The effect of repeated mating at short intervals on reproductive performance of gilts.

Three trials involving 87 gilts were completed to investigate the role of additional sexual stimulation on various reproductive parameters. Forty-five gilts were mated twice at 12-h intervals at second pubertal estrus with intact boars beginning 12 h after detection of sexual receptivity (control group). Forty-two gilts were exposed to a vasectomized boar 15 min following each fertile mating to provide additional copulatory stimulus (treatment group). This additional exposure improved (P less than .01) conception rate (100 vs 84%). No statistical differences were observed in number of corpora lutea (CL), number of viable embryos (VE) or number of total embryos (TE) at d 30. These results suggest that additional mating stimuli may have a beneficial effect on conception rate. While the use of additional males resulted in more pregnant females, it likely did not have an effect on litter size.