Line of action:

Status:

Execution date:

General Objective:

Reduce the use of antibiotics and biocides in inland aquaculture using ingredients with antiparasitic and antimicrobial action in the diet.

Specific objectives:

1. Validate alternative treatments to antibiotics and biocides, based on natural substances, under production conditions.
2. Reduce the number of formaldehyde and antibiotic treatments.
3. To reduce the environmental impact of the control of pathologies in continental aquaculture.
4. Define formulations and protocols for the use of the treatments developed.
5. To disseminate the potential of alternative treatments in the aquaculture sector.

The use of the formulations used has not allowed to reduce the consumption of antibiotics in rainbow trout farming. Therefore, the general objective of the project has not been achieved, registering outbreaks of bacterial diseases with the same incidence in the experimental and control groups. The formulations used were effective in reducing the intensity of parasitization, but no evidence was obtained of their hypothetical protective action against the most frequent bacterial diseases in rainbow trout culture.

Within the framework of the BIOSAN project, ANFACO-CECOPESCA selected and acquired several ingredients from which combinations/formulations were developed to be incorporated into trout feed. The experiments have allowed some conclusions to be drawn:

• The ACS formulation (garlic extract (A), caprylic acid (C) and Sangrotech® (S)) has a positive effect on the survival of rainbow trout under culture conditions and the garlic extract has a positive effect on the survival of trout.

• The other formulas that incorporated caprylic acid in their composition, CA and CS, seem to have a negative effect on rainbow trout, increasing mortality compared to control.

• The most surprising result of the experiments carried out is the absence of a relationship between parasitization and mortality: the experimental groups where the survival rate is highest are also the most parasitized. One hypothesis is that these formulations increase the tolerance of fish to parasite infestation, by improving their health status in some way; Conversely, in groups with high mortality rates, fish would be more sensitive to parasitosis and would die even with a low parasite load.

The results obtained have been shared with agents from the aquaculture and fisheries sectors, public administrations, research centres, technology centres and sectoral associations.

The partial substitution of formaldehyde and chloramine would reduce the impact of the activity associated with the consumption of abiotic resources, related to the manufacture of biocides, and also thanks to the reduction of ecotoxicity on fresh water associated with their use. Therefore, it is considered appropriate that the project has continuity, with a view to carrying out more studies and being able to achieve the general objective of this project.