GENETIC ANALYSIS OF PREWEANING BODY WEIGHTS IN CROSSBRED PIGS.

The body weights of large white Yorkshire (LWY) crosses (50 and 75 per cent) were analyzed from birth to weaning. The overall least squares mean body weights were 1.13 ± 0.02, 2.13 ± 0.01, 3.19 ± 0.02, 4.29 ± 0.02, 5.41 ± 0.03, 6.48 ± 0.03, 7.55 ± 0.04, 8.72 ± 0.05 and 9.97 ± 0.06 kg at birth, 1, 2, 3, 4, 5, 6, 7 and 8 wks of age, respectively. Genetic group, period, parity and litter size group affected all pre-weaning body weights highly significantly except for the non-significant effect of season on body weight at birth. Sexual dimorphism in favour of males was evident from 1 to 6 weeks of age. Body weights of piglets born in rainy and winter seasons and those from smaller litters recorded significantly higher body weights. Moderate to high heritability estimates were observed for body weights. The genetic and phenotypic correlations among the body weights studied ranged widely but were all positive. [ABSTRACT FROM AUTHOR]