Incorporation of the amino acid Tryptophan in feed reduces stress and improves immunological markers in corvinas

• The results have been presented at the follow-up meeting of the DietaPlus project
• The project studies the incorporation of functional feeds in aquaculture

On April 10 2018, the follow-up meeting of the DIETAplus project (Nutritional strategies for the improvement of productive performance: the use of functional feed in aquaculture) was held at the Faculty of Biology of the University of Barcelona within the framework of the call for National Plans of Aquaculture by the Ministry of Agriculture, Fisheries, Food and the Environment.

Scientists and researchers from several institutions that are part of the Project attended the meeting: Instituto de Investigación y Tecnología Agroalimentaria (IRTA, Dr Enric Gisbert, project coordinator), Autonomous University of Barcelona (UAB, Dr Lluís Tort), Instituto de Investigación y Formación Agraria y Pesquera (IFAPA, Dr Marcelino Herrera), and University of Murcia (UM, Dr María Angeles Esteban). Scientists from other institutions subcontracted for the Project also attended Instituto Ciencias Marinas de Andalucía (ICMAN-CSIC, Dr Carmen Sarasquete), University of Barcelona (UB, Dr Antonio Ibarz) and University of Cádiz (UCA, Dr Juan Miguel Mancera).

During the meeting, the following activities took place:

1. Administrative follow-up and economic justification of the project.
2. Addressing the status of the different tasks planned in the Research Project, tasks that focus on the development of feed for aquaculture aimed at improving the maintenance of the state of health and well-being of animals through the use of additives that improve the response of fish to situations of acute and chronic stress, as well as stimulation of the animal’s immune system and improvement of defences in mucous membranes (gills, skin and intestines). For these studies, the gilt-head bream (Sparus aurata) and the corvina (Argyrosomus regius) are used as models.
3. Presenting the methodologies used and reviewing the preliminary results of the different biological samples processed by each one of the partners of the consortium.
4. Planning future tasks to be developed to comply with the General and Specific Objectives proposed in the Research Project.

The results obtained so far have shown that the use of the amino acid tryptophan in the diet is able to mitigate the activation of the stress system in corvina specimens subjected to different types of stress. This has been proven following the analysis of samples of blood and tissues from animals subjected to different types of stress. Furthermore, the use of this amino acid as an additive in feed has also improved the immunological markers of this species under different experimental conditions. The results obtained so far have also shown that different dietary ingredients such as polyphenolic compounds, protein hydrolysates, immunostimulants and probiotics positively influence the general condition of the animal and mucosal immunity.

Finally, a series of Technical Conferences focused on the sector was scheduled with the purpose of transferring the knowledge generated by this research project to interested aquaculture producers. We must emphasise that the DIETAplus Project has been designed to provide an innovative response to the sector needs for development of an integrated approach to improve the existing dietary formulations for gilt-head bream and corvina. For this reason, it is essential for the Project to promote the sharing of these results with the aquaculture sector.