I find animal farming fascinating because they are basically just miniature bio-factories - converting feed and other additives into a higher-value food product

I find animal farming fascinating because they are basically just miniature bio-factories - converting feed and other additives into a higher-value food product. Of course, each different animal converts feed at a different rate of efficiency and over a different timeframe, in different controlled environmental conditions. I think there is a huge appetite out there for tasty, cheap, nutritious food. Fast food mega-companies are ignoring a huge opportunity here - imagine if McDonalds (or equivalent) was a food choice your could healthily eat for every meal? They would be better off thinking as their food as part of daily nutrition, instead of a meal out. They could adjust their operations and menus accordingly - with a significant increase in revenue.