Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
The disease in cattle known in veterinary practice as "sweet clover disease" is caused by the eating of improperly cured hay or silage made from the common sweet clovers, Melilotus alba and Melilotus officinalis. Its occurrence was originally described by Schofield in Canada (1921) and at about the same time Roderick recorded the etiology and pathology of the disease in a study made at the North Dakota Agricultural Experiment Station.
Wahl, Robert C.
"Sweet Clover Disease,"
Iowa State University Veterinarian: Vol. 3
, Article 9.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol3/iss2/9