The impact of a cyclic feeding regime on the expression of genes involved in appetite regulation and lipid metabolism in rainbow trout (Oncorhynchus mykiss)
The purpose of this study was to investigate whether a cyclic feeding regime alters growth, lipid content and the expression of genes involved in appetite regulation and lipid metabolism in rainbow trout (Onchorynchus mykiss). Progeny from two lots of diallel crosses were raised under a daily fed control or a cyclic feeding regime containing alternating reduced and compensatory rations. Although the cyclic feeding regime did not improve overall growth, there was some degree of compensatory growth seen during re-alimentation, and the reduced ration led to sustained reductions in condition factor and muscle fat content. Appetite-regulating genes showed little or no differences in expression between feeding regimes. However, the lipid metabolism genes involved in fatty acid synthesis and muscle lipid uptake showed differences in expression during reduced and compensatory ration. This study helps to clarify optimal cyclic feeding regimes in order to enhance growth characteristics preferential to the fish culture industry.