Nutrient digestibility and gastro-intestinal enzyme activity of Cyprinus carpio

Abstract

A feeding trial was conducted for 42 days followed by a nutrient digestibility study for 25 days to evaluate the water washed neem seed cake (WWNSC) supplementation at 0, 50, 100 and 150 g/ kg levels in the diets of common carp fingerlings. Triplicate groups of fingerlings with mean initial body weight of 10±0.15 g were each fed 4 iso-nitrogenous diets (D1, D2, D3 and D4). Daily dry matter intake of fish fed D1 and D2 was similar, and was significantly higher than that of fish fed D3 and D4 diets. No significant differences in dry matter and nutrient digestibility in different diets were observed. Supplementation of WWNSC up to 150 g/ kg diet did not affect both α−amylase and protease enzymes activity in the intestine of fingerlings. A very high α-amylase activity ranging from 24.25 to 27.60 μmol/min/g of intestine and very high protease activity 13.42–15.40 mg/min/g of intestine were observed in different dietary treatments.