Leviticus 27 10
You are not allowed to replace it or swap it, either for one that is better or one that is worse. However, if you do replace it then both animals become holy.
Compare with other 3 random translations
EAS Leviticus 27:10The person must not change a good animal for a bad animal. He must not change a bad animal for a good animal. If the person does change one animal for another, both the animals become holy.
NKJ Leviticus 27:10He shall not substitute it or exchange it, good for bad or bad for good; and if he at all exchanges animal for animal, then both it and the one exchanged for it shall be holy.
WEB Leviticus 27:10He shall not alter it, nor exchange it, a good for a bad, or a bad for a good. If he shall at all exchange animal for animal, then both it and that for which it is exchanged shall be holy.