Heritage breeds are becoming very rare, and endangered. This can further damage and stress the ecological system, and eventually we will not have nature’s varieties that are so important to maintaining natural balance.
Factory farms have become enormous, and today 99% of all chickens produced for food are a genetic mutation that barely reflects old fashioned chicken breeds. The genetic alteration of chickens through excessive breeding, and removing and adding specific genes, has developed a chicken that produces a mass of white meat, a chicken that grows 1.0/lb. for every 2.0/lbs. of feed consumed and ready to process in about 3-5 weeks from date of hatch. The fact that any chicken can weigh 4-6/lbs. in 5-6 weeks from date of hatch is a true testament to science, and technology, and should be considered very impressive. Ref1>Details
As a poultry breeder, I know from years of experience that most chickens do not even begin to fully feather in 5 weeks, so to actually be ready for processing, is incredible.
Factory chickens come by many names such as, Broilers, Hubbard, Ross, Cornish Cross, Black Broilers, Indian River, White Broilers, Arbor Acres, Red Broilers, Freedom Rangers etc. There are a few companies that specialize in poultry genetics, and I have had the pleasure of communicating with some of them. Ref2> Aviagen is well known for their extreme poultry genetics, and make no secret about their advanced capabilities to genetically manipulate specific cells, and genes to produce a chicken that fits perfectly into the factory farming system, with great success.
These types of birds are man-made, and not a natural chicken. They are designed by avian geneticists, to be fed a formulation of corn, soy, wheat, barley and other types of genetically modified, and cheap grains that we have come to learn are harmful not only to the environment to grow, but can also be the focus point of many allergic reactions and health issues.
Factory chickens are not sustainable! They do not reproduce, they are very poor egg-layers, and often have a compromised immune system requiring a medicated starter ration, vaccines, antibiotics and must be butchered or culled before 12 weeks otherwise their immune-deficient organs and weak bone structure can cause them to suffer broken legs, heart attacks, upper respiratory infections etc. but, they grow really fast on cheap grains, and can get as big as 10-12/lbs. and that translates into a whopping profit. Ref3> Details (ASPCA)
Whether these types of chickens are grown by small family farmers, large factory farms or as U.S. Commodity chickens, it does not change the facts. Factory farm chickens are NOT designed for the free-range; they are designed for factory and confinement growing conditions. They DO NOT forage, and certainly do not perform well on ANY pasture or outdoor-based system. In fact to force them to grow outside, on a pasture based system could be considered cruel and inhumane.
NOTE: I use the words "Pasture based" when referring to poultry only because it has become a term that the majority recognize. There is no such thing as "pastured chicken", and I do not like making that reference, especially since real chickens are opportunistic foragers.
Heritage birds are old fashioned or newer breeds, which follow a standard. They may breed true, be natural breeders, and some hens of heritage breeds make good mothers, others are good egg layers, many will set eggs, raise their young and forage well. The roosters are strong protectors over their flocks and heritage birds will range all day. They can fly and often protect themselves, and their young against some flying predators. They are sustainable and do not require artificial insemination to produce eggs or offspring. They roost high at night, because their poor night vision makes them a terrific meal for larger animals. Factory farm chickens can barely walk, let alone attempt to fly up onto a high roost for safe roosting. Ref4> Details (by Dr. Kevin Veterinarian)
If it is a question of size, know that some heritage breeds can reach very heavy weights, it just takes longer.
Some people may argue that factory chicken breeds are no more than just cross breeds, thus should be considered a heritage breed. Not only is that insulting to the companies that have spent millions upon millions of dollars on poultry genetics, but it is completely incorrect. You cannot cross a pure-breed English White Cornish with a White Plymouth Rock and develop a commercial Cornish Cross, which breeds true, or grows 1.0/lb. for every 2.0/lbs. of feed consumed. If it were true, all small family farmers would be doing this, and so would the factory farms. No, these genetics and gene alterations have been going on for many years, and eventually we will have a big broiler chicken that is ready for processing in about 2 weeks from date of hatch. That is not cross-breeding.
Heritage-breeds grown on free-range will thrive, especially when offered healthy forage and freedom to hunt, as their natural instincts demand. Heritage chickens are direct descendants of Jungle Fowl, and they originated in the jungles. They are not a pasture based animal, never were and never will be. It is simply not scientifically true, and it's uneth