Use of probiotics and organic fertilization with molasses during the nursery phase of the pink shrimp Farfantepenaeus brasiliensis in a super intensive system without water renewal
The cultivation of marine shrimp is one of the main economic activities developed in the aquaculture sector. Although Brazilian shrimp farming is developed with the exotic species Litopenaeus vannamei, native species such as Farfantepenaeus brasiliensis have already shown potential for cultivation. Aquaculture has expanded enough to have significant implications for the environment and natural resources. Among the negative impacts we can mention the spread of diseases and contamination of water by effluents. Strategies to minimize these impacts are already being used, such as nursery systems (intermediary between larviculture and fattening), systems with zero water exchange and use of probiotics.The aim of this study was to evaluate the effect of using probiotics and adding molasses as a carbon source on zootechnical performance, immunological parameters and Vibrio spp concentration. during the production of juvenile pink shrimp F. brasiliensis in the nursery phase in a BFT system (Bio-floc tecnology). The first experiment consisted of four treatments using probiotics in a BFT system i) Bacillus cereus var. toyoi, ii) Pro-W Inve® (Bacillus spp.), iii) Biomin® START grow (Bacillus spp., Enterococcus spp., Lactobacillus spp.) and iv) control treatment (without the addition of probiotics). The second experiment consisted of two treatments: molasses (with added molasses) and control (without added molasses). During the experiments there was no water renewal.The following water quality parameters were monitored daily: temperature, salinity, pH and dissolved oxygen. In addition, bacteriological monitoring of the genus Vibrio spp. during the experimental period (30 days) and hemolymph extraction was performed on days 0, 15 and 30 to analyze immunological parameters. The results were subjected to statistical analysis with a 5% significance level to determine differences between treatments. In experiment 1, probiotics were added daily, as indicated by the manufacturer, for Bacillus cereus var. toyoi a dose equivalent to that of other products based on Bacillus spp. In experiment 2 molasses was added whenever ammonia levels were ≥ 1mg / L in a ratio equivalent to 6g of carbon to 1g of ammonia.In the first experiment, the results showed that the prawns produced in the probiotic treatments had significantly higher zootechnical performance than the control group. In addition, the use of probiotics was efficient to significantly reduce the multiplication of Vibrio bacteria. In the second experiment, the addition of molasses contributed to improve the zootechnical performance of the shrimp, presenting significantly higher results compared to the control group, in addition to maintaining the concentration of Vibrio spp. stable during the trial period. Regarding immunological parameters, the concentration of granular hemocytes differed statistically only on day 15, where the Biomin treatment showed a higher value than the other treatments,while the total protein data showed no statistical difference. In the second experiment, there was no statistical difference in the immunological parameters analyzed. The use of probiotics and the addition of molasses were considered efficient and are recommended for the production of pink shrimp F. brasiliensis in BFT system during the nursery phase.