BRIDGEPORT — The University of Nebraska has conducted studies to evaluate the effects of biochar on digestibility and methane production in growing and finishing diets for cattle, Beef Feedlot Nutrition Specialist Galen Erickson told attendees at the 2019 Beef Feedlot Roundtable on Tuesday, Feb. 12, at the Prairie Winds Community Center. The studies are included in the 2019 Beef Cattle Report (http://extensionpublications.unl.edu/assets/pdf/mp106.pdf).
Biochar is organic material burned at high temperatures in a lack of oxygen. It has been used in a number of applications from gardening to reclamation and remediation of lands. Although biochar is not FDA approved for animal feeding, the initial research shows potential as a methane mitigation strategy in both growing and finishing diets. Erickson said the work was funded by the Nebraska Forest Service.
“A lot of people are interested in methane, and frankly we have to figure out how much methane your cattle are producing under these different situations,” Erickson said.
Erickson said studies indicate that cattle emit from the rumen between 115 to 132 grams of methane per day. For the study, six cross-bred steers were fed in headboxes at the University of Nebraska-Lincoln. Low inclusions of .8 percent and 3 percent biochar were tried in multiple diets along with a zero percent inclusion control diet. For the .8 percent inclusion, the amount of methane production decreased by 10.7 percent in the growing study and 9.9 percent in the finishing study. Methane production decreased by 10.6 percent and 18.4 percent in the growing and finishing studies, respectively, when measured as grams per pound of intake.
“It is more of a feed additive, not an ingredient,” Erickson said. “This would be something you would get more as a supplement than as an ingredient.”
How the biochar works exactly is yet to be understood, but the theory is either that biochar absorbs the gas in the rumen, or that it provides improved habitat for microbes in the rumen, allowing for the microbes to feed on and digest feed more completely, thus reducing the amount of methane that’s released.
According to the study, intake was not hindered with the biochar inclusion, and actually increased in the finishing experiment. The .8 percent diet appeared to be sufficient with no other benefits observed from increasing to a 3 percent inclusion.
Further studies will need to be conducted for safety before the product would receive FDA approval, but it does show promise. One attendee asked Erickson if the biochar studies are proactive given political rhetoric from New York Congresswoman Alexandria Ocasio-Cortez’s “Green New Deal,” and “farting cows” comments.
Erickson said he doesn’t overreact to that kind of rhetoric.
“The reason why we’re doing these studies is because we need to do a better job of managing our feed resources long-term,” Erickson said. “In the U.S., less than 4 percent of our greenhouse gas emissions are from cattle, and I’d guess that they’re between 2 to 3 percent.”
However, in a percentage it matters what the numerator and denominator are, Erickson said.
“The U.S. has a huge denominator because we burn a lot of energy,” he said.”Worldwide the denominator goes down and the numerator goes up because they don’t finish cattle on grain-based diets, and we kill at 500 days of age instead of 3½ years. There are a lot of things when you see the global numbers and percent and the U.S. numbers and percentage.
“When you see a percentage, what matters is what’s in the numerator and the denominator, all we’re trying to do is make the numerator less. And if we can come up with a way that is proactive that doesn’t cost you more, and maybe has a benefit, there is no harm.”
Realistically including biochar will not reduce the amount of greenhouse gasses from cattle in the U.S. from 2.5 percent to 0.
“But if it makes it drop down to 2 percent, that’s a good story,” Erickson said.