Effects of dietary Amazonian açai (Euterpe oleracea Martius) fruit on growth performance, skin coloration and antioxidant status of Colossoma macropomum

A 30-day feeding trial was carried to evaluate the effects of dietary lyophilized <i>Euterpe oleracea</i> (LEO) on growth performance, skin coloration, antioxidant status, and feed cost of tambaqui <i>Colossoma macropomum</i>. Six isoenergetic and isoproteic diets were formulated with 0.00, 0.63, 1.25, 2.50, 5.00, and 10.0% (w/w) of LEO, respectively. Growth performance and biochemical parameters in the intestine, liver, and muscle were assessed. The results showed that the zootechnical indexes were optimized in groups fed with diets 1.25% to 10.0% LEO (p &lt; 0.05). Muscle showed no increase in flavonoid and polyphenols content, neither <i>in vitro</i> antioxidant capacity (DPPH). Fish fed with 5.00% to 10.0% LEO had an increase in cyan color (p &lt; 0.05). Administration from 0.63% LEO increases by 39.57% the antioxidant capacity total (ACAP) intestinal (p &lt; 0.05). An estimated inclusion of 5.47 % LEO minimize intestinal TBARS levels (p &lt; 0.05). Higher levels of LEO inclusion increase the feed cost of tambaqui, but inclusion up to 1.25% LEO is economically feasible. Therefore, the inclusion of up to 1.25% LEO in the diet is recommended because growth and feed utilization are satisfactory, with higher intestinal antioxidant capacity, and viable feed cost.