Hello Dears, Mother Nature here!
I want to remind you that winter is just around the corner. It is time to ask yourselves if you are prepared for what I am about to unveil? You know, the furious winds, magical snow, glorious ice storms. Oh, I get chills just imagining it!
Here’s some advice to keep your cows and calves warm and cozy through it all.
Fur has limitations. It takes time for animals to acclimate to cold temperatures. This is due, in part, to the ability of the animal to grow a thicker coat. Unlike humans, cattle cannot just throw on another layer. Therefore, the point at which cows experience cold stress varies depending on the condition of their coats. With a summer or wet coat, temperatures below 59 degrees F will cause a cow to expend energy to stay warm. With a dry fall coat, that temperature drops to about 45 degrees F. Once their winter coat develops, and they continue to stay dry, cows can withstand temperatures of 32 degrees F. And finally, they can handle temperatures down to about 18 degrees F with heavy, dry winter coats. Depending on where you live, your cows may never develop a heavy coat. Younger animals are not able to tolerate as much cold as adults. Their thermoneutral zones are significantly higher than the numbers given above. To compensate, provide adequate bedding. Bedding provides them with a blanket, so to speak, to help stay in the thermoneutral zone. Also, consider using calf jackets on newborn calves.
Temperature is relative. When we speak of temperatures, additional factors, like wind speed and humidity, impact how cold it may really feel. Cold winds moving over an animal move heat away from it much more quickly than still air at the same temperature. Likewise, a wet coat will enable evaporative cooling which removes heat from the body more quickly than a dry coat. Let’s assume that the temperatures are 39 degrees F. If you add a wind speed of just 15 miles per hour, the temperature actually feels like a 19 degrees F. As for a wet coat, try standing in front of a fan after your next shower and you’ll get the idea. Provide your cattle with shelter from the wind and moisture. If you don’t have barns, be creative. Straw bales, old machinery, natural tree lines, snow piles can all make good windbreaks. Again, use bedding to keep them dry.
A little fat can be a good thing. Cattle in good body condition can withstand the cold better than thin cattle. On most dairies, this then means that calves and peak-lactation cows are the most vulnerable groups to cold stress. Calves are born with limited amounts of brown fat stores that are quickly utilized in the first few days to help them survive until they begin to consume enough calories to support their needs. Therefore, calves must be bedded and their energy requirements adjusted to help them grow. The low critical temperature for a young calf is around 59 degrees F. When the temperature drops to 32 degrees F, the calf needs 1.9 additional quarts of a 20/20 milk replacer mixed at 4.4 ounces/quart. Young calves have low starter consumption and they should then be given additional calories with milk feedings. Older calves can be expected to consume more calories with grain feedings. There are too many strategies of how to best accomplish this for me to cover here, so consult with your veterinarian and nutritionist to develop your plan.
With some planning and careful consideration of animal needs, perhaps you, too, will see that wintertime is a beautiful season.
Angela M. Daniels is a veterinarian with Circle H Headquarters LLC, a dairy and swine veterinary practice, food safety laboratory and DHIA milk-testing and contract research organization in Dalhart, Texas.