Genetic analysis of reproductive performance in crossbred pigs

Data pertaining to 1662 Large White Yorkshire (LWY)-Desi crossbred piglets maintained at All India Coordinated Research Project on Pigs, Tirupati were used for the present investigation. Significant influence of period on age at I service (AFS), age at I farrowing (AFF), service period (SP) and farrowing interval (FI) and that of season on AFS, AFF and gestation period (GP) were observed. The overall least squares mean AFS, AFF, Sp, GP and FI were 329.05 ± 2.9, 440.42 ± 2.80, 171.15 ± 2.97, 111.28 ± 0.26 and 283.87 ± 3.00 days, respectively. Period of farrowing and parity had a significant effect on all the litter traits studied. Genetic group had a significant effect on litter size at weaning and litter weight at birth while season of farrowing did not affect the litter traits studied. The overall least squares mean litter size was 7.59 ± 0.17 at birth and 6.94 ± 0.16 at weaning while the litter weights were 8.40 ± 0.18 at birth and 66.92 ± 1.42 kg at weaning. The genetic, phenotypic and environmental correlations of GP with litter traits varied from -0.49 to 0.69, -0.24 to 0.88 and -0.22 to 0.95 while the corresponding ranges among the litter traits were from -0.59 to 0.69, 0.62 to 0.88 and 0.09 to 0.95, respectively.