Cruelty to Animals

The basic source for the prohibition of cruelty to animals (tzaar baalei chayim) is Ex. 23:5, the commandment to help unload an overloaded animal. The Talmud discusses it in Bava Metzia 32bff. A lesser-known source is Midrash Ha-Gadol on Num. 22:32, where R. Yochanan derives tzaar baalei chayim from the verse "why did you hit your ass?" (Num. 22:32); the same idea is in the Sefer Chasidim, Secs. 44,169,666-670 (also quoting a Midrash on Zechariah 12:4). The Sefer Ha-Chinuch says that the process of kosher slaughter is designed to minimize the animal’s pain (R’eh, Mitzvah 451), and that plowing with kilayim (two species of animals) has a similar reason (Ki Setze, Mitzvah 550; see also Baal Ha-Turim on Deut. 22:10). Maimonides in his Moreh Nevuchim says that the prohibitions of slaughtering an animal and its child on the same day (oso ves beno) and taking eggs or young birds that the parent bird is sitting on (shiluach ha-kan) were commanded to avoid traumatizing the parent by the killing or taking of the children; but Nachmanides (Deut. 22:6) disagrees with this. The requirement of feeding one’s animals before eating is based on the same reason; see Sefer Charedim, Ch.4.