Observation

The planet is warming, storms are stronger, weather patterns are changing, and sea levels are rising.

We can carpool, save electricity by turning off lights or switching to LED bulbs, we can put solar panels on our homes.

But are fossil fuels the only source of greenhouse gases?

Methane, the gas belched out by cows, is 23 times more potent at trapping heat than carbon dioxide.

Can we do an experiment to reduce emissions from cows?

Question

Can methane emissions from cows be reduced?

Background Information

You may have heard that a cow has four stomachs. A cow has one stomach, but it is divided into four compartments.

Background Information, Continued

The rumen is the first compartment. It is filled with bacteria that break down complex carbohydrates found in hay, grass, and other plant material. These bacteria produce methane waste—a potent greenhouse gas. As the cow eats, it also burps. The gas of these expulsions comes from the bacteria and is largely methane.

Each year, a dairy cow emits between 80 and 120 kg of methane mainly from burping.

With 1.3–1.5 billion cows on the planet, livestock contribute 28% of all methane emissions.

How can we reduce these methane emissions?

1. Eat less meat.
2. Become vegan and eat no meat or dairy.
3. Feed cows and cattle a better diet with less corn and soy.
4. Find a food additive to reduce methane production.

How can we reduce these methane emissions?

Certainly, eating a vegetarian or vegan diet is a personal choice, but if people suddenly made this switch, it would impact the beef and dairy industry.

Feeding cows more grass and better quality feed has been shown to reduce emissions, but it is expensive.

In Australia, they tested Asparagopsis on bacteria from a cow’s gut and found that it blocked methane fermentation, so they fed the seaweed to cows at a rate of 2%. This reduced methane emissions from the cows by 99%!

What Approach to Reduce Methane Seems Reasonable?

Seems simple: Feed to cows seaweed to reduce methane emissions.

But, the seaweed is rather hard to get. There are no commercial growers

So, researchers at University of California, Davis are studying the impact of feeding lower rates of seaweed (Asparagopsis) to dairy cows to reduce methane.

Hypothesis

If cows eat seaweed, then it will block methane fermentation of the bacteria in the gut and reduce methane emissions.

How can we reduce these methane emissions?

12 cows
→ 4 fed alfalfa and hay + 1% seaweed and molasses mix
→ 4 fed alfalfa and hay + 0.5% seaweed and molasses mix
→ 4 fed alfalfa and hay + molasses

Measurements were taken every day, 4 times per day, for 2 weeks during the experiment using a Breathalyzer-type contraption that measured the methane in the cows' burps.

There is a video of the feeding with the methane capture system here:

Launch Video