Day of cycle affects changes in equine intrauterine pressure in response to teasing.

The study explores how the interaction with a male horse, known as “teasing”, influences intrauterine pressure in female horses during different stages of their reproductive cycle and how this pressure responds differently depending on the stage of the reproductive cycle.

Objective of the Study

The main aim of the study was to understand if “teasing” could cause a surge in intrauterine pressure, and if the varying reproductive stages of the mare could influence this response.

Methods

• Intrauterine pressure of mares was observed while they were exposed to a stallion (male horse) at three key stages of their reproductive cycle: two days before ovulation, on the day ovulation was detected, and two days after ovulation.

Findings

• It was found that significant increase in intrauterine pressure occurred when teasing was performed two days before ovulation, and on the ovulation day itself.
• This surge in pressure was noted during periods of low progesterone concentration in the plasma.
• In contrast, no significant increase in intrauterine pressure was noted when the mares were teased two days post-ovulation, a phase marked by elevated levels of progesterone.

Implication of the Study

• The study provides critical information that might benefit management practices in horse breeding. Teasing or exposure to a stallion can be recommended during the preovulatory period in mares as it could stimulate uterine clearance mechanisms, thus possibly enhancing their reproductive efficiency.