Use the orange frit in diets for Nile tilapia: growth performance and antioxidant system

Abstract

This study aims to evaluate the performance (Phase I) of juvenile Nile tilapia fed with diets containing different levels of orange frit ranging from 0.0%; 0.2%; 0.4%; 0.6%; 0.8%, respectively. Will also be evaluated the responses of the antioxidant system and fish blood profile (Phase II), before and after the thermal challenge. To determine the productive performance, 400 tilapia juveniles will be used, distributed in 40 aquariums (250 L), constituting a completely randomized design with five treatments and eight repetitions. The fish will be fed four times a day until apparent satiation. After completing Phase I (90 days) will be assessed weight gain, feed intake, specific growth rate and feed conversion. In the evaluation of hematological and biochemical profile will be determined: the complete blood count, erythrocyte indices and white blood cell count. To determine the antioxidant response will be evaluated the activity of the enzymes superoxide dismutase, catalase and glutathione peroxidase. To perform the Phase II batches will be used six fish/treatment, subjected to the thermal challenge for three days at a temperature of 32 °C. Another batch will be sacrificed for analysis of enzymatic activity of antioxidant response in addition to the blood profile. The results will be submitted to analysis of variance, the 5% level of significance, if there are significant differences will be held Tukey test.