SURFOLY - SUstainable Ruminants Feed with OLive pomace and polYphenols enriched charred olive stone

Sheep and goat farming is a source of employment in disadvantaged agricultural areas. The high quality products obtained are universally recognized as the result of a multifunctional and sustainable form of agriculture that contributes effectively to the safeguard of the environment and of the social cohesion of rural areas. The sector, however, does not guarantee economic sustainability nor in the MENA region nor in the EU. Any action that increases yields and quality of products, or makes available feed and supplements with better value for money, is an essential contribution to the sustainability of the sector. The regions bordering the Mediterranean share the cultivation of olive trees and the consequent olive oil industry among the main sources of profitability. The sector concentrates in a few months a high production of by-products (pomace and wastewaters), which is associated with a significant environmental impact, particularly high for wastewaters, where the presence of polyphenols can be toxic to vegetation and microbial population when used in soils, and contributes to the eutrophication of waterways. The dried pomace, on the other hand, finds application in the feed sector or as a fuel although the use is much lower than the availability. It is possible to increase the added value of the entire supply chain, both for breeders and for operators in the olive and oil agro-industry, through an integrated approach that valorizes the by-products of the oil industry into an innovative feed for sheep and goats. At the same time this can be done by significantly reducing the environmental impact on the life cycle of the supply chain, also through a mixed crop-livestock system.

SURFOLY promotes and demonstrates an innovative business and sustainable development model in the circular economy to produce two innovative animal feeds for lactating and fattening small ruminants (sheeps and goats) while supporting mix crop-livestock system and the olive industry in the Mediterranean area. The new feed contains olive oil by-products (pomace, stone and polyphenols from wastewaters) utilised in an innovative way to improve performance and product quality and reduce the overall environmental impact on the life cycle of the combined system olive mill - feed manufacturer - farm. Olive stone or dried pomace are then pyrolyzed in an innovative regenerative rotary kiln to obtain bio-char which is used to reduce the COD (Chemical Oxygen Demand) of olive mill wastewaters by absorbing polyphenols, hence reducing significantly the polluting impact of their use as a fertilizer or disposal. The polyphenols enriched char has antioxidant potential and can reduce methane emissions from ruminants therefore it is added to dried pomace to produce a nutrient mix which is eventually pelletised and used as ingredient in the new formula for sheep and goats. To further increase the mix crop-livestock model introduced by SURFOLY, when small ruminants are allowed to graze in olive orchards, digested biochar is released back as a carbon sink in the fields.

SURFOLY's scientific impact is substantial because it will produce experimental data, currently not available in the literature, on various aspects such as: biochar quality and production efficiency from olive stone and pomace in the removal of polyphenols from wastewaters; the energy and economic sustainability of the pyrolysis process on solid mill residues; the effect of the use of biochar and the release of polyphenols in the diet of meat and dairy small ruminants, in terms of animal welfare, palatability, quality and yield of products, and enteric emissions of methane, through direct measurements. The environmental benefit introduced by SURFOLY with the integrated business model cultivation-industry-feed-farming in a circular economy is also substantial. Finally, the economic impact of SURFOLY for farmers and the olive agro-industry and olive oil is significant, contributing respectively to a potential increase the economic value of cheese and meat, thanks to the combined effect of improving yield and product quality, and to a reduction in the cost of disposal of vegetation water, with a competitive cost expected for bio-char production. Given the high selling price of bio-char, this can effectively contribute to an added sustainability of olive mills.