Nutritional programming through broodstock diets to improve utilization of very low fishmeal and fish oil diets in gilthead sea bream

The complete removal of fishmeal (FM) and fish oil (FO) is required to promote the sustainable development of aquaculture and for that, fast growing high quality fish that are fed without FM and FO are necessary. Early nutritional programming may allow the production of fish better adapted to utilize diets with vegetable meals (VM) and oils (VO). The main objective of this study was to research in the potential value of fatty acids as modulators of early nutritional programming in marine fish for a better utilization of VO/VM. For that purpose gilthead sea bream (Sparus aurata) broodstock were fed four different replacement levels of FO by linseed oil (LO) and their effect on fecundity and spawn quality, egg composition, Delta-6-desaturase (Delta 6D) gene expression, progeny growth performance and their growth response to a challenge with diets low in FO and FM, but high in VO and VM. The results showed that feeding gilthead sea bream broodstock with high LO diets had very long-term effects on the progeny. Thus, FO replacement by LO up to 80-100% in broodstock diets for gilthead sea bream not only reduced fecundity and spawn quality, but also growth of 45 dah and 4-month-old juveniles, as well as Delta 6D gene expression. However, when the 4 month-old juveniles were fed with a low FM and FO diet, even those from broodstock fed only 60% replacement of FO by LO showed a higher growth and feed utilization than juveniles from parents fed FO. These results demonstrate the interesting potential of early nutritional programming of marine fish by broodstock feeding to improve long-term performance of the progeny. Further studies are being conducted to determine optimum nutrient levels in the broodstock diets and the molecular mechanisms implied to develop effective nutritional intervention strategies for this species. Statement of relevance: This study demonstrates for the first time in fish the potential of broodstock nutrition to conduct early nutritional programming of culture fish for a better utilization of low fish meal and fish oil diets by the progeny, showing its effect not only during reproduction and larval development but also during on-growing. (C) 2015 Published by Elsevier B.V.