A corn stalk is not suitable for animal feed. But by using a method to break down the lignin, the tough stalk suddenly turns into animal feed.
John Cone and Anton Sonnenberg, researchers at Animal Nutrition and Plant Breeding developed a groundbreaking method to break down lignin, the woody part in the crop.
Every year, 2,000 million tons of straw is produced worldwide. Straw contains a lot of lignin. Ruminants can eat straw but the higher the lignin content is, the more difficult the carbohydrates from the plant can be used that are needed to digest feed in the rumen.
Fungi can break down lignin
Certain fungi, such as the oyster mushroom and shiitake, are capable of breaking down lignin. These fungi first colonise their substrate with a network of fungal threads (mycelium) to make the fungi grow fast. They take nutrients from the substrate and break down lignin. The valuable carbohydrates are being spared. By stopping the process just before the mushrooms appear, vegetable material is obtained that is much better digestible for ruminants.
Breaking down lignin, the woody part in the crop, with fungi
Field trials show good results
The research team in Wageningen is experimenting with various fungi and various types of biomass, which lead to effective combinations to upgrade organic waste with a high lignin content, and hence use this as animal feed. Studies are being done with ruminants (cow, goat, buffalo, sheep). An oyster mushroom fungus for example can result in the uptake of twice as much energy from rice straw when fed to cows.
The first trials semi-commercial trials are planned in Indonesia. Iran en Thailand have also shown interest in this research.
Our research shows that wheat straw becomes 50% more digestible and with wood chips this is even 150%.