Dairy cows contribute more to nutritional needs than to harmful emissions

The removal of dairy cows from the United States would only make a small contribution to reducing greenhouse gas emissions while detrimentally impacting the country’s supply of essential nutrients. This is the conclusion of a recent study conducted by scientists at Virginia Tech and the U.S. Dairy Forage Research Center.

Dairy production has been linked to about 1.6 percent of the overall greenhouse gas emissions in the United States. At the same time, the dairy industry is responsible for supplying the protein requirements of 169 million people, the calcium requirements of 254 million people, as well as the energy requirements of 71.2 million people.

A growing collection of research has explored the potential for a shift away from animal products – and toward plant-based alternatives – to increase food production and reduce greenhouse gas emissions on a global scale. 

The current study investigated the effects of dairy product removal on emissions and nutrient availability in the United States under various removal scenarios, including depopulation, current management, and retirement. 

In the first scenario, consumers would stop using dairy products, resulting in the depopulation of the animals. Current management means that cattle management would remain the same and the milk would either be exported or used for products other than human food. Under the third condition, retirement, cattle would be reduced to numbers that could be supported by available pastureland.

Overall, the dairy cow removal scenarios reduced the availability of essential micronutrients such as vitamins A, D, B 12, and choline. At the same time, these conditions did not reduce harmful emissions relative to the current production system. 

“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,” said study lead author Dr. Robin R. White. 

“If dairy cattle are no longer present in U.S. 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.”

The results of the study suggest that the removal of dairy cows from U.S. agriculture would only reduce greenhouse gas emissions by 0.7 percent, while substantially lowering the available supply of essential nutrients for the growing American population.

“Production of some essential nutrients, such as calcium and many vitamins, decreased under all reallocation scenarios that decreased greenhouse gas emissions, making the dairy removal scenarios suboptimal for feeding the U.S. population,” said Professor White. 

The study is published in the Journal of Dairy Science.

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By Chrissy Sexton, Earth.com Staff Writer