Epidemiological studies relating to the control of Marek's Disease.
D000818:Animals; D001353:Avian Leukosis / Q000517:prevention & control*; D002645:Chickens; D006798:Housing; D010523:Peripheral Nervous System Diseases / Q000517:prevention & control / Q000662:veterinary; D011201:Poultry Diseases / Q000517:prevention & control*