Swiss research project: an alga for cow feed

Status: 11.11.2021 4:13 p.m.

Methane is harmful to the climate – and a large part of this gas comes from cows. Swiss researchers are now relying on algae in animal feed. Can that work on the farms? And do cows eat something that smells like fish?

By Johanna Wahl, ARD Studio Zurich

Fabian Wahl is standing in his laboratory in Bern with a row of small glass vials in front of him. Microalgae swim in it, so tiny that one cannot be seen with the naked eye. However, billions of single-cell organisms together color the water in the bottles green. Wahl is a member of the management of Agroscope, Switzerland’s center of excellence for agricultural research. The scientist and his team are looking for the perfect algae – which he then wants to feed to cows. The plan: reduce methane emissions from ruminants.

What sounds a bit like science fiction isn’t just of national interest. The work of the federal research institute Agroscope aims at a more sustainable agriculture. There are around 1.5 million cows in Switzerland as a milk country, and each of them releases several hundred liters of methane every day. Ruminant husbandry is a major source of global methane emissions. The climate-damaging greenhouse gas is produced in the digestive tract of cows.

The algae for animal feed is still just a research project. But Fabian Wahl is confident that it can work.

Image: University of Life Sciences FHNW

Clear requirement profile

And that is exactly what Wahl and his partners at the FHNW University of Life Sciences in Muttenz want to change. “There are algae that produce bioactive substances that prevent the process of methane production in the cow’s stomach,” says natural scientist Wahl. “We know macroalgae that can do that, and now we’re looking for a microalgae that can do it too.” In addition, the alga should contain as much protein as possible so that it is suitable for animal feed.

Once a suitable type of algae has been found, the second step should follow: Then the scientists plan to examine the algae more closely and cultivate it in larger quantities in the laboratory. This should happen in a bioreactor, which consists of a glass container and many tubes.

In there, the scientists mainly put water, a small initial amount of the selected microalgae, and a few nutrients. “Then all that is really needed is CO2 and light, like any plant that does photosynthesis, for the algae to grow,” explains Wahl. Except that as microorganisms they grow much faster than other plants.

Breeding on the farms

The team from Agroscope and the University of Life Sciences FHNW does not want to research solely for theory and science. The concrete plan for practice: With such bioreactors, farmers should in future grow algae on their own farms as feed for their cattle. “You have to imagine it like a photovoltaic system that is installed on the roof or on the facade,” explains Wahl. “The algae then photosynthesize in the tubes and grow thanks to light and CO2. If they have grown long enough, the farmer can virtually harvest them and then feed them to his animals.”

A pilot phase is to start with selected farmers by 2023. In practice, it would be an advantage if the farmers already had their own small biogas plant, notes scientist Wahl. Then they could use it to obtain the CO2 they need for growing algae.

How expensive is it?

The Swiss Farmers’ Association is interested in the research project and demands that farmers be involved as early as possible before the test phase. “We hope that there is this potential to reduce methane production so that agriculture can make a contribution to climate protection,” says Michel Darbellay, who is responsible for the area of ​​ecology and markets in the association. From the point of view of the farmers’ association, it would be an advantage to make agriculture more sustainable and climate-friendly without having to reduce animal populations. The costs of algae production must also be affordable for farmers. Darbellay emphasizes: “Our farmers need to stay competitive.”

The Agroscope Competence Center also keeps an eye on the financial feasibility of farmers. “The farmers could produce the protein-containing algae themselves on their own farm and would not have to buy external feed such as soy.” The costs for the bioreactor tubes are also relatively cheap. For Fabian Wahl it has been agreed that algae production would make economic sense for farmers.

Cows are sensitive to the smell of fish

The current research project was preceded by investigations in collaboration with the Swiss Federal Institute of Technology in Zurich and the agricultural training and testing company Strickhof in Lindau. There, instead of soy, the algae spirulina was added to the feed of cows. The aim was to find out whether the animals even accept algae as food; also about possible effects on milk or meat quality.

“It can of course be that algae have such a slight fishy odor, and animals are very sensitive there, but the cows really enjoyed eating the algae ration,” says Wahl, summarizing the results of the preliminary studies. Even with the milk and meat of the animals examined, the new feed did not lead to any loss of quality.

With around 1.5 million animals, Switzerland is a real “cool country”.

Image: dpa

Less soy imports from abroad

If algae could replace soy meal as a protein-containing animal feed, this would have even more advantages in terms of environmental protection. Almost all of the soy used as animal feed in Switzerland is currently imported from abroad, but algae can be produced on-site on the farms. And: In contrast to the cultivation of soy, there is no need for arable land to grow algae. The land could instead be used for other foodstuffs or for forest.

First of all, Fabian Wahl and his partners have to find a suitable microalgae. The perfect alga that the scientists are looking for ultimately has to meet several criteria: It has to produce a bioactive substance that prevents methane production in the cow’s stomach. It must also contain protein in order to be suitable as animal feed. In addition, the algae should not need higher temperatures for growth than are usual in Switzerland.

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