Without a fly control program in place, horn fly populations can swell up to 4,000 flies per animal. These pests can take up to 40 blood meals per day, leading to reduced weight gain and feed efficiency for your cattle.

Using a fly control solution like Altosid® IGR is one of the most powerful tools you have to fight against such a damaging and costly fly infestation. Working as a feed-through fly control product, the active ingredient (S)-methoprene is passed through to the manure, where horn flies lay their eggs— interrupting the fly life cycle.

Fly activity is influenced heavily by weather, and spring time means fly time. The warmer temps mark the start of fly season when overwintering horn flies start to emerge, ready to feed on cattle with painful bites and spread disease-causing bacteria.

To achieve the best results with Altosid® IGR and limit flies on cattle, we recommend following the 30/30 approach with just 3 easy steps:

  1. Know when to start feeding Altosid® IGR, which is approximately 30 days before the average daily daytime temperatures reach 65°F. This is when overwintering flies emerge.

  2. Continue feeding Altosid® IGR through the fall, 30 days after the first frost has been recorded. This is to help reduce overwintering pupae, giving you a jump start on the next fly season.

  3. Monitor fly populations, and supplement your efforts with a horn fly insecticide such as Prolate/Lintox-HD™ insecticidal spray to reduce the adult fly population if needed.

To learn more about our recommended approach to horn fly control, download our 30/30 White Paper.

Back to Blog