重低于平均水平的羔羊死亡率为27.8%，出生体重高于平均水平的羔羊死亡率为8.8%（P<0.05）。