Which of the following is a method of permanent identification for bovines?

Hot iron branding is a traditional method used for the permanent identification of bovines. This method involves applying a heated iron brand to the animal's skin, which leaves a lasting mark that can serve as an identifier throughout the animal's life. The brand often includes letters, numbers, or symbols that represent the owner's registration or farm.

Microchipping, although a form of identification, is not typically used as a permanent method for livestock in the same way as branding. It can be more easily removed or fail to comply with certain livestock management protocols. Ear tagging is widely used for identification as well, but it is not a permanent method since tags can be lost or damaged. Color coding can be utilized for temporary identification purposes, often related to sorting or grouping animals, but it does not provide a permanent record of ownership or identification.

Thus, hot iron branding stands out as the most recognized and historically established method for providing a permanent identification for bovines.