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
Many methods of artificial insemination and estus synchronization have been developed for swine in the last fifty years. This field study incorporates some of these methods into a commercially profitable situation. On two separate farms, sows were given rpegnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG) after weaning.
Williams, J. Koudy and Evans, Lawrence E.
"Estrous Synchronization and Artificial Insemination in Sows: A Field Study,"
Iowa State University Veterinarian: Vol. 45
, Article 6.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol45/iss1/6