Dietary Protein Requirements for Juvenile Hybrid Culter (Culter alburnus ♀ × Ancherythroculter nigrocauda ♂)

Abstract

This study was conducted to evaluate the effects of dietary protein levels on growth performance and digestive enzyme activities of juvenile hybrid culter (Culter alburnus ♀× Ancherythroculter nigrocauda ♂). Five solipidic experimental diets were formulated to contain graded levels of protein ranging from 29.54-48.98%. These were fed to triplicate groups of fish (11.44 ± 0.7 g/fish) for 8 weeks. Results from the feeding trial indicated that growth performance, body composition, and digestive enzyme activities of the fish were significantly different (P<0.05) between the groups. Growth performance had a generally increasing trend with increasing dietary protein levels. Weight gain (160.76%) and specific growth rate (1.71) of fish in the group where feed contained 40.07% dietary protein was significantly higher than the group where feed contained 33.58% dietary protein (118.76% and 1.40, respectively), but there was no significant difference compared with 45.04% dietary protein. Based on the statistical significance, our results indicated that the dietary protein level should not be less than 40% for juvenile hybrid culter.