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 control of estrus, and more importantly ovulation, may be desirable in a breeding program to service an animal at a predetermined time, to synchronize ovulation in a group of mares, or to spread ovulations over a prolonged period of time according to the various needs of managing the breeding animals. Ideally, the goal would be to control ovulation with enough precision that breeding could be done without the necessity of estrus detection.
Puderbaugh, Steven K. and Riese, Richard L.
"Exogenous Control of the Estrous Cycle in the Mare,"
Iowa State University Veterinarian: Vol. 45
, Article 4.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol45/iss2/4