Which is a common method of animal identification for livestock?

All of the mentioned methods—ear tags, microchips, and tattooing—are commonly used for livestock identification, making "all of the above" the accurate choice.

Ear tags are widely utilized due to their visibility and ease of application; they allow for quick identification of animals in the field. Each tag typically carries a unique number corresponding to the individual animal’s records, making it an effective tool for tracking health, breeding, and ownership.

Microchips provide a permanent and tamper-proof identification method that can be scanned to retrieve an animal's information. This method is becoming more popular, particularly in settings where animals may not be easily accessible or may have a high risk of tag loss.

Tattooing offers a long-lasting solution that is less likely to be lost compared to ear tags. It involves marking the animal's skin with a pattern or number that can be read for identification purposes. This method is often used in breeding and show animals where a discreet form of identification is preferred.

Together, these methods offer livestock producers flexibility in choosing the best identification method for their specific needs, contributing to the effectiveness of managing their herds.