That's just not how labor animals work. Just like human laborers, animals need rest, and they're darn expensive. You can't drive your workhorse or your ox 24/7,

That's just not how labor animals work. Just like human laborers, animals need rest, and they're darn expensive. You can't drive your workhorse or your ox 24/7, it would die early and you would just be squandering your investment. For meat on the other hand, you can lock your cow or pig or chicken in a cage exactly the size of its body with no stimulation except the food being shoved down it's throat, it'll get fat and you can sell if for meat. There is no downside to mistreatment.