Influence of boar contact on attainment of puberty in gilts after removal of the olfactory bulbs

Abstract
At 6-7 wk of age the olfactory bulbs were removed from gilts which were then exposed to vasectomized boars for 30 min/day, starting on day 160. Mean .+-. standard error of the mean age at 1st estrus was similar in these gilts (230 .+-. 15 days) to that in intact gilts not exposed to a boar (234 .+-. 8 days), but greater (P < 0.05) than for sham- and unoperated gilts exposed to a boar (204 .+-. 3 and 208 .+-. 9 days, respectively). There were no differences in growth rate or ovulation rate at 1st estrus. The main stimulus involved in the boar effect apparently is olfactory in nature.