Leviticus 27:11-13

27:11 If what is vowed is an unclean animal from which an offering must not be presented to the Lord, then he must stand the animal before the priest, 27:12 and the priest will establish its conversion value, whether good or bad. According to the assessed conversion value of the priest, thus it will be. 27:13 If, however, the person who made the vow redeems the animal, he must add one fifth to its conversion value.

Leviticus 27:27

27:27 If, however, it is among the unclean animals, he may ransom it according to its conversion value and must add one fifth to it, but if it is not redeemed it must be sold according to its conversion value.