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==Pregnancy==

==Pregnancy==

Gestation length in the mare is approximately 330-340 days, however it is usually consistent within the individual mare from one pregnancy to the next.

Mares are monotocious, meaning they normally produce a single offspring. Twin pregnancies do occur in the mare, but are rarely carried to full term and veterinary intervention is often used to prevent twin pregnancies in this species. Gestation length in the mare is approximately 330-340 days, however it is usually consistent within the individual mare from one pregnancy to the next.

===Maternal Recognition of Pregnancy===

===Maternal Recognition of Pregnancy===

The presence of a conceptus prevents luteolysis. In the presence of a conceptus, endometrial production of PGF2α is significantly reduced.

The presence of a conceptus prevents luteolysis. In the presence of a conceptus, endometrial production of PGF2α is significantly reduced.

* Day 6-22: the trophectoderm secretes a glycocalyx, which hardens to form a capsule. This prevents attachment of the embryo to the uterine endometrium.

* Day 6-22: the trophectoderm secretes a glycocalyx, which hardens to form a capsule. This prevents attachment of the embryo to the uterine endometrium.

* Day 7-17: Peristaltic contractions of the uterine myometrium move the embryo around the uterus. The conceptus begins to secrete oestrogens, but their role is unknown. If pregnant, upregulation of oxytocin receptors between day 10-16 is inhibited

* Day 7-17: Peristaltic contractions of the uterine myometrium move the embryo around the uterus. The conceptus begins to secrete oestrogens, but their role is unknown. If pregnant, upregulation of oxytocin receptors between day 10-16 is inhibited

* Day 17: The myometrium clamps the embryo in position at the base of the uterine horns, preventing movement.  

* Day 17: The myometrium clamps the embryo in position at the base of the uterine horns, preventing movement.

 

==Parturition==

==Parturition==