Foot problems and lameness in dairy cows is widespread throughout the modern dairy industry and can be quite costly to the dairy farmer. Cows that are lame spend less time walking and standing, and this will prevent them from spending adequate time at the feed bunk or watering trough. If pens are overcrowded or there’s excessive competition at the feed bunk, cows with sore feet will be too timid to come up and eat. Cows that don’t get enough to eat will not produce much milk. Foot problems and lameness account for significant economic losses on a dairy farm, and the blame lies squarely with the dairy farmer.
According to longtime hoof trimmer Richard Weingart, hoof trimming and the timely management of hoof health is often at the bottom of a long list of priorities, because hoof trimming is so labor intensive. It takes a lot of time to separate cows and set aside time to take care of feet. Foot problems tend to crop up one at a time, and it can be expensive to get a hoof trimmer out for just one cow, so the dairy farmer waits until there are many curled up hooves and sore feet.
Weingart suggests that cows in today’s dairy facilities should be examined three times per year in order to stay ahead of potential lameness problems. As is the case with most potential health issues, an ounce of prevention is worth a pound of cure. Not every cow necessarily needs to be trimmed that often, but by scheduling a visit with the hoof trimmer every four months, hoof care and hoof health become a proactive activity rather than a reactive activity.
Back when cows spent most of their lives out on pastures or traversing a rocky hillside, the need for hoof trimming was minimal, but with modern confinement dairy farming, cows spend much less time walking and there’s less abrasive activity to keep hooves worn down. Because hooves continue to grow, poor or nonexistent hoof trimming management will leave cows with misshapen hooves that will result in too much pressure being placed on another part of the foot. This forces a cow to adapt her walking and locomotion to favor a foot. Uneven hoof wear and heel erosion will lead to bruising, ulcers and infections that reduce her mobility.
Untrimmed feet often lead to sole ulcers. As the toe horn grows, the cow must shift her weight to the back of the foot, putting more pressure on the heel. This is not unlike a blister that develops when we walk with shoes that are too tight or rake leaves without gloves on our hands. Left untreated, sole ulcers will spread to the lower leg, where serious infections may occur. Weingart explained that at the time of trimming sole ulcers will usually be opened and allowed to drain. If they are too severe, Weingart will glue a wooden block to the opposite claw, which raises the infected claw off the ground, keeping pressure off it and giving the ulcer time to heal.
Additional problems that are seen less often but can lead to lameness are white line separation and foot rot. White line separation occurs when a crack develops between the outer layer of the hoof wall and the inner sole. Frequently an abscess will develop in the heel. Foot rot is an advanced infection of the interdigital skin between the claws of the foot. It is characterized by the development of a necrotic lesion. The accompanying cellulitis extends into the soft tissues of the foot, causing swelling and lameness. The lesion typically has a foul odor of rotting tissue. The incidence of foot rot appears to be higher during the winter months and in confinement-housed cattle.
Adding another layer of complexity to hoof care on dairy farms is digital dermatitis, commonly known in the U.S. as the hairy heel wart. Occasionally it is referred to as Papillomatous digital dermatitis, because what we refer to as a “wart” is really a papilloma. Digital dermatitis is an infection caused by a combination of many bacteria that work in conjunction with one another to create the wart. The conditions favoring infection are generally unhygienic, moist, humid and muddy conditions in which cows must walk or stand. While digital dermatitis is not fatal in and of itself, it does cause lameness due to the tenderness of the warts, and if left untreated, large warts can become infected. However, cows will be suffering from severe lameness long before infection sets in. Digital dermatitis is highly contagious and a frequent source of frustration for dairy farms that have it in the herd.
Digital dermatitis in cows can be found worldwide. While the bacterium causing the heel wart are ubiquitous and cannot be eliminated, the conditions that favor the establishment of heel warts in a herd can be managed. When skin is made soft by continuous exposure to moist and dirty conditions a cut or nick from a stone or pebble, or a scrape from a jagged piece of concrete, allows the bacterium to enter. On a cow’s foot the fleshy areas between the claws and on the heel are the most susceptible. A dry and clean walking and bedding environment is by far the single best way to prevent or reduce the incidence of digital dermatitis in dairy herds.
