401
Genetic Parameters and Genetic Trends For Growth Litter Traits in the Tai Zumu line
Litter weight characteristics are essential components for piglet survival in a context of animal welfare. This study explores consequences of a selection for prolificacy and production traits on litter weight characteristics in the Tai Zumu population from 2008 to 2013. Breeding values were estimated with the best linear unbiased predictor. A high selection pressure performed on litter size slowed down the genetic gain on piglets mean weight within litter (MW, -1g at birth from 2012 to 2013) that was previously sustain by selection against the age at 100kg (rg=-0.53 at birth and -0.56 at 3 weeks). Genetic trends for standard deviation of weight within the litter (SDW) slow down but are still increasing (+1.4g at birth from 2012 to 2013). A selection against SDW may be performed to improved homogeneity but must take into account MW due to unfavorable correlation.
Keywords:
Genetic trends
Breeding values
Homogeneity of weights
