Ask the Vet

Face Fly Controls and Pregnant Cows

For many producers a cattle mineral with an additive for face flies is one part of an integrated pest management program. (Progressive Farmer photo by Victoria G. Myers)


I have been using loose cattle mineral with an additive for fly control. It will only control horn flies. I want to switch to another product to help control face flies, but both the loose mineral and the supplement blocks I can find that will do this contain the active ingredient Rabon. The label says before using Rabon with pregnant or nursing cows, you are supposed to consult a veterinarian. I have a small cow/calf operation, and most of our cattle are pregnant or nursing, so I'm not sure what to do. I don't use ear tags, but I do use a fly rub-scrub with strips and bullets on it. I also make direct applications on an as-needed basis. These products are permethrins.


You are correct that Rabon can help with the control of face flies. I talked to a veterinarian at Bayer, and he is confident the product is safe when used according to the label. It has been used for more than 50 years, and a lot has gone into pregnant cows. We do advise calling the mineral company to see what its concerns are. I think you would be fine using it, but I would like to know what the company has to say.

Another option is a newer product, ClariFly, that is labeled as an aid for control of houseflies, horn flies, face flies and stable flies. I know it is offered in minerals and blocks, and as a premix. Keep up the integrated pest-management program. You are right on track.