Genetic Parameters for Growth Traits in Hampshire Sheep in Mexico
Univariate and bivariate linear models via Restricted Maximum Likelihood (ASReml) were used to estimate heritability, phenotypic and genetic correlation for growth traits measured at birth (BW), weaning (WW) around 60 days, 90 days (W90), 120 days (W120) and 150 days (W150) in Hampshire sheep raised in Mexico. From 2005 to 2009 a total of 1,133 individual records of lambs born on 10 farms from 612 ewes and 63 sires were analysed. Direct heritability estimates for BW, WW, W90, W120 and W150 were 0.38±0.11, 0.15±0.08, 0.17±0.09, 0.18±0.07 and 0.14±0.06, respectively. All direct and maternal permanent environmental effect correlations were positive for BM, WW, W90, W120 and W150. The phenotypic correlations between all traits were positive and ranged from 0.29 to 0.96. The genetic correlations among growth traits were positive ranging from 0.35 to 0.94. The genetic parameter estimates presented here can be used to estimate breeding values to support genetic improvement programs for the Hampshire breed in Mexico.