Fact Check-Why heat stress disproportionately affected cattle in Kansas

Following the death of at least 2,000 cattle in Kansas in June 2022, which authorities and industry experts attributed to extreme heat, humidity and low wind, some social media users questioned why other animals were not affected by these weather conditions.

But experts told Reuters that while all animals mentioned in this social media posts can indeed be affected by heat stress, several factors make cattle more vulnerable to it, and the number of cattle in Kansas (it is the state with the third-highest number of cattle) ( here ), is significantly higher than other species.

“Why did only the cattle die, and not the horses, donkeys, sheep, chickens, pigs, goats, etc?” reads a tweet that has been retweeted at least 5,100 times as of the writing of this article ( here ).

Some users also alleged, with no evidence, that the incident was an intentional action to create a food shortage ( here ) ( here ).

Other users sharing the claim attribute the deaths to billionaire Bill Gates ( here ) ( here ) ( here ), which Reuters previously debunked ( here ).

Iterations on Facebook can be seen (here) (here) (here).

The Kansas Department of Health and Environment (KDHE) has said it knew of at least 2,000 cattle deaths in the southwest of the state, caused by high temperatures and humidity (here) (here), a figure based on the facilities that had contacted the agency for help disposing of carcasses.


“All science from this episode point out to incredibly hot days, incredibly high humidity and little to no wind. So when you get all of this together, that factors into a loaded heat that this cattle can’t handle,” Joe Armstrong, Cattle Production Systems educator at the University of Minnesota Extension, the university’s science-focused partnership with government agencies, told Reuters via phone (here).

Armstrong pointed out to the animals’ thermoneutral zones. The thermoneutral zone, he explained, is the temperature in which the body doesn’t have to spend any energy in either making itself warmer or trying to cool down.

The thermoneutral zone is lower for cattle than for other species and they experience heat stress sooner in comparison to other animals.


Cattle are heavier animals compared to the other species mentioned in the social media posts. This also comes into play when considering their ability to combat heat loads, Michael Kleinhenz, assistant professor of Beef Production Medicine at Kansas State University told Reuters.

“When we talk about cattle, like this feedlot cattle, these are heavier muscle animals. Physically they are well conditioned, they have a layer of fat on them and that layer, means that they are well fed, but also, prevents them from cooling out as fast,” he said via phone.

Another key element to consider is that cattle are ruminant animals and the size of its rumen, in comparison to other animals like goats and sheep, is bigger. This translates in the creation of high loads of heat because of the fermentation that is produced in their stomach. More on that ( ).

And when it comes to other non-ruminant animals mentioned in the posts – like horses, donkeys, poultry and swine –, “we know that they don’t have that challenge of that giant fermentation inside their abdomen that produces heat,” Armstrong said.

As for swine and chickens, experts also pointed out to the difference in conditions in which this species are kept. For example, commercial swine and chickens are usually kept in barns which provide shade, while cattle are kept outside.

Another physical quality that helps horses and donkeys to deal with heat is sweating ( here ) ( here ) cattle on the other hand can’t effectively sweat, Kleinhez noted ( here ).


Both experts said the cattle death figures in the state should be seen in comparison to other animals mentioned in the posts.

“It’s just a numbers game, in a percentage basis there is an absolute [higher] amount of cattle in that area,” Armstrong said.

As of Jan. 1st, 2022, the latest data available from the United States Department of Agriculture (USDA) National Agricultural Statistics Service (NASS) ( here ) registered there were over 2.6 million cattle on feedlots in Kansas. In comparison, there were 65,000 sheep and lambs, 41,400 heads of goats (meat and other and milk). There were over 1.9 million heads of hogs as of Dec. 1, 2021, the latest data available for this group.

Reuters could not independently determine whether any other species listed in social media posts were affected by the weather events on the weekend of June 11 and June 12.

By June 23, the Kansas Department of Health and Environment (KDHE) had “not received requests to dispose of species other than cattle resulting from the June 11-12 event,” Philip Harris, Deputy Communications Director at the KDHE told Reuters.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here .