Growth performance, production and economic viability of Indian white shrimp (Penaeus indicus H. Milne Edwards) fed with varying dietary protein levels

Abstract

The growth efficiency, productivity and economic viability of Indian white shrimp (<i>Penaeus indicus</i>) fed with diet containing 40% (CP_high) and 34% (CP_low) crude protein (CP) levels were determined in a 90-day grow-out culture trial. Growth parameters including average body weight (ABW), specific growth rate (SGR), survival and feed conversion ratio (FCR) were not statistically different. CP_low had lower overall shrimp production (797.53 kg/ha, DOC 90), but was not significantly different from CP_high (843.78 kg/ha, DOC 90). The mean values for the water parameters of both treatments, such as DO, pH, salinity, temperature, TAN, NO₂-N, NO₃-N and PO₄-P, also showed no significant differences. However, the TAN values of CP_high were consistently higher from day of culture (DOC) 63 and increased significantly (<i>p</i> = .048) at DOC 90. Furthermore, the total bacterial and <i>Vibrio</i> counts in both treatments were not significant throughout the culture period. The economic analysis revealed that CP_low obtained higher net profits (6093 USD/ha/year), return on investment (72%) and discounted benefit–cost ratio (1.73). The current study found that feeding a low protein diet to <i>P. indicus</i> is economically viable and profitable and results in improved growth efficiency and productivity while also improving water quality and lowering nitrogen discharge.