Cattle production is often cast as an unsustainable industry, but while some of the criticism may be warranted, raising cattle can be beneficial to the environment as well as sustainable, according to Michigan State University.
In a study published in the journal Agriculture Systems, Michigan State scientists evaluated adaptive multi-paddock (AMP) grass-fed operations as well as grain-fed feedlot herds.
“Globally, beef production can be taxing on the environment, leading to high greenhouse gas emissions and land degradation,” said Jason Rowntree, Michigan State associate professor of animal science who led the study. “Our four-year study suggests that AMP grazing can potentially offset greenhouse gas emissions, and the finishing phase of beef production could be a net carbon sink, with carbon levels staying in the green rather than in the red.”
In addition to reviewing past studies, Rowntree’s team conducted new research at Michigan State’s Lake Station AgBioResearch Center in Lake City, Mich. (The feedlot data were collected in East Lansing, Mich., at the cattle property south of the university's main campus.) On any given day, a herd of more than 200 steers moves through 600 acres of grass in the Lake City fields.
The scientists tallied finishing phase data, such as carcass weight, daily weight gain and more, and compared them to greenhouse gases (methane, nitrous oxide and carbon dioxide) from digestion and fermentation, manure storage and handling and feed production and energy use on the farm. They also measured carbon losses arising from soil erosion.
Environmentally, AMP systems came out in the green, while feedlot emissions were in the red primarily because of feed-based nitrogen emissions from fertilizer.
However, beef production is a complex equation, not one solely tied to environmental factors. For instance, the feedlot model was considerably more productive, producing the same amount of beef on only half the land, the researchers said.
This leaves more land for various purposes such as growing human food or rewilding. It is also important to note that the carbon sequestration changes over time, and the researchers expect to see less over time. There is great potential that managed-grazing can offset the methane produced for many years to come, Rowntree said.
“AMP is not as productive as feedlots, based on yields, but the AMP grazing system produced considerably greater amounts of beef on a land basis as compared to continuous grazing, showing that improved management can increase the output of grass-fed beef,” he said. “Ultimately, in a closed system, this implies somewhat lower per capita beef consumption, but greater environmental benefits from what is consumed.”
Likewise, the same environmental benefits could be seen on the cow/calf system providing cattle for the feedlot, matching greater production per unit land with the environmental benefits of grazing, he added.
“We’re not advocating for one approach over another, but rather, we looked at different cattle production methods, and we see best practices and areas of improvement that support environmental stewardship in grass- and grain-fed systems,” Rowntree said.
In that vein, feedlot operations could be more environmentally friendly if they used fewer fertilizers and cover crops in the grain production component of feed. Using AMP grazing, land managers can let cattle graze an area with relatively high density, like wild migrating herds, but then provide for adequate plant recovery. This allows for a deeper, healthier root system and builds organic matter in the soil, which acts as a sponge for available moisture.