For cost effectiveness I would come down on the side of chickens, free range , a handfull of mixed corn , a drop of water, dont need a big shelter, or any special transport arrangements, no abatoir, or markets to drag them to , and they pay you with eggs and meat, and who takes a chicken to an expensive vet ? a flick of the wrist cures all ills.
Goats provide milk, meat, and entertainment par excellance.
Sheep are a total pain , good eating, suicidal maniacs with bad teeth, feet and endless health problems, vet bills and medication
Pigs are destroyers of worlds, but good to eat in various forms.
cows are s**t machines
horses are a waste of good grass.
women cost a fortune
so why do I keep em?