When you offer a sacrifice to ask my blessing, there must be nothing wrong with the animal. This is true, whether the sacrifice is part of a promise or something you do voluntarily.
Some of the priests will lay these pieces on the altar and send them up in smoke with a smell that pleases me, together with the sacrifice that is offered to please me.
But isn't it wrong to offer animals that are blind, crippled, or sick? Just try giving those animals to your governor. That certainly wouldn't please him or make him want to help you.