REGULATION OF VOLUNTARY FEED-INTAKE IN JUVENILE RAINBOW-TROUT FED BY HAND OR BY SELF-FEEDERS WITH DIETS CONTAINING 2 DIFFERENT PROTEIN-ENERGY RATIOS

The effect of increasing non-protein energy level in a 40 % protein di et on the voluntary feed intake (VFI) was investigated in juvenile rai nbow trout (Oncorhynchus mykiss). Fish were fed to satiety using two d ifferent methods, hand feeding or time restricted self-feeding. Regard less of the feeding methods, the VFI and the feed: gain ratio was alwa ys significantly higher for the fish fed the low energy diet than for those fed the high energy diet. In addition, no effect of the diet on the specific growth rate could be detected. It is concluded that fish were able to regulate with a great accuracy their feed intake when fed either by hand or by self-feeders. This regulation was precise enough to satisfy their energy needs and led fish fed the two different expe rimental diets to reach identical growth performance, regardless of th e feeding technique.