Hypervitaminosis induced by vitamin A supplementation in ration for post larvae of Nile tilapia

Abstract

The present study was carried out to evaluate the effect of the hypervitaminosis by supplementation of vitamin A in balanced ration, on the performance of Nile tilapia (Oreochromis niloticus) during sex reversal phase. The experiment was carried out during 30 days in a randomized experimental design with six treatments and five repetitions. Was considered an experimental unit an aquarium of 50L contends 70 post larvae. The first treatment was consisted by a ration where was added only commercial premix how a vitamin A (30 KUI) source. The others had been supplemented with 1.030, 2.030, 3.030, 4.030 e 5.030 KUI of vitamin A. At the end, the final average weight (FAW), the standard (SL) and total length (TL), the weight gain (WG), the biomass gain (BG), the apparent feed conversion (FA), the condition factor (CF) and the survival (SU) were assessed. The results of FAW, SL, WG and BG showed a negative linear effect (P<0,05) by the increase of the vitamin A in the ration. The hipervitaminosis of vitamin A above of 30 KUI damaged the post larvae Nile tilapia growth.