Chicken breeders are always trying to improve their flocks through genetic selection. They use a variety of methods to select the best birds for breeding, including body size, weight, egg production, and disease resistance. By carefully selecting the birds with the most desirable traits, chicken breeders are able to produce healthier, more productive flocks. In addition to traditional methods of selection, newer techniques such as DNA testing are also being used to identify the most promising birds for breeding. By using these methods, chicken breeders are able to rapidly improve the quality of their flocks.