Proven power of philanthropists
Fungus turns straw into better animal feed
While cows and goats are given straw to eat in many developing countries, this is not easy to digest. Professor Wouter Hendriks at Wageningen University & Research (WUR) is using fungi to turn straw into more valuable animal feed. His research has been made possible with support from the cooperative ForFarmers and the DeKa Foundation.
WHY THIS RESEARCH?
Although straw is an important source of feed for livestock in developing countries, the large quantity of lignin makes it difficult for cows and goats to digest.
In this project, scientists succeeded in turning straw into a high-grade form of animal feed that is still accessible, affordable and can be stored for long periods. This was made possible thanks to fungi that break down the virtually indigestible lignin in the straw, this resulted in an increase in digestibility of 85 per cent.
Farmers around the world produce 2000 million tonnes of straw every year. In a country like the Netherlands, straw is mainly used to cover the floors of stables, but in many developing countries it is given as feed to goats and cattle. However, ruminants have difficulty extracting carbohydrates from the straw because it contains so much lignin. To improve digestibility, Professor of Animal Nutrition Wouter Hendriks and his WUR colleagues are copying some tricks from nature.
OYSTER MUSHROOMS BREAK DOWN LIGNIN
Some species of fungus, such as oyster mushrooms, are pretty good at breaking down lignin. They colonise straw and other plant remains with a network of fungal threads, the mycelium. The lignin is broken down, releasing valuable carbohydrates that help the mushrooms grow. Adding these fungi to straw and then stopping the process just before the mushrooms (the visible fruiting bodies) appear results in fodder that is more easily digested in the ruminants’ stomachs.
Laboratory experiments show an increase in the digestibility of 85 per cent in the case of wheat straw. “In terms of nutritional value, we are basically turning it into grass,” explains Hendriks. “So we are upgrading low-quality biomass to very serviceable animal fodder. Goats at any rate are quite happy to eat it. And the process is simple enough for smallholder farmers to carry out. After four to six weeks, once the fungi have done their job, the farmer can store the straw in a closed, airless barrel. You fill the barrel to the brim, push the straw down, put on the lid and store it for years if need be. To process the next batch, the farmer can just use the fungus from the previous pile of straw.”
A group of Thai cows. Photo: Shutterstock
The fundamental research carried out by Hendriks and his team would never have been possible without the support of the philanthropic partners. “Such forms of cooperation are becoming increasingly important. It offers an opportunity for research that is off the beaten track but based on sound science and with the potential for a big impact.”
Hendriks believes in the combination of gifts from donors and investments by WUR as he sees this as leading to a proper partnership. “However, the researcher has to be prepared to invest in this personally — communication with donors costs time and energy. You need to involve people in the process, explaining every time why you made certain choices. It is a very different way of working. We had an open dialogue with our donors, asking them what they want and what they think is most important. This lets us all jointly flesh out the project and make it a success together.”
By adding fungi to straw and stopping the process just before the fungi appear, feed is obtained that is more digestible in the rumens of the ruminants.
After these positive results, the scientists and their sponsors are taking the approach further. They are starting with a follow-up study of the method’s applicability in practice, in which they will test the technology on farms. “In the first instance, we are concentrating on Indonesia and Thailand. We also want to start new fundamental research to find a ‘superfungus’ with the best properties for use on straw. It is fantastic that nearly all our financiers have said they want in on our project in this new phase too. They are very enthusiastic and committed thanks to the great results from the first study and want to continue on this journey with us and see what happens next.”
This is a revised version of an article that previously appeared in Wageningen World.