Elevation of the tailhead in this cow is the result of chronic cystic follicular degeneration which has led to chronic relaxation of the pelvic ligaments. These cows show frequent behavioral estrus. In the vernacular they are called buller cows. They can be of help in a heat detection program, however their behavior is not consistent. The elevated tailhead is sometimes referred to as the sterility hump.
Drost M (1970)