Mixed feeding schedule of low and high protein in the diet of Labeo rohita (Hamilton) fingerlings: effect on growth performance, haemato-immunological and stress responses

Four experimental diets D-1, D-2, D-3 and D-4 having 100, 300, 350 and 400 g protein kg(-1) diet, respectively, were prepared. Fingerlings of Labeo rohita (5.45 +/- 0.03 g) were fed with different diets following a mixed feeding schedule with the feeding cycle of 28 days that consisted of either 28 days feeding of diet D-1 or D-2 or 21 days feeding with D-1 diet and 7 days with either D-3 or D-4 diet. Different treatments were T-1 (D-1 for 28 days), T-2 (D-2 for 28 days), T-3 (D-1 for 21 days and D-2 for 7 days), T-4 (D-1 for 21 days and D-3 for 7 days) or T-5 (D-1 for 21 days and D-4 for 7 days). Fingerlings were sampled after three feeding cycles (84 days). Higher (P < 0.05) growth performance and protein utilization efficiency were found in the T-3 group, which was similar to the T-2 group. The blood count, NBT, lysozyme activity, serum parameters and stress indicator parameters also complement for the better immunity in the T-2 and T-3 groups. Therefore, it could be concluded that fingerlings feeding alternately a low-protein diet (D-1) for 21 days followed by a normal-protein diet (D-2) for 7 days in a cycle of 28 days for 84 days maintained better growth and health status.