Genetic parameters of pre-weaning weights in crossbred piglets using multi-trait animal model.

Variances and genetic parameters (heritability and correlation) were estimated for pre-weaning weights from birth to 6 weeks of age at weekly intervals in crossbred (Landrace X Desi) pigs. Data were analysed using multi-trait animal model incorporating dam's age (covariable), parity of sow, sex of piglet, season of birth and year of birth as fixed effects and direct additive genetic, maternal genetic and permanent litter as random effects. The estimates of direct additive genetic and maternal genetic heritability were 0.18 ± 0.04 and 0.14 ± 0.04; 0.73 ± 0.06 and 0.62 ± 0.06; 0.64 ± 0.06 and 0.37 ± 0.05; 0.42 ± 0.05 and 0.30 ± 0.05; 0.37 ± 0.04 and 0.33 ± 0.05; 0.43 ± 0.04 and 0.34 ± 0.06 and 0.47 ± 0.04 and 0.36 ± 0.05 for birth weight and subsequent weights at weekly intervals up to 6 weeks, respectively. The permanent litter effect ranged from 0.02 ± 0.01 (birth weight) to 0.11 ± 0.04 (weight at first week). The estimates of correlation between direct additive genetic component and maternal genetic component (i.e. ram) were moderate to high but all negative. ram ranged from - 0.79 ± 0.15 (weight at first week) to - 0.49 ± 0.26 (birth weight). The direct additive genetic and maternal genetic correlations between birth weight and weaning weight were 0.59 ± 0.04 and 0.62 ± 0.13, respectively, which revealed sufficient scope for selection based on birth weight itself. Early weights were found to be highly heritable with due influence of maternal and permanent litter effects, and thus, appropriate selection interventions may be aimed at this stage for favourable changes at subsequent ages.