Comparative study on the response of four different artificial diets in the growth and mortality of Free Swimming Larvae of Rainbow Trout (Oncorhynchus mykiss)

Abstract

The present study is a feeding trial experiment on Rainbow Trout free swimming larvae. The objective of the experiment was to evaluate growth and mortality of free swimming trout larvae at different formulated test diets. For it, trout alevins of initial average body weight of 0.08391 to 0.08907 gm were nursed in 12 floating net cages set in a circular tank for 60 days from 28th December 2008 to 24th February 2009 at Fishery Research Division, Godawari. The physicochemical parameters of water in the circular tank was recorded; where water temperature ranged from 8.5°C to 13°C, pH 7.0 to 8.5 and Dissolved Oxygen (DO) 6.5 – 9.0 mg /l. The alevins were fed with 4 different diets - Diet 1 (Normal diet), Diet 2 (Normal diet with buff liver), Diet 3 (Normal diet with chicken liver) and Diet 4 (Normal diet with mutton liver). The experiment was conducted at Completely Randomized Design (CRD) with three replications for each diet. Body weight, total length and condition factor of alevins did not show significantly variation at different test diets like Diet 2, Diet 3 and Diet 4 but the result was recorded good in terms of growth and survival for the Diet 1. Gross weight and feed efficiency was recorded varying from 34.76% to 71.12 %. The specific growth rate was recorded 3.043%/day or highest in test Diet 3. The FCR was recorded 2.8768 or highest in Diet 4. The coefficient of co-relation between length and weight was highest (0.972) in Diet 3