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
A black Angus steer was admitted to the Stange Memorial Clinic on March 3, 1954 with a history of weight loss. The animal had lost 200-300 pounds in five months while on full feed. There was swelling of the brisket . and the front legs, anorexia and considerable irritability upon handling. The temperature was normal and the animal showed no visible lesions. It was one of five animals in a herd showing similar symptoms. The ration consisted of clover and timothy hay cut the previous June, last season's ground whole corn, a commercial supplement and a salt and mineral mixture. A blood sample was citrated and sent to the chemistry department for vitamin A determination. The next day, March 6, the following results were returned: Vitamin A, 21.4 microgram per 100 cc. and carotene, 37.7 microgram per 100 cc. The normal value for vitamin A is 35 !1gm. per 100 cc. and the normal carotene value is 200 microgram per 100 cc. The reason for this deficiency while on the ration described is unknown. However, this condition has been diagnosed in a number of herds in a geographical area corresponding to the drouth area of 1953.
"Vitamin A Deficiency in an Angus Steer,"
Iowa State University Veterinarian: Vol. 16
, Article 10.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol16/iss3/10