ARS | Publication request: Genetic relationships among temperament score, weight, and backfat measurements in pigs

Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: November 16, 2007
Publication Date: September 22, 2008
Repository URL: http://asas.org/abstracts/2008sectional/Supplement_3-38.pdf
Citation: Holl, J.W., Rohrer, G.A., Brown Brandl, T.M. 2008. Genetic relationships among temperament score, weight, and backfat measurements in pigs [abstract]. Journal of Animal Science. 86(E-Suppl. 3):47. Abstract #31.

Technical Abstract: Genetic parameters for temperament score were estimated from generations five and six of a randomly selected, composite population composed of Duroc, Large White, and two sources of Landrace (n = 1,704). Temperament score (TS), weight (WT), and three backfat measurements (BF1, BF2, and BF3) were recorded at approximately 156 d of age. Temperament score ranged from 1 (calm) to 5 (highly excited); where 56.9%, 28.8%, 9.7%, 4.3% and 0.3% were scored as 1, 2, 3, 4, and 5, respectively. Pearson’s correlations of phenotypic data were -0.07, -0.04, -0.07, and -0.08 for TS with WT, TS with BF1, TS with BF2, and TS with BF3, respectively. Statistical model effects were year-week of measurement, sex, covariates of age for TS and WT or weight for BF1, BF2, and BF3, and an animal direct genetic effect. Model 1 was a five-trait linear mixed model. Model 2 was a five-trait threshold-linear mixed model, where TS was treated as a categorical trait. Estimated heritabilities using Model 1 were 0.19, 0.42, 0.41, 0.49, and 0.50 for TS, WT, BF1, BF2, and BF3, respectively. Model 1 estimated genetic correlations between TS and WT, TS and BF1, TS and BF2, and TS and BF3 were -0.26, -0.16, -0.16, and -0.20 respectively. Estimated heritabilities using Model 2 were 0.30, 0.37, 0.37, 0.46, 0.43 for TS, WT, BF1, BF2, and BF3, respectively. Model 2 estimated genetic correlations between TS and WT, TS and BF1, TS and BF2, and TS and BF3 were -0.35, -0.23, -0.20, and -0.24, respectively. Results indicated TS had a heritable genetic component and genetic correlations were slightly stronger in the combined threshold-linear model. Estimated genetic correlations between TS and backfat measurements adjusted to a common weight were negative for both models. Therefore, selection for more docile animals would be expected to result in faster growing, fatter pigs.