Cow footbaths: maximising detergent effectiveness
For a cow footbath to be effective, the disinfectant needs to be able to reach the skin, and for long enough. This page takes you through considerations for making sure this happens.
How clean are your cows’ feet?
No footbath will be effective when dirt is caked on the skin so the disinfectant cannot reach it. Pre-bathing in water (or a weaker disinfectant solution) can help clean the feet before the main disinfectant bath, but power washing is better.
An automated jet-wash bath can be useful for cleaning heels, and it also reduces splash on the teats and udder.
The areas immediately before and after the footbath are important - many footbaths fail because these passageways are deep in slurry. Positioning your footbath over a slatted passageway is a good way to avoid this. If you choose to use a cleaning pre-bath, separate it from the main footbath by at least 3 to 5 metres to allow water to drain off the feet before the cows enter the solution bath. This separation also reduces faecal contamination in the solution bath.
How many cows can pass through the bath before replenishment?
Dirty feet and dirty passageways before the bath inevitably lead to greater contamination, and the more cows that pass through before the disinfectant is replenished, the less effective it will be. Here’s what to keep in mind:
- Good cow flow helps reduce mucking in the bath and will ensure a better solution contact time. Stressed cows (with their heads up) are more likely to muck in the bath.
- Chemicals are generally stripped out of the bath as cows pass through and the chemical binds to their feet. Topping up with extra chemical throughout use can be helpful, but it takes guesswork to know how much to add to maintain the correct dilution. It’s better to replenish the whole bath regularly with a fresh solution using the correct dilution rate.
- A good rule of thumb is not to have more than one cow passage per litre of solution before replenishing. For example, a 300-litre bath is good for a maximum of 300 cow passages.
Some baths regularly replenish the solution automatically, either on a timer or on a cow-count basis. These are particularly useful for larger herds, but you will need to maintain them carefully to ensure that they automatically empty and refill properly.
Very cold water makes most chemicals less effective, so bear this in mind when footbathing in the winter. Warm weather means that volatile chemicals such as formalin evaporate sooner, so will quickly become ineffective if the solution is not freshly prepared.
Beware of high contamination for permanent footbaths, such as those cited at cross-overs in cubicle houses, or baths placed at the exit gates of robotic milkers. These can become grossly contaminated, and more quickly than you might think, as normal cow traffic soon exceeds the ‘one cow per litre’ rule.