Reasons for good preparation
1. To increase the likelihood of a successful mating and a positive pregnancy
2. To decrease the time spent at the Stud, thereby reducing the costs of agistment, veterinary costs, etc.
3. To identify Mares with ovarian or reproductive disorders that may result in decreased reproductive performance
4. To not waste the valuable time of the Stud Master
5. To have more control over your Mare’s situation.
A Mare exhibits a distinct breeding season during the Spring, Summer and early Autumn months when she should show repeated oestrus cycles of around 21 days in length. She has four to six days of oestrus where she has one or more follicles maturing in her ovaries and is receptive to the Stallion. This is followed by 16 to 17 days of anoestrus when she has an active progesterone secreting corpus luteam (cl) in her ovaries and she rejects the Stallion.
During the Winter, most but certainly not all non pregnant Mares pass through a period of sexual inactivity when neither follicles nor cl are present and the response to the Stallion is neutral. Between these periods there is a transition period in early Spring where cycles can be irregular or lengthened.
A number of outside stimuli act as the ignition switch for the hormonal changes that bring Mares into season.
- Light – increasing daylight length is the most fundamental and important stimulus to ovarian activity.
- Nutrition – an increasing plane of nutrition in early Spring increases the chances of Mares conceiving. If Mares are thin and out of condition, make sure that you boost their nutrition. Plan your pasture ahead of time so that you have adequate lush pasture available to flush up your Mares. Conversely, if the ribs are buried in fat and you can’t feel them, or the withers have a meaty look, you may need to design a slimming regime.
- Pheromones – a very definite stimulatory effect is obtained when a Stallion is within sight and smell of any Mares.
- Temperature – though less important than light, it is known that a “cold snap” in Spring can slow down the progress on non pregnant Mares in the transition phase indirectly through inhibiting grass growth.
You could: -
1. Take your Mare to a Stud for on farm breeding by live cover or Artificial Insemination (AI).
2. Keep your Mare at home and serve her by AI. You would usually do this when the Stallion is distant or you may wish to keep the Mare at home when she has a foal at foot.
3. Transport your Mare to a breeding station or centre where everything is done for a fee.
If you follow the first option you will need to contact the representative of the Stallion you are considering. They will supply you with details of costs, and a breeding contract, and will usually be aligned with a good reproductive Veterinarian. They should also advise when it is best for you to send your Mare. Your Mare should arrive at the breeding farm in good condition and free of injuries, just as she is coming into season. She will stay until she is confirmed in foal by ultrasound and/or palpation. One big advantage of a breeding farm is the ability to tease the Mares with a Stallion, a stimulus that encourages even coy or shy type Mares that show few outward signs of season.
This option is the most demanding for the owner.
If you follow the second option you must liaise with a good local Veterinarian, skilled in “reproductive work”. Facilities for palpation, ultrasound, and AI will need to be available (a good crush, under cover with power nearby). You need to develop good skills in observation to assess the stages of the oestrus cycle.
The advantages of this choice are that the Mare doesn’t travel and stays in familiar surroundings. There are no agistment costs. Disadvantages are the costs of transporting the semen, and more time involved for you to closely monitor the cycle to determine the correct time to breed.
When monitoring your Mare’s cycles a daily chat across the fence with a neighbour’s Stallion of any breed (even a Shetland will do) can evoke a response if she is coming into season. If no Stallion is available, she may react sexually to an unfamiliar Gelding. Taking her to visit the Gelding daily and recording the minutiae of her behaviour you may see a gradual increase and then decrease in her response to him.
Her friendliest day (she knickers seductively offers to sniff noses or swings her rump in his direction) could be her optimum time to breed. With a Mare’s cycle behaviour on record you can repeat the sequence and watch for (or alert your veterinarian to) the behaviours that led up to the receptivity of the previous cycle and make an educated guess as to when to call for an examination. If there are no definite signals even with careful monitoring, that’s your cue to call for help.
