Genotype By Parity Interactions Were Not Found for Growth in Australian Pigs

Abstract

Growth is known to be lower for gilt progeny in comparison to progeny from multiparous sows. Information about the effects of dam parity on other performance traits is often limited. The aim of this study was to quantify the effects of dam parity on performance traits and to evaluate genotype by parity interactions for growth rate of pigs. Dam parity had strongest effects on growth. Estimates of growth were 14 to 22 g/day lower in gilt progeny in comparison to progeny from older sows. Feed intake and feed conversion ratio were -0.023 to -0.066 units lower for progeny from older sows in comparison to gilt progeny. Dam parity had no biological importance for backfat and muscle depth. Growth was defined as a different trait for progeny from the first to the fifth parity of dams for analyses of genotype by parity interactions. Heritabilities varied from 0.13 to 0.20 for the three growth traits. Maternal genetic effects were low and slightly higher for progeny from older sows (0.047). Genotype by parity interactions for growth of pigs were not found based on high estimates of genetic correlations between different growth traits (range:0.83 to 0.98) and current selection practices that define growth as the same trait for progeny from different dam parities can be continued based on the results of this study.