Effects of dietary levels of protein on growth, feed utilization and physiological parameters for juvenile Dabry's sturgeon,Acipenser dabryanus

Abstract

Five semi‐purified diets were formulated to contain graded levels of dietary protein (340, 390, 440, 490 and 540 g/kg diet), and each diet was assigned to triplicate groups of eight juvenile Dabry's sturgeon for 50 days. Results showed that specific growth rate increased linearly with increasing dietary protein levels from 340 to 440 g/kg diet, then levelled off at higher protein levels. Higher dietary protein (440 and 540 g/kg) significantly increased the feed intake and feed efficiency ratio of fish compared to lower protein diets (340 to 490 g/kg diet) (p .05) among groups was observed in glycogen content. As dietary protein level increased, protein and ash content of fish dorsal muscle were greatly enhanced, whereas lipid content was significantly reduced (p < .05). Based on broken‐line regression analysis of SGR against dietary protein levels, the optimum dietary protein level for maximal growth of juvenile Dabry's sturgeon is 446.68 g/kg diet.