Dietary Protein Requirements Of Juvenile Barbless Carp, Cyprinus Pellegrini

The dietary protein requirements of juvenile barbless carp, Cyprinus pellegrini, were determined. Five isoenergetic diets containing graded levels of protein (29%, 34%, 39%, 44%, 49%) were fed to triplicate groups of fish (12.4 g) for 10 weeks in a recirculating rearing system maintained at 18-22 degrees C. Weight gain significantly increased as the dietary protein level increased to 44%, then slightly declined. Specific growth rate (SGR) significantly increased as the dietary protein level increased to 39%, then reached a plateau. In contrast, the feed conversion ratio decreased as the dietary protein level increased to 39%. The highest feed intake and protein efficiency ratio were obtained in fish fed the 34% diet. Broken-line regression analysis shows that the optimum dietary protein level for the maximum SGR is 39.3 +/- 1.7%, while second-order polynomial regression analysis shows that the maximum SGR occurs at 43.6% and that the minimum protein requirement is 34.7-37.3%. Together, these results indicate that the optimum range of protein for juvenile C. pellegrini is 37.3-43.6%.