Effects of tribasic copper chloride on growth, copper status, antioxidant activities, immune responses and intestinal microflora of blunt snout bream (Megalobrama amblycephala) fed practical diets

A study was conducted to investigate the effects of dietary tribasic copper chloride on growth, copper status, antioxidant activities, immune responses and intestinal microflora in blunt snout bream, Megalobrama amblycephala. Eight practical diets containing different levels of copper (0, 3, 6, 9, 25, 50, 100 and 150 mg Cu kg− 1) from tribasic copper chloride were fed to blunt snout bream (31 g of initial average body weight) in quadruplicate groups in outdoor cages. Growth, copper status, antioxidant activities, immune responses and intestinal microflora were analyzed after a 56-day feeding period. Weight gain and specific growth rates in fish fed diets supplemented with 3–6 mg Cu kg− 1 were significantly higher than those in fish fed the control diet (which supplemented with 0 mg Cu kg− 1) (p