ESTIMATES OF GENETIC PARAMETERS IN DANISH WHITE RABBITS USING AN ANIMAL MODEL : II. LITTER TRAITS

Abstract

Data from about 1000 litters were analysed to draw inferences of genetic parameters for doe litter traits, using restricted maximum likelihood (REML) procedures based on a doe repeatability model. The traits under analyses were litter size at parturition (LSB = 9.53 on average), litter size at weaning (LSW = 7.63), mortality during pre-weaning (Mort =18,02%), average offspring body weight at weaning (ABW = 7 40 g), and total litter weight at weaning (L TW = 5557 g). The statislical model contained a permanent environmental effect and that was significant for only LSW (0.106). The estimates of heritabilities were 0.188, 0.081, 0.113, 0.196 and 0.194 for LSB, LSW, Mort, ABW and L TW, respectively. Repeatability estimates for these traits were 0.188, 0.187, 0.145, 0.196 and 0.214, respectively. Genetic correlations between these traits were consistent with environmental and phenotypic correlations. The correlation between LSB and LSW was strongly positive. ABW was negatively correlated with mortality, LSB and LSW. Mortality was strongly and positively correlated with LSB, but negatively with LSW. The correlations of L TW with other traits were favourable, especially strong with LSW and ABW. Thus, selection for L TW would result in an effective overall improvement on litter traits.