The mare will show estrus (be on heat, come into season) several times during the breeding season (spring into summer). When the mare is season she will elevate her tail and stand with the back legs slightly apart. The clitoris will move in and out (winking), and she will urinate frequently. At the beginning of the breeding period estrus may last for a considerable length of time, up to two weeks. As the season advances estrus becomes shorter so that at the height of the season it lasts only three to five days. Ovulation occurs about forty-eight hours before the mare goes off estrus. Therefore mating in summer during the short estrus periods is more likely to succeed.
Breeding in the mare can take the form of ‘paddock mating’ where the stallion is allowed to run free with the mares and mate naturally, or it can take the form of ‘hand-mating’. Many studs employ a veterinarian to follicle-test in-season mares to determine when ovulation is about to occur. This ensures that the mare is bred at the optimum time and prevents overuse of the stallions. It also eliminates some risk of injury, as many mares wiLl lash out at a stallion, despite showing interest to the teaser, if the follicle is not quite ripe.
When it is determined to mate the mare, a tail bandage is applied which extends down the tail about 30 centimeters. The mare’s genitals are then washed down thoroughly with an antiseptic solution. When the stallion has an erect penis, it too should be washed in antiseptic solution. Both horses should be re-washed after mating. The stallion should be led up to the side of the mare to test her reaction. If she is receptive lead the stallion to the rear of the mare and allow him to mount. Sometimes the penis may need to be directed into the vulva of the mare.
If the mare is difficult to mate, check that she is on season and if so, restraints such as hobbles or a twitch may be applied. The hand-mating of mares is a skilled job for the horseman and should only be attempted after considerable experience is gained working on a stud under a stud groom.
There is usually a difference in the general condition of maiden mares entering the stud. Frequently they are turned out of racing just prior to or during the breeding season. Because it takes time to relax and become accustomed to the stud procedures, these mares are often very nervous. Also mares turned out to pasture after being hand fed most of their lives will take at least eight weeks to adapt to a whole grass diet, in which time weight loss can be expected. It is particularly desirable to obtain maiden mares as early as possible to get them settled in before the season begins.
Breeders generally believe that examination of a maiden mare for breeding soundness is unnecessary, and this may be true in most cases. However. there are a few specific conditions encountered in maiden mares which, if not found and corrected before breeding, may result in injury. These include an infantile genital tract, imperforate hymen, vaginal septum and sutured vulva as a result of a Caslick’s operation.
Special attention should be given to the teasing and breeding of maiden mares. Teasing is the act of using a stallion (or gelding treated with hormones) of negligible value to test the mares each day to see if they are in season. A mare that is not in season can be vicious. Often a very small stallion is used because he can mount without fear of penetration, to fully test the mare’s response. Once it is determined that the mare is receptive, the valuable stud stallion is introduced. There is often a degree of roughness in the teasing procedure, and this is especially undesirable whe handling young, inexperienced mares. Early mistreatment can result in the development of surly or vicious behavior in the presence of the teaser which makes it difficult to determine the right time for breeding. Maiden mares should not be teased too vigorously. Observe them after the teaser has gone, and when they are with the mares in their group. Each mare tends to develop a relatively consistent estrus cycle and characteristic behavior at the different stages. An experienced, competent observer is able to predict the proper breeding time.
Maiden mares can be very unpredictable in the early spring. At this time on, is ready to be served. they can go into a ‘spring estrus’ and exhibit signs of heat practically every day for extended periods especially if the weather is mild. Some will accept the stallion, others will not. An occasional mare might be showing true estrus, but the majority will not. Breeding at this stage is a waste of time and semen (particularly where a stallion has a heavy booking of mares). Patience is the best approach with these mares as they eventually settle into a normal cycle.
