eXtension does not endorse specific products. However, feed-through insecticide supplements work very well to control the fly population in stables when used correctly and fed according to label instructions. Feed-through insecticides are administered at specific levels in the animal's feed and pass through the feces, making the manure toxic to developing maggots and thus reducing fly production from manure. It is important to feed according to the instructions on the label and feed the appropriate amount of the supplement on a daily basis. Some of the products on the market are listed below by common name and the brands that they are sold under:

Cyromazine --- Serene, Solitude IGR
Diflubenzuron --- Equitrol II Feed-Thru Fly Control, SimpliFly with LarvaStop Feed-Thru Fly Control
Stirofos --- Equitrol Feed-Thru Fly Control

It is also important to note that additional fly control measures in and around your stable should also be followed, including frequent stall cleaning, removing manure piles regularly, composting manure, eliminating wet areas, keeping feeds stored tightly, etc.