Circular economy to convert grape waste into feed ingredient

• We’re working on the international NEWFEED project aimed at developing sustainable alternatives for feeding bovine and ovine dairy livestock

The European Union is the world’s biggest wine producer with an average production of 167 million hectolitres per year. This production, however, entails the generation of by-products that can both harm the environment and generate additional costs for the winegrowing industry.

In the case of wine production, one of the most common by-products is grape stems, which represent between 1.4% and 7% of the initial raw material. These percentages of waste necessitate the development of innovative and sustainable, circular economy-focused solutions to reuse this by-product.

Converting the grape stems generated by wineries into feed for bovine and ovine dairy livestock as well as demonstrating its technical and economic viability is the objective of the international NEWFEED initiative, which NEIKER is working on with partners from four countries including AZTI, UAGA (the Agrofarmers Union of Araba), RIERA NADEU and CESFAC (the Spanish Confederation of Compound Animal Feed Manufacturers).

“The current best-case scenario is that grape stems are reused as compost. However, this waste could also be used as an ingredient in ruminant feed, thanks to its high polyphenol content, which when used in appropriate doses can result in improved production efficiency for these animals”, said Asier García, a researcher at NEIKER’s Animal Production Department.

Boost digestibility

However, the formulation of grape stems as a food has a serious limitation: reduced digestibility. Therefore, in order to use this kind of by-product in large proportions in ruminant feeds, the grape stems need to be processed to improve digestibility.

Thus, in NEIKER we are working within the framework of the NEWFEED project to streamline the process of enzymatic hydrolysis, a chemical reaction catalysed by an enzyme that uses water to break one molecule into two or more fractions to improve the digestibility of the grape stem.

“In this project, we will also be responsible for achieving optimum levels to be used in the diet of ruminants and we will assess the effects of grape stems on different parameters like production yield, milk quality, and enteric methane emissions”, the NEIKER Animal Production expert added.

Part of the PRIMA programme and funded by the European Union’s Horizon 2020 programme, NEWFEED aims to help develop a sustainable and efficient agricultural, livestock, and food system to contribute to the fulfilment of the UN Sustainable Development Goals. The initiative, which was launched on 1 July, will last 48 months.

The solutions proposed are also in line with national and regional strategies and policies based on circular economy frameworks. They will be carried out in collaboration with the primary stakeholders using a diversified approach incorporating the perspectives of multiple players.