For all you unethical marijuana growers

I was just reading about a bust on a grow op and I was intrigued by the whole ventilation problem. Not necessarily the smell problem but the problem of replenishing CO2 in an indoor grow room. And while considering the methods of doing this, which usually involve pumping air into or out of the room, I came up with a quite different idea. I don't think it would actually be feasible and even if it was I would not suggest it as it verges on cruelty to animals. Actually it is cruel to animals there's no verging in this case. So my idea is this. Keep some type of animal in your grow-room. I'm thinking pigs. I don't know anything about numbers, but unless you have a huge grow I doubt you would want more than one or two. Why not mimic nature. That's basically what the rest of the grow room is trying to do. So why not use animals the way the natural environment does. We, as animals, breath in oxygen and expel carbon dioxide. And plants in return use that carbon dioxide to create energy and expel oxygen as a byproduct. Actually it works the other way around. The plants were first. We just developed a way to use their byproducts. But that doesn't really matter in this case. Of course as I said before, raising pigs in your grow room would be highly unethical as you would be raising them in a confined space in which they would never even see the light of day. But on the bright side you would have plenty of delicious bacon, ham, pork chops, etc. to eat when you start getting the munchies.