Dr. Bill Weiss, Dairy Nutrition Specialist, The Ohio State University (top of page) pdf file
The proper use of footbaths can be an effective component of a herd’s hoof health program. Digital dermatitis (also referred to as hairy heel warts, heel warts, etc.) and hoof rot are two hoof problems that can be controlled by the use of foot baths. The predominant active ingredient in most footbaths is copper sulfate and is quite effective. However, the cost of copper sulfate is high and because used foot bath solution is usually dumped into the manure stream, excessive copper loading of soils can occur when the manure is spread on fields. A recent study (Speijers et al., 2010. Journal of Dairy Science) evaluated different aspects of using copper sulfate footbaths. In one study, a 2% copper sulfate solution was compared with a 5% solution (both used for 4 consecutive milkings once per week) on cows that had a very high prevalence of digital dermatitis (65% of the cows had an active lesion on at least one foot). In a second study with cows that had a lower prevalence of digital dermatitis (~20% of the cows had an active lesion on at least one foot), the same comparison was made except cows walked through the footbath 4 consecutive milkings every other week.
A typical footbath holds 40 to 50 gallons of solution and should be changed after 150 to 300 cows walk through it. For a 200 cow herd that uses a footbath 4 consecutive milkings once a week, reducing the copper sulfate from 5% to a 2% would save about 2200 lb of copper sulfate per year. If the herd changed from a 5% solution weekly to a 2% solution every 2 wk, copper sulfate use would be reduced by about 3000 lb annually. However, these savings in copper sulfate must not come at the cost of increased hoof problems. The major findings of this study were:
- When a group of cows with a high prevalence of digital dermatitis walked through a footbath 4 consecutive milkings once weekly, both the 2 and 5% copper sulfate solution significantly decreased digital dermatitis, but the 5% solution had a slightly greater effect. The prevalence decreased from 69 to 13% over an 8 week period (82% decrease) with the 5% solution and decreased from 66 to 18% (73% decrease) with the 2% solution. Overall, if cows are walking through a footbath once weekly for 4 consecutive milkings, a 2% solution appears to be acceptable.
- When a group of cows with a moderate prevalence of digital dermatitis walked through a footbath 4 consecutive milkings every other week, a 5% solution was much more effective than a 2% solution. Prevalence of cows with an active lesion for digital dermatitis decreased from 20% to 7% (65% decrease) over an 8 week period when a 5% solution was used but only decreased 36% (from 22 to 14%) when a 2% solution was used.
Bottom line: Reducing the concentration of copper sulfate from 5 to 2% may not greatly affect the efficacy of a footbath when used weekly but will greatly reduce cost and environmental impact. On the other hand, reducing the frequency of using a footbath from weekly to every other week had a substantial negative effect on efficacy and a 2% solution was not adequate.