Have you noticed some of your cattle limping a little? Sometimes they may limp a lot, not just after they get off their beds in the morning. Most people when they see cattle limp think first, foot rot. That is a possibility, but if the sore footedness is almost always a back foot, think fescue foot in cold weather. If you’ve treated them with an antibiotic for foot rot with no response, it’s even more likely the problem is fescue foot.
Fescue foot is a result of cattle grazing endophyte infected fescue that for some reason has produced a large amount of ergovaline. Normally the culprit fescue will be tall, season-long or lush fall growth that came along after heavy nitrogen application. If sensitive cattle eat enough of the toxin-bearing fescue, it results in constriction of the animals blood vessels. The constriction means normal blood flow to the extremities of the animal’s body, such as rear feet and the tail, results in swelling of the pastern-hock area. A line of demarcation (shown below) that resembles a wire being wrapped around the leg appears along with a dry gangrene that may result in sloughing of the lower limb.
Sub-freezing weather worsens the damage due to frost bite. Once the break in the skin is evident, the animal is probably a goner. The hoof can completely fall off making it difficult for them to move around. In addition to the leg/hoof issue the animal has other issues. They will draw up and lose a significant amount of weight. They can be fed a high concentrate diet, good quality non-fescue hay and be pampered in a small rock-free pen and they don’t seem to get better.
In a herd of cattle you usually only have 10 to 15 percent that show the really bad hoof problems I’ve described. However, a higher percent may show other subtle symptoms such as grown out hooves in a few months. Once again, It’s most common on the rear hooves. A higher percent may show lost tail switches. The tail loss may not occur until fly season arrives. It’s not uncommon for you to be working cattle and need to grab the tail and twist it and the lower portion breaks off in your hand. More commonly you’ll just find the tail switch in the pasture.
It appears cattle carrying Brahman genetics are more likely lose tail switches. There are some other points of interest related to genetics and environment. Close observation of fescue foot problems over the years indicate it occurs more on cattle that are newly introduced to the high ergovaline fescue. For example, you may have brought cattle to fescue country from bermuda grass country like Texas or Oklahoma. Those cattle take a while to adapt and if our conditions are just right, you’re more likely to have a wreck with them. The toxin not only knocks hooves off, it drastically affects conception rates.
Cattle from the north, west or even the east, where fescue isn’t the main forage, require caution if you buy them to put on “toxic” fescue. The best practice is to buy cattle that have been on pasture conditions like they’ll find on your farm. If you’re buying semen for artificial insemination purposes, it’s nice to know if that bull’s progeny perform well under “hot” fescue conditions. More and more people seem to have that kind of knowledge if you work on it.