Editors Note: This is the second in a two-part series on locomotion scoring. Click here to read the first story in the two-part series: How to become a cow motion detector.
It doesn't take a genius to recognize a lame cow. She's the one with the limp, right?
Although that's the detection system many producers use to identify lame cows in their herd, you can do better. A tool called locomotion scoring can help you recognize lame cows long before they limp.
And since lameness takes a significant toll on production, reproduction and farm balance sheets, catching it early is critical to your bottom line.
Locomotion scoring is a five-point scale developed by researchers to perceive changes in how a cow walks and stands - which provide clues to a cow's lameness status. These quick-and-easy cues help identify cows that have developed lameness issues, but may not yet show any physical signs of lameness. The tool is easy to use and is something to add to your management toolbox. (To learn how to use locomotion scoring, please see "How to become a cow motion detector" in the August issue of Dairy Herd Management.)
You don't need to be an expert on foot and leg health to determine which animals are going to have problems down the road. All it takes is a few minutes of your time, a little information, and a way to keep track of where cows fit in the locomotion scoring spectrum. Invest the time to start using locomotion scoring on your dairy. It is one venture that will definitely pay you back.
An early-warning system
Wouldn't it be great if an alarm sounded before your tractor breaks down? Or a flashing light went off above cows about to come down with milk fever? Well, locomotion scoring does just that. Consistent use tells you if a cow has a problem long before she limps.
Most severely lame cows probably didn't get that way overnight, notes Steven Berry, University of California-Davis dairy management and health specialist. On the five-point locomotion scoring scale, many lame cows begin as locomotion score (LS) 2 or 3, and develop more apparent physical signs as their problem progresses. Early awareness of developing foot problems is important because milk production and reproduction start to slide long before cows ever limp.
Also, since locomotion scoring centers around prevention rather than treatment, the system will catch many lesions in the very early stages. You don't have to be highly knowledgeable of foot anatomy or disease to use locomotion scoring. Nor do you need to know how to fix the problem. That comes later. The only requirement to use the tool is the ability to discern if cows arch their backs when they stand or walk - a signal that shows up long before a limp.
Vern Oraskovich, University of Minnesota regional extension educator, adopted the system more than a year ago, and says it is very simple to use during dairy consultations.
"I just jot down cow numbers of those I think fall into LS 2 and 3 categories as I walk through the barn," explains Oraskovich. "Most of the time there is a problem when the foot is examined by a hoof trimmer or a member of the dairy management team, but it probably wouldn't have been noticed until the situation became more severe."
Russ Fisher, consulting nutritionist with Klaphake Feed Mill, Inc., in Melrose, Minn., also has been using the system for some time and notes that it doesn't require much time or effort. "It's just something to have in the back of your mind as you walk through your herd, something that can help you identify animals that may need some extra attention," he says.
Prevent bigger problems
Experts note that examining cows that score LS 2 or 3 - again, long before a limp appears - will help prevent the onset of more serious problems. Keep in mind that LS 2 cows are less distinct than those with more obvious symptoms, but they still merit examination. Cows that score LS 2 or higher suffer from some anomaly that prevents them from walking or standing normally.
Prompt attention prevents the development of more serious problems. Because once a cow reaches LS 3, research shows you'll note decreased milk production and decreased reproductive efficiency.
A well-managed herd should have less than 10 percent of cows above a LS 2, says Doug Hostetler, veterinarian at the University of Missouri-Columbia. "In these herds, less than 5 percent of cows should score four or five on the scale at any given time."
For Gary Reeck, Paynesville, Minn., foot health is a priority on his 300-cow dairy. And locomotion scoring is one tool that helps his team keep a handle on how cows fare. Cows that show a hint of lameness (generally LS 2 or 3) are reported to the hoof trimmer immediately. And trimmings are recorded so that management can track whether animals require excessive care. "Most of our trimming is purely for preventative care anymore," recalls Reeck. "I can't remember the last time we culled a cow for lameness."
In addition to scoring individual cow performance to catch lameness early, you also can use locomotion scoring to track lameness prevalence by pen and within your herd. These data can provide clues into management changes that you may need to make.
Monitoring scores will help keep performance in perspective and alert you if things begin to get out of hand. This is another area that benefits from a team approach.
"It's key that everybody be in the loop as to what's happening with your cows," says Fisher. "It's very helpful to me when a hoof trimmer lets me know immediately about problems he sees so we can get it solved as soon as possible."
If you've correctly identified lameness and made the appropriate corrective actions, lameness incidence on your dairy should decrease. Just keep in mind that in certain instances - like when subacute ruminal acidosis has led to subclinical laminitis - correcting the underlying problems can be more difficult and it will take longer for lameness to decrease. When the underlying problem occurs over several months, with sole ulcers and abscesses the eventual result, damage isn't immediately seen. Nor can it be corrected immediately.
"Responses to management changes should be monitored over time," recommends Hostetler, "and don't expect rapid results." Your goal should be to identify fewer and fewer lame cows each month.
If severely lame cows are still being identified in your herd after several months of locomotion scoring, you need to go back and determine whether the correct cause was identified. And investigate whether appropriate management actions have been taken.
"If there are a consistently high number of lame (LS 4-5) cows presented to the hoof trimmer, then intervention isn't occurring soon enough," says Berry. The goal is to identify cows that score a 2 or 3 to prevent the economic losses that occur when they become clinically lame with a LSscore of 4 or 5.
Limit your losses
Lameness ranks third behind reproduction and mastitis as the leading cause for economic losses on dairies. That's due to premature culling, increased veterinary treatment cost, increased labor, discarded milk, prolonged calving interval and reduced milk yield.
Studies at the University of California-Davis recently submitted to the Applied Animal Behaviour Science journal indicate a significant linear relationship between locomotion score and milk loss.
Cows' average milk production dropped between 2.5 percent to 4.3 percent for each increase in locomotion score. And, LS 4 cows produced approximately 10 percent less milk, on average, than LS 1 cows.
"We were surprised by the statistical significance of the linear relationship as cows were rated LS 2 and higher," admits Peter Robinson, UC-Davis extension dairy nutrition and management specialist.
Not surprisingly, the researchers also learned that cows tended to lie down more as lameness severity worsened, and it took cows longer to return from the milking parlor. This means cows spend less time at the feed bunk, and they may actually consume lower quality feed due to ration sorting by cows that arrived at the bunk first.
Higher scoring cows also show fewer heat signs. And if cows lie in alleys near the pen entrance to reduce walking distances, it increases her mastitis risk.
Still think it doesn't matter if a cow's feet are a little sore? Think again. These behavior modifications can be correlated back to locomotion score results and their linear relationship with milk production.
Lets put a few numbers to this concept.
If a 100-cow dairy averages 10 percent LS 4 cows, that's a 10 percent total milk loss. If the herd averages 22,000 pounds of milk annually, each of those 10 cows lose 2,200 pounds of milk for a total of 22,000 pounds every year. At a milk price of $12 per hundredweight, lameness skims $2,640 off the top of the milk check. Multiply that figure by 100 for a 1,000-cow dairy and losses climb to $264,000.
These days, who can afford to let milk output go limp?