Summary and Implications
The purpose of this study was to estimate the heritabilities and genetic correlations for body composition and structural soundness traits using 1449 gilts in a commercial sow unit. Evaluated body composition traits included body weight, loin muscle area, last rib backfat and 10 th rib backfat. Soundness traits consisted of 6 body structure traits, 5 leg structure traits per leg pair and overall leg action. Variance components were estimated using multivariate animal models. The heritability estimates for body composition traits were high, moderate for body size traits, low to moderate for body shape traits and relatively low for leg traits. Across all evaluated traits, only the heritability estimates for turned front legs did not differ significantly from zero. Several high genetic correlations were obtained among the body structure trait group. The majority of genetic correlations between leg structure traits were low and statistically insignificant. The genetic correlations between leg traits and overall leg action were not significant. However, there was a trend for structural defects being related to poorer overall leg action. The genetic correlations between structure traits and body composition traits were primarily low to moderate indicating that even in a case of antagonistic relationship it is possible to achieve genetic improvement in both composition and structural traits. The fact that non-zero heritability estimates were obtained for almost all studied traits warrants further investigations regarding associations of soundness traits with reproductive performance and sow productive lifetime.
Iowa State University
Nikkilä, Marja; Stalder, Kenneth J.; Mote, Benny E.; Lampe, Jay; Thorn, Bridget; Rothschild, Max F.; Johnson, Anna K.; Karriker, Locke A.; and Serenius, Timo
"Heritabilities and Genetic Correlations of Body Composition and
Structural Soundness Traits in Commercial Gilts,"
Animal Industry Report:
AS 654, ASL R2349.
Available at: http://lib.dr.iastate.edu/ans_air/vol654/iss1/98