Proven Parasite Control for Beef Producers
External parasites are a constant challenge in cattle operations, quietly cutting into performance and profit. Flies, lice, ticks, and mites are the most common culprits, each affecting cattle in different ways. Left unmanaged, these pests lead to decreased gains and overall poor herd health. A consistent parasite control plan helps cattle stay comfortable, productive, and healthy, making it a key part of any successful cattle operation.
Profit Robbing Pests
External parasites are a common problem in cattle, flies, ticks, lice, and mites, can all hurt herd health and performance in different ways. Flies are often the most visible issue, with horn flies, stable flies, and face flies causing constant stress. Horn flies feed on blood many times a day, leading to irritation, blood loss, and lower weight gain. Stable flies bite the legs, which is painful and causes cattle to bunch together, reducing grazing time and increasing heat stress.
Face flies are a bigger concern for disease because they feed on the eyes and nose and spread pinkeye, which can cause eye damage, blindness, and lower weaning weights, and docking at the sale barn or buying point. Flies can also help spread diseases like Anaplasmosis. Anaplasmosis is a blood borne illness that causes weakness, poor performance, lethargy, and even at times death. We also see ticks transmitting this from cow to cow.
Ticks are less common day to day, but can be more dangerous because they carry serious diseases. These parasites attach to cattle and feed on blood for several days, increasing the risk of infection. Ticks can also spread Bovine babesiosis, sometimes called Texas cattle fever, which leads to high fever and severe anemia. They also spread Theileriosis, an emerging issue in some areas that also affects blood cells and overall performance. In rare cases, ticks can even cause paralysis due to toxins released while feeding.
Mites and lice are much smaller and harder to see, but they can still cause major problems. Mites live on or under the skin and lead to Mange, a condition that causes intense itching, hair loss, thickened skin, and sores. Lice feed on skin or blood, causing irritation, itching, and hair loss. Cattle infested with lice and/or mites spend more time rubbing and less time eating, leading to weight loss and poor condition. Heavy infestations can reduce performance and make cattle more prone to illness.
While each pest affects cattle in its own way, the end result is similar: lost performance, added stress, and increased risk of disease.
Economic Losses
University studies, especially from land-grant schools like the University of Nebraska–Lincoln (UNL), the University of Florida, and Kansas State University, show that flies on cattle hurt both health and profits. In the United States, these pests cost the cattle industry more than $2 billion each year. The main problem flies: horn flies, stable flies, and face flies, cause loss by slowing weight gain, cutting milk output, and spreading disease.
Research from the University of Nebraska–Lincoln (UNL), the University of Florida, and Kansas State University shows clear points where fly control pays off. Horn flies are the worst for cattle on pasture and cause about $1 to $2 billion in losses each year. Studies show they can cut weight gain in stockers and heifers by up to 18 percent and lower calf weaning weights by as much as 15 percent. Stable flies are also very harmful, both in lots and on pasture. UNL studies show they can reduce daily gain by up to 0.44 pounds per day and cost the industry over $2 billion each year. Experts say it makes sense to treat cattle when numbers reach about 200 horn flies per head or just five stable flies per leg.
Flies also hurt cattle’s health and behavior. Stable flies bite the legs, which is painful. Cattle will bunch up to avoid bites, which means they graze less and deal with more heat stress. Studies show this stress causes about 71.5 percent of lost weight gain, according to the university studies. Horn flies feed up to 40 times a day, leading to irritation, energy loss, and blood loss. Face flies feed on the eyes, nose, and mouth and spread Moraxella bovis, which causes pinkeye. This can lead to blindness and lower weaning weights in calves.
More studies show how much control helps. Research from the University of Nebraska–Lincoln found that when horn flies were controlled on cows, calves were 10 to 20 pounds heavier at weaning. The University of Kentucky found that flies can cause stocker cattle to lose up to 60 pounds over a 100-day summer. Work from the United States Department of Agriculture Agricultural Research Service and UNL showed that controlling stable flies raised daily gain by 21 percent in grazing cattle.
Older data from 2005 to 2009 from The National Institutes of Health (.gov) helps show the size of the problem, and losses today are likely even higher. Pastured cattle lost about $1.26 billion from lower gains and blood loss. Dairy cattle lost about $360 million from less milk. Feeder cattle lost about $226 million from poor feed use, and cow-calf herds lost about $358 million from lower weaning weights.
All of this shows that fly control is not just helpful, it is key to making money. When producers manage flies at the right time, they can improve cattle health, boost performance, and protect profits.
Controlling External Parasites
Beef cattle producers use a wide range of tools to control pests, and most successful programs combine several methods rather than relying on just one. Research from universities like UNL and others strongly supports these efforts, showing clear improvements in cattle performance when parasites are controlled.
For flies, the most common control methods include insecticide ear tags, sprays, pour-ons, dust bags, back rubbers, feed-through products, and sanitation. Ear tags are one of the most widely used tools because they slowly release insecticide across the animal’s body through natural movement and grooming. Studies have shown these tags can reduce horn fly numbers by around 79%, and face flies by about 30%, with other methods like dust bags reducing horn flies by as much as 86%.
Sprays and pour-ons are also effective, especially for stable flies, but they require more frequent application to maintain control. Back rubbers and automatic sprayers allow cattle to treat themselves, which can improve coverage and reduce labor. Research from the University of Nebraska–Lincoln shows that untreated cattle exposed to stable flies can lose about 0.44 pounds of average daily gain compared to treated cattle, proving that control directly impacts performance.
For ticks, control methods are similar in terms of chemical tools but often require a more targeted approach. Producers commonly use pour-ons, sprays, and dips that contain acaricides (tick-killing compounds). Pasture management also plays a role, including rotational grazing to reduce tick habitat. Research consistently shows that controlling ticks reduces the spread of diseases like anaplasmosis and improves overall herd health. Many of the same insecticide classes used in fly control (pyrethroids and organophosphates) are also effective against ticks. A good integrated pest management (IPM) plan can address multiple pests at once.
For lice and mites, producers typically rely on pour-on insecticides, injectable products, and sometimes dusts. Macrocyclic lactones are especially effective because they control both internal parasites and external pests like lice and some mites. Research and extension data consistently show that treating lice and mites improves weight gain, hair coat condition, and overall health, especially in young or stressed cattle.
Across all three parasite groups, the strongest research-backed approach is integrated pest management (IPM). Studies show that relying on a single method, such as ear tags alone, can lead to resistance over time, while rotating products and combining methods improves long-term control. Controlled-release insecticides, like those in ear tags, have even been shown to achieve over 90% fly control and nearly eliminate fly-related pinkeye in some trials.
Without a doubt, external pests, particularly flies, try to rob profits from ranches. Research shows that parasite control pays off. Whether it is flies reducing weight gain, ticks spreading disease, or lice hurting condition and overall appearance, using a mix of proven tools helps cattle stay healthier, gain better, and perform more efficiently.
