Galactomannan-rich endosperm of Sesbania (Sesbania aculeata) seeds responsible for retardation of growth and feed utilisation in common carp, Cyprinus carpio L.

An 8-week feeding trial was conducted in a recirculation system at 27 +/- 0.2 degreesC to observe the effect of Sesbania endosperm on the growth and nutrient utilisation in common carp. Four experimental diets were formulated to contain 40% protein and fish meal was the major source of protein in all the diets including the control (diet 1). Endosperm. separated from Sesbania seeds were included at 7.2%, 10.8% and 14.4% levels in diets 2, 3, and 4, respectively, which was calculated to be present in 24%, 36% and 48% whole Sesbania seeds, respectively. Each treatment had three replicates, eight fish per replicate, with mean initial weight of 9.20 +/- 0.05 g. Fish were fed six times of their maintenance requirement (3.2 g x bodyweight (ka)(-0.8) d(-1)) ration daily. Based on the body weight gain (BWG), metabolic growth rate (MGR), feed conversion ratio (FCR), protein efficiency ratio (PER), protein productive value (PPV%) and energy retention (ER%), fish fed the control diet had significantly (P < 0.05) better growth performance and feed utilisation. The BWG, MGR, FCR, PER, PPV%, and ER% of fish fed diets 2, 3, and 4 were significantly lower than the control and differed significantly among themselves. Physical observation of the intestinal content of the fish fed diets containing endosperm showed loose, viscous and sticking material. Fish fed diets 2, 3, and 4 had significantly higher whole body moisture, lower crude protein, lipid and energy content compared to that of the control. Fish fed diets 2, 3 and 4 had also significantly reduced levels of muscle and plasma cholesterol compared to that of the control. The results of the study clearly demonstrated that the endosperm. content of the Sesbania seed is responsible for the reduced growth and nutrient utilisation in common carp. The strong antinutritive effect of the endosperm is due to its non-starch polysaccharide content, which results in increased viscosity in the intestinal content, thereby affecting the nutrient absorption and utilisation. (C) 2001 Elsevier Science B.V. All rights reserved.