Prostaglandins
unsaturated fatty acids responsible for the control of the estrous cycle and timing of parturition
Open Mare
a mare that was either not bred or did not conceive in the previous season
Corpus Luteum
a gland formed on the ovary following ovulation that produces the hormone progesterone
Winking
the mares exposure of the clitoris during the heat or receptivity to the stallion
Estrous
the period of sexual inactivity between two estrous cycles
Lactation
the production of milk by the mammary glands
Silent Heat
an estrous cycle with no outward signs of estrus or receptivity to the male
Estrus
the short period of sexual excitement when the female will accept the male in the act of mating
Dystocia
a retained placenta in the mare or difficulty giving birth
Diestrous
the extended period of time when a mare does not cycle or have a heat period
Colostrum
antibody-rich milk secreted by a mare just before and the first day after foaling
Relaxin
causes relaxation of the pelvic ligaments and the cervix at parturition
Placenta
the organ lining the uterus and holding the fetus which is attached via the umbilical cord
Amniotic fluid
the substance contained within the innermost of the fetal membranes, just outside the fetus
Foal Heat
a heat that occurs after parturition that is often not fertile
Anestrous
the time at which a mare does not cycle or have a heat period; usually in the winter
Semen
sperm cells plus fluid from the accessory glands
Waxed teats
when drops of sticky, clear, or amber-colored fluid excreted prior to parturition become dried and hard, coating the ends of the teats and giving them a waxy appearance
Artificial insemination
introducing sperm cells into the female reproductive tract by means other than natural service
Ovulation
the release of the egg from the mature follicle on the ovary
Polyestrous
having many heat cycles during the year, mares have more regular cycles at the peak of breeding season when there is more light and no cycles at all during the winter months.
Puberty
sexual maturity
Gestation
pregnancy
Oxytocin
stimulates uterine contractions and milk letdown
Testosterone
develops and maintains accessory sex glands; stimulates secondary sexual characteristics; regulates sexual behavior and sperm production
Follicle
a saclike structure within the ovary that gradually enlarges and, with one burst, releases an egg into the oviduct. following this rupture, CL is formed
Barren Mare
a mare that is in heat and bred but does not produce a foal
Photoperiod
refers to the number of hours of light in a day