EFFECT OF AN INTRA-UTERINE PLASTIC COIL ON THE OESTROUS CYCLE OF THE HEIFER

Abstract

A plastic coil was inserted surgically on Day 3 of an estrous cycle into one uterine horn of each of 10-heifers. Sham-operations were performed on 5 additional heifers. The estrous cycle in which the CL [corpus luteum] was on the operative side were significantly shorter than the cycles in which the CL was on the non-operative side or the cycles of the sham-operated controls. The average cycle length when the CL was on the non-operative side was not significantly different from the cycle length of the sham-operated controls. These results indicate that a plastic coil in the cranial portion of 2 uterine horn of the heifer results in a unilateral "inhibitory" influence on the CL.