Pre-weaning body weights of Large White Yorkshire (50%) pig crosses over generations

Data on body weight of Large White Yorkshire (50%) crosses (n=590) were recorded at weekly intervals from birth to weaning (8 weeks) for five filial generations and were and analysed by least-squares method. The overall mean birth weight was 1.03 ± 0.01 kg. The birth weight gained significantly (P<0.05) over generations and at F₅, it was 1.10 ± 0.04 kg. The pooled mean body weights at 2,4 and 6 weeks and at weaning (8 weeks) were 2.62 ± 0.04, 4.15 ± 0.07, 5.94 ± 0.10 and 8.01 ± 0.10 kg, respectively. The periodical pre-weaning body weights were increased significantly over the generations and at F₄, the respective values were 3.06 ± 0.06, 5.00 ± 0.10, 7.26 ± 0.14 and 9.61 ± 0.19 kg. The effect of sex was not found as a significant source of variation on the body weights from birth to weaning. The heritability and genetic correlations found out by sib-analyses for the pre-weaning body weights revealed that the estimates were positive and moderate to high, showing the presence of sufficient genetic variation and favourable associations for these body weights and suggestive of better scope for improvement through selective breeding.