June 25, 2020
Jim Dickrell
It’s one of those nasty problems that plague dairy farmers everywhere: Once a cow becomes lame, she tends to become a chronically lame cow.
She might get a bit better with hoof trimming and isolation, but the conditions that caused her to go lame initially often persist in facilities in how cows are handled and managed.
“Poor cow comfort and increased standing on hard surfaces was [in the past] recognized as a secondary factor increasing lameness severity,” says Nigel Cook, a dairy veterinarian specializing in cow comfort with the School of Veterinary Medicine at the University of Wisconsin. Cook participated in the recent 4-State Dairy Nutrition and Management Conference held virtually in early June.
“It is now becoming increasingly probable that standing alone could be the primary cause of claw horn disruption pathogenesis…not just a secondary factor,” he says. “Increased load bearing from insufficient rest is the most likely cause of inflammation!”
It works like this: Decreased lying time means hoof overload which causes lameness. Once cows become lame, they have abnormal resting behavior which doesn’t allow for proper hoof healing. That, in turn, means continued lameness. And the cycle becomes an endless loop of chronic lameness. Once a cow becomes lame, she frequently remains lame. In other words, ‘get lame, stay lame.’
Foot inflammation is the likely cause of lameness. And increased load bearing from insufficient rest is the most likely cause of inflammation. “Sole ulcers is short for standing up disease,” says Cook. “Cow comfort is the most important thing we do in preventing lameness.”
What that means is that pretty much all aspects of how cows are fed, housed and managed can play a role in their susceptibility to lameness. Over-stocking can create access problems to feed and time at the bunk, restricting lying time. Poor stall design can result in poor stall usage and reduced lying time. Poor pen design and barn ventilation can result in bunching, increased standing time and less lying time.
“Heat stress can have a massive effect on the cow,” says Cook. Heat stress in July means lameness in September.”
Cook says lameness is all about the micro-environment where the cow lives and spends her time. One study showed that cows had 3 ½ hours less lying time per day when the temperature humidity index rose from 68 to 79. “That insult alone can be linked to lameness,” he says.
Bedding material in stalls also plays a roll. Deeply bedded sand stalls are often regarded as the gold standard. “[But] there is equal pressure for new cases of lameness between mattresses and sand herds,” Cook says. “There are mattress herds with low levels of lameness.”
The impact of sand is really on reducing the chronicity of lameness, because it allows a more comfortable bed which encourages use and time to heal.
Mattress herd owners can control lameness if:
• They have excellent stall design.
• Identify new cases of lameness and treat effectively.
• Allow lame cows to recover on a bedded pack.
• Control infectious causes of lameness through effective foot bathing.
• Use sufficient bedding over mattresses to reduce hock injury.
Routine footbath use is critical to reduce pathogens which can cause lameness, says Cook. Footbaths should be used 4 times per week when first introduced to maintain control of these pathogens. Frequency can be reduced as control improves, with some herds using foot baths just once weekly.
Cook also recommends using an antibacterial agent that has evidence of efficacy against digital dermatitis and foot rot. These compounds should have no higher than 5 percent copper sulfate, no higher than 4 percent formalin (avoid formalin use in cold weather because it has activity issues at lower temperatures), and use of an acidifier with a pH no lower than 3.0.
“Use the bath as long as it is effective, about 150 to 300-plus cow passes,” he says. And don’t forget to treat all life stages of the cow, including dry cows. Longer foot baths, 10’ versus 12’, are preferred because they ensure each hoof will be treated at least twice.
Cows hooves also need to be trimmed twice per year, unless wear is an issue in your facility. “Good trimming should be done every 4 to 6 months,” Cook says. Most herds trim at mid-lactation and at dry off. But some herds, if they are seeing more lesions, will do their first trim at 80 to 120 days post-calving to head off problems.
Finally, here are the factors to reduce the risk of lameness:
• Less time standing on concrete.
• Less restrictive neck rail locations in freestalls, low rear curb heights and absence of lunge obstructions in stalls to encourage stall use.
• Wider stalls.
• Use of manure removal systems other than automatic scrapers to reduce surges of manure that contaminate hooves.
• Use of non-slippery, non-traumatic floor surfaces rather than slats.
• Access to pasture or an outside exercise lot.
• Wider feed alleys.
• Access to a trim chute for routine treatment and use of effective foot baths.
• Prompt recognition and treatment of lameness.
SIDEBAR: Lameness Can Start In Heifers
Over the past few years, veterinarians and hoof care specialists have noticed an increasing rate of lameness in first-calf heifers, particularly if those heifers are raised in sand-bedded freestalls with headlocks.
Heifers front claws are being permanently and irreversibly damaged in what has become known as corkscrew hoof damage, says Nigel Cook, a dairy veterinarian specializing in cow comfort with the School of Veterinary Medicine at the University of Wisconsin.. It’s caused by heifers placing stress on their front feet as they strain to reach for feed through headlocks.
To avoid this syndrome, consider:
• Raise heifers on bedded packs at least up to breeding age.
• If you use freestalls, consider using organic bedding. Avoid using recycled sand.
• Reduce use of headlocks to the breeding pen only, and use slant bars or post/rail restraints in grower pens and post-breeding pens.
• Use floors designed specifically for heifers, including micro-grooving floors.
• Provide access to outdoor pens and pastures.
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