Incorporation of fermented mustard oilcake in fish feed and its effect on growth performance and economics of Rui Labeo rohita (Ham. 1822)

Abstract

This study assessed the impacts of fermented mustard oilcake (MOC) on the diet of Labeo rohita on growth performance and economic returns. The three-month experiment was carried out in nine cages with three dietary treatments: T1 (NFD), T2 (50% FD), and T3 (100% FD), each replicated three times. Solid-state fermentation of MOC was prepared using Saccharomyces cerevisiae to improve its nutritional quality, which decreases anti-nutritional factors. Water quality parameters remain within acceptable limits and were unaffected by the dietary treatments. Results indicated that fish in the T2 group had significantly higher weight gain, specific growth rate (SGR), and average daily gain (ADG). Economically, T2 achieved the highest cost-benefit ratio (0.53) and net profit, demonstrating better feed efficiency. Although T3 showed moderate growth, the increased feed costs lessened profitability. Overall, a 50% inclusion of fermented MOC could improve growth and be economically feasible for L. rohita, promoting sustainable and cost-effective aquaculture practices.