In context, Old Major is asking his comrades (fellow animals) what they feel about the lives they're living..... and stating what he sees as the true nature of their lives...... their happiness, their purpose, and their condition. He isn't so much asking a question, as he is stating a point.
“Now, comrades, what is the nature of this life of ours? Let us face it: our lives are miserable, laborious, and short. We are born, we are given just so much food as will keep the breath in our bodies, and those of us who are capable of it are forced to work to the last atom of our strength; and the very instant that our usefulness has come to an end we are slaughtered with hideous cruelty. No animal in England knows the meaning of happiness or leisure after he is a year old. No animal in England is free. The life of an animal is misery and slavery: that is the plain truth.