With more than 40 years of proven success, Altosid® IGR isn’t merely a leader among the class of feed-through insect growth regulators (IGRs). It created the class. The gold standard in horn fly control since 1977, there have been no reported cases of resistance, which means you can rest easy knowing Altosid® IGR has you and your cattle covered in the fight against horn flies. Read more about how you can protect cattle from horn flies with the original feed-through fly control below.