Leviticus 22:21, 23

When a man offers a sacrifice of peace offerings to the LORD to fulfill a special vow or for a freewill offering, of the herd or of the flock, it must be perfect to be accepted; there shall be no defect in it.

In respect to an ox or a lamb which has an overgrown or stunted member, you may present it for a freewill offering, but for a vow it will not be accepted.