Effect of dietary fibre and feeding system on activity and oral behaviour of group housed gilts

The low feeding level common in practice for dry sows has been linked to the occurrence of stereotypies. In this experiment the effects of a high fibre diet offered at a restricted level or ad libitum during gestation, on activity and oral behaviour of group housed gilts were studied. A total of 54 gilts were allocated to three treatments and housed in groups of six in straw bedded pens with individual feeding stalls. The treatments consisted of: control (C) 2.0 kg of a conventional diet (13.0 MJ DE, 44 g crude fibre per kg diet) fed once daily; restricted fibre (RF) 2.3 kg of a diet containing 500 g unmolassed sugar-beet pulp per kg (11.3 MJ DE, 107 g crude fibre per kg diet) fed once daily; ad libitum (AF), the same fibrous diet offered ad libitum from a single space hopper. Direct observations at feeding time showed that RF gilts took longer to consume their ration than C gilts and that fibre fed gilts were less active in the post-feeding period. This was confirmed by time-lapse video-recordings, which showed that fibre fed gilts spent more time lying during a 24-h period. AF gilts spent, on average, 100 min day −1 feeding. Feeding the fibrous diet once daily reduced the incidence of oral behaviours relative to treatment C, and the oral behaviours which still occurred did not have the appearance of stereotypies. Very few abnormal oral behaviours were observed when the fibrous diet was offered ad libitum. The time spent rooting was reduced when the diet was offered once daily, but was reduced even further when the diet was offered ad libitum. This suggests that the feeding motivation of gilts which received a fibrous diet was less than that of the control gilts.