When beta-agonists first came on the market, I observed some strange new problems in fed cattle when they arrived at the packing plant. Brahman crosses, Holsteins, and many other types of cattle had occasional lots where on hot summer days cattle arrived that were stiff and sore footed. A few animals went down and had severe heat stress symptoms. Many people said my reports were just anecdotal.

At a special session during the summer meeting of the National Cattlemen’s Beef Association, the use of beta-agonists was discussed. Lily Edwards-Caloway and Tony Bryant from JBS reported their observations. Lily showed short video clips of feedlot cattle that walked stiffly and were reluctant to leave their pens at the plant. Lily said reports from their plants included observations such as: “tender footed,” “have no energy,” and “variable levels within a lot.” Both the JBS report and my observations showed what I called an “odd unevenness.”


In a particular lot, half the cattle were usually perfectly fine and about 5 percent to 10 percent of the animals had severe problems. All of the previously described observations have been at the plant and the worst problems occurred when cattle had to be removed from the stockyard holding pens to go to the stunner. Myself and others have seen plenty of cattle on beta-agonists at the feedlot that were perfectly fine. The problems often start at the plant. There are also groups of cattle fed beta-agonists that are normal at the plant.

Poor feed mixing is one possible explanation for the “odd uneven” effect. Another possible explanation is differences in feed intake. Another possible explanation for the odd variable bad effects may be interactions with certain types of implants and timing of implants.

It is my opinion that in certain groups of cattle, there are serious animal welfare problems. In the afternoon after the meeting was over, Tyson sent an email stating that they would not accept cattle fed Zilpaterol because some cattle have “difficulty walking or were unable to move.” These problems MUST be corrected. To me, it is discouraging. The meat plants have solved many of their welfare problems and have worked hard to really improve handling. Now they are getting more and more fed cattle that are difficult to move.
At the end of the NCBA meeting, I was asked to give a short statement. I said the stiffness, heat stress, and sore footed problems are NOT acceptable and must be fixed. My final statement at the NCBA meeting was “fix it or lose it” which referred to beta-agonists.

To read more about the use of beta-antagonists and the latest news on the use of feed supplements in the beef industry, check out the next issue of Meat&Poultry, publishing in September.