It’s not just the heat — it’s the humidity and no wind, and for cattle trying to cool off through rapid respiration, that distinction can be the difference between weathering a hot spell and losing animals. That’s what South Dakota beef producers learned last week as a heat event with 80%-plus humidity and little overnight relief pushed cattle to their limits.
A heat dome that settled over the central Plains and upper Midwest brought nights that never cooled below 70 degrees, high humidity and almost no airflow. For South Dakota cattle feeders, that combination proved deadly, with death losses now estimated in excess of 2,000 head statewide and reports of losses stretching from western Kansas to northwest Iowa.
Tucker Frederick didn’t see triple digits at his Hayti, S.D., cow-calf and finishing operation last week. He didn’t need to. Upper 90s heat, 70% humidity, no clouds and no wind proved to be its own kind of dangerous — one that cost him seven head of fed cattle and two calves despite shade, sprinklers and years of heat-mitigation experience.
Frederick manages a herd of 150 cow-calf pairs and has a feedlot with 1,300 head on feed.
Stagnant Air and Warm Nights: A Recipe for Disaster
Warren Rusche, South Dakota State University (SDSU) Extension feedlot management specialist, says the region has weathered plenty of hot spells this summer. What made this one different was the overnight low.
“If we can get down below 70 degrees, most of the time our cattle can handle that. It gives them an opportunity to get rid of some of the heat load and set them up for the next day. We didn’t have that this time.“
Rusche says the combination — triple-digit heat, high humidity and stagnant air layered on top of a warm night — was enough to overwhelm mitigation efforts producers had already put in place.
“The environmental conditions swamped any kind of mitigation strategies,” Rusche explains.
He says death losses in South Dakota feedlots were running in excess of 2,000 head as of early last week, with reports scattered well beyond the state’s borders. Producers in western Kansas and central Nebraska reported losses as well, and Rusche says he wouldn’t be surprised if the toll extended into eastern Nebraska and northwest Iowa — essentially the footprint of the heat dome itself.
Fat Cattle Hit Hardest
At Frederick’s place, the losses were concentrated in cattle within about 30 days of finishing weight — the biggest, fattest animals in the yard.
“We’re making these cattle bigger and fatter all the time,” Frederick says. “Well, that certainly has a drawback when it gets this hot. In the winter, it’s not so bad when it’s cold — it may even help, with thermal mass. But in the summer, thermal mass is exactly what you don’t want.”
Frederick also points to genetics as a factor. Cattle in the northern Plains are typically bred to handle cold winters, not extreme summer heat, and predominantly black hides don’t help matters in direct sun.
Shade made a measurable difference at his operation. Pens with shade structures fared better than those without, he explains, even though all of the fat cattle had access to sprinklers.
“That wasn’t enough to stop the problem,” Frederick stresses.
Cow-Calf Herds Face a Different Kind of Loss
While feedlot death losses are relatively easy to count, the toll on cow-calf herds is harder to measure, stresses Warren Symens, a cow-calf producer from Amherst, S.D.
“In the feedlot sector, it’s easy to count the losses. You don’t often see death loss in range cattle... but the loss that you experience is harder to calculate because you have sickness, weight loss and disease.“
Symens says cattle congregating in water to cool off create its own set of problems — stagnant water, foot rot, calves nursing on muddy udders and cows that stop grazing. He also notes heat and nutritional stress on pregnant cows can affect calves born the following spring, influencing weight gain, fertility and disease resistance well beyond birth.
Jamen Benson, a cattle producer from Lyons, S.D., avoided death loss altogether — a result he credits to a heat-mitigation routine his operation follows every year starting around Memorial Day.
“We put the bigger water tank out just so we have access to water and the shade,” Benson says. “Those cattle were way more comfortable in their confinement building, over the outside cattle.”
