Managing a dairy herd in extreme cold has its challenges. Dairy producers may see a decline in total milk production or an increase in somatic-cell counts due to mastitis. They also may see losses in reproductive efficiency and even decreased growth in first-calf heifers if extreme cold continues for extended periods.
Even though most lactating cows are housed inside throughout the year there are still important points to remember. The thermoneutral zone is where a cow doesn’t expend extra energy to either cool or heat her body. The range is between 40 degrees Fahrenheit and 68 degrees Fahrenheit for a lactating dairy cow. If ambient air temperature is on either side of that range, a cow will adjust her energy usage via thermoregulation. She’ll either warm or cool herself — instead of putting energy from her diet toward growth, reproduction, production and maintenance.
Factors affecting upper and lower critical temperatures are base air temperature, wind and humidity. Properly managing the herd through swings in the thermoneutral zone will improve overall performance.
Producers must remember to provide an adequate amount of water on a daily basis, especially during extreme cold. Adequate water consumption is critical to maintaining feed intake, milk-production levels, reproductive efficiency and overall metabolic function. On average a lactating cow consumes in excess of 15 gallons of fresh water per day. Water sources should be checked throughout the day in extreme cold to ensure they’re not frozen. It’s important not to let ice buildup happen near waterers, which can cause injury due to slips and falls.
Take a look at facilities. Ripped curtains, holes in a wall or doors that don’t close appropriately may cause unnecessary drafts that may cause frostbite. Check barn fans. If they’re not functioning properly, they’re not circulating air, causing increased humidity. That can result in increased pneumonia risk and frost buildup. If cows are housed outside, provide wind protection, and clean, dry and deep bedding.
Cattle with long hair are able to trap warm air in and around the hairs, allowing the body to stay warmer. But cattle with wet coats or coats that are covered in manure will provide less protection from the cold.
Continue to use a teat dip, particularly one that has an effective germicide and a skin-conditioning agent. That’s essential to minimizing mastitis risk. It may help to dab teat ends with a clean towel once post dip has been applied, if the cow will be exposed to wind chill directly post-milking. Don’t dry the entire teat, which essentially removes the dip. The other option is to just dip the teat end in extreme cold temperatures. Allow enough time for teats to dry before outside exposure. Warming the dip helps to reduce drying time. Remember that fresh cows with swollen udders are more susceptible to chapping.
It will still be necessary to adjust diet even though cattle produce their own heat as they digest feedstuffs. The adjustment should be based upon temperature, wind protection, overall body condition and milk-production levels along with the animal’s body growth and maintenance needs. Work with a nutritionist to adjust dry-matter intake and energy levels during extreme cold.
Ensure all smoke and fire detectors are in working order. Use caution and common sense if a portable space-heater is needed.
Ensure temperature-sensitive vaccines are properly stored. Frozen vaccine inactivates the medication. The same can be true for certain antibiotics.