The University of Calgary Lameness Research Team has been hard at work studying the use and effectiveness of footbaths on Alberta dairies.
While there is progress to be made in proper usage, the good news is: Results indicate footbaths are an effective tool in decreasing the prevalence of digital dermatitis (DD).
Let’s look at lesions
As part of the Alberta Dairy Hoof Health Project, seven Hoof Supervisor®-equipped trimmers collected data from 158 dairy farms over a 3½-year period. A total of more than 40,000 cows were examined by the trimmers. Of those, approximately 50 percent had a claw lesion. Similar data was collected in British Columbia and Ontario (Table 1).
The most common lesion in all three provinces was digital dermatitis (43 percent), followed by non-infectious causes like sole ulcer and white-line disease (Figure 1).
When it comes to most infectious claw lesions (DD, interdigital dermatitis, foot rot, heel horn erosions), the causes are multifactorial, although for all, hygiene is very important. Therefore, footbaths play an important role in control and prevention of these diseases.
Are footbaths falling short?
Another study led by our research team evaluated three critical aspects of a functional footbath on dairy farms: dimensions, refreshing and refilling of solutions, and products used.
University of Wisconsin researchers recommend a footbath 3 to 3.7 metres (10 to 12 feet) long and 0.5 to 0.6 metres (20 to 24 inches) wide, with a 28-centimeter (11-inch) step-in height (see article ‘An optimum footbath design’).
These dimensions optimize the number of foot immersions per cow pass, while limiting the footbath volume. In a study done in Alberta, the average dimensions of footbaths on dairies was 222 centimeters (7.3 feet) long by 76 centimeters (30 inches) wide by 16 centimeters (6.3 inches) deep.
In other words, most footbaths fell short of the recommended length, which is a critical factor for ensuring adequate coverage of all four feet as the cow passes through. However, most were deep enough to dunk the entire foot, providing more than 10 centimeters (4 inches) of coverage (Figure 2).
Refreshing and refilling of footbath solution
It is recommended to run a footbath twice a week or more and to refresh solution after every 200 cow passes. (Keep in mind, this number is somewhat variable and should be optimized for each farm, taking into account herd size, contamination with organic material, temperatures, etc.). Most dairies in our study are meeting those minimums (Table 2).
While copper sulphate is most commonly used on dairies as their main protocol, some use it in combination with formalin. Most follow one protocol (Table 3).
DD can ‘decrease dramatically’ with proper footbaths
In a separate study, University of Calgary Ph.D. student Casey Jacobs sought to determine how implementing a footbath affected the prevalence of DD infections. Ten Alberta dairy farms were enrolled in the following program:
- Five farms were assigned to an intensive copper sulphate protocol (5 percent solution, once a day, Monday through Friday; DD lesions scored on hind feet of all lactating dairy cows every three weeks*).
- Five farms did not change their previous footbath protocol (non-interference; DD lesions scored on hind feet of all lactating dairy cows every six weeks*).
- Controlled concentration and programmed refreshing of footbath solutions.
*Scoring was done in the milking parlour using the M-scoring system that classifies the foot in five categories: M0 (no lesions), M1 (small early lesion), M2 (larger active lesion), M3 (healing lesion), M4 (chronic lesion) and M4.1 (chronic lesion, with an active M1 lesion).
The farms that used the intensive copper sulphate footbath protocol experienced a decrease of all DD lesion stages and maintained a low prevalence of active lesions compared to farms with less specific and less frequent protocols – irrespective of product used.
Optimal frequency of footbath use to maintain low DD occurrence appeared to be greater than twice a week – regardless of product used. This frequency results in active DD occurrence equal to the intensive copper sulfate protocol.
To evaluate what happens to the prevalence of DD if a standardized footbath is implemented, a follow-up study was conducted on nine Alberta farms by Ph.D. student Laura Solano. The prevalence of DD in the lactating herds was followed over a period of four months. DD scoring was done every two weeks in the milking parlour and confirmed with observations in the trimming chute.
Two months after the start of the study, an automated footbath was implemented, with a computer-based weekly protocol of two consecutive days (four milkings) using 5 percent copper sulphate.
Controlled concentration and programmed refreshing of footbath solutions resulted in a decrease in DD on these dairy farms. All farms had a significant increase in M0 scores from 31 to 40 percent, whereas cows diagnosed with active M2 lesions transferred to more chronic stages of the infection (M3 and M4).
Cows affected with active M2 lesions decreased from 41 to 25 percent, whereas M3 and M4 lesions increased from 28 to 35 percent. This shows that when footbaths are well designed and carefully used, the prevalence of active DD lesions will decrease dramatically.
Key findings from studying footbaths
- Footbaths are an important component of claw health management.
- Footbath location should allow undisrupted cow flow and preferably allow passage of youngstock, dry cows and new additions to the herd.
- Footbaths should have proper dimensions.
- Not all products available are equally effective.
- Not all products available on the market have proven efficacy.
- Adequate frequency of use and product concentration are essential.
- Contamination of the footbath by manure reduces effectiveness.
- In low temperatures, the solution is less effective (especially formalin).
Research is underway to discover which footbath products successfully balance the health of animals, humans and environment and to clarify some of the “witchcraft” as practiced in the dairy industry.
The University of Calgary, in collaboration with the University of Wisconsin, is studying the impact of footbath solutions on the bacteria that cause foot lesions like DD in the lab.
article source: Progressive Dairyman magazine (Canada) vol 6 no 6 June 2016