Impact of dietary fats on fatty acids profile of threatened Asian cafish (Clarias batrachus, Linnaeus, 1758)

Abstract

Different fats in the diets were used to examine their impact on the fatty acid profile of asian catfish(Clarias batrachus) on feeding the diets for 12-weeks. There were seven treatments (FISOL, BETAL, SOYAL, LINOL, MIXOL, SATOL and NATFO containing Fish oil, Beef tallow, Soybean oil, Linseed oil, Mixed oil (i.e. containing in 1:1:1:1 ratio of Fish oil, Beef tallow, Soybean oil, Linseed oil), Vegetable oil and minced chicken meat as natural food, respectively, each with three replications, stocked with 30 grow-out having an initial average weight 55.83 + 3.14g in a circular plastic pools (capacity 300 L). The six feeds were formulated with basic ingredients (Soybean meal, 35%; soluble starch, 29%; Casein, 19.5%; carboxy - methyl - cellulose, 2%; papain, 0.5%; vitamin and mineral mix, 4.0%) with iso-energetic (19.55 kJ/g, F1-F6 ) diets and results were compared with natural food (F7) fed fishes. Each diet was hand fed two times daily during experimental period to triplicate homogenous groups of 30 fish. The muscle fillet polyunsaturated fatty acids (PUFA) content varied with different lipid levels suggesting that the dietary fat has impact on deposition of fatty acid in flesh. The muscle unsaturated fatty acids, including Docosa-hexaenoic acid (22:6n3, DHA) level, were comparatively higher in MIXOL diet followed by NATFO and LINOL diets, indicating selective deposition of fatty acids. It was concluded that addition of various fats in the diet has role in the composition of carcass fatty acid profile in Clarias batrachus and the MIXOL (Fish Oil : Tallow : Soybean Oil : Linseed Oil :: 1 : 1 :1 :1 w/w) could be safely used for better and/ or more deposition of healthy fatty acids (EPA and DHA) which are considered as human health beneficial fatty acids and also useful to economize the cost of the broodstock feed.