Genetic parameters of backfat thickness, age at 100 kg and ultimate pH in on-farm tested French Landrace and Large White pigs

Abstract

Genetic parameters of age (AGE) and average backfat thickness (ABT) at 100 kg, as well as of ultimate pH of Adductor femoris (pH ad), Semimembranosus (pH sm), and Semispinalis (pH ss) muscles, were estimated for the Large White (LW) and French Landrace (LF) breeds using a derivative free Restricted Maximum Likelihood (DF-REML) procedure applied to a multiple trait individual animal model. The data consisted of 24569 LW and 13360 LF pigs tested for AGE and ABT in 35 selection herds between 1989 and 1992, among whom 6358 LW and 3538 LF animals were slaughtered and measured for pH. Heritabilities of AGE, ABT, pH ad, pH sm and pH ss are, respectively, 0.25; 0.45; 0.22; 0.17; 0.22 in the LW breed and 0.23; 0.55; 0.13; 0.14; 0.18 in the LF breed, with standard errors ranging from 0.01 to 0.02. AGE and ABT exhibit slightly negative genetic correlations in LW (−0.12±0.03) and LR (−0.07±0.04) breeds. Low positive genetic correlations are obtained between AGE or ABT and the three ultimate pH measurements in the LW breed (from 0.01 to 0.20). These same genetic correlations are more variable in the LF breed (from −0.20 to 0.18).