Observations on the design and use of footbaths for the control of infectious hoof disease in dairy cattle.

A survey of 65 freestall-housed dairy herds in five different countries, with an average of 1023 milking cows, found that footbaths were used 1-4 times per day for 1-7 days per week, with between 80 and 3000 cows passing through the bath between chemical changes. The most common agents used were copper sulfate (41/65) and formalin (22/65). Twenty-seven herds (42%) used more than one chemical. The median footbath measured 2.03 m long by 0.81m wide, and was filled to a depth of 0.11 m with a volume of 189 L (range 80-1417 L). An observational behavioral study was conducted using a custom-designed footbath to test four different bath dimensions, with two different step-in heights. The number of immersions per rear foot was counted for each footbath design for each cow passing through the bath on two consecutive days. While a higher step-in height significantly increased the number of foot immersions, the effect was small compared to the effect of length. The probability of each rear foot receiving at least two immersions reached 95% at a bath length of 3.0m, and a significant increase in the frequency of three and four immersions per foot was observed between 3.0 and 3.7 m. In order to optimize the number of foot immersions per cow pass, while limiting the footbath volume, this study recommends a bath 3.0-3.7 m long, 0.5-0.6m wide, with a 28 cm step-in height.