Effect of feeding different lipid sources on growth, feed efficiency and tissue fatty acid composition of Clarias batrachus fry and fingerlings

Abstract

Summary Fry (0.46–0.53 g) and fingerlings (5.0–5.12 g) of the catfish Clarias batrachus were reared for 6 weeks on experimental diets differing in lipid sources. Triplicate groups of fish were fed ad libitum each of the four lipid sources (5 % of the diet), viz., (i) cod liver oil; (ii) sunflower oil; (iii) mixture (1:1) of cod liver oil/sunflower oil; and (iv) hydrogenated vegetable oil. These served mainly as sources of n-3; n-6; a mixture of n-3 and n-6; and saturated fatty acids, respectively. The results indicated that dietary lipid manipulation caused significant differences in weight gain, feed efficiency and tissue fatty acid profile of both fry and fingerlings. Deposition of fatty acids in the carcass very closely followed the fatty acid composition of the fed diet. The combination of n-3 and n-6 fatty acids elicited the best growth response, feed conversion and increased deposition of highly unsaturated fatty acids, suggesting the essential nature of both n-3 and n-6 fatty acids for maintenance of healthy stock and promotion of rapid growth in this species.