Aeromonas hydrophila in tilapia (Oreochromis niloticus) after the intake of aflatoxins

Abstract

The objectives of this study were to assess the effect of the intake of aflatoxin on the development of tilapia and to evaluate the impact of inoculation with Aeromonas hydrophila on performance parameters, so these two individual tests were performed. One hundred and twenty fingerlings aged 35 days old, with mean weight of 1.55 ± 0.005 g and mean length of 5 cm were used in each test, distributed in 20 tanks. Each experimental unit consisted of a 60 L tank with six fingerlings. In the first experiment, increasing levels of aflatoxin (0.350, 0.757, 1.177 mg.kg feed-1) were used as treatments and, for the control group, a diet without aflatoxin was used in a completely randomized design with four treatments and five replicates. In the second experiment, a control group of Nile tilapia fingerlings was used and received a diet without aflatoxin, inoculated with saline solution (group 1) and Aeromonas hydrophila (group 2), as well as groups of animals fed on diets containing 0.350 mg.kg feed-1 of aflatoxin (group 3), 0.757 mg.kg feed-1 of aflatoxin (group 4) and 1.177 mg.kg feed-1 of aflatoxin (group 5), and these groups were inoculated with Aeromonas hydrophila. The survival rate and the total length of fingerlings were influenced by the treatments (p < 0.05). The synergistic action of aflatoxins and Aeromonas hydrophila was effective and caused the death of experimental fish, thus affecting feed conversion and length.