By Sandi Alswager Karstens, University of Nebraska
Bitter cold temperatures and extremes in wind chills likely will continue this winter in the High Plains and upper Midwest regions of the U.S. These conditions are particularly stressful for groups of cattle that have not adequately acclimated to such conditions, a University of Nebraska-Lincoln beef specialist said.
The most susceptible animals are newborn calves in cow-calf operations and new cattle arriving in feedlots, said Terry Mader, UNL beef cattle specialist at the Haskell Agricultural Laboratory near Concord. Cattle that lack body condition for insulation also may be at risk from cold weather.
"Most cattle can easily handle cold weather conditions if they are dry and maintain dry hair coats, even if temperatures are sub-zero," Mader said. "The most adverse conditions occur around freezing (32 degrees) when cattle get wet and the pens turn sloppy and muddy. The presence of moisture or mud on the animal draws heat from the animal's body at a much faster rate than when the animal is drier in extreme cold temperatures."
One plus for cattle producers and feeders, Mader said, is that since cold temperatures and some snow have been around for several weeks, most cattle are generally already acclimated to current conditions.
Ideal feedlot temps
Mader said the ideal wintertime temperatures for feedlot cattle are around 20 degrees. At these temperatures, the snowfall that does occur is normally drier and will blow off the animal. Feedlot surfaces also remain firm and allow cattle easier access to feed bunks.
"Most cattle by this time in the winter have developed their winter coats and are able to withstand wind chills well below zero," Mader said.
Healthy, dry, well-conditioned and well-fed cattle can handle wind chills of 40 degrees Fahrenheit below zero, but tissue damage may start to occur when wind chills drop to around 60 degrees Fahrenheit below zero.
There are a number of things that can be done in feedyards and other cattle holding areas both before and after major weather events.
Mader recommends that managers smooth or knock down rough frozen pen surfaces with a blade or harrow. Sharp edges that form when cattle tracks freeze can cause bruising of the feet which can lead to foot injury.
"When pen surfaces are rough, cattle don't make their way to feed or water often enough which can cause decreased performance," he said.
Bedding such as wheat straw, corn cobs, or corn stalks also can be used to help insulate cattle from the cold ground during severe cold outbreaks.
Mader said these are better for bedding than hay-like materials because they are less palatable. Cattle will be less likely to eat the bedding and more likely to stay on the ration provided in the bunks. In feed yards, apply bedding after feeding to minimize bedding consumption.
Accumulation of snow in the pens can cause cattle bunching or piling on, which can lead to increased death losses. Therefore, when heavy snowfall or drifting snow does occur, Mader recommends removing the snow from the pens before the next storm arrives.
It is important to keep feedlot animals from going off feed during even the worst of weather conditions, Mader said. Erratic feed intake can result in digestive problems and loss of performance, possibly even death in severe cases.
Cattle that are within 30 to 45 days of slaughter are particularly prone to go off feed and can be difficult to get back on feed. Moving cattle to a higher roughage, storm ration may be advisable to keep the cattle on feed, even though UNL studies have shown that more energy in the form of grain is needed to maintain performance.
Depending on shelter provided, it may be better to sacrifice a little performance initially to prevent the entire pen from going off feed.
Finally, current feed cost suggest that it is cheaper to keep an animal dry, through good maintenance of pens and use of bedding, versus trying to feed the animal extra feed that will be required for maintenance if the animal has a wet or partial wet hair coat.