A third cause of lameness in dairy cattle, but not brought on by hoof growth, is laminitis, also known as coriosis. This is an inflammation in the laminar area, where the flesh of the leg transitions to hoof. (Laminitis in horses is referred to as “founder.”) The cause of laminitis is believed to be associated with a disturbance in the microcirculation of blood in the corium, which leads to breakdown of the dermal-epidermal junction between the hoof and pedal bone. As the pedal bone settles lower in the hoof it places more pressure on the sole, resulting in a sole ulcer.
Rumen acidosis coming from poorly balanced diets is considered to be a major predisposing cause of laminitis. This may occur when there is low fiber and high carbohydrate levels in the cow’s feed ration. Hot and humid conditions will also predispose cows to laminitis when feed intakes are disrupted for extended periods of time. The area of the foot where hoof material is constantly being formed is a sensitive area with a high level of vascular activity and prone to inflammation. Cows with laminitis will be limping due to sensitivity, and the red-pink inflammation at the top of the hoof is usually evident. A properly balanced feed ration that prevents rumen acidosis will prevent lameness from laminitis.
According to Weingart, hairy heel wart is by far the most frequent lameness issue he encounters on dairy farms. Once the disease is established on a dairy, every cow in the herd, including heifers, can be expected to get the wart sooner or later. All that can be done with foot warts is to manage them by aggressively treating them with antibiotic salves and balms. Besides keeping pens and alleyways clean and dry, Weingart recommends copper sulfate and/or formalin ( formaldehyde) footbaths with an acidifier that helps dry out the infection. (Caution: formaldehyde is a known carcinogen and is prohibited in many places.)
Just as we need to regularly trim our fingernails and toenails, cows need a touch-up at least twice per year. Even if cows aren’t exhibiting signs of lameness, getting them up on a table for trimming is a perfect time to examine them for other foot trauma, such as white line separation. The main goal of routine preventative hoof trimming is to maintain or reestablish proper weight distribution on the cow’s feet by trimming the toe horn and reshaping the underside of the claws.
On his hoof trimming rig, Weingart carries portable fence panels that can be assembled into a multitude of pens and lanes, allowing for smooth cow movement and reduced levels of stress for both cows and people. Weingart now uses a high-speed grinder, which allows him to quickly peel away hoof, reshape and balance the claws, and trim the toes. Unless a cow needs extra treatment, such as the opening of a sole ulcer, cows can be on and off the table in about five minutes.
Along with a biweekly trip through a copper sulfate footbath to help strengthen hoof horn, it is highly recommended that biotin (a B-vitamin) and zinc-methionine (a chelated mineral protein) be included in dairy cow and heifer diets. With many dairy barn environments being wet and humid, hoof horn can and will get soft and spongy, allowing for the bruising of the soft inner corium and penetration of rocks or pebbles in the hoof. Biotin and zinc-methionine have long, successful track records for improving hoof health.
Researchers consider hoof disease and lameness as being second only to mastitis as the most costly health issue for dairy cows. Along with the obvious pain that is caused to cows and heifers by lameness, dairy farmers must recognize the potential for economic losses when a cow is lame. Especially for dairy cows, a reduction in feed intakes will quickly result in loss of milk production. Two or 3 pounds of feed dry matter equates to 1 gallon of milk. Some estimates of the cost of lameness, including lost productivity and treatment, are in the hundreds of dollars per cow.
Some cows that endure lameness for an extended period of time will never recover. Hoof health and hoof care are part of the cost of doing business on any animal operation. In many dairy herds it’s not uncommon for at least 10 percent of the herd to have some type of hoof problem that prevents them from producing milk to their full potential or, in the case of heifers, reduction in growth rates. And in nearly all cases of hoof problems, the dairy farmer is able to prevent it from happening or can effectively manage it so that cows and heifers remain healthy and productive.