The putative effect of mellon-freeze dried on antioxidant status and growth performance and of Nile tilapia

Abstract

This study aims to evaluate the performance (Phase I) of juvenile Nile tilapia fed diets with graded levels of extract melon at 0; 0,1; 0,2; 0,4; 0,6 e 0,8% respectively. Will also be evaluated the activity antioxidant enzymes and hematological profile (Phase II), before and after subjected to heat-induced stress. To determine the growth performance, 396 tilapia juveniles will be used, distributed in 36 aquaria (250L), constituting a completely randomized design with six treatments and six repetitions. The fish will be fed four times a day until apparent satiation. After completing Phase I (60 days) will be assessed weight gain, feed intake, feed conversion and survival. In the evaluation of hematological and biochemical profile will be determined: the complete blood count, erythrocyte indices and leukocyte 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 groups will be used six fish/treatment, subjected to heat-induced stress for three days at temperature of 32°C. Another group will be sacrificed for analysis of enzyme activity in addition to the hematological profile. The variance analysis will be used to evaluate the growth performance (P < 0.05) using the Tukey analysis of multiples comparisons. The antioxidant enzyme activity and hematological parameters will be evaluated by a non-parametric test (Kruskal-Wallis) and complemented with Mann-Whitney test (P < 0.05). (AU)