Heritage breeds are ones that have been around long enough to prove their usefulness as either egg layers, meat breeds, or dual-purpose breeds, and to become genetically stable--able to reproduce offspring true to the breed. As such, heritage breeds cannot be hybrids ("mutts" - the offspring of two different breeds), because hybrids do not breed true offspring.
Heritage breeds can reproduce naturally, which means they may be more prone to broodiness, a requirement for a hen to incubate and hatch fertile eggs. As breeds that have been beneficial to farmers for generations, they are hardy breeds that can generally withstand living primarily outdoors in most standard climates. Some heritage breeds were originally bred for eggs or meat production but are now primarily raised for ornamental purposes. Heritage breeds may or may not be rare, depending on their current conservation status and popularity.
Blue Laced Red Wyandottes are considered heritage breeds.
The Livestock Conservancy (a group working to protect against the loss of the genetic diversity that is present in heritage breeds of chickens, turkeys, cattle, and pigs), gives the following strict 4-part definition of heritage breeds:
- APA (American Poultry Association) Standard Breed
- Naturally mating
- Long, productive outdoor lifespan
- Slow growth rate
Orpingtons are also heritage breeds.
Because some of the heritage breeds we offer at My Pet Chicken originated in other countries, we do not require a breed to be recognized by the American Poultry Association when we list a breed as "heritage." For our purposes, breeds that originated outside the United States and haven't yet been recognized by the American Poultry Association but meet the other criteria are also considered heritage breeds.