Feeding strategy in group-housed growing pigs of four different breeds

Abstract

Feeding strategy was studied in 205 growing boars in two blocks of 116 and 89 pigs of four breeds (Large White, Landrace, Duroc and Pietrain) respectively. Pigs were housed in groups of 12–14 individuals, with a single breed in each group. Feeding patterns were recorded with a computerized feed intake recording system. An individual meal criterion was applied to each pig to group visits into meals. Pigs were weighed every 10 days throughout the study to calculate average daily gain. For the four breeds, the number of meals or visits per day was negatively correlated with sizes of meals or visits (−0.88 ≤ r ≤ −0.74) and with duration of meals or visits (−0.86 ≤ r ≤ −0.69); size of meals or visits were positively correlated with duration of meals or visits (0.79 ≤ r ≤ 0.90). Total time feeding per day was negatively correlated with rate of feed intake (−0.79 ≤ r ≤ −0.67). Based on these results, four types of feeding strategies were described: ‘meal eater’, ‘nibbler’, ‘fast eater’ and ‘slow eater’. The feeding parameters most highly correlated with average daily gain were feed intake per day (0.79 ≤ r ≤ 0.93), feed intake per visit or per meal (0.28 ≤ r ≤ 0.54) and rate of feed intake (0.38 ≤ r ≤ 0.43). Pigs showing ‘meal eater and fast eater’ strategies may have some productivity advantages. Breed had a significant effect on many feeding parameters: visits and meals were more frequent in Large White and Pietrain pigs than in Duroc and Landrace pigs, whereas pigs of the last two breeds had a higher size of visits than pigs of the other two breeds. Landrace and Large White pigs spent less total time feeding per day than Pietrain and Duroc pigs; and rate of feed intake was higher in Landrace and Large White pigs compared to Pietrain and Duroc animals. This suggests a ‘specific feeding strategy’ for each breed: Duroc pigs were ‘meal and slow eaters’, Landrace pigs were ‘meal and fast eaters’; Large White pigs were ‘nibblers and fast eaters’, and Pietrain pigs were ‘nibblers and slow eaters’. Changes in light intensity not only affected feeding activity, but also altered the feeding strategy: from 7 to 14 h pigs behaved as a ‘nibblers and slow eaters’; from 14 to 20 h pigs showed a ‘meal eater and fast eater’ strategy, and from 20 to 7 h animals followed a ‘meal eater and slow eater’ strategy.