Cattle, pigs, and sheep have their tails amputated. Reasons for tail docking vary, according to the species. Generally, it is implemented to curb aggressive behaviors between frustrated animals in close quarters as well as keeping the rear of an animal clean, which lowers risk of bacterial and parasitic infection.
A common method of docking an animal’s tail is using an elastrator — a rubber ring that is tied midway around the tail, cutting off blood circulation. Over time the end of the tail shrivels and eventually falls off. This is often done by clamping down on the tail with a metal device and twisting the tail until the bones break and the tail is able to be ripped off. This is generally done without anesthetic.
In a study by the National Animal Health Monitoring System, over ninety percent of lambs in the United States had their tails docked.