Author Affiliations +
David E. Swayne,1 Richard D. Slemons2
1Southeast Poultry Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, 934 College Station Road, Athens, Georgia 30605, U.S.A
2Department of Preventive Medicine, College of Veterinary Medicine, The Ohio State University, 1920 Coffey Road, Columbus, Ohio 43210, U.S.A