Which of the following is not a permanent form of identification?

Ear tagging is not considered a permanent form of identification. It involves attaching a tag to the ear of an animal, which can be lost or damaged. While ear tags are useful for immediate identification and may be replaced, they do not provide a lasting form of identification that remains with the animal throughout its life.

In contrast, ear notching and ear tattooing create more permanent marks on the animal. Ear notching involves cutting a unique pattern in the ear, which lasts for the lifetime of the animal, while ear tattooing involves applying ink to a designated area within the ear, embedding a unique identification that is typically very difficult to remove or alter. Chemical branding, while less common, also leaves a permanent mark on an animal's hide.

This distinction is important in livestock management as permanent forms of identification are crucial for tracking animal lineage, health records, and ownership.