The Use of Rumensin® Premix in Dairy Cows

Factors Influencing its Effects on Milk Production and Milk Fat Percentage

Abstract

Monensin premix (Rumensin® Premix, Elanco Animal Health, Canada) has been approved in Canada for use in lactating dairy cows since 2004 at a dose range of 8 to 24 ppm (7-22g per ton). Several studies have found that monensin increases milk production and decreases milk fat percentage in lactating dairy cows. Recent research has found that some dietary factors influence the monensin effect on milk production and milk fat percentage. To assist bovine practitioners in making recommendations about the use of monensin in dairy herds, there is a need for knowledge about those dietary factors influencing monensin effects. The objectives of this project were to evaluate the effects of 16 ppm (15g per ton) of monensin on milk production (PROD) and milk fat percentage (MFP), and to find dietary factors influencing those effects.