Fecal Egg Count To Determine Deworming Treatment: Lessons Learned

By Frank Wardynski

Fecal egg count (FEC) has been shown to be an effective tool in determining if cattle should be dewormed at the beginning of the grazing season. Farmers that utilize FEC can feel confident they are making good decisions regarding their deworming practices.

Cattle with egg counts below threshold levels do not need to be treated. Treating animals with low FEC results in money spent on deworming products with no significant improvement in animal performance. In addition, treating animals with low egg levels can lead to anthelmintic resistance. Conversely, treating animals with high FEC will offer cost effective improvement to animal performance.

During 2016, Michigan State University Extension educators Frank Wardynski and Kable Thurlow conducted a state-wide testing program for beef cattle. Early results indicate that many cows exhibit low FEC and do not require treatment. Many mature beef cows have developed immunity to internal parasites. However, younger cattle including weaned beef calves and replacement heifers, exhibited higher FEC and are more likely to benefit from treatment according to last year’s data.

Manure samples can also be collected to determine if deworming treatment has proven to be effective. Comparing FEC samples collected at time of treatment and two weeks post-treatment allows evaluation of product effectiveness. Anthelmintic resistance is common in small ruminants and is being observed more frequently in cattle. Producers using the same class of dewormer annually are more at risk of having anthelmintic resistance in their herd.

The testing program will continue through 2017. The lab analysis is free to cooperative producers. The only cost to producers is the expense of shipping the samples. Protocols are already developed and can be sent out immediately.

Source:msu.edu