Aquatic weed Ipomoea aquatica as feed ingredient for rearing Rohu, Labeo rohita (Hamilton)

Abstract

Environment friendly management of the aquatic weed Ipomoea aquatica is possible through its utilization as ingredient in fish feed. In this study leaf meal of I. aquatica was fermented by phytase producing bacteria Stenotrophomonas maltophilia KUAKSP1 (GenBank Accession No. KY790423) isolated from the rumen of goat. Four experimental feed were formulated by replacing 0% (T1, Control), 25% (T2), 50% (T3) and 75% (T4) of fishmeal (FM) with the fermented Ipomoea leaf meal (FILM) as source of protein. Fingerlings of rohu, Labeo rohita were reared on these feed for eight weeks. The results showed that growth, daily retention of protein and nutrient deposition in L. rohita were significantly higher in FILM supplemented feed as compared to control. Best growth was obtained in 25% replacement of FM by the FILM supplemented feed (T2). α-amylase activity in T2 was significantly higher than control and other treatments (T3 and T4), while protease activity significantly increased in T3 and T4 as compared to T1 and T2. It was concluded that L. rohita could utilize limited amount of carbohydrate in the feed, there by sparing protein to render better growth of the fish. Keywords: Fermentation, Plant protein, Fishmeal, Phytase, Fish, Growth