Zilmax (zilpaterol hydrochloride) - Consumer Information Center

U.S. audiences only.

You have JavaScript disabled

This may result in reduced functionality and affect the graphical presentation of this site.
However, all content will still be available.

Answers About Zilmax^®

Sort by Topic

What is Zilmax?

Zilmax is an FDA-approved feed supplement. It helps cattle convert what they eat into more lean beef^1,4,5 that is consistently flavorful, tender and juicy.^2,3 With Zilmax, farmers can raise more beef from fewer cattle – and that helps keep beef affordable.^1,7

Keeping beef affordable.

With nearly one in five U.S. families struggling to put food on the table, we need an adequate beef supply to help keep it affordable. U.S. Farmers grow another 105 semi-loads of boneless beef per week when feeding Zilmax⁶, helping create a greater supply of beef¹ to help keep beef prices in check for all of us.⁷

Read more

Results of studies answer an industry question and confirm Zilmax safety

Despite years of safe use, a question was raised about Zilmax's impact on animal well-being. Animal scientists from USDA and seven independent universities evaluated the well-being of cattle fed Zilmax in multiple scenarios. Their findings, and an evaluation of the specific incident, reaffirmed that Zilmax had no impact on the animal well-being issue that had been raised. ²⁹

Read more
Listen to Dan Thomson, DVM, PhD, Kansas State University

How is the environment impacted?

Zilmax helps farmers conserve our natural resources⁸ because they can provide more beef with fewer cattle. Fewer cattle = less waste, and less use of energy, land and water.⁹

Read more

Who benefits from
the use of this
feed supplement?

We all do. Zilmax helps farmers provide beef that is:

Flavorful, tender and juicy.^2,3
An affordable choice for you and your family.⁷
Raised using fewer natural resources.⁸

Expert opinion:
The safety of beef from cattle fed this supplement.

Listen to Richard Raymond, M.D., former USDA Food Safety Undersecretary.

Zilmax supports a sustainable beef supply

Zilmax helps farmers raising beef conserve natural resources⁸, has been shown to be safe for cattle¹ and increases the supply of beef available for consumers, keeping prices affordable.⁷

Read more

Is it safe for cattle?

Yes. The FDA, Canadian Food Inspection Authority and other international scientific authorities have approved Zilmax as a safe and effective feed supplement for cattle.¹

Read more

We believe in continuous improvement.

A recent FDA Zilmax approval allows cattle farmers a more convenient and efficient method of feeding this supplement.

Read more

How much research has been done on cattle safety?

More than 65 animal safety and well-being studies – evaluating 182,555 cattle – confirm Zilmax has no negative effect on animal well-being.^1,10-20

Read more

Which experts evaluated the well-being of cattle?

Animal scientists from the USDA and seven independent universities evaluated Zilmax's impact on the key indicators of animal well-being:

USDA-ARS Livestock Issues Research Unit
Colorado State University
Kansas State University
New Mexico State University
Oklahoma State University
Texas Tech University
University of Nebraska-Lincoln
West Texas A&M University

Is the quality and taste of the beef the same?

Yes. Consumers like you sampled and enjoyed steaks from cattle fed Zilmax in the largest grilled steak taste-test study ever. The results showed that consumers rated beef from cattle fed the supplement as flavorful, tender and juicy² – the same when compared to beef from cattle that were not fed the supplement.

Read more

Beef quality:
"... consumers found no difference ..."

Listen to Chance Brooks, Ph.D., Associate Professor of Meat Science at Texas Tech University, explain results from consumer taste panels.

Can I expect a difference in tenderness?

No. Most consumers participating in taste panels could not detect a difference between steaks from cattle fed Zilmax and steaks from cattle not fed Zilmax.²

Read more

What impact does Zilmax have on the tenderness of beef?

Where else is Zilmax used?

Zilmax is approved for use in most of the major beef producing countries. Its first use dates back 20 years.

Read more

Is the beef from cattle fed this supplement safe to eat?

Yes. It's safe to eat the beef from cattle fed Zilmax. More than 30 years of research and development, as well as rigorous testing, support the safety of Zilmax. The FDA reviewed this research and concluded that beef from cattle fed Zilmax is safe.¹

Read more

Is the beef from cattle fed Zilmax safe to eat?

