Helping Your Cows Survive the Cold
In typical eastern NC fashion, the temperatures have been fluctuating between cold and warm(ish). As they begin to stay cold for longer and longer periods it’s important to think about your cattle and how to keep them warm, healthy, and thriving through the winter.
Protecting your young calves should be a top priority. They are your future and the continued success of your herd depends on them. Newborn calves are in the highest risk category, especially before they dry off. The wet hair coat, combined with cold temperatures and possible wind, do not protect the calf very well. Once it can nurse and get the proper amount of colostrum, and has a mother that licks it off almost immediately at birth, then it has a good chance of surviving. If the calf cannot get colostrum, which has 2-3 times the fat of “regular” milk, it does not have enough energy to maintain and regulate body heat. As calves get older, the use of windbreaks and shelters are helpful; proper nutrition is also critical in ensuring your calves weather the winter.
For cattle with dry, winter coats the critical temperature is significantly lower than in those newborn calves. This temperature, referred to as lower critical temperature (LCT), is the temperature below which the animal must burn extra energy to keep warm (November BEEF magazine article). Young calves have an LCT that is close to 60°F while mature cows can be closer to 30°F or possibly lower—depending on the animal. This all changes when precipitation is added into the equation…a 45-50°F LCT is not uncommon for cold, wet cows. Essentially this means that with each change in temperature below that LCT, the cow needs to increase her feed and energy intake to stay warm. The rule of thumb is that she needs an increase of 1% TDN for every 1°F than the critical temperature. This rises to 2% TDN for wet animals. Protein and energy needs should be met with the supplemental feed so that she can combat the cold stress.
We’ve covered calves and cows, all that we have left to talk about are bulls. The biggest risk you run with bulls in winter conditions are damages to sperm production and fertility. Extreme cold can harm the genitalia of the bull (frostbite, testicle damage) which results in a decrease in sperm production, or at least in viable sperm formation. Because bulls have to regulate their testicular temperature by drawing the testicles up towards the body when it gets too cold, the scrotum has to be fully functional. Scarring or frostbite from extreme wind and/or cold can reduce the effectiveness of this temperature regulation. It’s important to provide enough bedding during the winter for your bulls; the bedding will serve as insulation for the bull.