The modern type of animal production used in the United States is actually more protective of birds and their health than more traditional systems. In the United States, chickens and turkeys are usually raised in enclosed buildings called growout houses. More than 20,000 chickens or 4,000 turkeys are placed in a single building. Yet the health of the poultry flocks today is probably better than it has ever been. This is because of improvements in poultry housing, selective breeding for disease resistance, protection from potential disease carriers such as wild birds and continuous health oversight by poultry veterinarians. In contrast, the “village chickens” in Southeast Asia are raised in the traditional manner that has changed little in hundreds of years. They are fully exposed to the environment and to potential disease carriers, and they have minimal or no access to veterinary medical care.