January 28, 2021

Researchers Find Little Impact on Greenhouse Gas Emission with Dairy Cow Removal

Researchers Find Little Impact on Greenhouse Gas Emission with Dairy Cow Removal

In an exciting new study by Virginia Tech, researchers discovered that removing dairy cows from the United States agriculture system would only reduce greenhouse gas emissions by 0.7% while significantly lowering the availability of essential nutrients for humans. The team wanted to uncover the actual impact that dairy cows have on the environment, due to the recent push towards plant-based production in efforts to remove greenhouse gases.

“There are environmental impacts associated with the production of food, period. The dairy industry does have an environmental impact, but if you look at it in the context of the entire US enterprise, it's fairly minimal,” said Robin White, an associate professor in the department of animal and poultry sciences and a member of the research team. “Associated with that minimal impact is a very substantial provision of high quality, digestible, and well-balanced nutrients for human consumption.”

The team of researchers on this study included scientists from the US Dairy Forage Research Center, part of the United States Department of Agriculture (USDA), and Dairy Management Incorporated, who examined different scenarios for dairy cattle in the US that factor into management practices, retirement, and depopulation from the US agriculture industry. The researchers examined three different scenarios to see both environmental and nutritional impact.

Greenhouse gas emissions were unchanged in the herd management scenario, in which cattle become an export-only industry and the supply of available nutrients decrease. In this economically realistic scenario, the industry stays similar to how it is now, but the United States no longer benefits from the human consumable nutrients that dairy cows provide. The scenario where cows were retired, where cows lived out the remainder of their lives in pastures or free-range, resulted in a 12% reduction in agricultural emissions and all 39 nutrients considered declined. The depopulation scenario, where cows are killed off, resulted in a 7% reduction in agricultural emissions. Thirty of 39 nutrients increased for the depopulation scenario, though several essential nutrients declined. One significant factor in all of the scenarios is the use of the land that has to be managed after the removal of the cows. The impact on the industry downstream must be factored into the scenario results. 

"Land use was a focus in all animal removal scenarios because the assumptions surrounding how to use land made available if we remove dairy cattle greatly influence results of the simulations," White said. "If dairy cattle are no longer present in US agriculture, we must consider downstream effects, such as handling of pasture and grain land previously used for producing dairy feed, disposition of byproduct feeds, and sourcing fertilizer."

White also stated that the reasoning behind the minimal impact of dairy cows is due to the innovative new practices by the dairy industry. The efficiency of the industry, like with any industry, has improved over time.