A method for synchronizing ovulation in sows and gilts by a single injectionof hormones is disclosed. A hormone, gonadotropin releasing hormone (GnRH),luteinizing hormone (LH), follicle stimulating hormone (FSH), human chorionicgonadotropin (hCG), analogues, derivatives, agonists or combinations thereofis administered to an open sow post weaning at a specific time to stimulateovulation of mature responsive follicles. The sow is then bred, without heatdetection, at a specific subsequent timed interval after injection withhormone, with one or two artificial or natural breedings. In gilts, thehormone is injected at a timed interval from onset of estrus or at a specifictimed interval following Prostaglandin F2a for those gilts which have beenheld in a state of pseudopregnancy.
