Effects of Supplemented Dietary Curcumin on Growth and Non-Specific Immune Responses in Juvenile Wuchang Bream (Megalobrama amblycephala)

Abstract

The present study was aimed at evaluating the effects of the feed additive curcumin on the growth and non-specific immune responses in juvenile Wuchang bream (Megalobrama amblycephala). Six experimental diets were formulated to contain graded curcumin levels (0, 15, 30, 60, 120 and 240 mg/kg of diet, respectively). After 60 days feeding trial, fish fed the 60 mg/kg curcumin diet had significantly higher weight gain rate (WGR) and specific growth rate (SGR), and significantly lower feed conversion ratio (FCR) than the control group. The number of leucocytes (WBC), interleukin-1 beta (IL-1β), tumor necrosis factor-α (TNF-α), alternative pathway of complement (ACH50), and respiratory burst activity increased with increasing dietary curcumin levels up to 60 mg/kg, and thereafter declined. Significantly lower alanine transaminase (ALT) and aspartate transaminase (AST) activities were observed in fish fed the 60 mg/kg curcumin diet compared to those in the control group. Fish fed with the diets containing 60 and 120 mg/kg curcumin had significantly higher TNF-α and ACH50 activities than those in the control, and the fish fed diets supplemented with 60 and 240 mg/kg curcumin had significantly higher IL-1β activities than those in the control. The results suggest that appropriate dietary curcumin supplementation (60 mg/kg curcumin of diet) significantly improved growth and non-specific immune responses in juvenile M. amblycephala.