Hematological and biochemical profile and parasite prevalence of Nile tilapia fed dietary probiotics

Abstract

This study aimed to evaluate the effect of dietary probiotics (Bacillus cereus var. Toyoi e Bacillus subtilis C-3102) on hematologic response, biochemical glucose and cortisol profile, and ectoparasitic prevalence in Nile tilapia from GIFT variety. It was utilized four diets (D₁ = basal diet (without probiotic addition); D₂ = basal diet + B. cereus; D₃ = basal diet + B. subtilis; D₄ = basal diet + B. subtilis e B. cereus) and five repetitions. A total of 1000 juveniles of tilapia (60.56 ± 7.74 g) were randomly distributed in 20 masonry tanks with clayey soil bottom. After 201 days, the average values of hemoglobin of fish fed diets with B. cereus were greater (P<0.05) than those fed only a basal diet. There were no significant differences in hematocrit values, erythrocyte, mean corpuscular volume, variation in size of red blood cells, and corpuscular hemoglobin concentration average of Nile tilapia fed to probiotic diets (P>0.05). The biochemical profile of glucose and cortisol, leukogram values and parasite prevalence of tilapias were not influenced (P>0.05) by the dietary addition of probiotic B. cereus and B. subtilis. It is concluded that, regardless of the probiotic containing diets, there is a preferential site for the Monogenea parasitism (P<0.001) in the gills, while the skins and fins were the organs most affected by Trichodina spp. (P<0.001). The addition of probiotics Bacillus cereus and/or Bacillus subtilis in the diet of Nile tilapia was not able to benefit the biochemical profile of glucose and cortisol and hematological profile of white and red series at the end of fish culture.