Cold weather poses significant risks to livestock.
By: Aimee Nielson, University of Kentucky
While it may not be the all-time coldest temperature ever recorded—that was -37 in 1994—Kentucky is about to experience some brutal lows and bone-chilling wind. These conditions pose significant risks to livestock, and farmers need to prepare for the extra care the animals will certainly require.
“This will definitely be one for the record books,” said Matthew Dixon, University of Kentucky agricultural meteorologist. “The extent of the cold air outbreak is being pushed further by the amount of snow that has fallen recently.”
Across the state’s midsection, most saw 8 to 12 inches when the snow event finished late on Monday. An additional 1 to 2 inches fell Tuesday night and into Wednesday morning.
Dixon said lows on Feb. 19 and 20 will reach -5 to -15 degrees Fahrenheit in most parts of the state, some areas may drop even further. Wind chills could bring the real feel down to between -20 and -30 degrees in the Bluegrass and most of Central Kentucky. This will push the livestock cold stress index well into the emergency category.
As Arctic air builds in the state, livestock become vulnerable. As Arctic air builds in the state, livestock become vulnerable to deteriorating outside conditions. Dixon said that over the next week and possibly into early March, below normal temperatures look to remain in place, keeping the risk of livestock stress in place. “We just want to remind livestock producers to take proper precautions,” said Jeff Lehmkuhler, livestock specialist for the UK College of Agriculture, Food and Environment. “There’s always a risk for animals to fall through ice, if they have to search for water sources and end up walking out onto ice-covered ponds.”
Livestock producers should make sure animals have adequate shelter, water, dry bedding and feed to make it through this cold spell. Pet owners should bring pets indoors. UK livestock specialists said animals have a higher requirement for energy in the colder months, so producers should have high-quality forages and grains on hand to meet their needs.
The average horse, with a lower activity level, should eat between 1.5 and 2 percent of its body weight in feed per day to maintain its weight. UK equine specialist Bob Coleman said feed requirement goes up in the winter, as the horse uses more calories to keep warm. He recommended providing extra hay and adding grain to the diet if forage supplies are not adequate. For mature horses at maintenance, a good quality legume-grass mixed hay should be adequate, while young growing horses or broodmares in late gestation require a concentrate in their diets to meet the increased calorie needs due to the colder temperatures.
An owner adding concentrate for the first time should make the additions gradually to prevent digestive upsets. In addition, horses will need shelter to provide protection from the wind and any precipitation that may come. Coleman said it’s also important for horses to have access to clean water to ensure that the horses will eat adequate amounts of feed and reduce the risk of impaction. All horse owners need to take extra time observing horses during this cold snap to make sure they are all okay. Ones who are feeling the effects of the cold will need extra attention.
Ambient temperatures can impact the amount of dry matter cattle eat, providing an opportunity to compensate for increased maintenance energy needs. Producers either need to increase their animals’ feed intake or increase the energy density of the diet by feeding higher quality hay or adding more grain or fat to the grain mix, said Lehmkuhler.
He recommends that producers continue to monitor cows during wintertime and make sure to maintain the animals’ body condition.
“Poor quality hay may not provide adequate energy to maintain gestating cows that are entering the third trimester,” he said. “Consider having the hay tested to determine if you need to supplement during times of possible cold stress, especially for the enduring cold spells.”
He said to consider separating younger and thinner cows that may not have the same internal insulation as conditioned older cows and supplement them accordingly or offer them higher quality forage if available. Coleman said equine owners could employ similar strategies and separate animals according to body condition score.
“Producers should move cows to fields with natural windbreaks or provide manmade windbreaks, which are not the same as a barn,” Lehmkuhler suggested. “Poorly managed barns combined with poor ventilation may actually hamper efforts to improve the environmental conditions. Lastly, remember it is energy or calories that are really needed. If the protein level in the forage is adequate, do not make supplement decisions based on protein level; rather purchase the most affordable calories. Stay warm and keep the waterers flowing.”
The lower critical temperature (LCT) value for cattle is the lowest temperature or wind chill at which no additional energy is required to maintain core body temperature.
“As the temperature declines below this lower critical value, the maintenance energy value for the animal is increased to maintain core body temperature,” he said. “Animals maintain core body temperature by increasing their metabolism resulting in greater heat production, as well as other heat conservation strategies such as reducing blood flow to the extremities, shivering and increased intake.”
Several things can influence lower critical temperature value.
“Both external and internal insulation influences the LCT. External insulation is basically the depth and thickness of the hair coat, condition of the hair coat and thickness of the hide,” Lehmkuhler said. “Thin-hided breeds, such as dairy breeds, tend to have a lower insulating factor than thick-hided breeds like Herefords. The condition of the hair coat is extremely important as an external insulation barrier.”
The hair coat traps air, enhancing the insulating value. If the hair is wet and full of mud, air is excluded, reducing the insulating value and increasing heat loss from the skin to the environment. The density of the hair coat and if it is wet or dry impacts the wind chill temperatures at which cold stress is considered mild, moderate or severe. As little as 0.1 inch of rain can immediately impact cold stress severity by matting the hair down, reducing its insulating ability. Acclimation time, hide thickness, fat cover and other factors will also influence the degree of cold stress that animals experience.