Uterine contractions and fertility following clitoral massage of dairy cattle in estrus.

Lactating and nonlactating Holstein cows received 30 s of gentle clitoral massage to determine its effect on uterine contractility and oxytocin concentrations in blood. Clitoral stimulation caused an immediate single uterine contraction, and this could be repeated at 2.5-min intervals. Oxytocin concentrations did not change during intensive blood sampling following clitoral massage. Thus, the uterine response is interpreted as neurally mediated. Eighteen full-time inseminators were allotted to two groups, balanced so that each day half were inseminating control and half treated animals (5 s of clitoral massage following insemination). The 56-day nonreturns for 2090 controls were 74.3% versus 74.0% for 2049 animals receiving clitoral massage. Heifers were more fertile than cows (81.9% versus 70.6% nonreturns), but there was no indication that clitoral massage altered the nonreturn rate in either age group. Also, the time of day animals were inseminated did not affect nonreturn rate.