Line of action:

Status:

Execution date:

General Objective:

Development and innovation of economically, ethologically and environmentally efficient feeding processes and strategies for the conversion to an ecological aquaculture model focused on tench (Tinca tinca) and formulation of an organic feed for continental aquaculture.

Specific objectives:

1. Develop an ecosystem approach to tenciculture; determining how environmental biophysical processes interact in the biological cycle of tench in extensive and semi-extensive systems.
2. To experimentally characterize with NIRS technology (Near Infrared Reflectance Spectroscopy), the protein and lipid profiles of the nutritional materials, likely to be part of the organic diet of the tench throughout its biological cycle.
3. To evaluate simple techno-functional techniques that improve the bioavailability of carbohydrates in organic tench feed, phosphorus digestibility and the inactivation or destruction of anti-nutritional factors.
4. Formulate two tench feeds for the fattening period that are economically and environmentally viable.
5. To estimate the validity of two experimental organic feeds versus a commercial organic feed.
6. To validate the influence of both experimental feeds on meat nutritional quality indices using NIRS technology with respect to a commercial organic feed.
7. To evaluate the economic efficiency and social impact of the new agro-aquaculture strategy.
8. To disseminate the results of the project both to the key agents of the value chain of the continental aquaculture sector in Spain and to society as a whole.

The ECOACUI project has carried out a characterisation of the patterns associated with the biotope and trophic webs of ponds representative of those existing in dehesa areas, where tench is extensively cultivated. The main source of its nutrients comes from the organic matter of livestock, provided on a one-off basis when the animals are watered.

The nutritional quality of different organic raw materials has been evaluated, as an alternative to traditional ones, to develop new experimental feeds for the production of organic tench in semi-extensive conditions. The raw materials selected were: organic trout meal, normal soybeans and activated (sprouted) soybeans.

Predictive models of the selected parameters have also been developed using NIRS (Near-Infrared Reflectance Spectroscopy) technologies. An experimental evaluation of techno-functional processing techniques has been carried out to improve the bioavailability of carbohydrates in the selected seeds: seed activation.

During the project, four specific feed formulas (1 control and 3 experimental) have been obtained for tench (Tinca tinca), made with organic raw materials, being the control entirely of fishmeal. The experimental feeds had a soybean meal composition in a proportion of 25% and 50% and 50%, with the seed previously germinated. In three of them, alternative protein sources of vegetable origin of an ecological nature and typical of the region of Extremadura were used.

After experimentation with feed, it has been observed that those animals fed diets supplemented with soybean meal have carried out a lower incorporation and use of protein, as well as a lower growth and a decrease in certain parameters related to the immune response capacity and total antioxidant capacity.

Soy has been observed to reduce the fat content and hardness of meat. On the other hand, the use of activated soy improves the incorporation of natural antioxidants into the fish’s muscle.

The substitution of fish protein for vegetable protein in diets designed for tench has not given the expected results, observing a clear reduction in growth associated with the percentage of feed substitution.