Assessment the crude grape extract as feed additive for tambaqui (Colossoma macropomum), an omnivorous fish

Abstract This study assessed the effect of crude grape extracts (CGEs) as a feed additive in tambaqui juveniles (Colossoma macropomum). The growth performance, biochemical hematology, and enzyme digestive responses of tambaqui juveniles fed with diets containing different CGE concentrations (0, 20, 40, 60, and 80 g per kg) were also analyzed. The qualitative phytochemical assay displayed higher concentrations of lignans and mono-, sequi-, and diterpenes. The inclusion of 80 g CGE per kg diet produced the best results for weight gain, specific growth rate, and condition factor of tambaqui. Fish fed with the 80 g CGE per kg diet displayed higher plasma triglycerides, albumin, and lysozyme values. Hematologic parameters were not different. Juveniles fed with the 60 g CGE per kg diet had higher protease activity. The inclusion of 80 g CGE per kg diet has the potential for use in tambaqui aquaculture production, as it improved growth performance and immunity (plasma albumin levels and lysozyme activity) and, in general, did not affect the metabolic and hematologic parameters.