A genetic analysis of body weight traits in young Bauscat and Giza White rabbits

Abstract

AbstractThe effects of various genetic and environmental factors on body-weight traits were studied in 3051 records of Bauscat (B) and Giza White (G) rabbits in the period from October 1976 to September 1983. Sixty-five sires and 289 dams were used for analysis of data of body weight at 6 weeks and bi-weekly up to 12 weeks of age. Year and month of birth exerted a pronounced effect on body weights of rabbits. Sex differences on the other hand were small at all ages studied and no pattern of parity effects was observed. Effects of litter size at birth were significant for 6-week weight but not for weights taken at later post-weaning ages. Body weights at the four ages studied decreased as litter size at weaning increased. Litter-weight effects on body weights decreased significantly as the age of the rabbit advanced. Sire and dam affected significantly most of the body-weight traits studied. The proportion of variance attributable to both sire and dam components for all body weights studied in G rabbits were generally larger than those in B rabbits. Heritabilities from sire and dam components of variance for body weights n i B rabbits were substantially lower than the corresponding estimates in G rabbits. Genetic and phenotypic correlations among body weights at all ages studied were positive and of moderate or high magnitude, and tended to decrease in value as the differences between the two ages increased.