Performance, hematology, and immunology of pacu in response to dietary supplementation with fructooligosaccharides

The objective of this work was to evaluate the effects of dietary supplementation with fructooligosaccharides (FOS) on the performance, hematology, and immunology of pacu (Piaractus mesopotamicus) juveniles. A total of 0 (control), 2.0, and 4.0 g kg(-1) of the probiotic were added to the fish diets. Fish (49.3 +/- 4.3 g) were allotted into 12 tanks of 60 L, in a completely randomized design (n=4). After 60 days, final weight, weight gain, specific growth rate, and feed conversion ratio were improved in the fish fed with the prebiotic, although feed intake was not affected by the treatments. The number of red blood cells was higher only in fish fed with 2.0 g kg(-1) FOS. The opposite was observed for the hematimetric indices mean corpuscular volume and mean corpuscular hemoglobin, which decreased in fish fed with 2.0 g kg(-1) FOS. The number of defense cells, such as leukocytes and thrombocytes, also increased in the prebiotic treatments. The evaluated immunological parameters were not influenced by prebiotic supplementation. Dietary FOS supplementation improved pacu growth and health.

Automated summary

The study showed that dietary supplementation with fructooligosaccharides (FOS) had positive effects on the growth performance and blood health of pacu juveniles, especially with the addition of 2.0 g kg(-1) FOS in the feed, leading to increased weight gain and specific growth rate. Additionally, the number of defense cells in the prebiotic treatment groups also increased.