Feed Supplements Are Worth Their Weight

New Trials Help Cattle Feeders Determine if ZILMAX® or OPTAFLEXX® Offers Greater Value for Their Feedyard

Desoto, KS, August 23, 2011 – Today’s cattle-feeding climate — volatile markets, rising input costs, lower cattle numbers and limited natural resources — requires cattle feeders to continually find opportunities for additional value and to reduce risk.

Reliable technology is key for maximizing inputs and resources while adding marketable value. Feed supplements, including ZILMAX ® (zilpaterol hydrochloride) and OPTAFLEXX® (ractopamine hydrochloride), are helping the beef industry meet today’s growing world demand for beef while minimizing risk in a volatile market.

“Whether selling pounds on the animal or on the carcass, cattle feeders can improve their utilization of natural resources, increase beef production and improve profitability by using the appropriate technology and production practices for their marketing strategy,” says Ty Lawrence, Ph.D., Associate Professor of Animal Science at West Texas A&M University. “Knowing the market greatly impacts which products and practice offers the best return.”

Know the best for your market

Even though they both are feed supplements, improve feedyard efficiencies and deliver carcass value at harvest for steers and heifers, the amount of carcass value and product investment for ZILMAX and OPTAFLEXX differs greatly.

To help cattle feeders evaluate the two products, Merck Animal Health invested in two large-scale feedyard trials conducted using heifers in southern Alberta, Canada, and steers in the panhandle of Texas.

“Outcomes of these two trials — one looking at 3,444 heifers in Canada and the other evaluating 2,788 steers in Texas — were clear. If you’re selling cattle on the live market, feed OPTAFLEXX at the end of the feeding period. If you’re selling on a carcass basis, ZILMAX delivers significantly more carcass value and return on investment to the cattle feeder,” says John Hutcheson, Ph.D., director of technical services for Merck Animal Health.

Tool for selling cattle on the live market

“Live market sellers realize value from the total weight of their cattle, not by carcass weight,” says Dr. Lawrence. “These cattle feeders need to ensure their feed supplement delivers more live weight value than the input costs of the product.”

The additional live weight gain and the product investment make OPTAFLEXX a good value proposition for cattle feeders selling on the live market. The product is fed the last 28 to 42 days on feed and is shown to increase live weight in beef steers an average 17 pounds and hot carcass weight by 14 pounds when fed a 200 milligram dose.

“Even though ZILMAX — with 19 pounds — and OPTAFLEXX — with 17 pounds — deliver nearly the same response in live weight gain, the return on investment with ZILMAX is a breakeven for the live weight market,” says Dr. Hutcheson. “ZILMAX’s real value is realized in its greater contribution — significant increases in carcass value.”

Tool for selling beef on carcass basis

“ZILMAX delivers an average of 33 pounds of carcass weight and 19 pounds of additional live weight when fed for the recommended 20-day feeding period, in beef steers,” says Dr. Hutcheson. “Therefore, to realize the value of product investment, cattle feeders benefit when they sell their cattle based on carcass value.”

In both the steer and heifer head-to-head trials, cattle supplemented with ZILMAX delivered carcasses that were 21 pounds heavier than those from OPTAFLEXX-supplemented cattle, whether fed 200 or 300 milligrams per head per day. Along with additional salable red meat, carcasses from cattle supplemented with ZILMAX improved Yield Grade and provided higher cutability. All of these benefits bring significant value to cattle feeders and down the food chain.

“In today’s market, additional carcass value is a tremendous advantage for feedyards,” says Dr. Hutcheson. “After adding in costs for the product and ration, as well as factoring in premiums and discounts for Yield Grade and Quality Grade outcomes, ZILMAX returned an additional profit of $20.35 per head in the Canada heifer trial and $19.75 per head in the Texas steer trial over OPTAFLEXX.”

The additional carcass value also is complimented by the preservation of the eating quality. Carcasses from heifers fed both ZILMAX and OPTAFLEXX yielded no difference in Warner-Bratzler shear force measurements at 3.51 kilograms — well below meat science established thresholds for consumer satisfaction.

“To stay competitive in the marketplace, cattle feeders rely on proven, safe technologies — like ZILMAX and OPTAFLEXX — to produce sustainable, quality beef,” says Dr. Lawrence. “Matching the right feed supplement to their marketing strategy will yield great results for our cattle feeders.”

About Merck Animal Health

Today's Merck is a global healthcare leader working to help the world be well. Merck Animal Health, known as MSD Animal Health outside the United States and Canada, is the global animal health business unit of Merck. Merck Animal Health offers veterinarians, farmers, pet owners and governments the widest range of veterinary pharmaceuticals, vaccines and health management solutions and services. Merck Animal Health is dedicated to preserving and improving the health, well-being and performance of animals. It invests extensively in dynamic and comprehensive R&D resources and a modern, global supply chain. Merck Animal Health is present in more than 50 countries, while its products are available in some 150 markets. For more information, visit

Legal Notes

ZILMAX® is a trademark owned by Intervet International B.V. or affiliated companies or licensors and is protected by copyrights, trademark and other intellectual property laws. This press release contains information on veterinary products based on international registration dossiers and may refer to products that are either not available in your country or are marketed under a different trade name. In addition, the approved indications as well as safety and efficacy data for a specific product may be different depending on local regulations and approvals. For more information, read the product labeling that applies to your country or contact your local Merck Animal Health representative.

OPTAFLEXX® is a registered trademark of Eli Lilly and Co.