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
Because feed comprises over 80% of the cost of producing fat cattle, considerable research has been directed towards improving utilization of the energy in feeds by ruminants. Attempts to get more energy from cattle feeds have included grinding, pelleting, steam flaking, feeding ensiled high moisture grains and feeding high concentrate rations.
Nissen, Steven and Trenkle, Allen
"Rumensin: A New Feed Additive for Feedlot Cattle,"
Iowa State University Veterinarian: Vol. 38
, Article 3.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol38/iss1/3