Death risk and preweaning growth rate of piglets in relation to the within-litter weight distribution at birth

Abstract

This study investigated whether the death risk of piglets and the preweaning growth rate of the surviving piglets depend on the within-litter weight distribution at birth. The litters were produced either by sows from one of six commercial breeds ( n = 363) or by Dutch Landrace sows ( n = 456). The birth weight and sex of all piglets and the weight and age at weaning of piglets which survived the suckling period were known. All litters were classified as one of five litter types on the basis of the within-litter birth weight distribution. The results indicate that the within-litter birth weight distribution is neither an important determinant of the within-litter variation in birth weight, nor an important determinant of the preweaning death risk of liveborn piglets. The average preweaning growth rate differed between litter types, but this was entirely due to differences in average litter size at birth. Within each of the four litter types with two discrete subpopulations, the average growth rate of the piglet type with the lower average birth weight was less than that of the piglet type with the higher average birth weight. In two litter types this difference was still significant after correction for litter size and birth weight.