In last week’s PCC Update (sign up here), we began a discussion on horn fly control that was prompted by an article on page 2 of our Summer 2024 Newsletter. Most of today’s cow-calf producers have been programmed by the chemical companies to treat the symptoms of the horn fly problem while they totally ignore the problem. That’s good for the chemical companies – but it’s not good for anyone else.
Horn flies not only irritate cattle with their painful, blood-sucking bites, but they also take big bites out of our profits. In 2020, it was estimated that horn flies cost the cattle industry $1 Billion every year. Since today’s calf prices are more than twice what they were in 2020, it is probably costing the industry over $2 Billion every year now! Research has shown horn flies can reduce daily gains by as much as half a pound per day. That could amount to 50 to 100 pounds per calf at weaning.
Controlling horn flies with insecticides is not working because horn flies have the ability to develop a resistance to all of the chemical insecticides that have been used. Consequently, the horn fly problem continues to get worse every year! Cattlemen are constantly searching for new insecticides to treat the symptoms of the horn fly problem. The end result of using chemical insecticides is the creation of genetically superior flies – and genetically inferior cows.
Solving the horn fly problem can only be accomplished through genetics. We need to produce cattle that have a bred-in genetic resistance to horn flies. The practice of using insecticides to control horn flies started in the 1940s. Prior to that, cattle had some genetic resistance to horn flies. As I said last week, selecting and breeding for genetic fly resistance is easy – and since the heritability of fly resistance is very high, you can accomplish much in a relatively short period of time.
I am going to wait until next week to discuss the specifics on “How To Solve the Horn Fly Problem.” Stay tuned. In the meantime, DO NOT treat your cows with any chemical insecticides. Once the cowherd has been treated, you will no longer be able to identify your best and worst cows.