Banca de QUALIFICAÇÃO: MARIA ROSALBA DE ALCÂNTARA FARIAS

Multi-strain probiotic and citric acid as a growth and health promoter in Colossoma macropomum

Antimicrobials. Lactic acid bacteria. Biosafety. Pisciculture. Tambaqui.

Fish farming has played an important role in the global food supply, contributing to food security, standing out as one of the most important production chains for Brazilian aquaculture. However, the increase in the incidence of diseases in fish has caused great losses to producers, making it necessary to develop strategies for better production performance and control of pathogenic microorganisms in aquaculture production. Therefore, the main objective of this work will be to evaluate the effect of dietary inclusion of multi-strain probiotics from an indigenous lactic acid bacteria lineage and organic citric acid on the performance and immunity of tambaqui in the rearing phase. The study will be carried out at the Multiple Laboratory for the Production of Aquatic Organisms – LAMPOA/UFOPA, during a period of 90 days, the experiment will be conducted in a completely randomized design, with two production systems: biofloc system (BFT) and recirculation system of water (RAS), and four treatments: without probiotic and organic acid supplementation in the diet (CTL), with probiotic supplementation in the diet (P), with citric organic acid supplementation in the diet (CA), with probiotic supplementation and dietary citric organic acid (PAC), with three repetitions each.

720 juvenile tambaqui (Colossoma macropomum) will be used (around 30 g in average weight) distributed in 24 500 L polyethylene tanks with constant aeration. In the pre-experimental period, a palatability test will be carried out to evaluate the treatments: without supplementation of the test substances (CTL), organic citric acid (AC) and probiotic + organic citric acid (PAC). For the AC treatment, the feed will be supplemented at the following concentrations (0.5%, 1% and 3% kg-1) and for the PAC treatment the feed will be supplemented with the concentrations (3x109 CFU/ml + 0.5% kg-13x109 CFU/ml + 1% kg-1, 3x109 CFU/ml + 3% kg-1 The following will be evaluated: zootechnical performance (weight gain, final biomass, productivity, apparent feed conversion, specific growth rate), monitored. water quality parameters (temperature, dissolved oxygen, pH, electrical conductivity, total ammonia, nitrite, alkalinity, turbidity, total settleable solids), hematological analyzes and somatic indices (hematocrit, hemoglobin concentration, hematometric indices, total leukocytes, thrombocytes totals), biochemical evaluation of blood and serum, immunological analysis, intestinal histology and immunity by challenging tambaqui juveniles with Aeromonas hydrofila.