Lameness Large Factor in Cow Culling

By Ron Johnson, Dairy Editor
Thursday, December 20, 2007 1:27 PM CST

Want to lose hundreds of dollars? Just let one of your dairy cows go lame.

“Lameness is one of the most costly problems on today’s dairy farms,” said Jan Shearer, during last week’s Professional Dairy Producers of Wisconsin (PDPW) Hoof Care Training Seminars. “It accounts for an estimated total loss of nearly $300 per cow affected.”

Shearer, a professor and Extension dairy veterinarian at the University of Florida, Gainesville, noted that 15 percent of all cows culled from U.S. dairy herds in 1996 were sent packing as a “direct effect” of lameness. What’s more, nearly 50 percent of the rest that were culled went to slaughter due to the “indirect effects” of being lame. These “indirect effects” that lameness contributed to were poor reproduction and lower milk yield.

Admittedly, those numbers are 11 years old, but Shearer said it’s “doubtful” that the role lameness plays in culling “has improved much since that time.” Why is that?

“Most lameness results from laminitis and (hoof) claw disorders,” Shearer reminded. “But infectious diseases of the foot’s skin are also very common.”

These foot diseases include foot rot and foot warts. Then add in claw disorders like sole ulcers and white line disease.

“When severe, these conditions cause severe pain and lameness that can be very debilitating,” the veterinarian said. “Prompt” treatment, he added, is critical.

Treating lame cattle right away is not only important from the standpoint of keeping them productive and in the herd. Shearer asserted that it’s also important from an animal welfare standpoint.

The good news is that hoof trimming can remedy some of these problems. For example, trimming can get rid of claw horn that has grown so long that it interferes with proper standing and walking.

Trimming can also remove claw horn that’s next to lesions. A good trimmer will make sure to take off all the loose and dead horn around affected areas.

“This should be accomplished with little or no bleeding, if possible,” Shearer cautioned. “Excessive or unnecessary damage to the corium (also called the “quick”) only prolongs recovery.”

Proper trimming might also mean adding hoof blocks. When blocks are applied to healthy claw, they can take some of the cow’s weight off her injured or diseased foot. That, in turn, can lessen her pain and help her heal.

Sometimes bandages and antibiotic creams can help. But Shearer called these “generally unnecessary.”

He added, “Exceptions include infectious foot skin disorders such as foot warts, claw lesions accompanied by excessive bleeding, or claw lesions where there hasn’t been excessive removal of the claw horn capsule.”

Foot baths can help, too. But these are not the kind cows simply walk through.

Instead, these “stand-in” foot baths let cows remain in them 10 minutes or more at a time, Shearer explained. Stand-in foot baths can help combat a number of disorders, like foot warts, heel erosion, and foot rot.

Foot baths that cows walk through have a place, too. They can help control and prevent infectious foot problems.

Shearer cautioned that foot rot also requires treatment with antibiotics that work throughout the cow’s system. If foot rot is not treated promptly, surgery might be needed. In extreme cases, the cow might have to be put down.

Why do cows go lame in the first place? One reason is an injury to a foot, like stepping on a nail or sharp stone.

Another cause is laminitis. This condition sets a cow up for hoof claw disorders.

Nutrients essential for proper hoof growth don’t get to where they’re needed. And, tissues that would normally become claw horn don’t develop properly. The final result is weaker claw horn that’s less resistant to damage and can’t stand up to the day-to-day impact of hard surfaces such as concrete.

More bad things can happen to hooves because of laminitis. Enzymes released during the course of the disease damage bundles of collagen that suspend the cow’s third phalanx - a bone in her foot. This damage lets the bone sink and turn.

Other aspects of laminitis are thought to be linked to hormonal changes that take place when a cow calves. One idea is that the same hormones that relax a cow’s pelvic muscles so she can calve easier also relax the tissues that hold up the third phalanx.

These changes do not have to send a cow to the packing plant. They can be overcome.

“Researchers have found that housing animals on soft surfaces throughout the transition period permitted recovery of the suspensory tissues, preventing permanent damage,” Shearer pointed out. “In problem herds it’s necessary to review the nutrition and feeding program, herd management, and cow comfort.”

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