Americans' annual consumption of beef in 2000 was 64 pounds. Total red meat consumption (beef, veal, pork, and lamb) was 114 lbs. Annual consumption of poultry (chicken, turkey) in 2000 was nearly 50 pounds annually.
from How Much Meat We Eat Meat is a luxury in much of the world. I doubt that many countries eat as much as we do.

Raising your own meat under survival conditions requires properly mineralized soil (nutrition from soil to plant to animal to you), and enough land to feed them year-round, as you couldn't depend on outside sources.

A beef calf needs enough good nutrition to get him up to 700-900 lbs, and that happens more slowly on straight forage (no grain), but it's the most natural. Rotating pastures (see Joel Salatin's book Salad Bar Beef) is best for ongoing pasture maintenance and can probably sustain more cows on the least land while keeping it in good shape, but you still need a goodly amount of land.

Sheep eat grass, goats eat browse.

Chickens need short grass and grain, and are often good foragers if you choose your variety carefully. Free-range birds can hunt weed seeds and insects. If you had to use commercial feed exclusively, one layer hen would require 80-90 lbs of feed per year. Or, you would have to grow enough feed on your land to equal that amount.

Eggs are a great source of protein and fat, and can replace a lot of meat. Some chicken breeds will lay through the winter if they aren't stressed too much by cold. My Buff Orpingtons stopped laying early in Nov, and didn't crank up again until the days got longer in May. My current girls, Columbian Wyandottes, started laying in June and popped out eggs daily all through winter (a surprise), through the wet spring and summer, and up to when they started molting (fall). They are also less finicky about wet weather and are great foragers. Chickens lay the most eggs their first laying year, and less every year after. Some of the egg laying machines produce about 300 the first year, 200 the second and about 120 a year for the next 3 years , averaging about 800 for a 5 year lifespan. But many of these are poor foragers, so that increases the amount of feed you have to supply.

According to the book by Gene Logsden, Small-Scale Grain Raising, with decent soil you can grow one bushel of grain per plot:

Field corn: 10 x 50 ft (56 lbs, shelled)
Oats: 10 x 62 ft (32 lbs)
Barley: 10 x 87 ft (48 lbs)
Rye: 10 x 145 ft (56 lbs)
Buckwheat: 10 x 130 ft (48 lbs)
Grain sorghum: 10 x 60 ft (56 lbs)
Wheat: 10 x 109 ft (60 lbs)

These are estimates, but nine bushels (approx. 500 lbs) of assorted grains might be raised on 1/6 of an acre.

Choices would depend on climate,season, weather and soil, and you would have to keep in mind that for chickens, corn would have to be at least cracked (they can swallow it whole, but they don't get the nutrition out of it), oats* have to be threshed of their tight hulls, and barley* has to have the awns at least clipped.

* Hull-less oats and barley are available, which eliminates the worst of this problem.

And don't forget the lesser-known grains and pseudo-grains: Millet, the 'old wheats' (einkorn, emmer, kamut), triticale, flaxseed, grain amaranth, quinoa (must be rinsed before eating, humans or chickens). The wider the range of feed, the better the nutrition.

Sue