Ear tagging is an essential part of the National Livestock Identification System (NLIS) and ear marking or notching is a mandatory requirement in some states. It also has business benefits by enabling livestock to be identified on-farm, leading to improved management.

Flexible plastic animal ear tags are probably the most widely used for cattle identification. Placing the tag in the animal by piercing a hole in the ear with a secure backing is most common.

Numerous brands and types of tags are on the market. Ear tags have limitations in brushy areas; however, more flexible tags have seemed to aid in retention.

Retention and legibility are the most important considerations for all tags. A producer may purchase preprinted tags or choose to write his or her own numbers on the tags.

Some tags have special markers for writing on them, others are designed to have numbers inscribed in them. It is important to make sure tags are large enough to be read at a distance and that numbers remain readable.

Ear tags can be purchased in different colors and types. When applying ear tags, it is important to avoid the cartilaginous ribs of the ear as well as to choose a flexible portion of the ear.

Some producers find it helpful to tag steers and heifers in opposite ears or with different-colored tags, which aids in sorting.