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Bitter cold temps will create prolonged period of livestock cold stress

Bitter cold temps will create prolonged period of livestock cold stress

Bitter cold temps will create prolonged period of livestock cold stress

UK specialists warn producers to keep a close watch of animals during upcoming cold spell.

Published on Jan. 3, 2014


Bitter cold temperatures are on the way, and they will move the livestock cold stress index into the emergency category for a prolonged period, said Matt Dixon, agricultural meteorologist with the University of Kentucky College of Agriculture, Food and Environment.

A low pressure system will bring extremely cold arctic air into the region into next week. Highs on Monday, Jan. 6 will only reach the single digits for much of the state with some locations in Northern Kentucky potentially not getting above zero. Temperatures Monday night and Tuesday morning could drop between zero and minus 10 degrees. Breezy west-northwest winds will accompany these temperatures and put wind chill values down below minus 10 degrees during the day on Jan. 6 with some locations having wind chill values 20 below zero that night.

Dixon said this is the coldest air that the state has had in several years.

“Lexington has not seen the mercury drop below zero since Jan. 22, 2011, and that same year, Paducah dropped to a low of minus 4,” he said. “The forecast low of 5 degrees below zero for Lexington has not been realized since January 2004. The record low was set in 1963 when Lexington got down to minus 21 degrees.”

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 that 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. If an owner is adding concentrate for the first time 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. He 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 all horses are 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 UK beef specialist Jeff Lehmkuhler.

Lehmkuhler recommended that producers continue to monitor cows during the 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 can employ similar strategies and separate animals according to body condition score.

“Producers should move cows to fields with natural windbreaks or provide man-made 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.”

Lehmkuhler said 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,” he 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 acts as insulation similar to home attic insulation that 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.

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