Robustness scores in fattening pigs based on routinely collected phenotypes: determination and genetic parameters.

The objective was to determine operational proxies for robustness based on data collected routinely on farm that allow phenotyping of these traits in fattening pigs (from approximately 75 to 150 d of age), and to estimate their genetic parameters. A total of 7,256 pigs, from two Piétrain paternal lines (Pie and Pie NN), were tested. Individual performance indicators were recorded together with indicators such as insufficient growth, observable defects, symptoms of diseases, and antibiotic and anti-inflammatory injections. These indicators were combined into three categorical robustness scores: R1, R2, and R3. The robustness score R2 (selectable or not selectable animal) that combined information from status at testing and mortality had the highest heritability of 0.08 ±â€…0.03 for Pie NN line and a value of 0.09 ±â€…0.02 for Pie line. This robustness score was also highly and favorably genetically correlated with initial body weight and average daily gain, and unfavorably correlated with daily feed intake in both lines (ranging from 0.73 ±â€…0.06 to 0.90 ±â€…0.08). Estimates of genetic correlations of R2 with backfat depth and feed conversion ratio were moderate and unfavorable (0.20 ±â€…0.13 to 0.46 ±â€…0.20). The results showed the interest of using routine phenotypes collected on farm to build simple robustness indicators that can be applied in breeding.