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Nutritional study, White studies impact of removing livestock

by Wyoming Livestock Roundup

Robin White of Virginia Tech University says recent assertions that “healthy” diets should include a reduced portion of animals products to improve environmental impacts and human health led to a recent research project to assess the impacts of a livestock-free system.

Taking aside the impacts to the environment, White says, “We used least cost ration formulation to identify what optimal diets people would be in food production system with and without livestock. Least cost formulation is a way to objectively formulate rations.”

White’s team adjusted daily intake of different human food ingredients to minimize diet costs while also considering nutrient requirements of the population need to be satisfied from the total weight of food produced in the U.S. 

“This gets to the question of scalability,” she says. “How feasible is it to give people a ration without animal products included?”

Current data

White looked at current U.S. rations to provide context for the research.

When breaking down diets by category of food on a weight basis, as well as cost, Americans spend roughly four dollars per person per day, and the carbon footprint is about 3.2 kilos of CO2 per person per day. 

“The as-fed intake on this ration is about 1.5 kilo per person per day, and the dry matter intake – which is an important number – is just under half a kilo a day,” White explains. “Most people say that’s about right for the average American.”

The average diet composition is roughly one-third animal products, 23 percent vegetables, 22 percent fruits, eight percent “concentrate” and 11 percent other products. 

Least cost rations

Looking at the least cost ration in her research, White notes the types of food consumed change a bit in the system with animals but not tremendously. 

“We see some substitution of grains instead of fruits, which is entirely reflective of the cost of the two,” she explains. “In our system without animals, a dramatic shift happens in the ideal ration that would be put together.” 

Comparing the data, the cost of a diet with animals is slightly higher, at $2.81 a day, compared with $2.05. The carbon footprint is also slightly higher, at 1.4 kilos versus 0.95 kilos.

“But if we compare those to the fact that our current ration is 3.3 kilos, they both achieve commendable reductions in carbon footprint,” White comments.

Dry matter

“If we start to look at the as-fed intake, there’s additional concerns about the healthfulness and the feasibility of those rations,” she says. 

In the system without animals, roughly two kilos of feed must be consumed per day, including water. 

“But, if we look at the composition of that ration, we all know what that dry matter is going to look like, and it’s not attractive, right?” White comments. “It’s roughly 1.2 kilos of dry matter a day that we need to consume in a system without animals.”

“That’s almost three times what we currently consume of dry matter,” she emphasizes. 

As the research team began to think about limits to physical intake, White says, “We might be pushing those limits in this type of diet.”

Dry matter, defines White, is feed without water. She notes, “All feeds have some component of water, which is made up of some constituents that contribute to nutrient value – fiber, protein and fat.”

She continues, “Dry matter takes up physical space, so if we look at the body cavity, there’s a set amount of physical space.”

Water passes through the digestive system very quickly, but dry matter takes much longer to digest. 

Cereal grain are approximately 90 percent dry matter, as an example, says White, “So if we talk about a ration that’s 85 percent concentrate, there’s an immense amount of dry matter in that ration. It’s going to be quite difficult to digest that.” 


A secondary challenge in a food production system with no animals is the ability to get enough nutrients. 

“We talked about these rations as if they are an apple to apple comparison,” she says. “In this case, they are not, because there is insufficient production of nutrients.”

Both rations were deficient in vitamin D, vitamin E, vitamin K and foline.

“But, our ration from the system without animals had increased nutrient deficiencies,” White notes. “It was additionally deficient in calcium, vitamin A, B12, EPA, DHA and arachidonic acid.”

“We’re producing something that, even in comparison to our ideal ration in the current system, is perhaps unhealthy in terms of the quantity you need to consume, and it’s still deficient in many of our micro-nutrients,” White says.

Take home messages

In looking at the project overall, White comments animal agriculture has an important role in providing nutrient-dense food at advantageous prices. 

“We’ve all probably been told that we’re in the business of making protein,” White says. “These results didn’t highlight the importance of protein, but the exclusive reason for that is because we allowed humans to consume protein meal.” 

If there is an upper limit on the amount of soybean meal people could consume in a diet without animal products, protein would be implicated as well.

“Animal agriculture builds nutrient dense foods,” White says. “It’s important as an animal agriculture community to highlight we could feed people without animals. It would be possible, but if we look at the ration it requires, we’d be feeding people the way we feed hogs.”

The objectives of hog farming are very different than the objectives of raising children, for example, says White. 

Finally, when the system is expanded beyond the boundaries of the U.S., White explains, “We need to keep in mind that our agriculture system needs to produce the types of foods that our diets demand.”

Rather than continuing to do studies to look at an ideal diet and assuming the ag industry can adapt, White suggests that considering what systems can produce and how populations can be fed with that system. 

White concludes, “This work hopefully highlights the fact that animal agriculture should be a part of sustainable food production system.”

Read more about White’s project in the 2018 Midland Bull Test Edition. 

Saige Albert is managing editor of the Wyoming Livestock Roundup. Send comments on this article to

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