COUNTY AG NEWS
Caring for dairy and beef cattle in winter requires extra care. Cattle can handle the cold pretty well so long as they have some type of windbreak available. If a cow has good winter hair, she does fine until temperatures drop below 20 to 30 degrees F. Below that, she compensates for heat loss by increasing energy intake; she must increase heat production to maintain body temperature.
A cow needs to eat more roughage in cold weather, to give her the calories for heat energy. More total pounds of roughage in her diet (extra grass hay, or even straw) can keep her warm, since the fermentation and breakdown of cellulose creates heat energy. High quality alfalfa hay supplies protein, calcium, vitamin A and other important nutrients, but not enough roughage for heat energy in cold weather.
Alfalfa alone is not adequate for cattle in cold temperatures; cows will gobble it up and stand around shivering, losing weight. Cows with normal winter hair coats need about one third more feed when exposed to wind chill temperatures at or near zero.
Critical temperature for any cow or calf will vary according to hair coat, moisture conditions, age, size of animal, fatness (fat under the skin is good insulation against cold), length of time exposed to adverse conditions, and amount of wind.