A review of the effects of prostaglandins on sexual behavior in boars

Artificial insemination (AI) is the primary method of breeding sows in many countries worldwide. In general, semen for AI is collected using the gloved hand technique from boars trained to mount an artificial sow, although automated collection systems have been developed and are in use on some operations. The proportion of selected boars that are successfully trained for semen collection and the rapidity in which training occurs impacts efficiency in operations supplying semen for commercial sow units. An accumulating body of research suggests that injections of prostaglandins may be a useful tool for accelerating the process by which boars are trained for semen collection and may restore libido in older, already trained boars that are displaying decreased sex drive. In some experiments, however, prostaglandin therapy failed to alter libido and variation in effectiveness of the compound could be related to genetics, age or weight of boars, different products or doses of products employed, or some undetermined management practices. Thus, the compounds should be used judiciously and with veterinary consultation. Whether prostaglandins play a physiological role in controlling male sexual behavior in swine and the mechanisms by which pharmacological manipulation of circulating concentrations of prostaglandin enhance libido are largely unresolved and warrant further scrutiny.