Livestock Breeds Conservancy

So I am working on a new concept for the farm. I am thinking about raising threatened and endangered livestock. Many people do not know that certain breeds and types of livestock animals are no longer considered valuable to comercial farming so they are becoming all but extinct. Breeds like the large black pig (raised in the past for lard, they also produce excellent hams), Milking Devon Cattle (a breed brought to this country by the pilgrims), Tenessee Fainting Goats (a good meat goat) and the San Clemente Island Goat (a milking breed), American Karakul Sheep (a multi-purpose sheep, formerly prized for its wool), The Java Chicken, the Beltsville Small White turkey and the Sliver Fox Rabbit.

All of these breeds are listed as either Thretened or Endangerd with the American Livestock Breeds Conservancy (http://albc-usa.org/). They tend to be breeds that are dual or muli-purpose(meat and whatever other advantage each offered). They were orginally breed for the small-holder family farms of the early 20th century.

I am thinking of maintaing two female and one male of each of the larger breeds and prehaps 10 - 20 of the poultry and rabbit breeds. That should fill up our five acres (and our freezer) pretty well.

Any Advice?