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Genotype by diet interactions on growth and processing traits in rainbow trout (O. mykiss), sea bass (D. labrax), sea bream (S. aurata) and meagre (A. regius) fed diets highly substituted in both fish meal and fish oil by vegetal ingredients
With oceanic resources depletion, limitation of marine ingredients in aquafeed is a major challenge for the industry. Our study estimated and compared genotype by diet interactions (G*D) on production traits in 4 major fish species reared in temperate and Southern Europe (rainbow trout, seabass, seabream, meagre). DNA-assigned sibs were challenged with a diet containing marine ingredients (MB) or with a plant-based diet (PB) containing only 2% of fish meal and 2% of fish oil (FOM). Similar to higher heritabilities were estimated in PB condition. Limited G*D was estimated for all traits. However, seabream stopped growing and genetic correlation on growth decreased. Moreover, 90% of the meagre fed with PB died after a sudden drop of water temperature. It was hypothesized that marine fishes mostly lived on their initial reserves acquired before the challenges and that expected non limiting FOM concentrations may be detrimental.
Keywords:
Aquaculture
genotype diet interactions
