Lifetime Reproductive and Lamb Crop Yields of Fat-tailed Naeemi and Imported Border Leicester Merino Ewes in Intensive System of Production

摘要

Local fat-tailed and imported thin-tailed sheep breeds are used for lamb production in hot arid zones. These animals are exposed to an extended summer (seven months) and shorter autumn, winter and spring seasons. The present study examined relative reproductive and lamb crop yields of low and high prolific Naeemi (N) and Border Leicester Merino (BLM) ewes under the intensive management system respectively. Mating systems used were N x N pure breeding and BLM x N rams in three-way crossing. The BLM ewes gave birth to 1.48 lambs per ewe per year as compared to 0.78 lambs per ewe per year for N. The weight of lambs born per ewe was 35% higher and weight weaned 45% higher for BLM ewes compared to N ewes.