“Do not muzzle an ox while it is treading out the corn” (Deuteronomy 25:4).
This pithy little command is set within other instructions which include one providing that a poor man’s wage be paid before day’s end because he is poor and is counting on it. That is an ethic which seems reasonable, but why should a human being care about how an animal feels? Maybe, because humans who treat animals without regard to their sentient state, are more likely to behave capriciously and unjustly in relation to people. The animals may not know right from wrong but their owners do not cease to be moral beings in relation to them.