Footbath Practices for Lameness Prevention
Jason Hartschuh, Assistant Professor, OSU Extension Field Specialist, Dairy Management and Precision Livestock, Ohio State University Extension
Whether you are milking cows in a traditional parlor or through an automated milking system, a cow’s locomotion is important. She needs to make a minimum of 2 trips to the parlor and 9 to 14 trips to the feed bunk to eat. When a cow has a sore foot, she doesn’t feel like walking anywhere and will eat less frequently. While in a conventional parlor, she will still be herded with the rest of the cows to get milked. A cow with a sore foot will make fewer trips to the robotic milker and often appears on the fetch list. Each case of lameness costs approximately $336.91 in lost milk production, treatment of lameness, reduced reproductive performance, and increased culling. Also for each additional week a cow is lame beyond the first signs of clinical lameness, this cost goes up $13.26. Barn hygiene practices, such as preventative hoof trimming and regular alley scrapping, are critical for hoof health, but these practices also need to include the regular use of a footbath with a disinfectant to control foot rot and digital dermatitis.
The more regular your footbath practices, the easier it will be to get the cows to walk through the footbath. While many locations can work for a footbath, it needs to be in a location that all cows will walk single file through it and be easy to set it up. A cow needs to step in a foot bath a minimum of 2 times with each foot. For this to happen, the foot bath should be a minimum of 10 feet long with no additional benefit for footbath lengths being over 12 feet. The solution depth in the foot bath should be 4 inches deep, with a recent study showing that the step in height can be up to 10 inches which will retain the chemical solution better and not impede cow flow through the footbath. The higher step-in height maintains the appropriate chemical depth of at least 3.5 inches after 300 cows pass through the footbath. The minimum width a cow will pass through is 20 inches, but 24 inches for the footbath is better. Cows will move better through a footbath with solid walls at least 3 feet above the footbath and tapered outwardly at a 70° angle. These high walls ensure cattle are getting their feet in the treatment. One side should be removable in case a cow goes down in the footbath.
Proper footbath management includes the selection of an effective disinfectant, determining the number of times a week to use the footbath, and the number of cows passing through the footbath before too much manure has caused the disinfectant to be ineffective. Footbaths are effective for approximately 150 to 350 cow passes. Barns with automated manure removal and cleaner hooves will be at the higher-end, but barns that are only scraped 2 or 3 times a day will be at the low end. The number of times a week a cow needs to pass through a footbath solution varies, but on average, each cow should pass through a footbath 3 times a week. When an outbreak of digital dermatitis is experienced, increase the number of times a cow passes through an effective footbath to 4 or 5 times per week.
While there are multiple products available to use in a footbath, only three of them have multiple scientific studies conducted on them. These three are copper sulfate, formalin, and zinc sulfate. No matter what antibacterial product is used, the solution pH should be between 3.5 to 5.5 so that it doesn’t damage the skin with a normal pH of 4.0 to 5.5. Copper sulfate is the best option due to its antibacterial properties and the hardening effect on the claw horn at a cost of about $42 per cow per year with 4 uses per week. Unfortunately, organic matter rapidly neutralizes copper sulfate, so dirty footbaths are less effective. Copper sulfate concentrations should be maintained between 3 to 5%. The biggest issue with copper sulfate is the environmental concern of copper accumulation in the soil leading to plant toxicity. If manure applications are appropriately managed so that other nutrients are applied at crop removal, copper build-up will be slow, but soils should be monitored.
Formalin also kills bacteria and hardens the claw horn but is a suspected carcinogen. Over time, formalin breaks down into water and carbon dioxide. Treatment concentrations of formalin should be maintained at 3 to 5%, with caution to not exceed 5% due to the risk of chemical burn. Formalin is not as effective at temperatures below 50° F, and open claw lesions may heal slowly after walking through formalin, making it a better product for control than treatment. If using formalin, be sure to store and use it in a well-ventilated area.
Zinc sulfate is not as widely researched but has efficacy in controlling digital dermatitis at a concentration of 5 to 20% zinc sulfate. Unlike the other antibacterial products, zinc sulfate is less soluble, making it harder to get into the solution. Some companies offer premixed solutions that are much easier to mix into the footbath. When using these premixed products, be sure to follow the product mixing directions.
When the foot bath needs to be changed multiple times each day, it can be beneficial to have a premix tank for the footbath solution. This allows the old footbath to be drained, and the new solution quickly pumped into the footbath. This allows one person to mix up the day’s footbath solution using the proper personal protective equipment to handle the full-strength chemicals, and others would only need to handle the diluted solution.
Utilizing proper footbath practices will help keep cows walking to the feed bunk and milking parlor. Lowing the number of clinical and subclinically lame cows on the farm also boosts employee morale as they have fewer cows that don’t want to move causing them to be frustrated.
