Dietary calcium and phosphorus requirements of rohu Labeo rohita fry

A 90-day feeding experiment was conducted to determine the quantitative requirements of calcium and phosphorus, and the optimum ratio of calcium: phosphorus in the diet of rohu Labeo rohita fry for growth and carcass nutrient deposition. Triplicate groups of fry weighing 0.69±0.1g were fed on diets containing calcium and phosphorus at five different ratios namely 1:0, 1:1, 1:2, 1:3 and 1:4. The basal diet was composed of casein, gelatin, dextrin, carboxymethyl cellulose, α-cellulose, oil and a vitamin and mineral mixture devoid of Ca and P. Calcium as calcium lactate and phosphorus as disodium hydrogen phosphate was supplemented in graded levels into five different purified basal diets. Growth performance of Labeo rohita fry was significantly higher (P<0.01) on the diet having a calcium: phosphorus ratio of 1:4. Supplementation of both Ca and P significantly increased (P<0.01) the carcass protein, lipid, ash, phosphorus and calcium. Experimental data reveals that optimum calcium and phosphorus ratio for L. rohita fry is 0.19: 0.75.