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GreenFeed provides research opportunities, practical applications for producers

by Wyoming Livestock Roundup

Measuring the rate of metabolic gases produced by ruminants has been a goal of scientists for many years, and Patrick Zimmerman’s GreenFeed system allows for easy monitoring of greenhouses gases from cattle.

Beginning in 2010, Zimmerman built the first prototype of the GreenFeed system to address complications in gathering gas emission data from cattle. 

“There weren’t any good tools for making measurements of metabolic gases that come from the muzzles of ruminants,” says Zimmerman, inventor of GreenFeed and founder of C-Lock, Inc. “Those gases are as important as monitoring the water pressure and temperature in your car, in terms of being able to tell what is going on with animals.”

“GreenFeed provides a standardized platform so users anywhere in the world can produce secure, comparable measurements that can be monitored in near-real time,” says C-Lock, Inc.’s website. 

The system resulted from Zimmerman’s more than 40 years of experience in measuring traces gases from biological systems and was developed by C-Lock, Inc.’s scientists and engineers.

Zimmerman notes that engineers Scott Zimmerman, Tom Zimmerman and Mike Billars are critical members of the C-Lock, Inc. team.

C-Lock, Inc. works to utilize science and engineering techniques to monitor, analyze and reduce greenhouse gas and other pollutant emissions, with a focus on agricultural practices, according to their website.

How it works

The GreenFeed system works similar to a laboratory fume hood, explains Zimmerman.

“When an animal approaches it, a sensor reads an RFID ear tag,” he says. “The system is programmed for each individual animal, its age and size.”

At the appropriate time, the system releases pellets or concentrated feed. As the animal consumes the feed, the system collects and measures what is in their breath.

“Cattle have to belch every 40 seconds or they will bloat,” says Zimmerman. “The system measures that gas.”

As cattle eat, their food is utilized in the body and some carbon dioxide is produced as a result of maintenance and muscle use. 

“We can make meat out of grass because the animal has microbes in its rumen that allow it break it down,” he explains. “Because there is no oxygen, they can’t break the grass down to CO2, so they break it down into other compounds that are absorbed.”

Zimmerman notes that one of the byproducts of breaking down organic matter is methane, which is measured by the GreenFeed system.

The data is collected by 18 sensors in the unit, which monitor different variables, and is sent to C-Lock, Inc.

Why monitor gases?

Zimmerman emphasizes that emissions can tell a lot about cattle health and intake.

“By looking at the emissions, we can tell if an animal gets sick, and if their intake drops, we can see it quickly,” explains Zimmerman. “If the feed changes, it also changes those values quickly.”

The data collected from emissions provides a good check for producers on feed quality and intake.

He also adds that gas emission can help with efficiency.

“It turns out that these gases are directly related to efficiency,” he says, “so you can identify those animals that are efficient.”

Because other technologies to test efficiency require waiting for the offspring of the bull to grow, Zimmerman says the system has the potential to look at the efficiency of breeding stock.

The systems have been developed to fit seamlessly into producer’s operations, adds Zimmerman.

“The animals train themselves to use the system,” Zimmerman says.

He also adds that producers can obtain easy-to-use data from C-Lock, Inc. 

“We have developed mathematical formulas to convert the data into plain information that people can use,” he adds. “We know that farmers and ranchers don’t need another job.” 

Next steps

Currently, Zimmerman says GreenFeed systems are present primarily in research labs around the world. Systems are utilized in New Zealand, Australia, the United Kingdom, Sweden, France, Ireland and across the U.S.

There are also two units in semi-commercial dairies – one in Sweden and one at Michigan State University.

“We think this system has practical implications as well,” says Zimmerman. “For example, in a typical dairy, producers cull between seven and 10 percent of cows each year because they get sick, don’t get pregnant or die. We think you could cut those losses.”

He also mentions that in feedlots, similar results could be seen by reducing the impacts of dietary changes and stress on animals entering the feedlot.

“Our system shows sick animals before producers can see them,” he says. “Our strategy is to get them in the hands of early adopters in the commercial sector to document their performance.”

They are also working to get the data synthesized  into peer-reviewed scientific journal articles. They have data from GreenFeed units in continuous use from 2010 to the present.
He also adds that the more systems that they are able to build, the more cost- effective they will become.

“We have been working to build a system that can slip seamlessly into producer’s operations and produce information to help them make better decisions to save money and make them more profitable,” Zimmerman comments.

Saige Albert is managing editor of the Wyoming Livestock Roundup and can be reached at

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