Influence of different sources of dietary lipid on the growth, feed efficiency and survival of snakehead, Channa striatus (Bloch, 1793) growout

Abstract

A 84-days-long experiment was conducted with a view to observe the effects of different feeds on growth and survival of Channa striatus grow-outs to develop a rearing technique for promoting its aquaculture. There were seven treatments (L3HUF, H3HUF, MUSOL, LINOL, MIXOL, SATOL and NATFO), each having two replications, stocked with 20 grow-out having an initial average weight 27.36 ± 0.09 to 32.54 ± 0.41 g in a circular plastic pools (300 l capacity). The six feeds were formulated with basic ingredients (soybean meal, 41 %; soluble starch, 25 %; casein, 20 %; carboxy methyl cellulose, 2 %; papain, 0.5 %; vitamin and mineral mix, 3.5 %) with iso-energetic (19.3 kJ/g, F1–F6) diets and results were compared with natural food fed fishes. Each diet was hand fed two times daily for 84 days to triplicate homogenous groups of 20 fishes. The fishes fed with live tubificid worms showed significantly better results in terms of weight gain and specific growth rate (%) compared to the rest six treatments. The survival was recorded cent percent in all the treatments. Results showed that the feed efficiency and growth performance significantly (p < 0.05) changed with various types of dietary lipid. At the end of the 84 days study the weight gain was recorded as 51.65 ± 0.35, 51.15 ± 0.21, 50.95 ± 0.35, 53.20 ± 0.28, 59.15 ± 0.21, 55.53 ± 0.41 and 61.44 ± 0.24 g for L3HUF, H3HUF, MUSOL, LINOL, MIXOL, SATOL and NATFO respectively. The best growth recorded in natural food fed fishes followed by MIXOL, SATOL, H3HUF, LINOL, L3HUF and MUSOL. The hepatosomatic and viscerosomatic indices ranged between 2.1–2.5 and 3.4–4.3 respectively in F1–F7. The feed efficiency in terms of feed conversion ratio recorded as 2.02–3.04 among all the feeding trials. It could be concluded, based on the results of this trial, that a diet formulated with a gross energy of 19.3 kJ/g is sufficient to promote good feed efficiency and growth performance in C. striatus grow-out however, the best growth recorded in mixed oil (MIXOL) containing 50 % mustard oil and 50 % linseed oil.