Environmental Factors Affecting Weaning Weight of Libyan Barbary Lambs Under Range Conditions

Abstract

Weaning weight records on 39728 Libyan Barbary lambs were collected from the cereal project at Azizia in the Jafara plain. The project included nine locations. The objectives of this study were to evaluate the importance of factors affecting weaning weight of lambs and to establish correction factors for weaning weight of Libyan Barbary lambs under range conditions.

Least square procedures were used to evaluate the important factor affecting weaning weight of lambs. Sex, birth type, birth year, location, age at weaning and age of dam were the factors that contributed significantly to variation in weaning weight of lambs.

The results indicated that ram lambs were 2.4 kg heavier than ewe lambs. Single born lambs were 4.45 kg heavier at weaning than multiple born lambs. Yearly variation in weaning weight were attributed to environmental conditions. Differences in weaning weight among locations might be due to differences in rainfall as well as management differences between these locations.

Average daily gain was found to be 0.17 kg/day as obtained by partial linear regression. Age of dam significantly affected weaning weight of lambs. Lambs from 5 year old ewes weighed 4.23 kg more than lambs from 2 year old ewes. Additive correction factors were recommended to eliminate variability in weaning weight due to these environmental factors. Interactions between the environmental factors attributed significantly to the variation in weaning weight of lambs.