Valorisation of brown seaweed ( Sargassum wightii ) waste as a feed ingredient in rohu ( Labeo rohita ): Effects on growth and metabolism

A study was conducted to assess the role of supercritical-fluid-extracted-seaweed residue as a feed ingredient. 120 Labeo rohita fingerlings with an average weight of 1.83 ± 0.25 g were randomly distributed into four experimental groups and fed with diets containing seaweed waste as a dietary supplement at 0, 150, 250 and 350 g/kg of feed for a period of 60 days. The beneficial role was assessed in terms of growth-performance, metabolic, and defense mechanism. Animals fed with seaweed-waste showed significantly (p < .05) higher weight gain and specific growth rate (SGR). Activities of metabolic enzymes such as ALT, AST, LDH, MDH and SOD showed significantly (p < .05) lower activity in the animals fed with seaweed waste in the diet. The highest lysozyme activity was recorded in the animal's group fed with 250 g/kg of seaweed waste in the diet. Significantly, higher serum serotonin level was recorded in the animals fed with 250 g/kg of seaweed waste. It can be inferred, that the supplementation of seaweed waste as a fish feed ingredient at a 250 g/kg inclusion level improves the growth-performance, metabolic, and defense mechanisms in fish. Inclusion of seaweed waste as feed ingredients in the aqua-feed industry could possibly play an important role in reducing the cost of feed with added functional benefits.