No animal that has a blemish was acceptable in worship. This is highlighted in Leviticus 1:1–7:38. To make atonement or to offer praise to the holy God, one had to bring the best sacrifice possible. An animal with a blemish is considered to be incomplete and therefore unholy. It was not worthy to be offered as a sacrifice.
19 if it is to be accepted for you it shall be a male without blemish, of the bulls or the sheep or the goats.