Calf jackets can be a good idea, especially in colder environments. They serve as a barrier to environmental conditions such as low temperatures and drafts, without restricting airflow. This can be particularly beneficial for newborn calves who are unable to properly regulate their body temperature during the first few weeks of life.

Studies have shown that calf jackets can create a micro-environment for the calf, which helps maintain body heat. This can lead to increased daily live weight gains, improved coat condition, and fewer health issues. Additionally, calf jackets can result in significant savings on feed, medication, and bedding costs by better conversion of energy to growth rather than warmth, and reduce the risk of illness from chills and drafts.

It’s important to note that the effectiveness of calf jackets can depend on various factors, including the environmental temperature, the calf’s age, and the overall management of the calf rearing operation. In general, they are most useful for calves under 3 weeks of age, particularly in temperatures below their lower critical temperature, which can range from 13°C at birth to 8°C at 3 weeks of age.