Restoration of fatty acid composition of common carp Cyprinus carpio (Linnaeus, 1758) fed terrestrial oil based diets using fish oil finishing diet

Abstract

This study investigated effects of fish oil finishing diets on growth performance, fatty acid profiles and proximate composition of common carp Cyprinus carpio. Three isonitrogenous, isolipidic and isoenergetic diets were formulated. Diet 1 contained 50% fish oil and 50% canola oil and Diet 2 contained 50% fish oil and 50% poultry fat. The finishing diet (Diet 3) contained 100% fish oil. Fish were given different dietary treatments viz., T1 = 60 day feeding with Diet 1, T2 = 40 day (1-40) feeding with Diet 1 and 20 day (41-60) feeding with Diet 3, T3 = 60 day feeding with Diet 2, T4 = 40 day (1-40) feeding with Diet 2 and 20 day (41-60) feeding with Diet 3 and T5 = 60 day feeding with Diet 3. There was non-significant difference in the growth performance and proximate composition of fish in all the treatments. Inducing a dietary shift from canola oil based and poultry fat based feeds to fish oil based feeds supplied as finishing diet (i.e., T2 and T4) significantly increased long-chain PUFA concentrations in common carp as compared to those fed only canola oil (T1) and poultry fat (T3) based feeds. Amongst T2 and T4, treatment T2 appeared to be better with comparatively higher n-3 PUFAs and n-3/n-6 ratio.