Many beef producers are more mindful of complete insect control in late winter due to the threat posed by the disease Theileria, which is carried by the Longhorn Tick. Indeed, we sometimes see ticks on cattle during herd checks before the official start of Spring.
If you have not already added an IGR to your mineral, it should be added as soon as possible. The IGR has very limited efficacy when added later in the season. Pour-ons and back rubs can also be set up to help with control. Environmental management by preventing build up of manure near cattle can reduce fly populations. Do not use pour-on dewormers for fly control. Not only is this costly from an economic standpoint, your dewormers will quickly lose efficacy against worms due to the development of resistance. We have very few effective families of dewormers available, so we must use them judiciously to preserve their efficacy.
We typically recommend waiting until June 1 to place insecticide fly tags so that they remain effective through the fall fly season. We have had a few producers place them in March this year with the intention of replacing them mid-summer when they reach the end of their period of efficacy. Early placement has been in hopes of reducing transmission of Theileria through season-long tick control. Always place the appropriate number of tags per animal and remove them at the end of their effective period to reduce the development of resistance to the insecticide.