Your Veterinarian will be able to determine the stages of the Mare’s cycle by palpation, giving you a reference point to continue monitoring yourself. If there are indications that your Mare isn’t cycling normally, or time is becoming an issue, your Veterinarian can use hormones to manipulate the cycle and make it more predictable, a Prostoglandin (PG) injection that triggers the oestrus cycle within five days.
The Veterinarian will re-visit and probably detect a ripening follicle and predict ovulation, giving you an indication as to when you should call the stud farm to ship the semen. Studs that deal with transported semen typically ship it a self contained cooling unit called an equitainer. You may consider purchasing your own equitainer if you routinely use transported semen.
Because most Stallion owners offer a live foal guarantee, they will continue sending shipments until the Mare conceives. However you need planning and precision to keep down the ancillary costs that eat up money, because the success of Artificial Insemination depends on timing.
For the purposes of the Stallion’s schedule at Stud, the Stud Master needs to know a few days ahead of time that your Mare is approaching her breeding date. If you can, place your order on the day that the cycle begins so that semen can be collected and shipped to you on the day that you expect her to ovulate. When the semen arrives you want your Veterinarian to check the sample under a microscope for motility and to AI the Mare on the same day.
Your Veterinarian may come back the next day and palpate your Mare to make sure ovulation has taken place as expected or, if not, perform a second AI. If the Stallion owner doesn’t ship two bags of semen routinely, try to convince them to do so as it cuts down on the transport costs of shipping semen on successive days. If you can’t arrange this you will need to arrange another shipment quickly so return the container to the Stud immediately.
If your Mare’s Vulva conformation predisposes her to contamination from manure or urine, your Veterinarian may advise a caslick operation to sew up the Vulva right after insemination or a little later once pregnancy has been confirmed.
With Mares that have a breeding history that indicates that they “hang on”, where the follicle ripens but fails to ovulate past the three to five day cycle, the Veterinarian may give the Mare HCG hormone to trigger ovulation.
Many fertile Mares take at least three breeding cycles to catch. If you are unfortunate enough to have a Mare ovulate before semen arrived or she didn’t ovulate as expected, your Veterinarian can give PG to shorten the next cycle.
If you follow the third option everything is done for you. Usually these operations specialise in frozen semen or embryo transfer.
The hard facts about frozen semen: -
Semen is super cooled by liquid nitrogen. Frozen semen stays viable indefinitely while it remains frozen, however the freezing process results in lower overall viability of any given sample. Chilled semen remains viable for three to four days at the most.
The advantages of frozen semen are that it allows access to stallions not available in New Zealand. Ordering needs to be done well in advance so that the semen will be available when you need it. The disadvantages are that not all Stallions freeze well so ask the agent for information on conception rates beforehand.
The total cost of getting a Mare pregnant with frozen semen will generally be higher than other methods because: -
1. The initial cost of the semen may be higher than for local Stallions.
2. Specialised containers are required to store frozen semen, therefore if you need to store it for some time you will have to pay someone to do this for you and you should insure it.
3. There is often no live foal guarantee offered, so read the contract carefully. If you fail to get your Mare in foal the money is lost.
4. Veterinary costs are considerably higher. A more accurate monitoring of the Mare’s ovulation is required to ensure the insemination is carried out at the optimum time.
5. The thawing process requires precise temperature measurement and control and therefore special equipment, which adds to the cost.
To maximise your chances with frozen semen, ideally you should use a young Mare or one with a very good reproductive history.
Your Pregnant Mare
Ultrasound will diagnose the pregnancy within 14 to 18 days of the service. A scan at 17 to 18 days can pick up a second fertilised embryo (a problem in thoroughbred and warmblood lines) with a high degree of certainty. Your vet can “pinch” one embryo at that time if twinning has occurred, although in some cases the Mare will re-absorb one twin naturally. If you allow both to develop, it may result in the Mare aborting both at seven or eight months.
Prior to foaling the use of a foal monitor is advised. It is usual to alert your Veterinarian when foaling is due in a few days. While you don’t expect to need help it helps both of you if the Veterinarian is aware and available if needed.
If all goes well it is usual to have a post partum check the next morning to check the Mare and make sure that the placenta has all been expelled, and to check the foal.