Line of action:

Status:

Execution date:

General:

Development, optimisation and multidisciplinary study of the suitability of new functional feeds, formulated based on the principles of sustainability and environmental protection, in which part of the fishmeal and fish oil will be replaced by algae meal and which will be supplemented with probiotics. These feeds will be used in the fattening of turbot (Scophthalmus maximus) fingerlings to commercial size, and the suitability of the final product for human consumption will also be studied.

Specific:

1. In vivo evaluation of the effect of functional feed with micro- and macroalgae on the growth, metabolism and health of turbot fry up to market size.

2. Evaluation of the nutritional quality and suitability for consumption of the final product.

3. In vivo evaluation of the effect of probiotic-enriched functional feeds on the growth, metabolism and health of turbot fry.

A0 Coordination meetings and sharing of project results

A1 In vivo evaluation of feedingstuffs formulated for fattening up to market size

• Production of algal biomass
• Manufacture of functional feedingstuffs
• Cultivation of turbot fry with experimental diets up to market size
• Animal sampling for analysis of metabolic, immune, anti-inflammatory, digestive enzymes, and gut histology and microbiota parameters

A2 Evaluation of the physical-chemical and nutritional quality of animals

A3 Sensory evaluation of turbot fillets

A4 Scientific and social dissemination

• Scientific and popular science articles
• Presentation at congresses
• Dissemination and promotion of the project
• Presentation of the project results

Firstly, it has been observed that the in vivo effect of functional feeds on the parameters studied was not different from those obtained with the use of a commercial feed used in turbot cultivation during its fattening phase to reach a commercial size. However, it should be noted that there is an improvement in the metabolic response to stress challenges that are common in aquaculture practice.

Secondly, the results achieved in the nutritional evaluations reflect that there is only a difference in the amount of omega-3 acids present in the fillets obtained after feeding diets with microalgae. After evaluating the influence of diet on the preservation of turbot fillets, significant differences were found in turbot fillets since the shelf life of the product was extended in the case of fillets from diets with microalgae. From the sensory and discriminatory evaluation, it is observed, on the one hand, that there are no differences in the sensory attributes studied and, on the other, that the fillets obtained with the diets tested cannot be distinguished from each other.

Finally, the addition of three probiotic microorganisms in one of the previously formulated feeds, which contained microalgae, was evaluated. In the in vivo evaluation of these feeds, results similar to those achieved in the first evaluation were obtained in terms of the composition of the fillets at the nutritional level, a fact that also occurred with the rest of the parameters studied. However, these latest results should be taken as preliminary since they require a more in-depth study.

• The results achieved in the execution of the project have obtained a very positive evaluation among the research groups. In fact, its high potential for application in the marine aquaculture industry has been highlighted.
• The activities developed in the project have been carried out by the different research groups belonging to the beneficiary entity, the universities of Cádiz and Almería and the collaborating entities of the Universities of Cantabria and Malaga.
• A Technical Manual and a video have been prepared to show the procedure that has been followed in this project for the sampling of turbot. In addition, an explanatory video on the feed manufacturing process has been produced (available on the ALGADIET II Project YouTube channel).
• The day to disseminate the results of the project, held in Cádiz on September 20, 2022, can be seen on the YouTube channel of the Spanish Institute of Oceanography.