INDUSTRY INSIGHTS
The true cost and impact of Horn Flies By Central Life Sciences When left untreated, horn fly infestations can reach up to 4,000 flies per animal, staying on cattle both day and night. However, studies have shown that at a level of even 200 flies per animal, your bottom line and animals will begin to see the effects. Losses from horn flies cost the industry an estimated $1 billion each year due to the stress they inflict and disease they spread, inciting weight loss as high as 50 pounds per yearling. With several different factors contributing to profit loss on a beef operation, horn flies shouldn’t be one of them. Disease Without a fly management program in place, beef heifer mastitis can spread quickly throughout a herd, leading to blind quarters, decreased weaning weights and a decreased bottom line. The first step in protecting your cattle against the damaging effects of beef heifer mastitis is educating yourself on the disease. Once you understand what it is, the better you can implement proper practices and preventative measures to protect your herd. This disease occurs in cattle when one or more teats become inflamed, leading to infection. An often-overlooked issue, mastitis destroys milk-producing tissues, which may result in blind quarters. When mastitis and blind quarters occur, milk production is drastically affected and weaning weights decrease— studies show that milk production accounts for 60% variation in calf weaning weight. Horn flies tend to feed on the blood vessels in the skin of the teat, causing irritation. The horn flies can 44 | Ohio Cattleman | Spring Issue 2022
carry mastitis-causing bacteria that enter the teat orifice and move upward in the quarter, destroying milk-producing tissues. With up to 40 blood meals a day, female horn flies only leave the animals to lay eggs in fresh manure. As the flies go from animal to animal, the disease can quickly spread throughout the herd. When beef heifers mature in confined areas with high fly populations, the occurrence of mastitis increases. Weight Gain Horn flies have a painful bite that can present a number of risks to cattle and interfere with their ability to maximize weight gain potential. In addition to causing blood loss, a horn fly infestation also leads to increased cattle stress and annoyance. This can cause cattle to burn excess energy to combat the flies, interrupt grazing patterns, and cause cattle grouping. The result of horn fly infestations exceeding the economic threshold results in reduced weight gains, decreased milk production, and reduced calf weaning weights. Breaking the Life Cycle Understanding effective horn-fly control begins with understanding the pest’s life cycle. Female horn flies that have been biting and taking their blood meals, moving from animal to animal and spreading disease, eventually leave the animals to lay their eggs in fresh manure. One to two days later, the eggs hatch into larvae; then after three to five days the larvae pupate. In untreated manure, pupae will molt
into adults six to eight days after that, becoming the next generation of biting horn flies. Disrupting this life cycle is an essential component of any effort designed to control horn flies. Beef operators should implement an integrated pest management (IPM) program established around a feed-through fly control product like Altosid IGR. Feed-through insect growth regulators pass through the digestive system and work in cattle manure where horn flies lay their eggs, limiting future fly populations. Rather than controlling flies through direct toxicity, insect growth regulators interrupt the fly’s life cycle, keeping the horn fly larvae from developing into breeding, biting adult flies. Horn flies are more than an annoyance to cattle, they pose serious health and economic risks. To protect animals and profits, consider a horn-fly control program built around a feed-through solutions like Altosid IGR.
