Glossary

Breeding Terms

Corpus Hemerrhagicum (CH)
This is the content of the follicle after ovulation. It is filled with blood and then becomes the corpus lateum.
Corpus Lateum (CL)
A growth at the site of ovulation.  It produces progesterone.
Diestrus Phase
The phase of the estrous cycle immediately following ovulation. It normally lasts 14 days.
Estrous Cycle
One entire heat cycle. From one ovulation to the next. It normally lasts for 21 to 23 days.
Estrus Phase
The first phase of the estrous cycle. It normally lasts from 4 to 7 days and ends with ovulation.
Follicle-Stimulating Hormone (FSH)
A hormone produced by the pituitary gland. It causes the ovaries to produce egg follicles.
Follicular Phase
See estrus phase
Gonadotropins
A hormone produced by the pituitary gland (or later in pregnancy by the placenta). It acts on the ovaries to produce sex hormones.
Hypothalamus Gland
A gland located in the brain that controls the pituitary gland.
Luteinizing Hormone (LH)
A hormone produced by the pituitary gland. It causes the follicle to mature and ovulate.
luteolysis
The process that causes the disappearance of the corpus lateum.
Ovulation
The process of the follicle releasing the egg into the ovaries.
Progesterone
The pregnancy hormone. 
Prostaglandin (PGF2a)
A hormone found in the lining of the uterus.
Winter Anestrus
The period of sexual inactivity in a mare, lasting typically from October through April in the Northern Hemisphere.