BLUP Values of Birth to Weaning Growth Traits of Awassi Lambs in Iraq

This study was carried out on the research station of sheep and goat (Abo Gharib, west of Baghdad, Iraq) to investigate the effects of some environmental factors on some growth traits in Awassi lambs as well as estimating heritability of these traits. Records of Awassi lambs included 1318 birth weights (BW), 821 weaning weights (WW) and 821 pre-weaning daily gains (DG) as recorded over three years (2007–2009). Records belonged to 120 sires. Restricted Maximum Likelihood (REML) method in a mixed model (paternal half sib) was utilized to estimate the heritability (h2) for above mentioned traits. The general statistical model included fixed effects due to parity, sex, year and month of birth, type of birth and age at weaning as covariate. The Best Linear Unbiased Prediction (BLUP) values of sires for all studied traits were estimated. Results showed that the means of BW, WW and DG were 3.85, 26.64 and 0.181 kg respectively. Studied traits were significantly (P < 0.01) affected by all fixed effects except the effect of sire on WW and DG, which was significant (P< 0.05). Heritability estimates (h2) of BW, WW and DG were 0.23, 0.12 and 0.19 respectively. The lowest and highest BLUP values for the mentioned traits were -0.325, 0.255 kg, -1.142, 1.284 kg, and -0.103, 0.053 kg respectively.