Merck Animal Health
beef@merck.com

REFERENCES

IMPORTANT SAFETY INFORMATION

Zilmax has a withdrawal period 3 days prior to slaughter. Not for use in animals intended for breeding. Do not allow horses or other equines access to feed containing zilpaterol. Do not use in veal calves. Not to be fed to cattle in excess of 90 mg zilpaterol/head/day in complete feed. If pen consumption of complete feed exceeds 26.5 lb/head/day (90% dry matter basis), zilpaterol should not be fed in complete feed.

For complete safety information, please refer to the product label.

References

FDA. Freedom of information summary. Original new animal drug application NADA 141-258. Zilmax (zilpaterol hydrochloride) Type A medicated article for cattle fed in confinement for slaughter. http://www.fda.gov/downloads/AnimalVeterinary/Products/ ApprovedAnimalDrugProducts/FOIADrugSummaries/ucm051412.pdf. 2006. Accessed Apr. 26, 2007.
Mehaffey, J. M., Brooks, J. C., Rathmann, R. J., Alsup, E. A., Hutcheson, J. P., Nichols, W. T., Streeter, M. N., Yates, D. A., Johnson, B. J. and Miller, M. F. Effect of feeding zilpaterol hydrochloride to beef and calf-fed Holstein cattle on consumer palatability ratings. J. Anim. Sci. 2009. 87:3712-3721.
Hilton, G. G., Montgomery, J. L., Krehbiel, C. R., Yates, D. A., Hutcheson, J. P., Nichols, W. T., Streeter, M. N., Blanton Jr., J. R. and Miller, M. F. Effects of feeding zilpaterol hydrochloride with and without monensin and tylosin on carcass cutability and meat palatability of beef steers. J. Anim. Sci. 2009. 87:1394-1406.
Hilton, G. G., Garmyn, A. J., Lawrence, T. E., Miller, M. F., Brooks, J. C., Montgomery, T. H., Griffin, D. B., VanOverbeke, D. L., Elam, N. A., Nichols, W. T., Streeter, M. N., Hutcheson, J. P., Allen, D. M. and Yates, D. A. Effect of zilpaterol hydrochloride supplementation on cutability and subprimal yield of beef steer carcasses. J. Anim. Sci. 2010. 88:1817-1822.
Boler, D. D., Holmer, S. F., McKeith, F. K., Killefer, J., VanOverbeke, D. L., Hilton, G. G., Delmore, R. J., Beckett, J. L., Brooks, J. C., Miller, R. K., Griffin, D. B., Savell, J. W., Lawrence, T. E., Elam, N. A., Streeter, M. N., Nichols, W. T., Hutcheson, J. P., Yates, D. A. and Allen, D. M. Effects of feeding zilpaterol hydrochloride for twenty to forty days on carcass cutability and subprimal yield of calf-fed Holstein steers. J. Anim. Sci. 2009. 87:3722-3729.
Data on file.
Schroeder, T. C. and Tonser, G. T. Economic impact of Zilmax adoption in cattle feeding. J. Agri. Res. Econ. 2011. Volume 36, Number 3.
Capper, J. L. and Hayes, D. J. The environmental and economic impact of removing growth-enhancing technologies from United States beef production. J. Anim. Sci. 2012. 90:3527-3537.
Capper, J. L. The environmental impact of beef production in the United States: 1977 compared with 2007. J. Anim. Sci. 2011. 89:4249-4261.
Woiwode, R. and Grandin, T. Field study on the effect of zilpaterol on the behavior and mobility of Brahman cross steers at a commercial feedlot. Final Report to the National Cattlemen's Beef Association. 2013.
Frese, D. A., Reinhardt, C. D., Bartle, S. J., Rethorst, D.N., Bawa, B., Thomason, J. D., Loneragan, G. H. and Thomson, D. U. Animal health and animal welfare implications of beta adrenergic agonists (BAA) in feedlot cattle. Final Report to the State Beef Councils. 2014.
Hales, K. E., Shackelford, S. D., Wells, J. E., King, D. A., Hayes, M. D., Brown-Brandl, T. M., Kuehn, L. A., Freetly, H. C. and Wheeler, T. L. Effects of feeding dry-rolled corn-based diets with and without wet distillers grains with solubles and zilpaterol hydrochloride on performance, carcass characteristics, and heat stress in finishing beef steers. J. Anim. Sci. 2014. 92:4023-4033.
Merck Animal Health, Research on file, Report #2014-7: The effects of technology use in feedlot production systems on the behavior and mobility of finishing steers.
