AgWatch

Cold Temperatures Signal Start Of Fescue Foot Season

SPRINGFIELD, MO.
   Single digit temperatures and wind chill factors below zero are the key weather conditions that can trigger fescue foot symptoms in cattle that have been grazing on “hot” fescue.
   “Hot” fescue contains the wild-type of endophyte that produces ergot-like toxins under certain conditions. These conditions usually involve an excellent growing season, high levels of nitrogen fertilizer, either commercial or from animal manures according to Eldon Cole, a livestock specialist with University of Missouri Extension.
   “The toxin level tends to be greatest in the spring when it concentrates in the stem and seedhead. However, lush fall regrowth can contain adequate levels in the leaves to create a constriction of the blood vessels in the cattle that graze it,” said Cole.
   The poor circulation resulting from the toxin, creates lameness in the rear legs of cattle. This causes those areas to be prone to freezing and frostbite during the winter.
   Telltale symptoms in the very early stages of fescue foot include: lameness in the rear legs, swelling below the hock, picking of rear hooves and licking or flipping them to stimulate blood flow, as well as a reluctance to get up and move (and when they do the cattle act like they are “walking-on-eggs”).
   “As conditions worsen over the next few days, as a result of continued consumption of hot forage or extreme cold weather, a break in the skin may appear,” said Cole. “The skin break usually encircles the pastern area near the hoof. At first glance it looks like they have a wire wrapped around that area.”
   Once the skin break appears, the chances of saving the hoof decreases dramatically and a cow without a hoof becomes a liability.
   “Cows that show some of the lameness symptoms with no break, probably will show excessive toe growth in the future. They can lose the tail switch without showing the typical foot symptoms,” said Cole.
   All cattle in a herd will not always show fescue foot symptoms. According to Cole, this is due either to their physiological makeup or their grazing habits.
   “There does appear to be a genetic basis for sensitivity. Breeds seem to be equally susceptible to the fescue foot problem while Brahman crosses tend to be very sensitive to tail switch loss,” said Cole.
   The best preventive practice is for a producer to watch their cattle very closely early in the morning as they get up and start moving around.
   Cole says any animals that show hints of lameness (which can’t be explained by foot rot, rocks between the toes or any injury) and are grazing lush fescue should be pulled off that pasture immediately.
   “It’s best to isolate the limpers in a dry lot or a non-fescue pasture. Feed them some grain, alfalfa and/or orchard grass hay. The important thing is to change their diet so no additional toxin is consumed,” said Cole.
   Giving antibiotic won’t help the problem unless it helps prevent secondary infection.
   “If the antibiotic treatment straightens them out, they probably had a foot rot episode instead of fescue foot,” said Cole.
   The perplexing problem about fescue foot, according to Cole, is it may occur out of the blue and not show up in that pasture for years to come.
   “Other pastures seem to be chronic problems and those are the ones that need to be renovated and put into a species of grass/legume that will not cause fescue toxicosis,” said Cole.
   Fescue foot occurs more often in wet falls following a dry summer. The level of toxin lowers in the plant throughout the fall and early winter. Therefore, landowners that have known, hot pastures, should save those for late grazing.
   The toxin may be in hay and it also lowers during storage but does not completely leave the hay. However, dilution of the hay or pasture intake will help reduce the severity of fescue foot.
   No feed additive has proven to be effective at preventing the problem, according to Cole.
   If you experience fescue foot in your herd, contact any of the MU Extension livestock specialists in southwest Missouri: Eldon Cole in Mt. Vernon, (417) 466-3102; Gary Naylor in Dallas County, (417) 345-7551; and Dona Goede in Cedar County, (417) 276-3313. Δ

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