Effect of some Non-genetic Factors on Lamb’s Growth Traits of Awassi Sheep

Abstract

This study carried out on 96 Awassi lambs (from two private farm near Kirkuk city - Iraq, during autumn lambing seasons 2015 and 2016 to investigate the effect of farm-year, ewe’s age and lamb’s sex on lamb’s birth (BWT), 90 days weaning weights (WWT) and 7 months’ weight (FWT), daily weight gains pre and post weaning ((DWG1, DWG2). Results indicate that farm-year had significant (P<0.05) effect on BWT, WWT, FWT, DWG1 and DWG2 in favor of the 2^nd farm-year in BWT, WWT and DWG1, while 1^st farm-year had the high values in FWT and DWG2. Dam’s age affected significantly (P<0.05) BWT, FWT and DWG2, lambs born from 4 years old ewes significantly (P<0.05) surpassed lambs born from of 2, 3 and 5 years in BWT, lambs born from 3 years surpassed those of 2 years in FWT and 2, 4 and 5 years in DWG2. Lamb’s sex exerts significant (P<0.05) effect in BWT, WWT, DWG1 and FWT in favors of male lambs. All phenotypic correlations were significant (P<0.01) positive except the significant (P<0.05) correlation between BWT with DWG1 and the insignificant correlations between BWT with FWT and DWG2 BWT and the negative significant correlations between DWG2 with pre weaning traits.