A team of Japanese scientists painted zebra stripes on black cows in 2019 to keep biting flies away — and it worked.
Specifically, the scientists hypothesized that painting a zebra-striped pattern on domestic cattle would reduce the number of biting flies plaguing livestock. Biting flies are a more-than-annoying scourge for ranchers worldwide, including in Wyoming.
Their findings were that the frequency of biting flies landing on the painted cattle decreased by over 50%. Furthermore, the cattle were more relaxed since they weren’t reflexively fighting off so many flies.
Could zebra-striped cattle be a solution for Wyoming ranchers? Science says yes, but Wyoming ranchers say there isn’t much of a flying chance it’ll work here.
“That’s a little far-fetched,” said Dennis Sun, publisher of the Wyoming Livestock Roundup. “Think of what it takes to paint a cow like a zebra, and paint washes off. Then what are you going to do?”
That Bites
Biting flies are a problem for all livestock. The blood-sucking nuisance pests are small, swarm by the thousands, and have detrimental effects if left unopposed.
“If you don't have some kind of fly management, cattle are more restless,” Sun said. “They're walking more and not eating as much. They can cause cows and calves not to put weight on. Yearlings that you're grazing won’t put as much weight on because they spend all their time fighting flies, and it keeps them restless.”
According to a 2018 study published in the Journal of Medical Entomology, infestations of the stable fly, a widespread Western biting fly, interfere with livestock feeding, reproduction, and resting behaviors to a cost of $2.2 billion a year.
“Stable flies, Stomoxys calcitrans (L.), are serious pests of humans and animals worldwide,” the study reads. “Biting stable flies reduce the productivity of livestock, cause pain and suffering in companion animals, and disrupt human recreation.”
Other studies have found that biting flies reduce grazing and bedding time and increase defensive behaviors like foot stomping, head throwing, skin twitching, and tail switching in beef, dairy, and pastured cattle.
Cattle are also known to resort to “bunching” when swarmed by biting flies, which increases heat stress and risk of injury. These factors can result in the loss of animals and profits for ranchers.
Shoo Fly, Don’t Bother Me
There are remedies for biting flies. Sun knows of several that work reasonably well.
“One way is to use insecticide ear tags,” he said. “Another way is to place scratchers, big fabric tubes that you stretch between two posts and cover with a mix of insecticide and diesel. Cattle come in, learn to go under it, and they'll rub against it. That works very well.”
Another option is to supplement cattle feed or salt licks with chemicals that prevent biting fly pupae from developing. While the adults suck blood, their larvae and pupae subsist on animal waste and fermenting vegetation.
Most Wyoming ranchers use several biting fly remedies to keep their cattle happier and healthier. Mark Eisele, owner and operator of the King Ranch in Cheyenne, is familiar with all these methods but favors one that’s yielded great benefits.
“We put (chemicals) that are basically larvicides in our mineral and salt mix,” he said. “It kills the eggs before they hatch. It passes through and doesn't get absorbed by the animals’ system, and it's no threat or risk to the public. It just kills the flies, and that’s been an enormous improvement for animal health.”
The problem with existing methods is that they aren’t long-term. Ensuring these methods keep working requires effort and attention.
“Scratchers work good, but you have to recharge them every six weeks,” Sun said. “The insecticide ear tags are supposed to work for six months, but I think they’re done after four. They’re not as effective as we’d like, but they’ve all been proven to work.”
So what about taking artistic liberties to liberate cattle from flies?
Of All Stripes
In the 2019 study, six pregnant Japanese Black cows were covered with black-and-white painted stripes, black painted stripes, and no stripes. Each cow experienced all three treatments in three periods over nine days, while scientists observed the number of fly landings and the cows’ anti-fly behaviors.
The conclusion was that flies landed 50% less on the cows covered with zebra-like black-and-white stripes, which reduced the cattle's defensive behaviors.
The scientists presented their research as an alternative fly deterrent for cattle ranchers. Painting zebra stripes on cattle could reduce the use of pesticides and other chemical deterrents, which could have health benefits for humans and livestock.
It’s not as far-fetched as some might believe- ask a zebra.
A 2022 study determined that zebra stripes, this time from actual zebras, repel biting flies under naturalistic conditions. It also said that the idea that zebras evolved their striped hides to repel flies, rather than for camouflage or sexual selection, is “the best-supported hypothesis.”
