Abstract: A total of 183 piglets weaned from 15 L were used to evaluate phenotype/genetic and environmental correlations in 4 F1 population genotypes of piglets. Traits investigated include litter size at weaning, litter weight at weaning, average piglet weight at weaning and survival rate from birth to weaning at 8 weeks. The F1 genotypes comprised of Native X Landrace (reciprocal crossbred), Land race X Native (Main crossbred), Native X Large white (reciprocal crossbred) and large white Native (Main crossbred). Each of the genotypes varied in their ability to breed true. Estimates of phenotypic, genetic and environmental correlations were highest between litter size and weight (0.65-0.70, 0. 80-0.82, 0.64-0.73 and 0.72-0.80) for the main crossbreds and reciprocal crossbreds, respectively. Estimate of correlation between filter size and weight were slightly lower in the main crossbred compared with their reciprocal genotypes. Estimates of correlation between litter weight and average piglet weight at weaning and between litter size and litter weight were low and mostly negative. The estimates of phenotypic correlation between survival rate and other traits were lower than their respective genetic correlations. Results obtained suggest that both genetic and environmental sources of variation significantly affect litter size, litter weight and average piglet weight at weaning as a result of different physiological and biochemical mechanisms. The observed negative correlations among some of the traits suggest the impact of pleitropic genes at work. Maternal effect could also be responsible for lowly correlation between survival rate and other weaning traits.
P.E. Nwakpu and P.N. Onu , 2007. Correlations Between Some Weaning Traits in Four Strains of F1 Piglet Genotypes . Journal of Animal and Veterinary Advances, 6: 1238-1241.