Therefore, timed-AI programs were designed to: 1) control follicular wave dynamics, 2) induce regression of the corpus luteum (CL), and 3) induce the ovulation of a dominant follicle. To accomplish this, most timed-AI programs utilize the sequential administration of gonadotropinreleasing hormone (GnRH-1), prostaglandin F2α (PGF), and a second administration of GnRH (GnRH-2).