Over the years, traditional breeds have lost their commercial importance and crossbreeds and hybrid strains have been developed into the modern chicken.

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. 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.

Broiler Industry
The modern broiler industry has developed a hybrid that is unlike any other breed. Today's broiler can achieve a 4-pound live weight in six weeks. Twenty years ago, it took 14 weeks to achieve a 5-pound live weight. These advances are the result of scientific progress in genetic, nutritional, and environmental research.

Turkey Industry
The modern turkey industry has developed a hybrid white turkey that is larger and faster growing than purebred or wild turkeys. Modern turkeys are so large they can no longer breed naturally. All modern turkeys are artificially inseminated. Artificial insemination allows selective breeding so that breeders can raise fewer males and achieve higher rates of hatchability.