干旱区生态环境知识资源中心

A total of 1789 records of 644 Barki ewes, collected during 1963-1977, were analysed for effects of weight of ewe, year and age of ewe on number of ewes conceived per ewe joined, number of lambs born per ewe joined, number of lambs weaned per ewe joined, kg weaned per ewe joined and g weaned per kg metabolic body weight of ewe joined (GW/kg0.75). However, only 1194 records of 524 ewes were available to study effects of the same variables on number of lambs weaned per ewe lambing, kg weaned per ewe lambing and g weaned per kg metabolic body weight of ewe lambing (GW/kgL0.75). Weight of ewe affected (P < 0.01) all traits with a significant influence of linear and quadratic components. Ewes ranging in weight from 46 to 50 kg had the maximum productivity. However, judging by GW/kg0.75 or GW/kgL0.75, ewes ranging in weight from 41 to 45 kg were the most efficient. Year affected (P < 0.01) all traits while age of ewe, independent of age, had no significant effect on all traits.