2008 Volume 61 Issue 10 Pages 780-783
The present experiment was conducted to assess the effects of labial stimulation after artificial insemination (AI) on the conception rate in Holstein cattle. In this experiment, 295 heifers were randomly assigned to a control group and an exposure group. The labia of the heifers in the exposure group were stimulated for 15 seconds after AI. The conception rates in heifers in the exposure group (69.2%) tended to be higher than those in the control group (64.7%). The conception rate of heifers in the control from July to August tended tobe lower, but this tendency was not observed in heifers in the exposure group. When we analyzed the effect of the efficiency of labial stimulation on the Temperature-Humidity Index (THI), the conception rates in the control in THI ≥z 72 group (46.8%) were significantly lower (P<0.01) than those in the THI <72 group (73.9%). However, this difference was not observed in the exposure group.