Curbing emissions in cattle feedlots
Research looks to curb methane gas emissions
Albertans love their beef. But families who live near feedlots may not be quite as enthusiastic. What’s more, the methane they’re smelling is a significant part of the province’s greenhouse gas emissions, a critical factor in climate change.
But now Alberta-based research may lead to reduced emissions — and happier neighbours.
New feed additives, new ways to use forage crops and “new thinking” about farm operations are part of the story. So are new emissions-measuring techniques, adapted from approaches used in Alberta’s oil and gas industry.
And Lethbridge scientists at Agriculture and Agri-Food Canada’s research station are playing a leading role in learning more about the emissions. Livestock operations continue to be a significant source, explains researcher Sean McGinn.
“That’s quite clear and generally recognized by the agricultural research community,” he says.
From 50 to 60 per cent of the nitrogen in the feed given to cattle is lost as ammonia right there in the feedlot, McGinn says. Nearly 10 per cent of Canada’s greenhouse gas emissions come from agriculture, he points out — and 90 per cent of that is from cattle manure.
As well as creating health hazards, like the white haze seen in some confined areas, it also reduces the desired nitrogen level in manure.
With funding from the Alberta Livestock and Meat Agency, he and colleague Tom Flesch at the University of Alberta have been investigating how much airborne nitrogen is deposited on land downwind from the feedlot, and how much is carried much further. They’ve also been measuring the levels of methane and nitrous oxide, two more greenhouse gases related to cattle’s digestive system, and stored manure.
Using “open path lasers” that move over the feedlots, they’ve been able to measure the emissions. That technology was first used to measure flarestack emissions in the oilpatch.
In the U.S., observers point out, large animal feeding operations have been required to measure and report air releases of “hazardous substances” from animal waste.
Researchers in Lethbridge are also showing how an inhibitor compound created in Switzerland can control methane. Karen Beauchemin says the feed additive has proven itself in feedlot trials and is being registered for use in North America.
“It is a very promising emission control alternative that could be available within three to five years,” she says.
Adjusting the cattle’s diet — by harvesting forage crops earlier, for example — has also proven effective. And Karen Koenig, who’s also a researcher in Lethbridge, says not overfeeding protein to the animals can also reduce emissions.
Distillers grains, a byproduct of the ethanol industry, are a case in point. Their nutrients are highly concentrated.
“When added to diets as an energy supplement, it often results in overfeeding protein, which increases ammonia emissions,” she points out.
By contrast, Koenig says, adding tannins to their diet can bind the nitrogen while it’s in the animal’s gut, and keep more of it in the resulting manure.
“There are supplements on the market with these products in them already, but we are evaluating them in terms of ammonia and methane management.”
Looking west, Koenig says a research project in the Fraser Valley is studying crop production in the context of a “whole farm” approach that also includes dairy cattle. The selection of crops, their fertilization, the number of cuts and the feed quality are all taken into consideration.
“We are looking at what is needed to meet the needs of the dairy cow,” she says. “It’s a whole farm system that does not oversupply nutrients to the animal.”