mare | Horse Racing Free Tips

Does Weather Make Mares Moody?

Mares that tend to be moody might show signs of mellowing as the weather cools. Colder weather goes hand-in-hand with shorter days, and daylight influences a mare's hormones. These hormones control her reproductive cycle; from early spring until late fall, a mare is in estrus—her body produces eggs that mature and are released every 19 to 22 days.

During estrus, a mare has increased hormone levels, which can lead to impatience, aggressiveness and overall crankiness. As the days get shorter, the mare begins producing melatonin, which puts her body into anestrus, where no eggs are released. This transition begins in late fall; by the time the winter solstice comes, a mare is in the deepest part of anestrus. During this time, she may seem calmer and more easygoing.

If a mare's personality changes, it's worthwhile to keep a journal to see if the change is hormone related, as not all changes are. Year-round tracking, including daily observations, can be helpful, and including vital signs is a must. Noting her reactions in different situations and environments over multiple months will offer the ability to compare her attitude in different seasons to help identify hormone-related behaviors.

Study: Mare Size Affects Birth Process

Drs. Christina Nagel, Maria Melchert, Christine Aurich and Jörg Aurich created a study to determine if the size of the mare affected the birthing process. The team used 23 pregnant mares and studied hormone and heart-related changes that occur in the mare and the fetus around birth. The groups consisted of six Shetland Pony (small); eight Haflinger (medium) and nine warmblood (large) mares.

They discovered that foal weight was approximately 10 percent of mare weight, no matter the size of the mare. Placenta weight was highest in Warmbloods; it did not differ between the small- and medium-sized mares. Progestins and cortisol were also highest in the larger mares. Progestin concentrations decreased as foaling got closer and cortisol increased as parturition was imminent in all sizes of horse studied.

Heart rates in all mares increased before foaling, but the most pronounced increase was in the small mares. Overall, the small mares foaled earlier than the larger mares.

Missed heartbeats during foaling occurred regularly in the larger mares, but only occasionally in the small- and medium-sized mares. The scientists report that this is most likely because of differences in heart efficiency. Small- and medium-sized mares occasionally had missed beats during the expulsive phase of foaling and the first two hours after delivery. The researchers suggest that this is an effect of breed, not size.

The team concludes that fit, athletic horses have highly efficient respiratory and cardiovascular systems; while at rest, these horses have reduced heart rates. Fetal heart rate also went down toward birth, with the most prominent reduction in full-sized horses.

The authors determined that mare of different sizes show both similarities and differences in cardiac and endocrine changes as the time for them to give birth nears. They note that late pregnancy puts substantial strain on the mare's cardiovascular system, but that mares are well adapted to these demands, no matter their size.

Read the full article here.

Can Surgical Removal Of A Mare’s Ovaries Fix Unwanted Behaviors?

A Danish study investigated if removing a mare's ovaries could offer relief from unexplained unwanted behavior. The changes in behavior were assessed by the owners of the horses. Some mares used in the study had ovarian cancer; others had no veterinary-diagnosed reason for their unwanted behavior.

Removing the ovaries was final attempt to resolve the unwanted behaviors as drug use to stop their reproductive cycles had failed and no issues with their reproductive tract could be found. Unwanted mare behavior can range from being uncooperative to aggression aimed at humans or other horses.

Drs. Daniel Taasti Melgaard, Martin Soendergaard Thoefner, Trine Stokbro Korsgaard, Morten Roenn Petersen and Hanne Gervi Pedersen, used the records of 28 mares that had their ovaries removed six to 24 months earlier and followed up with the horse owners, asking them to complete a questionnaire and respond to a telephone interview. Ten of the horses in the study had normal ovaries, 14 of the mares had ovarian cancer in one or both ovaries, and the other ovaries of the other horses were not examined for the presence of cancer.

Eight out of the ten mares (80 percent) with normal ovaries had improved rideability after their ovaries were removed; rideability improved in 57 percent (eight out of 14) in the mares with ovarian cancer. Mare behavior improved in about 40 percent of the cases studied.

The researchers conclude that mares without ovarian cancer may benefit as much from ovary removal as mares with ovarian cancer, showing improved rideability and behavior, though there is no obvious explanation as to why mares with normal ovaries benefited. The team noted that owner perception of improved behavior could be a placebo effect because they assumed the operation would work. They also stress that horses have a through diagnostic workup to rule out other issues before an ovariectomy is performed,

Read the full study here.