Nutritional evaluation of termite (Macrotermes subhyalinus) meal as animal protein supplements in the diets of Heterobranchus longifilis (Valenciennes, 1840) fingerlings

Özet

250 fingerlings of Heterobranchus longifilis had an average weight of 2.04±0.21 g were fed five crude protein 42.5% isonitrogenous experimental diets coded Tm1 &#8211; Tm5 were tested on the fingerlings. Termite meal was used to replace fish meal in the diets at 0% (Diet Tm1- control diet), 25% (Diet Tm2), 50% (Diet Tm3), 75% (Diet Tm4) and 100% termite meal inclusion levels (Diet Tm5). The experiment was in triplicates and the fingerlings were fed 5% body weight twice a day for 12 weeks. Termite meal had a crude protein of 46.3% and ash content of 3.6% while fish meal used has 71.5% crude protein and 18.2% ash and these differed significantly (P<0.05). The lipid content of 11.3% and 8.0% respectively for termite meal and fishmeal also differed significantly (P<0.05). The water stability of the experimental diets ranged between72.3%-76.9%. The highest mean weight gain of 9.6 g/fish, relative growth rate of 488.0% and specific growth rate of 0.9%/day were recorded in fish fed 50% termite meal inclusion diet. The feed striking time ranged between 5.0-6.0 second. The lowest feed conversion ratio of 2.9 and highest protein efficiency ratio of 0.8 were also recorded in fish fed 50% termite meal inclusion diet. The lowest incidence of cost (2.1), highest profit index (1.6) and best benefit cost ratio (1.2) were also from 50% termite meal diet. Based on the broken-line analysis, 50% inclusion levels of termite meal will yield the best result in a practical diet for H. longifilis fingerlings for a profitable and sustainable aquaculture venture.