Use of approved beta agonists in the United States for promotion of growth and lean-meat yield has created challenges in the global market, such as current trade barriers in Russia. During last week’s Cattle Feeders Business Summit hosted by Merck Animal Health in Denver, Merck nutritionist David Yates, PhD., outlined some of the issues surrounding these products, which cattle feeders add to rations during the final days of finishing for improved performance and carcass value.

There are two beta agonists approved for use in cattle in the United States. Optaflexx (ractopamine), which FDA approved in 2003 and Zilmax (zilpaterol hydrochloride), which gained approval in 2006.

Beta agonists and tradeBeta agonists have been used in human medicine for a much longer time, as bronchial dilators for treatment of asthma.

Another beta agonist, clenbuterol, is not approved for use in food animals in the U.S., and sometimes causes sometimes causes confusion about other beta agonist products. Clenbuterol is approved for use as a bronchial dilator in horses, but is sometimes used illegally as a growth promotant in cattle in Asia and other parts of the world. The product stimulates dramatic muscle growth, and in parts of Asia is known as “lean-meat powder.” However, Yates says, clenbuterol accumulates in animal tissues and residues in meat can be toxic to humans.

Zilmax and Optaflexx do not accumulate in animal tissues and have been shown through extensive testing to be safe at the dosages used in livestock production. Yates says a human would need to consume 3.75 tons of Zilmax-fed beef to equal a single asthma-inhaler dose of a similar human medication – albuterol – for a four-year-old child.

Yates sees Russia’s ban on beef products from animals fed beta agonists as primarily a politically motivated non-tariff trade barrier intended to protect the country’s domestic pork industry. Russia has been a top customer for U.S. beef livers for example, but now most livers are going to Egypt at a reduced price.

One of the challenges created by Russia’s ban is that cuts from a single animal typically go to various markets based on demand and value. Meat companies direct cuts from the overall mix of animals to those markets, rather than specifying cattle production practices for a specific market. One exception is the European Union, which typically imports entire carcasses to meet its requirements for beef raised without hormones or beta agonists.

Merck has taken a country-by-country approach toward gaining international approvals for Zilmax-fed beef. Countries currently allowing the technology primarily are in North and South America and Southern Africa. Yates sees potential for approvals in Asia and Australia, but is less optimistic about Europe and Russia. The company also has applied for global approval through the Codex Alimentarius Commission