Project
SMP 2117 Sustainable and circular use of agro processing in Ethiopia.
Ethiopian population is growing fast and so is the demand for human food, including animal based products. Animal production will have to be intensified and made more sustainable, certainly as e.g. grazing areas for cattle are reducing significantly in the fertile highlands due to the allocation of land for agricultural crops for human food, whilst also reducing the acreage under fodder. Efforts for sustainable intensification are taken seriously by the government of Ethiopia, as laid down in the Livestock Master Plan. These efforts are supported by several international donor projects.
Reduced grazing opportunities and reduced fodder production can be compensated by better utilisation of by-products from the agro-processing industry, which is a necessity in a country with the largest cattle herd in Africa. A large volume of by-products has become available with the growth of the number of breweries in the country. There are two major by-products from breweries: brewers spent grain and brewers spent yeast. Brewers spent grain is directly sold to dairy farmers as animal feed, brewers spent yeast is more difficult to process as it requires specific technology for further valorisation into animal feed or e.g. into pharmaceutical or cosmetic products.
During the brewing process, yeast is added to initiate fermentation and after this, it becomes brewers spent yeast (15% of total by-products generated). The product contains a high level of nutrients and there are several technologies that can turn this waste into a valuable resource. However, it is highly susceptible to rapid contamination and spoilage as a result of the activity of microorganisms. This has hampered the large-scale use of some technologies for re-using the brewers spent yeast. Drying the spent yeast can make it last longer, but this is an expensive process that requires large amounts of energy. These presently used technologies are not feasible in Ethiopia.
In order to avoid unnecessary wasting, the Ethiopian feed manufactures, with the breweries and milling engineers are looking into options to improve the use of brewers spent yeast as a raw material for the feed industry.