As we enter into the coldest weather of the year in the Southeast, it is very important we manage our cattle herd for these cold days ahead. These are the critical months to maintain body condition on cattle. Energy requirements are at their highest during extreme cold weather, and I continue to be concerned over the quality of forage we have available this year. High input fertilizer cost deemed it necessary for a lot of cattle producers to either reduce our eliminate fertilizer applications in hay fields. This will leave hay crops at a below average energy level (TDN). The use of lower quality forage during cold weather will leave cattle in a reduced energy balance meaning loss body condition. This lost body condition will have a direct impact on reproduction and performance this spring.
With the beginning of cold weather, I wanted to look at some issues concerning the relationship between temperatures and feeding demands of brood cows. I would suggest you closely monitor your cattle this winter. When the weather is cold and wet, cows need extra feed to just keep warm. A cow needs to eat more roughage in cold weather to give her the calories for heat energy. If she doesn’t have enough roughage, the pounds will melt off of her as she robs body fat to keep warm.
High quality feeds is not as efficient as roughage in producing long term heat because cows will readily gobble up the feed and stand around shivering. If a cow has a good winter hair coat, she will do fine in dry weather until temperatures drop below 32o F. With a wet hair coat due to rain and snow, this critical temperature can rise to as high as 59o. At these points, she will require an increase in feed intake to produce the body heat and stay above her lower critical temperature level.
Lower critical temperature is defined as the lower limit of cattle comfort during cold weather. When below this level, an increase in feed is required to maintain the cow’s current body status. When figuring lower critical temperature, you must also take into account the wind and moisture make effective temperature lower than thermometer temperature. You must always determine the wind chill factor when arriving at amount of degrees below a cow’s critical temperature point. Critical temperature for any cow or calf will vary according to hair coat, moisture, age, size, amount of body fat, length of exposure and wind. Cold stress is also less severe if the storm is brief, compared with the chill and stress of continuous bad weather.
Critical Temperature for Beef Cows
|Coat Description||Critical Temperature|
|Summer or Wet||59o|
A rule of thumb to compensate for cold is to increase the amount of feed (energy source) by one percent for each two degrees of cold stress. For thin cows, cows with poor hair coats or a wet hair coat figure a 1 percent increase for each temperature drop. Example A: A wet cow will require 9 percent more feed at 50o than that same cow at 59o. Example B: A cow exposed to a wind chill temperature of 28o on a dry day will require 4 percent more feed than the same cow at 32o.
Many producers overlook the effects of cool, wet weather when supplementing cattle. I would suggest you become familiar with the critical temperature of your cow herd and make feeding decisions based upon this. I would also encourage you to look at alternative energy sources like complete beef feeds or low moisture supplement tubs like STIMU-LYX to add more energy to your cattle herd during the cold days ahead. By doing this, your cows will remain in better condition and be more productive as they calf this spring.
I hope each of you had a Merry Christmas and look forward to a new year with the hope of good prices and prosperous crops.
Jimmy Hughes is AFC’s animal nutritionist.