The doe, like the ewe, cow and mare has a bipartite uterus which means
that it has two separate parts called horns.
When the doe is born she has all of the eggs (oocytes) that she will need for a lifetime.
By the time the doe is old enough to breed she has a few hundred oocytes,
called primary oocytes, that are surrounded by cells called follicles.
The oocyte begins to enlarge and the follicle develops many layers of cells until
the mature oocyte is enclosed in a graafian follicle.
This is the beginning of estrus which lasts 24 to 48 hours.
The graafian follicle secretes estrogen which stimulates uterine growth and production of prostaglandin.
At this time the doe will accept the buck for mating.
The follicle ruptures 24 to 36 hours after estrus begins releasing the oocyte.
This is called ovulation.
The empty follicle fills with blood and lymph which plugs the opening.
The cells that line the follicle develop into the corpus luteum which secretes the hormone progesterone.
If the egg is not fertilized, the corpus luteum will cease producing progesterone
10 to 12 days after ovulation.
A prostaglandin (PGF2α) secreted by the uterus will cause the corpus luteum
to regress (luteolysis) after about another 2 to 3 days.
The resulting scar tissue is called the corpus albicans.
The regressing corpus luteum allows other large follicles to mature.
A new oocyte is released into the oviduct to be fertilized by a sperm.
The presence of the blastocyst in the uterus will signal the uterus to stop producing PGF2α
allowing the corpus luteum to continue producing progesterone.
This must happen about 15 days after ovulation in order for the pregnancy to continue.
The corpus luteum of pregnancy (corpus luteum verum) will remain for 150 days acting
as a gland to produce progesterone which is necessary in the goat to maintain the pregnancy.