Grant Dewell, ISU extension beef veterinarian; Erika Lundy, ISU extension beef specialist; and Denise Schwab, ISU Extension beef specialist
Caring for cow herds during the winter can be challenging when it becomes bitterly cold. In general cows are cold tolerant and are comfortable down to 20°F. Most cows are managed outside even under extreme conditions and can benefit from extra care when effective temperature (ambient temperature and wind chill) drops below 0°F.
Windbreaks can be an important strategy to offset the impact of strong winds on reducing the effective temperature. Bedding also is a good management tool to minimize the effect of cold on cattle and can be critical for neonatal calves and to protect teat ends and scrotums.
Most importantly: provide additional nutritional energy to meet the cow's need to generate heat to maintain body temperature. Feeding cows in the late afternoon will help cows get through cold overnight temperatures as rumen heat production peaks about 6 hours after being fed. During periods of continual cold weather cows will need approximately an extra pound of corn for every 10° of cold stress below 20°F.
Be prepared to provide extra bedding and feed during major storms, and remember that severe weather may prevent you from easily getting feed to cows. Backup feeding areas may be needed. With sustained power loss you may also need supplemental ways to keep water tanks thawed out, and equipment may not be easy to start.
Talk with your local beef extension specialist, veterinarian and nutritionist about what you can do to provide best care for your cows during extreme weather.