The ‘jumping’ procedure is recommended for young, nervous or timid maiden mares. ‘Jumping’ is simply a precaution to protect the stallion and, indirectly, to avoid any excitement that might cause the mare to injure herself. She is restrained as for breeding (twitch, leg strap or hobbles) and then a quiet, gentle teaser is allowed to mount the mare. Actual intercourse is prevented by directing the penis to one side. This procedure can be repeated several times to accustom the maiden mare to stud procedure. At the same time it gives the attendants an idea of how she reacts.
Brood Mare Management at Foaling
Ideally, the mare should arrive at the stud at least six to eight weeks before the foaling date. This allows her time to recover from traveling stress and allows her system time to develop antibodies against local germs. On the mare’s arrival, the stud groom should be furnished with her medical record containing the following: Anticipated foaling date and date of last service. Type and date of any recent hormonal therapy. Caslick’s operation. Vaccination status. Date of last thorough worming. Behavioral idiosyncrasies (for example, resists a stallion, can’t be tied up, cycles irregularly, or doesn’t exhibit estrus). After successful mating the mares will usually be grouped into early, midseason and late foaling groups, and dry mares (those not in foal). About seven to ten days before foaling, the mare should be moved to a home paddock—a grassed individual paddock close to the house which can be illuminated to dusk level. Valuable mares should be observed every hour.
Barren and Empty Mares
`Barren’ usually means chronically unable to go in foal and ’empty’ mares that have had foals but have not been rebred. Occasionally, a may produce ten or twelve foals in as many consecutive years, but on average this cannot be expected. A certain percentage of mares fail to conceive each year because of natural causes, accidents, infections and human error. The breeder who breeds only one or two mares each year should make a particular effort to get the mare in good breeding condition well ahead the season. The mare should have a pre-breeding check-up to assess t – physical condition. Age will be a factor, as mares over the age of fifteen to go in foal less regularly. Teeth should be attended to, and if they beyond repair a special ration is advisable. In addition, a vitamin-mineral supplement is often beneficial to older mares.
Many older mares may be chronically lame or sore. Mares retired racing often have arthritic conditions which plague them in later life. In these cases consideration may be given to special shoeing. Sometimes a blood sample from a mare in poor physical condition will reveal an anaemia or even an infection. If a mare is barren, the possibility of a parasitic infection should never be overlooked, particularly in stables where horses are often yarded for periods. Proper worming program should be in force on all horse-raising establishments. On the other hand some mares stay fat on little or no grain, appear gaunt and do not have a glossy or thrifty appearance. Often these mares have a history of erratic heat periods and fail to conceive despite repeated breedings. Some of these mares respond well to thyroid extract, while others fare better on a restricted diet together with exercise.
A veterinarian should be consulted to examine mares that do not gc foal. The vet will look for evidence of discharge from the vagina, or on the buttocks and tail. Special attention should be paid to the confirmation in the region of the anus and vulva. The anus and vulva should have a nearly vertical line. If the line falls forward to any great extent from to anus, there may be trouble from so-called ‘wind-sucking’. This refers the movement of air into the vagina, sometimes carrying with it fecal material which has dropped on to the edges of the vulva. Further examination of the mare is made internally by the vet to examine the ovaries and womb infections can be introduced by contaminated hands or instruments at a previous foaling, during breeding or as a result of ‘wind-sucking’. Mares that become wind-suckers should have a `Caslick’s operation’, in which the lips of the vulva are stitched together except for a small opening at the lower end for urination. At breeding time the stitches are removed to allow service, and then replaced to prevent entry of infection during pregnancy. The stitches must be removed again a week or two before foaling.
Most breeders commence teasing their empty mares in early spring. Though all mares cannot be expected to have a regular estrus cycle at this time of the year, most will cycle within a short time. When an empty mare sheds her winter coat, it is a good sign that she is ready to begin breeding. However, while it is important to get mares in foal as early as possible (so that the foals are bigger at yearling sales), most mares cycle best and are most fertile in mid-summer. A complete and accurate teasing chart is valuable for recording changes in heat periods, as mares tend to follow fairly consistent patterns from year to year.