ULTRA SABER(TM) Pour-On is not recommended for use on veal calves. ULTRA SABER Pour-On is not effective in controlling cattle grubs. Therefore, this product can be used on cattle at any time of the year without fear of host-parasite reactions commonly associated with grub treatment products. ULTRA SABER Pour-On should be used in an integrated pest management system, which may involve repeat treatments and the use of other pest control practices. Continual exposure of horn flies to a single class of insecticide, (eg, pyrethroids or organophosphates) may lead to the development of resistance to that class of insecticide. In order to reduce the possibility of horn flies developing resistance, it is important to rotate, on a seasonal basis, the class of insecticide used and/or the method of horn fly control. For advice concerning current control practices with relation to specific local conditions, consult resources in resistance management programs and your Cooperative Agricultural Extension Service. | Merck Ultra Saber Pour-On Insecticide for Beef Cattle and Calves | Size 30 oz