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 n utrient utilisation in common carp. Four experimental diets were formulated to contain 40% protein and fish meal was the major source of protein in al l the diets including the control (diet 1). Endosperm. separated from Sesba nia 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% who le 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 gro wth 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 fee d 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 significantl y among themselves. Physical observation of the intestinal content of the f ish fed diets containing endosperm showed loose, viscous and sticking mater ial. Fish fed diets 2, 3, and 4 had significantly higher whole body moistur e, lower crude protein, lipid and energy content compared to that of the co ntrol. Fish fed diets 2, 3 and 4 had also significantly reduced levels of m uscle and plasma cholesterol compared to that of the control. The results o f the study clearly demonstrated that the endosperm. content of the Sesbani a seed is responsible for the reduced growth and nutrient utilisation in co mmon carp. The strong antinutritive effect of the endosperm is due to its n on-starch polysaccharide content, which results in increased viscosity in t he intestinal content, thereby affecting the nutrient absorption and utilis ation. (C) 2001 Elsevier Science B.V. All rights reserved.