Merck Animal Health, Research on file, Report #2014-7: The effects of technology use in feedlot production systems on heat stress of finishing steers.
Merck Animal Health, Research on file, Report #2014-7: The effects of technology use in feedlot production systems on health parameters of finishing steers.
Merck Animal Health, Research on file, Report #2014-9: The effects of Zilmax on the general well-being of feedlot cattle.
Merck Animal Health, Research on file, Report #2014-9: MRI provides objective diagnosis of hoof health in feedlot cattle supplemented with Zilmax.
Merck Animal Health, Research on file, Report #2014-9: The effects of Zilmax on various physiological indicators of thermal regulation in black-hided feedlot steers and heifers during moderate heat stress.
Merck Animal Health, Research on file, Report #2014-5: Objective movement of calf-fed Holstein steers fed in confinement when supplemented with Zilmax.
Samuelson, K. L., Hubbert, M. E. and Loest, C. A. Effects of Zilmax on performance, carcass characteristics and traveling ability of crossbred steers consuming rations with different concentrations of urea. New Mexico State University, Clayton Livestock Research Center, Agriculture Experiment Station, U.S. Department of Agriculture. April 2014.
Merck Animal Health, Research on file, Report #2012-2: Consumer assessment of steaks aged for 14 or 21 d post-mortem from high-quality, black-hided British finishing steers fed zilpaterol hydrochloride, ractopamine hydrochloride, or no beta-agonist.
Guelker, M. R., Haneklaus, A. N., Brooks, J. C., Carr, C. C., Delmore, R. J., Griffin Jr., D. B., Hale, D. S., Harris, K. B., Mafi, G. G., Johnson, D. D., Lorenzen, C. L., Maddock, R. J., Martin, J. N., Miller, R. K., Raines, C. R., VanOverbeke, D. L., Vedral, L. L., Wasser, B. E. and Savell, J. W. National Beef Tenderness Survey-2010: Warner-Bratzler shear force values and sensory panel ratings for beef steaks from United States retail and food service establishments. J. Anim. Sci. 2013. 91:1005-1014.
Voges, K. L., Mason, C. L., Brooks, J. C., Delmore, R. J., Griffin, D. B., Hale, D. S., Henning, W. R., Johnson, D. D., Lorenzen, C. L., Maddock, R. J., Miller, R. K., Morgan, J. B., Baird, B. E., Gwartney, B. L. and Savell, J. W. National Beef Tenderness Survey-2006: Assessment of Warner-Bratzler shear and sensory panel ratings for beef from US retail and foodservice establishments. Meat Sci. 2007. 77:357-364.
Brooks, J. C., Belew, J. B., Griffin, D. B., Gwartney, B. L., Hale, D. S., Henning, W. R., Johnson, D. D., Morgan, J. B., Parrish Jr., F. C., Reagan, J. O. and Savell, J. W. National Beef Tenderness Survey-1998. J. Anim. Sci. 2000. 78:1852-1860.
Morgan, J. B., Savell, J. W., Hale, D. S., Miller, R. K., Griffin, D. B., Cross, H. R. and Shackelford, S. D. National Beef Tenderness Survey. J. Anim. Sci. 1991. 69:3274-32.
National Cattlemen's Beef Association. Project Summary. Retail Beef Tenderness Surveillance. National Cattlemen's Beef Association, Centennial, CO. http://beefresearch.org/CMDocs/BeefResearch/PE_Project_Summaries/12_Retail_beef_tenderness_surveillance.pdf. 2013. Accessed Feb. 12, 2015.
United States Department of Agriculture. Agricultural Marketing Service. Beef Grading Historical Records. http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELDEV3023642. Accessed December 01, 2014.
National Agricultural Statistics Service. Agricultural Statistics Board. United States Department of Agriculture. Cattle. http://usda.mannlib.cornell.edu/usda/nass/Catt//2010s/2014/Catt-01-31-2014.pdf. 2014. ISSN: 1948-9099. Accessed February 24, 2015.
Thomson, D. U., Loneragan, G. H., Henningson, J. N., Ensley, S. and Bawa, B. Special Report: Description of a novel fatigue syndrome of finished feedlot cattle following transportation. JAVMA. July 1, 2015. 247:66-72.
Food and Agriculture Organization of the United Nations, Statistics Division. http://faostat3.fao.org/download/Q/QL/E. Accessed November 11, 2015.