Building better soil with biochar

Beating cattle belches with biochar while improving feed efficiency

By Jim Algie

The addition of relatively small amounts of biochar to cattle diets could reduce greenhouse gas emissions while also improving feed efficiency in ways that support the greening of Canada’s cattle industry.

That’s the hypothesis for a five-year $1.1-million federally funded study underway at Alberta’s University of Lethbridge. It may also be among the most promising areas for adapting new research into the use of biochar in commercial-scale agriculture.

For Dr. Erasmus Okine, an animal nutritionist who heads the study, the complex multi-phase project continues more than 28 years of studying feeding efficiency in cattle. A recent focus is on methane reduction.

Okine, who also serves as the vice-president of research at Lethbridge, described the project in an interview with Better Farming as a “proof-of-concept study implementing an integral approach to the reduction of greenhouse gases.”

The project involves a group of researchers from both the federal and Alberta governments as well as the universities of Alberta and Manitoba. It builds on laboratory and genetic research that suggests cattle with reduced methane production also demonstrate improved feed efficiency, Okine said.

“Methane is a wasted energy source for cattle,” he said. “It’s very high energy, but they belch it out about once every minute.

“The methane production decreases the amount of energy for growth. When you reduce methane, you increase the efficiency of energy use by cattle.”

Research in cattle selected for low methane production has found up to a 30 per cent reduction in the emission of the gas. Animals that produce low levels of methane also show increases in levels of a different fatty acid that is used in glucose production, lab results suggest.

Scientists leading the new Lethbridge study seek to test this theory. They’ll work with a dozen live animals in metabolic chambers at the university and focus on their methane emissions. Researchers will also work with 1,000 more animals under feedlot conditions.

“If we can help reduce methane, it gives cattle producers a social licence,” Okine said. “They are doing something about greenhouse gas emissions; that’s number one. Number two, there are economic aspects to it because it improves their returns,” he said.

Researchers are awaiting Canadian Food Inspection Agency (CFIA) permission to proceed with feeding trials this spring. They’re to use tested non-toxic products from two suppliers, Colorado-based Cool Planet and Alberta-based Blue Rock Animal Nutrition. Both responded to a call for samples.

One cow can emit as much as 500 litres (132 gallons) of methane daily in minute-by-minute belches, a federal government announcement of the study in February said. Cattle production is estimated to account for about 38 per cent of Canadian agriculture’s greenhouse gases.

    stephenallen75/iStock/Getty Images Plus photo

The experiment will rely on biochar from wood generated through pyrolysis, the burning of biomass in the absence of oxygen. The research will also seek to examine the meat from animals in the experiment and the effect on soil of their char-containing manure, which is thought to improve the retention of phosphorus and nitrogen, Okine said.

Precise explanations for what biochar does in digestion will take much more research than the new study will provide. However, Okine and his colleagues believe the presence of absorbent, porous char promotes bacterial activity in the rumen.

“There are about 10 to the power of 11 bacteria in a millilitre of rumen fluid,” he said. “Our theory is that biochar increases the number (of bacteria) and the surface area (on) which the microbes are allowed to work efficiently,” Okine said. Such additional activity by bacteria in the rumen tends “to reduce the number of methanogens, the number of microbes that produce methane.”

Okine expects beneficial effects from as little as two grams of biochar in a 10-kilogram daily feed ration.

“Sometimes things work in the lab and then don’t work as much in the field,” he said of the current four-year research plan. “If it doesn’t work, I’ll be the first to let the world know.” BF

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