I think they know how very vulnerable they are. I live by a cattle farm, and all of my life I have taken time to go and watch the way they behave when I am near to them. Cows will stop and stare right into your eyes, and even when you walk slowly toward them, they flee. Only once did I see one of them stand fast. I red bull stared me down, cornered me near an old stone feed house, and had I not taken a loose brick, throwing it in the bull's direction, it would not have allowed me to leave. I was, to say the least, quite concerned in that moment of "squaring off."
It's a real mystery, if one can consider the plight of cattle, that they have endured the trials of *time at all. Their blatant vulnerability leaves them at the whim and mercy of whatsoever is empowered to overtake them, be it humans, or beasts of prey such as wolves, lions, bears and the like. They are by no stretch of one's imagination - "fit for the slaughter" - as it were.
Having said that, I am truthfully baffled by their presence to date, so it's easily deduced that humans saw two special things about them. Their peaceful nature so as to protect them and regard them as holy, and their capacity for being herded for food. The life of the cow is to be regarded as holy in either case.
Temple Grandin is a functioning Autistic scientist/engineer/designer. Her work in making cattle's lives better through functional designs to make the slaughter industry more humane was due to her regard for animals that are bred to be mutilated. She grew up with cows, like me, and regarded them as wondrous loving animals. Did she eat meat? No, but that is attributed solely to her autism, and her regard for them from her humanity.
It's no crime to eat meat, and I doubt that cattle contemplate their existence, although, like Grandin, I believe they feel pain, fear and other emotions which should be regarded by our consciences if in fact we are going to dine on their bodies.
That they have survived thousands of years without becoming extinct is not to be taken for granted. So much so, that it should be evident to us that humans and cattle share a very special reality - we, too, are fit for the slaughter. We are destroying ourselves, and it's surprising that we've made it this far ourselves. If they KNEW, and I knew they knew they were going to be on the table, I would only eat them if they walked toward my blade on their own volition. Time is on their side and ours - tho' fit for slaughter.