The use of artificial insemination (AI) has increased rapidly in commercial swine production. Extensive research has been conducted to optimize the reproductive potential of AI to equal or better that of natural insemination. Despite advances however, litter size and farrowing rate are less than optimal in most production systems (PigCHAMP, 2000). In an attempt to improve reproductive parameters in response to AI, considerable labor is performed to maintain boar contact during insemination. It has been shown that during courting, a mature boar produces derivatives of 16-androstene pheromones (Pearce and Hughes, 1987), which are found in the urine and saliva (Hughes et al., 1990). These pheromones were found to have a signaling function involved in stimulating puberty (Pearce and Hughes, 1987) and Mattioli et al. (1986) demonstrated that spraying 5A?-androst-16-en-3-one in front of sows for 2 s, induced a rise in oxytocin. These reports suggest a role of the boar in altering the physiological response of the female. If pheromones emitted from the saliva and urine of boars influence the onset of estrus and oxytocin release, it could be hypothesized that these pheromones may also play a role in influencing sperm transport. Therefore, this study was conducted to test for the effect of boar contact during insemination on volume of semen and number of sperm expelled from the uterus following AI, and on fertilization rate and number of two-cell embryos. The results could provide information on the importance and necessity of providing boar stimuli during AI on quality of insemination, sperm transport, and fertility.