Effect of growth potential (body weight and breed/castration combination) on the feeding behaviour of individually kept growing pigs

The feeding behaviour of eight Pietrain boars (PP/M), eight Large White boa rs (LW/M) and nine barrows (LW/C), and six Meishan barrows (MS/C) was studi ed at three different stages of growth (S1, S2, S3) corresponding to averag e body weights (BW) of 23, 39 and 57 kg, respectively. The PP, RW and MS br eeds were considered as lean, conventional and fat types of pigs, respectiv ely. All animals were reared individually. The light pattern was 12 hours o f artificial light. The type of pig significantly affected the daily volunt ary feed intake (1659, 1746, 1970 and 1622 g/d in PP/M, LW/M, LW/C and MS/C , respectively). Daily number of meals was higher in PP/M (14.4) than in LW /M and LW/C (12.2 on average) and in MS/C (7.3) whereas meal size was lower in PP/M (125 g vs. 166 g in LW pigs and 250 g in MS/C). Feed intake increa sed linearly with BW; the increase was lower in PP/M and MS/C ( + 15 g per kg of BW gain) than in LW/M ( + 26 g per kg) and in LW/C ( + 35 g per kg). With increasing age, number of meals per day decreased. Simultaneously, the ir size increased but the increase was more important in MS/C than in other types of pigs. The pattern of feed intake was mainly diurnal and more pron ounced with the increase of BW (57 and 66% of feed intake during the day at Si and S3, respectively). The results obtained in the present experiment c learly indicate that differences observed in composition of BW gain between types of pigs are associated with differences in VFI but also with differe nces in feeding behaviour. (C) 1999 Elsevier Science BN. All rights reserve d.