In general, Stanton reminds us that all animals must have shelter from the wind. Because animals are spending a lot of energy to stay warm, provide extra access to food. Also, be sure fresh water is available to all animals at all times. A lactating cow needs to drink at least 15 gallons of water a day, and a weaned heifer needs at least 5 gallons. Snow is not an alternative to water.
Stanton offered more specific recommendations for young stock. Newborn calves should not be moved outdoors until they are 100 percent dry, she said. When you do move them, use an enclosed box or trailer with bedding to shelter them from the wind. At temperatures below 42°F, calves are spending energy just to maintain body heat and are vulnerable to frostbite, hypothermia and starvation.
Preweaned calves need more feed during weather like this. The high temperature in Madison, Wis., yesterday was -13°F. At this temperature, Stanton explained, a 100-pound calf needs 1.59 pounds of dry matter from milk (about 7 quarts of whole milk) just for maintenance. A 200-pound calf needs 2.7 pounds of dry matter (about 10 quarts of whole milk). This does not take into account wind chill or calves that are even slightly damp. This means that calves cannot get enough energy from 4 or even 6 quarts of milk per day in this weather, noted Stanton.
For calves to maximize energy use, be sure they are dry, have enough bedding to at least partially cover their back leg and consider calf blankets. Calves spend approximately 16 hours a day lying down, so make sure they have a warm surface to do so. Stanton also warned to not wean calves during this extreme cold as it will leave them vulnerable to illness and weight loss.
Weaned heifers' energy needs greatly intensify in this weather, as well. Maintenance requirements can roughly double for most animals when temperatures dip below zero and the wind starts to blow. (See chart below.)
The energy demands of a 600-pound Holstein heifer in -13°F weather with no shelter from the wind.
|Wind speed||Coat condition||Percent increase in maintenance energy demands compared to 32°F and 5 mph|
The energy demands of a 926-pound Holstein heifer at 90 days pregnant in -13°F weather with no shelter from the wind.
|Wind speed||Coat condition||Percent increase in energy demands compared to 32°F and 5 mph|
Lastly, don't forget to take care of yourself and your employees. Wear layers and stay safe, said Stanton. The most vulnerable people are the sick, elderly and the young. Frostbite can occur within 10 minutes when wind chills dip well below zero, and even faster when skin is wet.
The author is an associate editor and covers animal health, dairy housing and equipment, and nutrient management. She grew up on a dairy farm near Plymouth, Wis., and previously served as a University of Wisconsin agricultural extension agent. She received a master's degree from North Carolina State University and a bachelor's from University of Wisconsin-Madison.