How many lame cows are on your dairy? Do you know?
If you have a small farm, the answers to these questions are probably, none or, very few, and, yes. If you have hundreds or thousands of cows, the answers are more likely to be that you don’t know and no.
Lameness has a higher prevalence than mastitis on many well-managed dairy farms. Lameness is expensive. Lame cows produce significantly less milk than they should. They are more likely to be culled. They are less likely to become pregnant.
How can you reduce the number of lame cows in your herd? The simplest and most effective way, according to Dr. Gerard Cramer, an internationally recognized lameness expert at the University of Minnesota, is to do a better job finding lame cows. The number of lame cows on any given day is the total of newly lame cows that have not yet been effectively treated and the total number of chronically lame cows that do not get better.
So, wouldn’t doing a better job finding lame cows be expected to increase, rather than decrease, the total number of lame cows? That could be true for a dairy that does a poor job of detecting lame cows, but for most farms, the key to reducing the number of lame cows is finding and effectively treating them. For example, if you only treat lame cows once a week, the total number of lame cows on any given day includes a whole week’s worth of newly lame cows. But, if you treat lame cows every day, that total will only include today’s newly lame cows plus any others that have been treated but have not yet recovered. Most lame cows, if treated early, show significant improvement in just a few hours after treatment. So going from treating once a week to twice a week should reduce the number of newly lame cows by almost 50%.
There is another reason why better detection reduces the total number of lame cows. Dr. Cramer explains that lameness is a disease of inflammation. Inflammation can cause a lot of changes in body tissues, including bone. The longer the inflammation lasts, the more likely bony changes are to occur. This happens with some hoof and sole lesions. Bone spurs develop on P3, or the pedal bone, which is the lowest bone in the leg and is located mostly within the hoof. Once spurs develop, they typically do not go away, and the cow is much more likely to be lame again, with a similar lesion in the same place, in the future. Thus, delaying treatment can turn acutely lame cows into chronically lame cows. Nobody wants more chronically lame cows on their dairy. Chronically lame cows are at extreme risk for culling and, on some farms, make up a large part of the cows that are trimmed at every hoof trimming visit. Delaying detection and treatment can thus increase both the number of newly lame cows and the number of chronically lame cows on any day on your farm. Remember, too, that lame cows are lame because they have significant pain. As animal caretakers, we have a responsibility to reduce that pain promptly when reasonably possible.
Forty years ago, a typical Minnesota dairy farm had around 40 adult cows. They were most commonly housed in tiestall or stanchion barns. Farmers saw them walk at least twice a day. Lame cows were hard to miss. Some farmers would lift affected feet and treat them themselves, but probably the most common thing farmers did was to call their veterinarian. Veterinarians used a variety of devices to restrain lame cows, including clamps, beam hooks, straw bales, straps, posts, ropes with a variety of clever knots and strong farmers. Treating lame cows was almost never fun, especially if the cow was lame on a front foot. Sometimes feet were really dirty or covered with caked manure. More commonly though, especially in clean, just-limed barns, the hooves were rock hard. This made finding lesions difficult. Hoof knives were never sharp enough. Because of all of this, hardly any dairy farmers or dairy veterinarians miss lifting feet. However, as farms transitioned to freestall facilities, detecting lameness became harder, and regular use of professional hoof trimmers became more common. Along with this came the practice of leaving lame cows for the hoof trimmer to fix on hoof trimming day. As farm sizes grew, hoof trimmers started coming to farms more frequently, and so leaving lame cows for the hoof trimmer became a more accepted practice. However, that does not mean is it right or the best practice. Every farm needs a way to deal with a severely lame cow promptly, which usually means today. For larger farms, this usually means having a hoof trimming chute on the dairy and a staff member trained to examine and treat lame cows, or having the hoof trimmer come for lame cows. For smaller farms, it might mean calling the veterinarian, calling the hoof trimmer or treating them yourself. Not every lame cow can be fixed, but detecting lame cows and treating them promptly can significantly reduce the number of lame cows on most dairies. Doing this will mean the answer to the opening question is none or very few.
Information for this article came from, “A veterinarian’s role in creating more days with 0% lameness,” presented by Dr. Cramer at the 2021 AABP Annual Conference in Salt Lake City, Utah.
       Bennett is one of four dairy veterinarians at Northern Valley Dairy Production Medicine Center in Plainview, Minnesota. He also consults on dairy farms in other states. He and his wife, Pam, have four children. Jim can be reached at bennettnvac@gmail.com with comments or questions.