Effect of varying levels of dietary protein on the growth performances of Indian white shrimp Penaeus indicus (H. Milne Edwards)

A 120 days grow out culture trial of Indian white shrimp, Penaeus indicus was carried out to ascertain the effect of different dietary level of protein in pond system. Three experimental feeds with crude protein (CP) - 30 (P30), 35 (P35) and 40% (P40) levels and their effects on growth performance of shrimps were studied for a period of 120 days. Shrimps fed with P30 and P35 recorded significantly higher average body weight, 14.29 +/- 0.06 g and 14.24 +/- 0.19 g respectively compared to the group fed with higher protein feed, P40 (13.13 +/- 0.16 g). There was no significant difference (p < .05) in proximate composition of shrimp muscle fed with different feeds. The feed conversion ratio (FCR) was significantly higher in P40 (2.38 +/- 0.61) while it was comparable between P30 and P35 (2.10 +/- 0.01 and 2.11 +/- 0.28 respectively). The protein efficiency ratio (PER) was significantly different among the treatments (1.58 +/- 0.05, 1.33 +/- 0.02 and 1.03 +/- 0.03 in P30, P35 and P40 respectively). Productivity (kg/ha) was also significantly lower (P > .05) in P40 (2519.85 +/- 18.02) while it was comparable between P30 (2930.17 +/- 114.20) and P35 (3007.01 +/- 153.02). The present study revealed that a protein level of 30-35% in practical diet is optimal for grow out pond culture of Indian white shrimp, P.indicus.