Genetic parameters of feeding behaviour and performance traits in group-housed Large White and French Landrace growing pigs

Data on feeding behaviour of 3 710 group-housed and ad libitum fed growing pigs were recorded using ’Acema 48’ electronic feed dispensers. Genetic parameters for six feeding behaviour criteria and the main production traits routinely recorded in French central test stations (three ’boar’ traits and three ’sib’ traits) were estimated in two breeds (Large White and French Landrace) using a multiple trait animal model DF-REML procedure. Heritability estimates for feeding behaviour criteria ranged from 0.36 to 0.54 and were markedly higher than that for the food conversion ratio (0.20). Heritability of daily feed intake was 0.42 in both breeds, whereas heritabilities of rate of feed intake, feed intake per meal and time per meal were slightly higher (0.45-0.54). Daily feed intake showed a very close genetic correlation (around 0.85) with average daily gain but also unfavourable genetic correlations with ultrasonic backfat thickness (around 0.5) and lean percentage (around -0.4). Daily feed intake was genetically independent of food conversion ratio, whereas average daily gain showed a favourable genetic correlation (around -0.35) with that trait. Among the feeding behaviour criteria, feed intake per meal and rate of feed intake showed the highest genetic correlations with daily feed intake (around 0.5) and average daily gain (around 0.4). They also showed moderately unfavourable genetic correlations with ultrasonic backfat thickness (around 0.25) and carcass lean percentage (around -0.25) and seemed to be genetically independent of food conversion ratio. The value of including a trait relating to feed intake pattern among traits selected for is discussed on the basis of this set of genetic parameters. Les données de comportement alimentaire de 3 710 porcs en croissance élevés en groupes et alimentés à volonté ont été récoltées à l’aide de distributeurs automatiques d’aliment «Acema 48». Les paramètres génétiques de six critères de comportement alimentaire et des principaux caractères de production mesurés en routine dans les stations publiques de contrôle des performances (trois caractères « candidats » et trois caractères « collatéraux») ont été estimés dans deux races (Large White et Landrace français) à l’aide de la méthode du maximum de vraisemblance restreinte (REML) appliquée à un modèle animal multicaractère. Les héritabilités des critères de comportement alimentaire sont comprises entre 0,36 et 0,54, et sont nettement supérieures à celle de l’indice de