Caring for the lactating dairy herd in extreme cold conditions also has its challenges, explained Tracey Erickson, SDSU Extension Dairy Field Specialist.
"If not properly cared for, producers may see a decline in performance including total milk production, increasing somatic cell counts due to mastitis, losses in reproductive efficiency and even decreased growth in young first calf heifers if the extreme cold continues for extended periods of time," Erickson said.
Below, Erickson outlines some factors dairy producers should consider to limit the negative impacts of extreme cold on a dairy herd.
The thermoneutral zone is the environmental conditions where a cow does not expend extra energy to either cool or heat its body. In dairy cattle this range is between 40 degrees to 68 degrees Fahrenheit for a lactating dairy cow.
"Even though a majority of lactating cows are housed inside throughout the year, there are still some important factors to remember," Erickson said.
If the ambient air temperature is on either side of this range, Ericson said the animal will adjust its energy usage via thermoregulation.
"It will either warm or cool itself instead of putting the energy from the diet towards growth, reproduction, production and maintenance," she said.
Factors that can affect the upper and lower critical temperature, when combined are the base air temperature, wind, and humidity.
"Adequately managing the dairy herd through these swings in the thermoneutral zone will improve overall performance of the lactating dairy herd," Erickson said.
In extreme cold conditions, Erickson reminds dairy producers to remember to provide an adequate amount of water on a daily basis.
"Adequate water consumption is critical to maintaining feed intake, milk production levels, reproductive efficiency and overall metabolic function," she said.
On average, a lactating dairy cow consumes in excess of 15 gallons of fresh water per day.
"Water sources should be checked throughout the day in extreme cold to make sure they are not frozen and working properly," Erickson said. "It is important to not let ice buildup happen near waterers which can cause injury due to slips and falls."
Erickson encouraged dairy producers to take an inventory of their facilities.
"Do you have ripped curtains, holes in your wall, or doors that do not close adequately? Is it causing unnecessary drafts which may cause frost bite," she said. "Check your barn fans, if they are not functioning properly they are not circulating the air causing increased humidity in the barn, resulting in increased pneumonia risk and frost buildup."
If cows are housed outside, Erickson said it's important to ensure they have enough wind protection and adequate clean, dry, deep bedding.
"Keep in mind, cattle with a good long hair coat are able to trap warm air in and around the hairs, allowing the body to stay warmer," she said. "Whereas a wet haircoat or a haircoat covered in manure will provide less protection from the cold letting the body heat out and cold air in."
Other considerations to keep in mind when inspecting the dairy barn, is making sure that all smoke and fire detectors are in working order.
Using caution and common sense if a portable space heater is needed. Do not place near flammable items such as paper towels or bedding, making sure they cannot be tipped over easily.
Continuing to teat dip, Erickson said, is still a necessity and essential to minimize mastitis risk.
"You still want to use a teat dip that has an effective germicide while also providing a skin conditioning agent," she said. "Some practices that may help, if the cow will be exposed to wind chills directly post milking are dabbing the teat end with a clean towel once the post dip has been applied. Do not dry the entire teat which essentially removes the dip. The other option is to just dip the teat end in extreme cold temperatures."
Erickson also said it is important to allow enough time for the teats to dry before exposure to colder temperatures outside the milking parlor or barn.
"Warming the teat dip helps reduce drying time," she said. "Keep in mind fresh cows with swollen udders are more susceptible to chapping."
Even though dairy cattle are ruminants and producing their own heat as they digest feedstuffs, Erickson said it will still be necessary to make diet adjustments based upon the temperature, wind protection, overall body condition, milk production levels, along with the body growth and maintenance needs of the animal.
Work with your nutritionist to adjust diet dry matter intakes and energy levels during extreme cold weather periods.
Dairy producers should also make sure temperature sensitive vaccines and antibiotics are properly stored.
"Frozen vaccine inactivates the vaccine and they are now no good, costing you money while providing no benefit to the animal. The same can also be true for certain antibiotics," Erickson said.