Which of the following methods can be used to identify sheep?

Ear tagging is a widely used method for identifying sheep due to its effectiveness and practicality. It involves placing a unique identification tag in the ear of the sheep, which allows for easy visual identification. This method is not only cost-effective but also provides clear visibility of the sheep's identification number or code, making it easier for farmers and handlers to manage and monitor their flock.

Ear tags are durable and can withstand various environmental conditions, making them suitable for outdoor use. They can also be customized with different colors, shapes, and sizes, helping to organize and identify individual sheep or groups within a herd. Additionally, ear tagging is a non-invasive method, which minimizes stress for the animals compared to some other identification methods.

Other methods like microchipping, while accurate, may be more expensive and less practical for large flocks. Branding can be intrusive and stressful for the animal, and collar identification may not always be suitable due to the risk of losing the collar or it getting caught in vegetation. Therefore, ear tagging stands out as a preferred and efficient identification method for sheep management.