Modern day chickens evolved from red jungle fowl. Red jungle fowl are smallish birds that live in jungles (hence the name). They are medium sized birds that eat fruits, seeds, and many varieties of worms, insects, small snakes and reptiles, and even small mammals. They will scavenge the carcasses of dead animals, and especially relish the maggots that feed on these carcasses.
The modern day chicken has evolved into a much different bird than it's ancestors. The modern chicken grows much faster, lays far more eggs, and has been genetically changed to better suit domestication. A red jungle fowl would survive in a modern day poultry environment, but would be far less efficient than a modern bird. However, a modern day chicken would not survive long in a typical jungle environment. Predators, diseases, and many other dangers would soon cause them to die.
As to their feed, modern birds need to be fed the diet that they have been genetically engineered to thrive on. Corn is cheap, energy dense, and readily available. It is the primary ingredient that these birds have been raised on for many years, just as the jungle fowl have been raised on their particular diet. However, corn has one big drawback---it lacks some of the amino acids that chickens need to thrive and produce at an optimum level. These amino acids can be provided by allowing them to eat bugs, worms, snakes, small reptiles, and letting them scavenge carcasses. But, this is not practical in most cases, and the proper amino acids must come from another source. This source has become soymeal. It too, is relatively cheap, available, and does a fairly nice job of balancing the ration needed for these modern chickens.
I often see posts on this board about how bad GM corn is for their birds. However, the same people are allowing their birds to free range. Did you know that the Bt gene is naturally found in bacteria that live in soil? The same bacteria is produced commercially, and applied to organic plants (yes, it's used on organic produce, and you likely have eaten a lot of it).
The bacteria is called Bacillus Thuriengensis. The substance that causes the larvae of Lepidoptera to die is simply a protein, and it plugs up the holes in the gut of these larvae. This causes them to starve to death. It is totally harmless to mammals, other insects, and birds. I know---you can find dozens of websites on the internet that say otherwise. But---would you rather eat food that has been treated with a naturally occurring protein, which your digestive enzymes break down naturally, or food that has been treated with some of these incredibly toxic chemicals that were previously used? I know which one I'd rather eat, because I've seen the results of birds and animals that have been poisoned by some of these chemicals. NOT a pretty sight.
I'm sure that I will be chastized by my supposed "ignorance" by some on this board. That's fine. I have lived in rural South Dakota all my life, and have seen the results of these toxic chemicals (Toxaphene, Furadan, counter and I even remember some farmers using DDT). Our world is much safer now due to the genetic engineering that has been in use for the past 15 or so years.
