What happened to the animal if it was not redeemed?
Leviticus 27:27 (ESV)
27And if it is an unclean animal, then he shall buy it back at the valuation, and add a fifth to it; or, if it is not redeemed, it shall be sold at the valuation.
If the original owner did not redeem the animal, the priest could sell it and use the proceeds for the sanctuary.
27 And if it is an unclean animal, then he shall buy it back at the valuation, and add a fifth to it; or, if it is not redeemed, it shall be sold at the valuation.