Self-feeding behaviour of rainbow trout, Oncorhynchus mykiss, offered diets with distinct feed oils

摘要: Abstract Previous short-term two-choice trials showed that rainbow trout preferred fish oil (FO) over vegetable oils, with rapeseed (RO) being the best and linseed (LO) less accepted. The present study examined whether these preferences were reflected in differences self-feeding behaviour of a no-choice situation longer growth period (12 weeks). Triplicate groups (individual BW 112 g) fed by means self-feeders diet containing either FO, RO, LO or blend olive/fish (OFO, 1/1). same diets hand-fed to triplicate twice day until visual satiation. was not affected feed composition. Overall, self-fed had an almost 10% better than fish. Fish fatty acid retentions (gain/intake, measured groups) high intake levels n − 3 (LO-groups) lower similarly intakes monoenoic acids (FO, OFO-groups), likely because (partial) catabolism linolenic from LO. Feed unaffected oil. In trial, cumulative number demands LO-group 30% other groups, consistent preference for seen before choice situation. reduced characterized low anticipatory feeding activities near absence excitatory morning peak, which represented up 35% total demands. It remains uncertain resulted hunger (metabolic feedback associated excessive amount acid) sensory properties (hedonic response). Nevertheless, similarity LO-fish implicates only signals strong enough prevent eating, but also ingested similar amounts as groups. Hence, latter, more eager feed, must have demanded they could ingest. summary, data show appetitive fast-growing is mediated dietary oil, what has practical relevance adapting reward strategies.