This seems like a question of cow-liberation vs miscowlibration.

How do you inform a cow?

@CertaintyOfVictory Offering it fake food and it trying to take a bite?

If he says "the sky is green" to a cow, does that count as a lie? The cow doesn't understand English, so wasn't mislead.

It would be possible to lie to a cow, such as by training it with an expectation that is broken, but it would be more involved than an off-hand sentence.

@Mira I will leave that interpretation up to Eliezer.