The Effect of different dietary protein levels in different ratios of carbon to nitrogen on growth performance and body composition of common carp (Cyprinus carpio) in Biofloc Technology

The aim of this study was to investigate the growth performance and body composition of common carp (Cyprinus carpio) in biofloc system. Firstly, 750 fingerling fishes with an average weight (17±0.05gr) were randomly divided into 30 polyethylene tanks with a volume of approximately 250 liters of water (25fish/tank). The treatments consisted of 3 levels of carbon to nitrogen ratio including 15, 20 and 25 and 3 levels of dietary crud protein content of 25%, 30% and 35% with three replicates for each treatment was performed over a period of 56 days. The highest feed conversion ratio and also lowest percentage of weight gain and specific growth rate were observed in treatment with protein 35% and C/N25 compared with control group (P0.05). The lowest amount of crude lipid was obtained in control treatment that it was significantly different compared with some treatments (P