Effects of heat-treated Moringa oleifera leaf-meal on the growth performance of Oreochromis niloticus fry

Abstract

The high cost as well as the uncertain availability of fish-meal have led to the need to identify alternative plant protein sources for feeding Oreochromis niloticus.  Moringa oleifera is a promising protein source for inclusion in fish diets.  The study was conducted to determine the suitability of heat-treated M. oleifera leaves as an alternative protein source for Oreochromis niloticus fry.   Four experimental diets were formulated to contain heat-treated moringa leaf-meal at levels of 5% and 10% of the total dietary protein.  Diet A contained 5% boiled moringa and 95% fry-meal: Diet B contained 10% boiled moringa and 90% fry meal : Diet C contained 5% steamed moringa and 95% fry-meal and Diet D contained 10% steamed moringa and 90% fry-meal.  Diet E was the control diet containing fish-meal as the protein source.  A standard 24-day fry feeding trial was carried out in 10 fry tanks that were randomly allocated to the five dietary treatments.  Each tank was stocked with 15 000 fry, the standard stocking  at Lake Harvest.  No feed-related mortality was observed during the whole experimental period.  The growth rate, feed conversion ration (FCR) and protein efficiency ratio of fry fed the five diets were similar.  The daily body weight gain ranged from 0.012 to 0.014 grams for fry fed boiled moringa and the control diets.  Fry fed diet C, D and E had higher FCR values of 1.1, 1.1 and 1.0 respectively, compared to those on diets A and B, which had values of 1.2 and 1.3 respectively.  In general, fry fed steamed moringa diets had better growth performance than those on boiled moringa diets although the differences were not significant.  The results suggest that steam-heated moringa leaf-meal can be used to substitute 10% of dietary protein in Nile tilapia fry without significant reduction in growth performance.