Sorry, but having lived on a farm for 14 years, I just have to say it.
As far as efficiency, ease, cost and reliability of raising meat, the answer is raising rabbits, rabbits and rabbits. (In cages I mean.) The darned things thrive on cut meadow grasses and alfafa, plus a little salt. They are extremely low maintence, carry almost no diseases, are extremely efficient as far as weight gain to fodder weight, and are a snap to clean and butcher. And they breed like, um, . . . rabbits.
Chickens and pigs are filthy, troublesome, and consume huge amounts of feed grain. (Don'tya just love coming out every morning and watching your chickens poop in their fresh water!)
Mannyrock