StettlerLocal.com December 16, 2021, contributed by Yaremcio Ag Consulting, Ltd.
Colder temperatures increase stress on livestock. When temperatures dip below -20o C, mature cows are not able to generate enough heat to stay warm. The amount of stress is more acute with smaller calves and especially those that are less than 450 pounds.
It is natural for animals to eat more feed when it gets cold. Provide extra hay or silage, which are higher energy, higher protein feeds. It is not sufficient to have cows eat extra straw in this situation. Straw is difficult to digest, and it will slow passage rates. This reduces feed intake.
Thin animals cannot tolerate the cold as well as those that are in good shape. They do not have the fat layer to provide insulation. When they become energy deficient, they will mobilize available fat to keep warm. This causes animals to lose weight.
Feeding extra grain is recommended. At -30o C, increase grain intake by an extra two pounds of grain per head per day over and above what was previously being fed at -20o C. If temperatures drop to -40o C, four pounds of extra grain per head per day needs to be added.
Provide shelter by having a wind fence in place, or a good shelterbelt reduces cold stress. Having lots of bedding in the pen or loafing area further protects them from the wind and cold ground. If the calves can hide in a hutch, supply enough straw so that only their ears can be seen when they are lying down. If possible, move the thinnest or smallest animals into a barn to protect them from the weather. A cow laying on dirty or wet snow could potentially lose 25% of the heat that is generated.
The amount of grain-fed needs to be reduced when the forecast indicates a moderation in temperature will occur. Start reducing grain two to three days prior to warmer weather. By the time temperatures reach -20o C, the ration should be back to normal grain feeding rates. If grain is not reduced by this time, the cows can experience heat stress.
Barry Yaremcio
Ruminant Nutritionist