Mango (Mangifera indica) meal can partially replace corn meal in diets for piava (Megaleporinus obtusidens)

ABSTRACT: Mango (Mangifera indica) production is expanding in many countries, and its discarded residues have the potential to be used in the manufacture of fish diets. This study evaluated replacing part of the corn meal (CM) with mango meal (MM) in diets for piava (Megaleporinus obtusidens) in terms of zootechnical performance, plasma glucose, and intestinal enzymes. Piavas (n = 160) were distributed in a completely randomized design (four treatments and four replications) and were fed for 45 days with diets containing different levels of MM inclusion (0, 33, 66, and 100%). There was no microbiological contamination (mold, total coliforms, Bacillus cereus, and Salmonellasp.) in MM. The MM diet had higher total phenols and total tannins (P < 0.05). Diets with 100% of the CM replaced by MM reduced the growth performance and increased the feed conversion ratio (FCR) and plasma glucose levels in piava (P < 0.05). According to the second-order regression analysis, the optimal level of MM inclusion in the diet estimated based on weight gain and FCR was 23.68 and 19.75%, respectively (P < 0.05). The gradual increase in MM levels replacing CM in the diet reduced the activity of the intestinal enzymes amylase, lipase, and alkaline protease (P < 0.05). In conclusion, we recommended replacing 19.75-23.68% of CM with MM, which can be used in piava diets.