Science supports stripes. But is that enough for Wyoming ranchers?
Stripe Skepticism
Sun doesn’t deny the veracity of these stripe studies but questions their practicality. There aren’t any striped cattle bred in Wyoming, and trying to do a cosmetic upgrade on a thousand head doesn’t seem worth the trouble.
“Stripes would probably be option 10 out of 10,” he said. “You’d go through a lot of paintbrushes.”
On a more practical note, Sun believes what works for Japanese Black cattle might have something to do with their more luxurious lifestyles. In Japan, cattle spend more time in barns than their American counterparts.
“They’re more docile than our cattle,” he said. “They live in barns most or all of the time, and they’re fed year-round.”
It’s also worth noting that Japanese Black cattle are one of the four breeds of wagyu cattle. Their beef is touted for its extensive marbling, due to an increase in fat from a feed-heavy diet rather than a grazing diet, which is the backbone of most Wyoming cattle ranches.
When thinking about the vastness of many Wyoming ranches and the struggle already inherent in managing thousands of cattle, Sun doesn’t see painted zebra stripes catching on in the Cowboy State.
“I think it’s too far-fetched,” he said.
Nature Knows Best Deterrent
Eisele was familiar with the zebra-stripe study and believes its conclusions make natural sense.
“Stripes are a ‘nature knows best’ deterrent,” he said. “It’s a natural thing to deter pests and predators in the wild. We see it all the time.”
Eisele also said he wouldn’t consider painting zebra stripes on the cattle on the King Ranch, but encouraged ranchers to “keep an open mind” about innovative techniques.
He doesn’t have an incentive to zebra stripe his cattle, especially with an effective deterrent already in place, but it’s important to “keep an open mind.”
“As a producer, you have to be aware of what the next best thing will be,” he said. “If we didn’t keep an open mind, we would have bypassed a lot of the great techniques for production, convenience, animal comfort, and human comfort all at the same time. Painted stripes probably isn’t the most practical solution at the moment, but you can't rule anything out.”
Like Sun, Eisele would consider zebra stripes a last resort if no other fly deterrents were available. Nevertheless, he would consider them if necessary.
“If my larvicide isn’t available, what’s my next option? If you keep checking the boxes until you’re down to zebra stripes, it’s better than nothing,” he said.
The Vampire Defense
While there are tried and true biting fly deterrents for Wyoming ranchers to use, there’s always an urge to find better solutions. Sun said one of the newest innovations uses a natural herb notorious for warding off villainous bloodsuckers.
“Some of the protein tubs you can get for cattle are using garlic to help them cope with flies and the heat,” he said.
The danger of many of these solutions is the risk of chemicals entering the bloodstreams of cattle. That could be detrimental to the cow and the consumers of their meat and milk.
“We have to be careful about what we use,” Sun said. “You don't want chemicals that seep through the skin and get into their blood when they go to slaughter. Those could last a couple of weeks or a month.”
Until someone breeds zebra-striped cattle, Sun doesn’t believe any Wyoming ranchers will turn to painting stripes as a viable fly deterrent when more practical solutions work well enough. Besides, there’s a critical consideration that barn-living Japanese Black cattle and naturally striped zebra don’t have to worry about.
“Paint washes off,” Sun said. “You can’t use that again next year.”
How The Cow Gets Its Stripes?
Genetics is becoming increasingly important in agriculture, especially with genetic technology’s enormous potential and increasing accessibility. Eisele said cattle producers are always interested in optimizing their livestock through genetic engineering.
“There's a huge focus on genetics and how genetics play a role in animal health,” he said. “Producers in the southern U.S. have a problem with ticks and heat. That’s why you see more bromine-type crosses, what we call big-eared cattle, in the south. They can tolerate hot climates and pests better.”
The zebra got its stripes after millions of years of evolution on the arid plains of Africa. Japanese Black cows got their stripes in a few hours from scientists with a can of white paint. Could the future of fly-free cattle be selective breeding for stripes?
“It would certainly be on the table,” Eisele said. “The potential is there, and I'm sure there are several people, universities and companies that are working on it as we speak. I would not rule it out.”
Andrew Rossi can be reached at arossi@cowboystatedaily.com.
