The rex is a commercial breed.
The animals are smaller than most commercial breeds and have very little fat.
There are only a few commercial breeds of tick resistant cattle available.
Litter sizes are typically somewhat smaller than commercial breeds.
The lambs are late maturing and produce smaller carcasses relative to commercial breeds.
Among the earliest of the commercial breeds was the Angora, which some say may have developed in the Carpatian mountains.
Some commercial breeds of hen can produce over 300 eggs a year.
This was partly due to the difficulty in selectively breeding the proper color pattern, and also to the rise of new commercial breeds on the market.
Used in many different countries, the Belgian Landrace is also one of the "four major commercial breeds" in France.
The breeds the couple raise are rare, and the pigs don't grow as quickly as more commercial breeds.