Effects of different dietary protein-energy ratios on growth, carcass amino acid and fatty acid profile of male and female Cherax quadricarinatus (von Martens, 1868) pre-adults

Cherax quadricarinatus or redclaw is considered a good option for freshwater aquaculture and has been cultivated in several countries. However, nutritional studies are scarce. In present research, the effects of different protein-energy (P/E) ratios in diets for male and female of pre-adults were investigated. Its influence on growth performance, carcass amino acid and fatty acid profiles were determined. Six different dietary P/E ratios: 12, 13, 14, 15, 16, and 17 mg of crude protein (CP) kJ⁻¹ g⁻¹ of food for 70 days were tested on male and female pre-adults (initial weight 10.8 ± 0.6 g). The experimental treatments were assigned in triplicate. The significantly highest (p <.05) and lower growth indices, feed utilization and survival were observed for male and female pre-adults fed a diet with a P/E ratio of 16 mg/kJ and diet with a P/E ratio of 12 mg/kJ respectively. Amino acids and fatty acids contents of the carcass on males and females (p <.05) were significantly influenced by the diets with higher P/E ratios. The two-slope broken line regression analysis and the quadratic model (second-order polynomial) regression analysis of specific growth rate in redclaw pre-adults male and female suggest that the diet containing P/E ratio of 16 mg/kJ is optimal. A diet with a dietary P:E ratio of 16 mg/kJ (240 and 80 g/kg of protein and lipid respectively) is recommended to stimulate growth performance and proper carcass amino acid and fatty acid profiles of both male and female pre-adults.