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
Thyroprotein, a synthetic feeding material known to induce cows to more milk for a short time, is now on the market in various forms. Consequently, some dairymen are feeding it without questioning either the economy of milk production over longer periods or the ultimate effect on the health of their cows and the offspring, says the chief of Bureau of Dairy Industry in his 1949 report.
"Thyroprotein In Dairy Cattle Feeding,"
Iowa State University Veterinarian: Vol. 12
, Article 7.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol12/iss2/7