Validation of blood biomarkers of feed efficiency in the Large White, Duroc and Piétrain lines
Validation de biomarqueurs sanguins de l'efficacité alimentaire dans les lignées Large White, Duroc et Piétrain
Résumé
The use of early biomarkers is an interesting approach to improve selection efficiency for traits that are difficult to measure. The aim of this study was to validate juvenile IGF1 and leptin as biomarkers of growth and feed efficiency in Large White (LW), Duroc and Piétrain purebred lines. To determine plasma concentrations of IGF1 and leptin, blood samples were obtained from 8-9-week-old piglets at the end of the post-weaning phase. After data curation, 337 LW, 192 Duroc and 189 Piétrain pigs had both plasma concentrations and production performance recorded during the growing-finishing phase, namely average daily gain (ADG), daily feed intake (DFI) and feed conversion ratio (FCR). Nested linear mixed models including successively the biomarker concentration and the weight at bleeding (BBW) as covariables in addition to the usual effects were compared using a likelihood ratio test. In the three lines, adding IGF1 concentration in prediction models of growth and feed efficiency traits increased the goodness-of-fit, with the covariable being significant (P < 0.001), except for FCR in the Piétrain line. Augmenting this model with BBW increased the model likelihood in the LW and Duroc breeds for any traits, as BBW was highly significant (P < 0.001) although IGF1 was not significant anymore. These results suggested that IGF1 is a biomarker of growth and feed efficiency that captured the same information as BBW. In the Piétrain line, IGF1 contributed to increase the likelihood of the model along with BBW for ADG and DFI. Hence, IGF1 seems to be a relevant biomarker for the Piétrain breed but to have limited utility for the LW and Duroc breeds if pigs can be weighed in the post-weaning phase. The same approach was applied to juvenile leptin, but it was found not to be a useful biomarker of growth or feed efficiency for the three lines.