Heritability of pre-weaning growth performance traits in Mengali sheep in (Balochistan) Pakistan

Genetic parameters were estimated for weights at birth (BW), 30 days (MW), 120 days weaning weight (WW), and pre-weaning average daily gain (PRADG) of four flocks of Mengali sheep maintained at the Experimental Station CASVAB, Quetta, (ESC), Mastung, Noshki and Quetta over a period of 5 years from 2005 to 2009. Records on 2750 lambs descended from 581 ewes and 56 rams were included in the analysis. Variance components were estimated fitting animal model using restricted maximum likelihood (REML) procedure. Genetic parameters were computed by pos-processing of the variance components. The heritability estimates for BW, MW, WW, and PRADG were 0.39 ± 0.06; 0.125 ± 0.02; 0.177 ± 0.03 and 0.23 ± 0.05, respectively. BW was highly heritable while other growth traits were found moderately heritable, showing larger proportional of environmental variances. In general, heritability estimates were moderate in early growth traits of Mengali sheep. Hence it was suggested that improvement can be achieved by mass selection.   Key words: Genetic parameters, Mengali sheep, heritability estimates.