Feeding sundried cassava leaf meal as a replacement for deoiled rice bran in the diets of rohu, Labeo rohita, fingerlings: effect on growth, enzyme activities and gene expression of igf-i and igf-bpi

Abstract

A 75-day feeding trial was conducted to evaluate the nutritional implication of feeding diets containing graded levels of sundried cassava leaf meal (SCLM) to Labeo rohita fingerlings. Four isonitrogenous (300 g/kg crude protein) and isoenergetic (18 MJ/kg) diets were prepared by replacing de-oiled rice bran (DORB) with 0 (diet 1), 130 (diet 2), 260 (diet 3) and 390 g/kg (diet 4) of SCLM. The diets were fed to the triplicate groups of L. rohita fingerlings (average weight, 2.03 ? 0.03 g) in a completely randomized experimental design. At the end of the trial, diet 3 had similar (p > 0.05) percentage weight gain (106.38 ? 4.41%), specific growth rate (1.29 ? 0.04%/day) and feed conversion ratio (2.38 ? 0.08) relative to the control group. Intestinal digestive enzyme activities, hepatic and muscle transaminases and proximate body composition of L. rohita fingerlings were not significantly (p > 0.05) influenced by the dietary treatment. Superoxide dismutase activity of the group reared on diets 3 and 4 was significantly (p < 0.05) higher than that of diet 1. Based on the second-order polynomial regression analysis on the expression of IGF-I and IGF-BPI, it was concluded that as much as 166.5 g/kg DORB can be replaced by SCLM for optimal growth performance, in the diets of L. rohita fingerlings.