A great deal of attention is often given to choosing the sire for a foal, often more than choosing the mare. Unfortunately, due partly to heavy investment in marketing and advertising by the stud stallion industry, there is a myth that the stallion is more important that the mare. However, this is a mistake since half of the foal's genes come from the mare, so it is just as important as the sire in terms of determining the foal's genetic potential. In addition to providing half of the genes, the broodmare provides the foal's nourishment and environment for the 11 months of pregancy, then after birth its milk until it is weaned, as well as much of its early education. Consequently, the broodmare's contribution is not only as great as the sire's, but in fact more. As such, selection of the mare deserves careful attention, certainly more than it often receives.


Following are some common terms for broodmare and their definitions:

  • Breeding Mare. A mare (female horse) which is being used for breeding or will be used for breeding.
  • Broodmare. A mare which is used mainly for breeding. The difference between 'broodmare' and 'breeding mare' is that a broodmare is intended to be used mainly or entirely for breeding, whereas the term breeding mare is more general, since it includes both horses which are occassionaly used for breeding and horses whose primary function is breeding.
  • Brood Mare. Same as broodmare, just an alternative spelling.
  • Dam. The mother of a horse.
  • Sire. The father of a horse.

The offspring, when born, may be a 'filly' or a 'colt' or a 'foal' or a 'yearling'. For an explanation of these terms, see female horse terms and male horse terms.

Choosing a Breeding Mare

Breeding is a major investment: there is the cost of the breeding mare, stud fees, cost of boarding the mare for 11 months of pregnancy, cost of boarding the mare and foal until it is weaned, plus all the veterinarian fees during pregnancy, at birth and afterwards. In addition to all this expense, there are also substantial risks: mare may not be able to carry foal to term, foal may be permanently damaged during birth or thereafter, foal may not have the qualities you are looking for. In light of the size of the investment and the associated risk, it is worth carefully selecting a breeding mare that is likely to give you a live and healthy foal that meets your requirements (ability, temperament and appearance). Some tips for doing so:

  • Try to select a mare who has demonstrated that she has the traits you wish, preferably showing these in competitions of the appropriate level. All to often, 'breeding mares' are simply mares that aren't good enough for anything else. In fact, one should only be breeding with a mare that has demonstrated both that it has the genetic capability you wish (be it jumping, racing or simply pleasure riding) and who has the temperament you desire (be it quiet, spirited, or competitive).
  • If possible, use a mare which has a proven breeding record. In other words, one that consistently brings foals to term and live birth with minimal issues. Be aware that there can be issues with older breeding mares.
  • If the mare has already had foals, try to view them and talk to the owners to get an idea of the temperament and other qualities she tends to pass on to her offspring. The breeding mare owner and the relevant breeding club can likely help you trace down her offspring.
  • If the mare has any health issues (e.g. prone to laminitis) or behavioral issues, think carefully about the possible risk of her passing such traits onto her offspring. Of course, if any issues are due to a genuine accident or other non-genetic cause, then the mare may still be satisfactory for breeding.
  • If buying a mare for breeding, try to select one which is not too old and can still be ridden. This way, if breeding does not work out as planned, you will still have the options of riding her or selling her.
  • Try to select a mare with a good pedigree. Firstly, she is more likely to produce a quality foal. Secondly, the quality of the dam's pedigree will in large part determine the value of the foal and the price you can sell it for should you choose to do so.
  • Before buying or renting a breeding mare, one should make the investment in having an equine vet examine it to confirm the general health of the horse and specifically its breeding health. Although this is an additional cost, it is a very small fee compared to the enormous cost of investing in an unsound horse.

Buy, Lease or Borrow

If you already have a suitable mare, you can breed with it. However, if you don't have a mare, your options are to:

  • Buy. If you are committed to breeding long term, buying a broodmare may be the most cost effective option. However, if you are not experienced, you may be better leasing or borrowing one initially.
  • