Submitted to: World Congress of Genetics Applied in Livestock Production
Publication Type: Proceedings
Publication Acceptance Date: 5/10/2010
Publication Date: 8/1/2010
Citation: Schneider, J.F., Rempel, L.A., Rohrer, G.A., Brown Brandl, T.M. 2010. Genetic Parameter Estimates Among Scale Activity Score and Farrowing Disposition with Reproductive Traits in Swine. Proceedings of the 9th World Congress on Genetics Applied to Livestock Production, Leipzig, Germany. August 1-6, 2010. CD-ROM Communication No. PP2-180.
Interpretive Summary: An experiment was conducted to evaluate behavioral tendencies of female swine and to determine the genetic associations of behavior to reproductive traits. Scale activity score (SA) at 5 months of age ranged from 1 to 5 (calm to very excited). Farrowing disposition score (FD) ranged from 1 to 3 (quiet and careful to agitated). Reproductive traits included age at puberty, number born alive, number born dead, litter birth weight, average birth weight, number weaned, litter weaning weight, average weaning weight, and wean to estrus interval. Linear mixed models (MTDFREML) were used incorporating fixed effects, covariates and an animal direct genetic effect. Estimated heritabilities for reproductive traits were similar to those found in the scientific literature. Genetic correlations among SA and FD with reproduction indicated that selection based on the combination of SA and FD could improve reproductive performance. Prior to attempting selection, FD needs to be redefined to provide more variation than found in this analysis. If the “quiet and careful” score for FD was split into three or more sub-categories, additional variation in FD should be found. This could make selection based on FD feasible.
Technical Abstract: Scale activity score (SA) at 5 months of age ranged from 1 to 5. Farrowing disposition score (FD) ranged from 1 to 3. Reproductive traits included age at puberty (AP), number born alive (NBA), number born dead (NBD), litter birth weight (LBW), average birth weight (ABW), number weaned adjusted for cross fostering (NW), litter weaning weight (LWW), average weaning weight (AWW), and wean to estrus interval (WEI). Linear mixed models (MTDFREML) were used incorporating fixed effects, covariates and an animal direct genetic effect. Estimated heritabilities were 0.26, 0.05, 0.41, 0.10, 0.04, 0.19, 0.32, 0.11, 0.09, 0.32, and 0.04 for SA, FD, AP, NBA, NBD, LBW, ABW, NW, LWW, AWW, and WEI, respectively. Genetic correlations among SA and FD with reproduction ranged from -0.92 to +0.57.