Effects of dietary protein level on growth and body composition of mudfish, Heterobranchus longifilis fingerlings

Abstract

Heterobranchus longifilis fingerlings of mean weight 1.648 g were stocked in plastic aquaria of 0.049 m3 at a rate of 10 fish per aquarium. Fish were fed with diets containing 30, 35 and 40% protein in triplicate for 10 weeks using fish meal as the main protein source. Growth of H. longifilis was significantly different (P < 0.05) among treatments with increasing dietary protein levels. Mean weight gain, length increase, relative growth, specific growth rates, survival and feed conversion ratio for fish fed 40% protein diet were 6.99 ± 1.70 g, 43.58 ± 7.64 mm, 469.26 ± 114.28%, 4.05 ± 0.19% day^-1, 100% and 1.12 ± 0.06, respectively. Protein efficiency ratio was also significantly higher (P < 0.05) for fish fed diet containing 40% protein compared to fish fed 30 and 35% protein. Percent protein in carcass of fish (22.92%) was significantly higher (P < 0.05) and the fat level was fairly similar with all diets fed. Results of this study indicate that H. longifilis fingerlings had the best growth when fed with a 40% dietary protein.

Keywords: Heterobranchus longifilis, fingerlings, dietary protein, growth, body composition

African Journal of Biotechnology Vol. 12(9), pp. 971-975