Partial substitution of fish oil with extruded linseed in rainbow trout diet : effects on growth performances, fillet yields and fatty acid composition
Substitution partielle d'huile de poisson par de la graine de lin extrudée chez la truite arc-en-ciel. Effet sur les performances de croissance, les rendements de transformation et le profil en acides gras des filets
Résumé
This study investigate the impact of a partial substitution of fish oil by extruded linseed on the lipid profile of trout fillets, animal performance and fillet yields. 6 batches of 55 rainbow trouts (500g) were divided into six tanks of 1800L and fed for 120 days (final average weight: 1500g). 3 groups fed a control control (C, (commercial diet) and the three others this C diet added with 6.5% of extruded linseed as partial substitution (44%) of fish oil (Diet L). The partial substitution of fish oil by extruded linseed increased the levels of C18:3n-3 (+35%) in fillets without decreasing the level of long chain polyunsaturated fatty acid and without affecting the growth performance. In addition, an increase in fillet yields is observed with L diet because of a lower deposition of perivisceral fat. The partial substitution of fish oil by the extruded linseed is an effective solution to limit the use of fish oil for trout aquaculture.