PROBLEM TO BE SOLVED: To provide a fish feed additive and fish feed that promote the weight gain of fish.SOLUTION: A fish feed additive for promoting weight gain contains a legume or extract thereof. A fish feed composition for promoting weight gain contains the feed additive.SELECTED DRAWING: NoneCOPYRIGHT: (C)2018,JPO&INPIT【課題】魚類の体重増加の促進をもたらす魚類用飼料添加物および魚類用飼料を提供する。【解決手段】マメ科植物又はその抽出物を含む、体重増加促進用の魚類用飼料添加物およびこれを含む体重増加促進用の魚類用飼料組成物。【選択図】なし