During the winter months, spring-calving beef cows are in mid-gestation. This is the stage of production when cows have their lowest nutrient requirements. However, even though the cows’ requirements are relatively low during this time of year, there are still a few factors that demand special attention during winter.
Two factors that are often overlooked in winter are the weather and its effect on the cows’ nutrient requirements and proper ventilation in barns.
Cattle are most comfortable and perform best within the thermoneutral zone – where the ambient temperature is neither too hot nor too cold. The low end of this zone, known as the lower critical temperature, is the point when the animal requires additional energy to maintain its body temperature.
Adding to the challenge, a wet hair coat (caused by snow, rain, sleet, or high humidity in a barn) can cause the lower critical temperature to increase, which means that the cow’s requirements will begin increasing as soon as the wind chill drops below this point.