Alright first off your friend is an ass, you can tell him I said that.

Anyway.

Where did you even get that? At the end of the day it is and always has been about the methods used to kill the animals, and their treatment prior to slaughter. I will never agree with eating animals, but it is something I could at least tolerate and accept as a reality of life were it done in an even remotely humane way. Remember the CFEs? Go read about those. And I beg of you, take a visit to a factory farm and follow it up with one to a slaughterhouse.

Also, cows don't exist in the wild. Where the hell have you seen a wild cow? We breed them to kill them. Unless you want to go to Aurochs (an EXTINCT) animal, they do not exist. Also, a wild cow would look NOTHING like a domestic cow.

You mention how cows are "going to die anyway." Technically everything is "going to die anyway." Just because the stray dog over there is "going to die anyway" doesn't mean we toss it into a meat grinder, yeah? And, we create them to kill them. Were there no demand for meat, the life would simply never exist. There would be no life to take away.

If you want to factor in the price and nutritional value of adding mashed potatoes and corn, then I get to do the same. It would be quite the substantial addition in both areas. You do not get to claim chicken+corn+mashed potatoes for $1.60.
I will argue that chicken + beans is not all that superior, if at all, to beans+rice. Rice is not the shitty filler food people make it out to be.

I should point out that when I go out, they always give me way too much food. I as well get at least two, if not three, meals out of it. Same ratio.

Cows have the number of stomachs they do so they get any and all nutritional value out of what food they eat. Meaning yes, they can eat moldy or crappy food that would literally kill a horse and wouldn't hold up too well in a person. That does not mean the food is not disgusting.
Also, *go to a fucking factory farm.*
They are HUGE. Just because the COW itself doesn't take up much space doesn't mean the farm doesn't. The FARMS are huge. Also, in KS, they still actually graze some of their cows. So knock off hundreds of acres that the farmer owns. Land that NOTHING is done to so the cows can wander around and graze. That land could be used to produce plants.
Reading back over this, I'm slightly astonished. You really know very little about how farms work, don't you? Where did you grow up? I'm a country girl, and let me tell you... you can't keep a cow on a 2x3 plot. Hell, a small horse requires at least 12x10 at the bare minimum. A full sized beef cow? Saying it could live in a 2x3 plot is like saying you could live on a 1x1 plot. The only cows they do that to are the calves they're going to kill for veal. Not moving makes the meat more tender, you see. As if baby cow meat isn't tender enough already.

"what happens to all the cows? chickens? all the livestock we had, do we just let them go fend for themselves in the wild?"
Um. Wow. No. See what I said above. There's this nifty little marketing force called supply and demand. As I explained previously, we create these animals in order to kill them to supply meat to fill the demand. If demand were to go down, so would supply. We would simply stop breeding them. It's not like they contribute to any ecosystem; nothing would happen were beef cows and broiler chickens to no longer exist.

Also, I was being facetious. I have indeed completely K-12 schooling. I know of and understand the great depression.