USDA NAHM's Beef Survey Reveals Declining Efficacy Of Popular Dewormers

CattleNetwork
December 7, 2009

Pour-on dewormers commonly used by beef producers simply are not working like they used to, according to new research data from the U.S. Department of Agriculture (USDA) National Animal Health Monitoring System (NAHMS) Beef 2007-2008 cow-calf survey.

The NAHMS survey compiled valuable information on health, production and management practices - including use of anthelmintic dewormers - in the U.S. beef industry. In a presentation to members of the Academy of Veterinary Consultants (AVC), Bert Stromberg, Ph.D., Professor of Parasitology at the University of Minnesota, presented key findings from the NAHMS study on the effectiveness of anthelmintic treatment programs.

According to the producer survey, about 80 percent of beef producers use anthelmintic dewormers at least once per year on their cows.

"The vast majority of producers that deworm are doing so based on a set schedule as opposed to using any type of diagnostics to help them make decisions on whether they really need to deworm or if their program is working," says Stromberg. "And less than 6 percent of producers do any sort of fecal testing to evaluate the efficacy of their deworming program."

The survey also reveals that while a vast majority of producers deworm their adult cows, far fewer deworm what Stromberg would suggest are the most important animals from an economic and physical standpoint-the calves, replacement heifers and stockers. Data show that only 70 percent of operations deworm their replacement heifers at least once per year; 55 percent deworm weaned stockers at least once per year; and only 53 percent deworm their preweaned calves at least once per year. Younger animals are more susceptible to health and production losses due to subclinical parasitism, as their immune response is underdeveloped.

Full text: http://tinyurl.com/y89p8b4