Benson also fed an electrolyte supplement, which he describes simply as “Gatorade for cattle,” during the worst of the heat. He did note an uptick in foot rot, which he attributes to cattle standing in one place more often during the hottest days, and expects some lost rate of gain once cattle cross the scale.
The Recovery Roadmap: Documentation, Disposal and LIP Claims
Rusche’s top recommendation for producers dealing with losses: Document everything. Headcount records, photographic evidence and third-party verification from a veterinarian or nutritionist can all support a claim under the Livestock Indemnity Program, which helps offset the financial impact of weather-related losses. Producers should contact their county Farm Service Agency office to begin that process.
Carcass disposal has added another layer of urgency. South Dakota law gives producers roughly 36 hours to dispose of dead animals, and with rendering trucks stretched thin during a widespread event, burial has been the most practical option for many operations — provided producers document losses thoroughly beforehand.
Looking ahead, Rusche says producers shouldn’t assume the risk has passed. With more heat events possible between now and mid-September, he recommends getting ahead of forecasts where possible: Shifting cattle to pens with better airflow, spreading bunched cattle out, adding water capacity and rethinking shade placement, since trees that block winter wind can also block summer airflow.
Symens offers a broader piece of advice for producers navigating the aftermath.
“What works for one outfit doesn’t always work for the next one down the road,” Symens says. “Reach out to each other, reach out to your neighbors, check on each other. It’s important for everybody’s health that we take care of each other.”
Lessons Learned From the Heat Event
No single strategy prevents losses outright — even producers with shade, sprinklers and years of preparation were caught off guard by the heat event with no overnight relief. Proactive planning layered with flexibility and a willingness to adjust if conditions turn out worse than expected are key to minimizing loss during a heat stress event.
Here are some lessons learned shared by the South Dakota producers:
- Before Event
• Start heat prep on a schedule, not a forecast.
• Watch overnight lows, not just daytime highs.
• Rethink shade placement for summer, not winter. Rusche notes that trees positioned to block winter wind can also block summer airflow — it’s worth evaluating pen layout with both seasons in mind. - During Event
• Shade made a measurable difference. Frederick says pens with shade structures outperformed those without, even though all pens had sprinkler access.
• Sprinklers alone aren’t enough.
• Bedding isn’t just a winter tool. Frederick lays corn stalks or straw in pens during extreme heat, since bare dirt or black feedlot surface absorbs and radiates more heat than a covered surface.
• Electrolyte support helps cattle that go off feed.
• Confinement barns with fans outperformed open lots. Benson says cattle in his fan-ventilated barn were noticeably more comfortable than cattle outside.
• Feeding at night can help. Frederick shifted feeding to nighttime hours to help keep cattle cooler during the hottest stretch.
• Give cattle room to spread out. Rusche recommends spreading cattle across available pen space when possible, rather than keeping groups tightly bunched, to reduce shared heat load.
• Fresh pasture and rotation matter for cow-calf herds. Symens says rotating cows onto ungrazed pasture with taller grass gives both cows and calves more natural shade and easier grazing during heat stress.
• Watch water quality, not just water access. Symens flags that cattle congregating in shallow water can turn it stagnant, contributing to foot rot and disease spread — access to fresh, deep drinking water is preferable to a wallow. - After Event
• Document losses immediately and thoroughly.
• Contact FSA early. Producers should reach out to their county Farm Service Agency office as soon as losses are confirmed — paperwork and documentation requirements take time to assemble.
• Plan carcass disposal before you need it. With state disposal windows as short as 36 hours and rendering trucks often backed up during widespread events, several producers say burial — with documentation completed first — is the most reliable option.
• Expect a performance hit even in cattle that survive. Both Frederick and Benson say cattle that go off feed during the heat will show reduced rate of gain, though the full extent often isn’t clear until cattle cross the scale.
• Herd health effects can surface later. Symens notes heat and nutritional stress on pregnant cows can affect calf performance, fertility and disease resistance well into the next calving season.
