Oiler

A cattle oiler applies insecticide to animals as they pass under or against it. The oiler is set in a doorway, a lane or a gate that cattle walk through regularly, and the rubbing action does the application.

That takes fly control out of the chute and puts it in the daily routine. Cattle rub as they pass, and the herd gets treated without being penned and handled.

Oilers work best where cattle already travel: between pasture and water, or along a lane to shade. Placement is most of the job, since an oiler in a spot cattle avoid treats nothing. Check and refill the oiler regularly, and follow the label on whatever insecticide is used.