The use of calf coats helps to prevent loss of body heat in calves, allowing for better conversion of energy to growth rather than warmth. The coats also help reduce the risk and costs associated with pneumonia and scours caused by chills and draughts. With healthier calves and improved energy conversion, target growth weights at 7 weeks of age are optimised.
Dairy breed calves do not have enough body fat to maintain their own body temperature in cold weather. There is a temperature range when the amount of body heat produced by the calf is balanced by her body heat loss. This range is called the “thermo neutral” zone. This is typically between 10°C—20°C.
Below 10°C (including wind chill) calves will burn energy just to maintain core body temperature. A calf requires 2% more energy for every 1°C below the thermo neutral zone. Therefore at 0°C the calf requires 20% more energy just for maintenance. Keeping the calf warm is the most cost effective way of maximising the feed given.