a1 Departments of Infectious Diseases and Dairy–Poultry Science Kansas State University, Manhattan, Kansas 66502
1 Contribution No. 157, Department of Infectious Diseases and Contribution No. 810, Department of Dairy and Poultry Sciences, Kansas Agricultural Experiment Station, Manhattan, Kansas 66502.
2 Employed by the U.S. Department of Agriculture, Consumer and Marketing Service, Meat and Poultry Inspection and presently doing graduate study under Public Law 85-507, Government Employees Training Act.