Genetic parameter estimates for growth traits of Large White pigs in Kenya
Variance components and genetic parameter were estimated for piglet growth traits of Large White (LW) pigs managed under intensive production systems in Kenya. Data were on piglet performance of LW pigs born between 1982 to 1996. Growth performance traits of the piglets that were considered, were body weight (BW, in kg) at birth (BW0), three weeks (BW3), eight weeks at weaning (BW8), 12 weeks ( BW12), 24 weeks (BW24) and 36 weeks (BW36); and average daily gain (g/day) from birth to eight weeks (DG0-8) and from weaning to 24 weeks (DG8-24). Variance components and genetic parameters were estimated using univariate and multivariate animal models. Direct heritability estimates from univariate analyses were 0.38, 0.24, 0.47, 0.39, 0.36 and 0.26 for BW0, BW3, BW8, BW12, BW24 and BW36, respectively. Maternal heritabilities were 0.42, 0.25 0.15 and 0.18 for BW0, BW3, BW8 and DG0-8, respectively. Genetic correlations among growth traits were positive and ranged from 0.45 to 0.98 while phenotypic correlations ranged from 0.54 to 0.95. Early piglet growth was highly heritable and under the influence of maternal effects. Selection programmes for genetic improvement of early growth performance should be based on models that account for direct and maternal genetic and litter effects.
Keywords: Additive genetic effects, body weight, swine, litter effects, maternal effects
South African Journal of Animal Science Vol. 38 (3) 2008: pp. 166-173