Leviticus 22:28 KJV
And whether it be cow or ewe, ye shall not kill it and her young both in one day.
Leviticus 22:28, King James Version
In context
27 When a bullock, or a sheep, or a goat, is brought forth, then it shall be seven days under the dam; and from the eighth day and thenceforth it shall be accepted for an offering made by fire unto the Lord.
28 And whether it be cow or ewe, ye shall not kill it and her young both in one day.
29 And when ye will offer a sacrifice of thanksgiving unto the Lord, offer it at your own will.