The compensatory response of pigs previously fed a diet with an increased fibre content. 1. Growth rate and voluntary feed intake

Abstract

The compensatory response of pigs induced by previously feeding a fibre-rich diet was investigated on 54 gilts from 25 to 105 kg body weight (BW). The experiment consisted of two growth periods: a restriction period imposed by feeding the pigs a HF diet (high-fibre) up to 50 (group HF50) or 80 kg BW (group HF80), followed by a realimentation period with diet LF (low-fibre). Pigs of the control groups were continuously fed either diet LF (group LF105) or diet HF (group HF105). During restriction, the HF50 and HF80 animals consumed on average the same amount of feed as the LF animals. In spite of this, their average daily body gain was respectively 111 and 87 g lower than in the LF animals. During the first stage of realimentation (50 to 80 kg BW) group HF50 animals consumed a greater (P<0.01) amount of feed daily (2.80 kg) than animals of the remaining groups (2.56 kg, group LF105; 2.69 kg, group HF80; and 2.68 kg, group HF105). Consequently, the HF50 pigs had the greatest (P<0.01) daily gain, whereas pigs of groups LF105, HF80 and HF105 grew more slowly (1021 vs 965, 920 and 923 g/day, respectively). During this period, the pigs of groups HF50 and LF105 utilized feed slightly better than those from groups HF80 and HF105. During subsequent realimentation (80-105 kg BW), the performance of pigs did not differ significantly among groups. Our results confirm that the compensatory response lasts a few weeks after changing restriction to realimentation and is more intensive in young than in old pigs. In the case of our study, compensatory growth resulted mainly from a higher voluntary feed intake.