Leviticus 22:21, 23

“If you present a peace offering to the LORD from the herd or the flock, whether it is to fulfill a vow or is a voluntary offering, you must offer a perfect animal. It may have no defect of any kind.

If a bull or lamb has a leg that is too long or too short, it may be offered as a voluntary offering, but it may not be offered to fulfill a vow.