Question:
I bought my 12 yr old QH mare in June. My question is this (please pardonmy ignorance) How often can I expect her to come in heat and what signswill she display? How long does it last? She has shown no behaviorssince I've had her that have made me think she may be in heat. Also- whatdo I need to know about her cycle? Is there anything I need to be awareof?
Answer:
there are tons of books and information on the subject, I suggestyou purchase a good book on broodmares.
However, to briefly (if that's possible) to answer your questions, thereproductive cycle of a mare is generally 21-23 days between the "heat"or when the mare is ready to be bred.
The natural breeding season of a mare is from about May through Augustnorth of the equator and the opposite south of the equator.
The 21-23 day cycle is broken down in to various stages. The first stageis the folicular stage or pro-estrus stage lasting about 2-3 days. Thisis when there is a rise in estrogen levels and a change of attitude inthe mare towards breeding. Sometimes mares will show signs of wanting thestallion to breed, but generally the signs are not obvious until theestrus or "heat" cycle which follows.
The estrus cycle or "heat cycle" is when the mare is ready to breed. Thislasts generally 4-8 days. A follicle begins to mature, estrogen increasesand tissue changes occur along with the attitude of the mare. Many timesyou will see "winking" of the labia (virgina), squatting, lifting of thetrail and slight urination (vs peeing) sometimes with mucus. The vulvaand cervix relax . During this period, several follicles may develop,however at about 20mm, they all die off except maybe one or two (possibletwinning here). These follicles will reach maturity when they are about35-55 mm. As it enlarges, the ovum (egg) inside the follicle is wrappedin cells which the sperm (if they are lucky) penetrate and fertilize theovum, thus becoming the fertilized egg which eventually grows into a foal11 (hopefully) months later.Ovulation occurs when the follicle ripens during estrus, the ovum isreleased from the follicle into the mare's reproductive tract where itattaches to the uterine wall. Ultrasound or palpation detects this.
The luteal stage (metrestrus) occurs about 12-30 hours after ovulationand the mare will sometimes still receive the stallion, gut generallywill not. If the mare is not bred, the follicle and ovum is sloughed off.If fertilized, it attaches to the uterine wall and teh placenta forms theattachment. Since progesterone levels are increased, the estrus (heat)cycle becomes depressed. Many breeders simply say the mare is "out ofheat."
Now in regard to signs of estrus or heat. First off, one need tounderstand that not all mares "show" signs or that signs may be nominalor only under certain conditions or that you may see every sign very loudand clear.
If you don't recognize estrus, don't feel bad. It takes knowledge,observation and understanding. So, learn exactly what a mare's estrouscycle is all about. This you can learn in a course through your localextension service or through a course at a veterinarian school or throughbooks. There is also a transitional time between winter and early springin which a mare's behavior can be very erratic and certainly notreliable. If one uses lights, this negates this problem (at least for afew years). Another trick is to use an estrogen shot that will bring youmare into cycle. But for now, you need to keep records which will helpyou learn. Keep teasing records. Record what you observe, when youobserve it and what is going on. Another reason why you may not see theestrus cycle is bad vibes between the stallion and mare. The mare couldbe fearful of or intimidated by the stallion or visa versa, though theformer is usually the norm. IOW, the gal could simply hate the guy. Andstill another problem that can occur is that the mare won't show her"heat" due to psychological reasons such as a foal by her side. Thenthere is the large subject of infertility which most certainly affectsthe ability of a mare to show signs of "heat."
Recognizing heat signs in a mare means you need the ability to be openminded in your observations, particularly if you mare doesn't show signsreadily.
Check your mare regularly and look for signs of secretions and slightlyswollen tissue of the cervix. You may not be able to tell if they areswollen or not, unless you know what is normal (hence the recordkeeping). The cervix will relax when ready to receive the stallion.
Behavior patterns of your mare will change. She will squat, raise hertail, urinate frequently, and "wink" her labia. The "wink" is the samething you see after a mare pees or urinates, only in "heat" this isfrequent and the urination is of small amounts.
Signs will vary from barely visable if at all to violent.
Teasing is a good way to tell if a mare is in her "heat" cycle. Sometimesyou see a mare "show" or "strut" her stuff to a gelding or even anothermare. Generally, maiden (virgin) mares, mares with foals by their side,shy or intimidated mares will only show signs of "heat" if a stallion isnearby. This is called the teasing process.
Another method of "heat" detection is through palpation which will tellif there is a follicle and approximately what size. One must be very goodat the "feel" in order to be accurate in palpation. Generally,veterinarians are used, but some people who are skilled in palpation willdo their own mares.
The best time to breed is of course, during the estrus or "heat" cycle.The ovulation happens about a day or two prior to the end of this cycle.Sperm will last for roughly 48 hours. Generally the mare is served orcovered by the stallion on an every other day schedule beginning with thethird day of "heat" or when the follicle is about 35-40 mm. This ofcourse, changes if one uses AI (artifical insemination) either byshipping semen or collection and insemination at the farm.
As you can see, there is lots to learn. Some are easy. Some aren't. Mostare inbetween. Hope all of this helps you begin to understand the estruscycle of the mare.
Montgomery County Adult Horse Committee
