Large litters and low losses - a successful breeding goal in piglet production?

Abstract

For this analysis individual birth weights of 13'019 piglets of BHZP-line 01 and 13'794 piglets of line 03 were available within two years. Genetic parameters were estimated for individual birth weight with random effects of animal, sow and litter. Litter size, mean birth weight and standard deviation of birth weight were estimated as a trait of the sow. Estimated heritabilities of individual birth weight were h(2)=.098 for line 01 and h(2)=.147 for Line 03. Heritabilities for litter size, mean birth weight and standard deviation of birth weight were estimated with. 119,.354 und .104 in Line 01 and .114, .276 und .130 in Line 03. Genetic correlations in Line 01 und Line 03 between litter size and mean birth weight were -.254 und -.661, between litter size and standard deviation of birth weights .563 und .280. Selection only on litter size reduces mean birth weight and increases the standard deviation of birth weights. In a further step two different selection strategies in combination with three different breeding goals were compared in a selection index. It could be shown, that a combination of litter size and mean birth weight causes a high genetic gain in the trait number of piglets weaned by increasing the number of piglets born alive and low (or none) increase of lost piglets. A high economic gain per generation can be reached, without increasing the number of piglet died before weaning.