Can information about solid food be transmitted from one piglet to another?

When weaned early, piglets commonly take some time to accept solid food, resulting in a growth check and reduced welfare. The transmission of information about food between animals has been demonstrated in other species and it would be advantageous if this occurred in piglets. This experiment investigated the effects of pairing piglets that were consuming solid food with newly weaned piglets. Six litters of piglets did not receive solid food until weaning. In each litter four piglets (3 Plus 1 spare) were weaned at 21 days of age and housed together for 7 days and offered one of two foods (3 litters per food). At 28 days of age the remaining piglets were weaned and four pairs of piglets were formed, such that there were three experienced animals paired with three inexperienced observers, each pair having visual contact and varying degrees of physical contact (1: none, 2: through wire mesh, 3: housed together), and a pair of inexperienced piglets (4: housed together) to act as controls. Food intake and weight gain were recorded over a period of 7 days. There was no effect of food type on food intake or live-weight gain of the pairs but the inexperienced pigs had higher gains on food 1 than food 2. The inexperienced pairs ate less food than the other pairs and the experienced/observer pairs that were housed together had the greatest weight gain. The level of variation between piglets was such that there were no significant effects of pairing treatment on the weight gain of the inexperienced animals. Total time spent feeding increased with time from pair formation. The number of simultaneous feeding events was higher for the experienced/observer pairs housed together than for the inexperienced pairs. This experiment has indicated that food intake is stimulated when an inexperienced piglet is housed with an experienced piglet and, with further work, this could be exploited to alleviate the weaning check.