Leviticus 22:28

Ye shall not kill it and her young in one day - This precept was certainly intended to inculcate mercy and tenderness of heart; and so the Jews understood it. When it is necessary to take away the lives of innocent animals for the support of our own, we should do it in such a way as not to blunt our moral feelings; and deplore the necessity, while we feel an express gratitude to God for permission, to do it.