Phosphorus requirements and optimum calcium/phosphorus ratio in the diet of mrigal Cirrhinus mrigala (Ham.) fingerlings

An experiment was conducted to investigate phosphorus requirements and the optimal calcium/phosphorus (Ca/P) ratio on growth and carcass tissue composition of mrigal Cirrhinus mrigala (c. 6 g). Five purified diets were formulated to contain Ca/P ratios of 1:0 (0.35:0), 1:1 (0.35:0.35), 1:2 (0.31:0.63), 1:3 (0.24:0.71), and 1:4 (0.19:0.75), respectively. Growth performance and feed conversion ratio of mrigal responded significantly (P<0.01) to the Ca=0.19:P=0.75 diet. Carcass protein, lipid, and P percentage also increased significantly with the higher P level. Based on this study, it may be concluded under the given conditions that the optimum Ca:P ratio in mrigal feed is 0.19:0.75.