JustiFLY Feedthrough is an insect growth regulator (IGR) larvicide available for use on-farm that effectively treats horn flies as well as disease-caring face flies, biting stable fly and nuisance houseflies. JustiFLY Feedthrough add-pack is priced to allow beef and dairy producers cost-effective fly control by stopping the larvae from developing once in contact with treated manure. The add-pack allows producers full-season fly control while utilizing their own specific mineral choice. There's no longer a need to change minerals to economically include fly control. It is also ideal for pastures and calf hutches where knocking down horn fly populations is critical to animal comfort, weight gains and feed conversion. JustiFLY Feedthrough in a convenient 360-gram (12.7-ounce) add-pack for use with free choice minerals to control flies on pasture and confinement cattle. The economically priced 360-gram add-pack treats one 50-lb. bag of free choice mineral. Justifly Feedthrough - Part high-tech killing machine, part economic stimulus plan.