This report represents the first trial of a study consisting of a commercial mixture of functional oils (Essential, Oligo Basics USA LLC, Wilmington, DE) used alone and in combination with Monensin to evaluate the effects on steers performance when fed a high concentrate diet. One hundred and twenty steers, average initial weight 322 kg, were divided into five treatments with four pens per treatment and six steers per pen. The treatments were Control (C), Monensin (223 mg/hd/d) (M), Monensin (223 mg/hd/d) + Essential (250 mg/kg DMI) (ME), Essential Low (250 mg/kg DMI) (EL), and Essential High (500 mg/kg DMI) (EH). All steers were fed the same diet on an ad libitum basis, treatments M and EL for 172 days and treatments C, ME, and EH for 179 days. Steers were harvested at an average weight of 617 kg. Results to date suggest that cattle provided functional oils in their diet perform equally as well in the feedyard and in carcass composition as cattle provided a more traditional ionophore in their diet.