These earmuffs may look adorable but they serve a very important purpose. The calves must be protected from the cold as it can lead to severe frostbite, hypothermia, and even death. These muffs help protect from the wind chill.
According to Dr. W. Dee Whittier, Bovine Specialist at the Department of Large Animal Clinical Sciences, wrote in a paper titled 'Calves and the Cold', "Frostbite is the damage to body tissues that occurs when these tissues freeze. The extremities are most at risk. Frozen ears and tails result in changes of cattle appearance but do not affect cattle performance significantly."
Dr. Whittier continues, "Newborn calves are most at risk because they are wet and because they have a large surface area in relation to their total body mass. Calves are not fully capable of maintaining temperature the first several hours of life. Newborn calves have a circulatory system that is less able to respond to cold changes as compared to more mature animals."
Turns out, when it comes to detecting frostbite, if the ear-tips are frozen, there's a high chance that the feet are experiencing some damage as well.
If that does occur, Dr. Whittier recommends to thaw the tissues as quickly as possible. And once the tissues are thawed, you must prevent re-freezing from occurring. Which means housing with heat for several days. Damaged tissues are more prone to re-freeze and can do so very easily.