Search

Saccharomyces cerevisiae is rich in bioactive ingredients and nutrients such as essential amino acids, peptides, cell wall carbohydrates, nucleotides and B vitamins. Diets with this immunostimulant product may offer improves in growth performance and immune of farmed fish. This study evaluated the effects of a commercial immunostimulant based on S. cerevisiae on growth performance, hematology and immunity of Arapaima gigas subjected to handling stress after 30 days of supplementation (0, 4, 6 and 8 g kg−1). Diet with 6 and 8 g kg−1 of immunostimulant increased final biomass, final length, body weight gain, daily weight gain, daily feed intake, specific growth and decreased the cholesterol levels. After handling stress, supplemented fish with 4, 6 and 8 g kg−1 of immunostimulant had increase in glucose levels and decrease in globulin levels, while supplemented fish with 4 and 6 g kg−1 had decrease in cholesterol, and supplemented fish with 4 and 8 g kg−1 in globulin levels. Protein levels decreased in supplemented fish with 4 g kg−1, while hematocrit decreased in all treatments and lymphocytes number and burst respiratory of leukocytes decreased in supplemented fish with 8 g kg−1 and submitted to handling stress. For A. gigas, since 6 to 8 g kg−1 of immunostimulant has not negative impacts on the hematological and biochemical parameters, thus such concentrations may be used as a growth promoter in A. gigas. Made available in DSpace on 2020-12-09T09:10:57Z (GMT). No. of bitstreams: 1 CPAF-AP-2020-Growth-and-hematological-and-immunologica.pdf: 261909 bytes, checksum: d538d950672be57c8f92749a731c3c6e (MD5) Previous issue date: 2020

The present study evaluated the effects of dietary yeast supplementation on the growth and blood parameters of Arapaima gigas. Fish were fed with commercial feed supplemented with NuPro® at 0, 10, 40 and 80 g / kg for days and, did not exhibit any difference in growth. Blood was analyzed at the end of the feeding trial and after handling stress. A significant reduction in albumin and triglycerides levels was observed with increased supplementation of NuPro® in the diet of A. gigas. The interactive effect of diet and stress influenced plasma glucose levels, with a modulation at all levels of supplementation after stress, while in the control group the level was significantly high. NuPro® improved the innate immune response of A. gigas at all the tested concentrations, with a significantly higher levels number of thrombocytes, leukocytes, lymphocytes, monocytes, and neutrophils than the control group. There was also an increase in the number of thrombocytes after stress. As the inclusion of NuPro® in the diet improved the innate immune response at all the concentrations tested and effectively modulated plasma glucose levels, this product can be recommended as an immunostimulant for A. gigas fingerlings with the inclusion of 40 g/kg of feed. Made available in DSpace on 2020-12-09T09:08:44Z (GMT). No. of bitstreams: 1 CPAF-AP-2020-Innate-immune-response-of-pirarucu.pdf: 276238 bytes, checksum: 221944425940fbbc325ab8e961ff9479 (MD5) Previous issue date: 2020

The current study tested the efficacy of a dietary immunostimulant additive (Aquate Fish?®) on the growth performance, and on the physiological and immune responses of Arapaima gigas. Two trials were carried out: a feeding trial for 30 days with the experimental diets and a challenge trial for 7 days, in which fish were bacterial challenge (Aeromonas hydrophila) following by 60 s handling stress. During the feeding trial, fingerlings were fed diets supplemented with 0 (control), 6, 9 and 12 g Aquate Fish?®/kg diet. Dietary supplementation did not influence feed intake, feed conversion and condition factor, but increased the final biomass, number of erythrocytes, thrombocytes, leukocytes, lymphocytes, monocytes, hemoglobin, glucose, globulins and plasma triglycerides in fish fed at a concentration of 12 g/kg diet. After bacterial infection, mortality occurred only in fish fed control treatment, whereas respiratory burst of leukocytes, number of leukocytes and lymphocytes increased in fish that received 12 g of dietary supplementation. The results indicated that dietary supplementation with 12 g of Aquate Fish?® improved biomass and immunity performance of A. gigas fingerlings, without negatively affecting blood biochemical parameters. Made available in DSpace on 2019-09-10T00:56:00Z (GMT). No. of bitstreams: 1 CPAFAP2019Growthphysiologicalandimmune.pdf: 184829 bytes, checksum: d15cf60e4f16da2c64a7003e57d1da27 (MD5) Previous issue date: 2019

The hematological and biochemical responses of pirarucu fingerlings (Arapaima gigas) fed with diets containing different concentrations of a glucomannan product derived from yeast and algae were evaluated in order to ascertain the effect of these diets on fish physiology. Four treatments were conducted, with three replications, with 12 fish in each tank. The product evaluated (MycosorbA+®) was incorporated into the commercial diet, at four concentrations: 0, 1, 2 and 4 g.kg-1, called M0%, M0.1%, M0.2% and M0.4%, respectively. After 45 days of feeding, blood samples from six fish in each replicate were collected to perform the analyses. Their weight and length were determined to calculate the condition factor and weight gain, but no differences (P > 0.05) were observed among the treatments. No changes to the hematocrit, hemoglobin or erythrocyte levels or to the hematimetric indices of the pirarucus were observed. The glucose and triglyceride levels of the pirarucus in the M0.1% and M0.2% groups were significantly lower than those of the M0% group. The M0.2% group showed higher albumin levels (P < 0.05) than M0% and M0.4%. The M0.4% group showed a total cholesterol level that was significantly higher than in all other treatments. MycosorbA+® contributed towards increasing the levels of defense cells in A. gigas. It would be possible to use this product at concentrations of between 0.1% and 0.2%, given that they increase the levels of some defense cells and plasma albumin concentrations, without changes to hematological parameters, cholesterol and triglyceride plasma levels or condition factor.

Aeromonas hydrophila is causing substantial economic losses in world aquaculture. This study determined the tolerance limit (LD50-96h) of A. hydrophila in Arapaima gigas, and also investigated the clinical signs after intradermal inoculation.