Genetic analysis of performance traits in Harnali sheep

Abstract

Harnali sheep is a new synthetic strain developed for superior carpet wool, better growth and adaptability. The present investigation was undertaken to evaluate the Harnali sheep for seven performance traits namely birth weight (BW), weaning weight (WW), six month body weight (SMW) , yearling body weight (YBW), adult body weight (ABW), age at first lambing (AFL) and grease fleece weight (GFW) with a mixed model methodology. The overall least squares means for BW, WW, SMW, YBW, ABW, GFW and AFL were estimated as 3.51±0.58 kg, 13.61±0.22 kg, 19.45±0.24 kg, 27.26±0.31 kg, 37.90±0.34 kg, 1662.65±35.46 gm and 789.98±10.40 days, respectively. The period of birth had significant effect on all the performance traits except GFW. The effect of sex was found significant on all the performance traits. The male lambs were significantly heavier than females at all ages. The effect of dam’s age at lambing was found non-significant on all the performance traits but dam’s weight at lambing significantly influenced all the performance traits and indicated heavier lambs born from heavier ewes. Heritability estimates were high for BW, WW, SMW, YBW, ABW and GFW as 0.68±0.19, 0.49±0.17, 0.65±0.15, 0.44±0.17, 0.42±0.17 and 0.54±0.17, respectively while moderate estimates was obtained for AFL as 0.38±0.16. The phenotypic correlations of WW and SMW were significant and positive with BW, YBW and ABW with moderate to high in magnitude ranging from 0.22±0.04 to 0.71±0.07. The phenotypic correlation between BW and SMW was high and positive (0.71±0.07). The genetic correlations among performance traits were low to high ranging from -0.03±0.04 to 0.61±0.12. Keeping in view the heritability and genetic correlations among performance traits it is concluded that SMW can serve as a good selection criterion in sheep at early age as it has high heritability and positive and high correlations with body weights at later ages and favourable correlation with age at first lambing.