In a Canadian study published in the July 2017 issue of Journal of Dairy Science, researchers compared a quaternary ammonium compound-based (QAC) footbath to a more conventional copper sulfate (CuSO4) footbath. Five farms used a standard 5% footbath concentration of CuSO4. Another five farms used a 1% footbath concentration of QAC (per the manufacturer’s recommendation). An additional five farms that did not alter their standard hoofcare routine were also included. These dairies averaged 143 cows and a prevalence of active digital dermatitis (DD) lesions (hairy warts) of 15%. The protocols for the CuSO4 and QAC interventions had cows walking through freshly prepared footbaths once a day after milking Monday–Friday for 12 consecutive weeks.
In the CuSO4 group, the prevalence of chronic DD lesions decreased over the 12 weeks of the study. For the QAC group, chronic DD lesion prevalence decreased at the same rate for weeks 0–6, but then leveled off between 6 and 12 weeks. The QAC treatment also did not decrease the proportion of cows with active DD lesions. The researchers concluded that QAC was inferior to CuSO4 for footbath control of hairy warts. This is unfortunate, as a viable alternative to CuSO4 would be useful to reduce the amount of copper that ends up in pastures and crop fields (via manure handling and application systems).