Describe the Issue or Situation.

Beef Deworming Effectiveness Study in Breckinridge County

For years, cattle producers have questioned the effectiveness of dewormers in their herds. The uncertainty surrounding whether dewormers are truly working could be costing producers significantly in lost income. Poor weight gain in calves and underperforming cows can create major setbacks on any farm. To address this issue, Breckinridge County partnered with Dr. Jeff Lehmkuhler and utilized a grant to participate in a Fecal Egg Count Reduction Trial (FECRT). This involved collecting manure samples from farms across three counties to evaluate parasite loads and dewormer effectiveness.

Deworming practices varied widely among farms—from those using two products twice a year, to those that had not used dewormers at all in over three years. Producers and veterinarians alike are seeking a clear answer to the question: “Are my dewormers effective?”

Describe the Outreach or Educational Program Response (and Partners, if applicable).

Education and Local Impact

Breckinridge County alone sells over $13 million in beef animals annually, making herd health a critical economic factor. Educational outreach through local veterinarians and production meetings remains a cornerstone of herd management. However, as in many cases, seeing is believing.

With the cooperation of local producers, we were able to collect the physical proof needed to answer that lingering question. Dr. Jeff Lehmkuhler, Dr. Arnold, and Kevin Johnson (of MERCK) were searching for on-farm trial participants for the FECRT. Once informed about the program and participation requirements, producers and veterinarians began planning ahead to ensure they could be included. Initially, recruitment was difficult as most producers had already worked their herds for the season. However, after understanding the value of the study, many committed to participating in future trials.

Initial Results and Provide the Number and Description(s) of Participants/Target Audience.

In the first year, only 5% of cows tested fell below the trial’s thresholds. Rather than interpreting this as a reason to stop deworming, it was taken as evidence that current deworming practices were effective in the cow herd—a very welcome result.

Calves, however, showed a wider range of results. Pre-deworming fecal egg counts ranged from 1.65 to 172.5 eggs per 3 grams of manure, while post-deworming counts ranged from 0 to 14.85. These were promising outcomes overall. 

Provide a Statement of Outcomes or Program Impact. Please note that the outcomes statement must use evaluation data to describe the change(s) that occurred in individuals, groups, families, businesses, or in the community because of the program/outreach

Years 2 and 3: Adjusting Practices

Following the initial findings, producers were convinced of the need to reevaluate their deworming protocols. During years 2 and 3, many adopted the theory that administering an oral dewormer at the time of weaning could improve calf health.

A follow-up round of fecal testing is scheduled after year 3 to confirm the effectiveness of this adjusted protocol. Regardless of lab results, the practical outcomes are already clear: calves have shown better weaning performance, quicker start to weight gain, and an average 15% increase in weaning weight.