Feeding behaviour of pigs in groups monitored by a computerized feeding system

Electronic feeding systems for progeny testing pigs, allow selection to occur under conditions found on commercial farms. This paper reports on the feeding behaviour of six groups of 10 pigs, balanced for sex and initial body weight (mean starting and finishing weight: 32·1 kg v. 68·5 kg), monitored on such a system, for an average of 38 days. These data represent 26 542 feeder visits for which the pen, identity of the pig, feeder entry and exit times, and the amount of food consumed are known. The results show significant time-of-day effects for frequency of feeder visits, feeding rates, mean feeder occupation time, mean food intake per feeder visit, total food intake and total feeder duration (all P 0·05). Individual pigs were found to possess different types of meal regulation, as measured by prandial correlations. Pens were found to have significantly non-random sequences of feeder entries (e.g. yen 1, P < 0·001). The range of feeder visits (three to 69) observed, was higher than reported in any previous study. Physical performance on the system, in terms of gain in body weight and total food intake was best predicted by total feeder occupation time, suggesting that individual pigs could adapt to the physical and social constraints imposed by the system, by altering aspects of their feeding behaviour. The results suggest that feeder access competition resulting from social synchrony and facilitation strongly influenced the feeding behaviour of pigs on this computerized food intake recording system