Earthworm (<i>Eisenia Fetida</i>) Meal as Fishmeal Replacement in the Diet of <i>Oreochromis Niloticus</i> (Linnaeus, 1758) Fingerlings

ABSTRACT With the rising cost and ecological impact of traditional fishmeal, there is an urgent need for sustainable and locally available alternative protein sources in aquaculture. This study evaluated the effectiveness of Eisenia fetida meal as a sustainable protein substitute for fishmeal in the diets of Oreochromis niloticus fingerlings under controlled conditions. A 90‐day feeding trial tested diets with 0%, 25%, 50%, 75%, and 100% fishmeal replacement. Growth performance, feed utilization, survival rate, and production cost were assessed. Partial replacement at 50% and 75% significantly improved final body weight, daily and specific growth rates, and feed conversion ratios (FCR) compared to the control. The 75% replacement diet achieved the best balance between biological performance and economic benefit, reducing production costs by up to 24.7 ETB/kg while maintaining high survival (82.22%) and growth outcomes. Complete replacement (100%) reduced costs further but compromised growth. The study confirms that Eisenia fetida meal, when properly processed, offers a viable alternative to fishmeal for intensive aquaculture operations, with the potential to improve sustainability and profitability.