Over the years, traditional breeds have lost their commercial importance and crossbreeds and hybrid strains have been developed into the modern chicken.
The Commercial Egg Industry
In the modern Egg Industry, the birds are hybrid White Leghorns or sex-linked hybrids that resemble New Hampshire Reds and Barred Plymouth Rocks. Sex-linking is where a plumage trait, like slow feathering or a certain color pattern, is linked to the sex chromosome so that there is a distinct physical difference between the sexes of day-old chicks. This saves time and money separating the female for production. Today's egg producing hens can lay over 300 eggs per year; this is over twice the average of 150 eggs per year in 1947.
Commercial white egg layers are from White Leghorn Background
Commercial brown egg layers are usually a form of Sex-linked Hybrids
The Commercial Broiler Industry
The modern Broiler Industry has developed a hybrid that is unlike any other breed. Today's broiler can achieve a 4-pound market in six weeks. Twenty years ago, it took 14 weeks to achieve a 4.5-pound market weight. These advances are the result of scientific progress in genetic, nutritional, and environmental research.
The Commercial Turkey Industry
The modern Turkey Industry has developed a hybrid white turkey that is larger and faster growing than purebred or wild turkeys. The modern hybrid turkeys are so large they can no longer breed naturally. All modern turkeys are artificially inseminated. Artificial insemination allows selective breeding of the sexes so breeders can raise fewer males and achieve higher rates of hatchability.
