Effect of Feeding Enriched Formulated Diet and Live Feed on Growth, Survival and Fatty Acid Profile of Deccan Mahseer, Tor Khudree (Sykes) First Feeding Fry

Abstract

Deccan mahseer (Tor khudree) has recently been included in the IUCN list of threatened species due to its declining population. Intervention of nutritional strategies for better growth and survival of early stages for grow out and ranching is essential. The present investigation intended to study the effect of various dietary combinations containing live and inert feed enriched with cod liver oil on growth and survival of Tor khudree first feeding fry, while effects on whole body fatty acid composition of fry were also studied. Cod liver oil as a source of essential fatty acids was used for enriching both live and inert formulated feed. The experimental design consist of four treatments viz. T0 (inert diet without enrichment), T1 (inert diet enriched with cod liver oil), T2 (inert diet enriched with cod liver oil+unenriched Artemia) and T3 (unenriched inert diet+enriched Artemia) fed to four distinct experimental groups for a period of 60 days. At the end of the experiment growth, survival and fatty acid profile of the fry were examined. Fry fed combination of unenriched inert diet and enriched Artemia (T3) had the highest growth and feed efficiency in terms of percentage weight gain (PWG), specific growth rate (SGR), average daily growth (ADG) and feed conversion ratio (FCR). Survival percentage was also significant in T3 compared to other groups. Enrichment of dietary components had a direct effect on the whole body fatty acid profile of mahseer fry with significant (P<0.05) changes in the eicosapentaenoic acid (EPA 20:5 n-3) and docosahexaenoic acid (DHA 22:6 n-3) composition. This study provides avenues for improving the growth and survival of mahseer fry through enrichment and concurrent co-feeding strategies with dietary formulated diet which can further reduce feed cost during fry rearing.