In the many published studies, using either of these two compounds, heifers fed the ionophore gained 0.10 to 0.20 pounds per day more than non-ionophore fed heifers. This yields an increase in feed efficiency of about 8 to 10 percent over non-ionophore fed heifers. Neither product is approved for use in lactating dairy cows, and neither product has a withdrawal period. Bovatec has been used for coccidiosis in sheep and is now approved for control of coccidiosis in cattle less than 800 pounds. Rumensin is approved as a coccidiostat in goats, but not in cattle.
Daily costs are similar for both products.
These should only be considered for use in a replacement feeding program that includes a well-balanced ration. This requires forage testing and ration balancing for several age groups of heifers. Without a balanced ration these additives cannot be utilized to their full potential. In addition, a balanced ration will minimize the chances of over feeding and thus over conditioning heifers when an ionophore is fed.