Studies indicate that lameness is one of the top three reasons why cows get culled from a dairy. However, lameness can be caused by a variety of different factors – diet, disease, injury, and poorly-designed cows areas.
During the summer and fall, lameness often increases. Tak-ing the time now to review the lameness problems your herd experienced the past few months can help you pinpoint the causes and help you make changes to minimize problems next year.
Analyze your records
Review your records with your veterinarian and look for common factors such as age, lactation number, stage of lactation, cow group, or common findings by your employees or hoof trimmer when cows were trimmed and treated.
I usually try to divide lameness cases into two groups: infectious problems and laminitis. This can help define the problem's source as either environmental or nutritional.
In my practice, laminitis is the No. 1 cause of lameness during the summer. As cows' dry matter intakes go down due to hot weather, most producers increase the percentage of grain in the ration. This attempt to keep energy in the diet up – and, therefore, milk production up – often leads to acidosis.
I've reviewed farms with acidosis-induced laminitis and found the percent forage in the ration as low as 32 percent to 34 percent. This leads to poor rumen health, cows going off feed, and an increase in displaced abomasum and lameness cases. Pay close attention to the diet and don't let the forage level drop below 40 percent.
Consider using rumen taps to check your cows' rumen pH. Conducting the sample is not difficult, but some cows do not tolerate the procedure well. Wait five to six hours after feeding before taking samples. Take six to eight samples in a group of cows fed the same ration. If an average pH is not easily determined, check an additional six or eight cows.
If the group's average pH is less than 5.5, you have a definite acidosis problem. If the pH is between 5.5 and 5.8, the ration is suspect. If the pH is above 5.9, no acidosis exists.
If you have a large percent of infectious lameness cases, look at your housing – specifically, the flooring where cows stand. If cows are confined, the concrete may be staying wet from sprinklers, misters, waterers or manure. Wet feet on hard concrete magnifies foot problems. The best solution is placing cows on dirt or grassy areas for as little as two hours, one to three times daily.
If cows experience foot rot, it's best to remove them from wet, muddy areas. Examine cow areas and look for water tanks that overflow and poorly-managed sprinklers. Dirt areas at the end of concrete walks must have proper drainage systems. Many producers use lime to help keep these areas dry, which also lowers bacteria numbers. Maintaining footbaths properly can help, but they must be managed well.
Another common environmental problem is hairy heel warts. Again, footbaths can be used. But if overused or left contaminated, the footbath can be a source of infection.
I shy away from antibiotic footbaths because of cases where antibiotic milk residue occurred from cows drinking footbath solutions.
As an alternative to antibiotic footbaths, I prefer regular spraying of feet with antibiotics (tetracycline, lincomycin or lincomycin-spectinomycin).
When using a sprayer, use it daily for seven days for the entire herd, then once or twice monthly after that. In addition, spray fresh cows and heifers for seven days after calving.
And, don't forget your dry cows, since they can go for 60 days or more without treatment in the barn. Footbaths work well in this last group.
So, review your cases of lameness now and address the causes. Waiting until next summer is too late.
Jim Brett is a practicing veterinarian in Montezuma, Ga.