Although techniques may have changed, the primary purpose of marking livestock remains a method for identification. As systems have developed, the uses of identification have extended beyond ownership disputes. In Australia, ear tagging and marking now form the basis of the National Livestock Identification System (NLIS), the system used for tracing cattle, sheep and goats for biosecurity, food safety, product integrity and market access purposes. Similar systems exist in other countries, such as the National Animal Identification System in the United States, the British Cattle Movement Service, and the National Animal Identification and Tracing system being developed in New Zealand.
Under the NLIS, cattle must be marked with an ear tag or a combination of a rumen bolus and visual ear tag. Sheep and goats are marked with a visual ear tag or an RFID ear tag. Branding of livestock is also included within the NLIS in Western Australia, and the requirement for ear marking varies by state. It is intended to ensure the safety and quality of meat by tracking livestock from birth to slaughter. For example, all cattle treated with a hormonal growth implant must be permanently identified with a triangular ear mark in the middle of the right ear. Furthermore, marking livestock in this way allows for a database of animal residency and interaction with other animals to be kept. This aids in disease identification and management, and can help prevent widespread outbreaks.
In addition to differentiation of livestock between farms, forms of livestock marking are important to differentiate livestock within farms. Numbering systems using neck chains, nose printing, tattooing and electronic systems are common for identifying individual animals within a farm. This may be required to keep track of the age of animals, and also assists in identification in sale rings or during exhibiting shows.
Branding remains particularly important for identifying breeds of horses, such as Thoroughbreds, Stock Horses and Arabians. It is required by regulations in Australia, New Zealand and the United States, among other countries. Branding of horses is usually performed by freeze branding, altering the pigment of the hair.
Livestock branding and marking has evolved from a simple system for identifying ownership to a complex RFID and electronic-based tracking. While ownership is still an important part of livestock marking, new technology has significantly extended its usefulness. It is now a vital part of strategies developed to ensure the quality and safety of meat, and to prevent the spread of disease.