I suppose that there have been flies as long as there have been cattle. They just seem to attract each other. The significant problem is that by this time of the year there are million of them on our herd and the cattle suffer. They lose weight and risk infection as the flies suck their blood.
We have never found an organic way to eleminate this problem.
The way flies are killed is to put an ear tag on the top of the ear and when the flies land on it they pick up just enough chemical to die. The tag does not inject anything into the cow. The cow is just the carrier of the tag.
Most ranchers use the same type of tag every year and that means you get a population of flies that are not affected any longer to that type of tag. We use tags from a company that has five different types and each year you use a different one.
Normally we use two tags on each cow, but this year they offered an oversize tag that is suppose to do the work of two tags. We shall see.
After a long day of rounding up cattle and getting them into a chute to get the tags we saw a vast difference from when the cattle were in the lane coming into the corral. It cannot be captured in a photo, but there was a black cloud 8-10 feet over the herd of flies following the herd.
The tag will last 3-5 months depending on weather and other environmental conditions. Normally by September we are again working the herd to protect them from flies.
The cattle in the lane headed to the barn. You can not see the black cloud of flies over them, but when you are behind them you are covered with flies ourself.
Once in the corral there is a lot of tail swatting to get the flies off their back.
This is an example of a cows back. Every inch of it is covered like this.
The tag is just a simple plastic device placed on top of the ear for the flies to land on it.
attachment A contented cow knowing in a few moments she will be fly free.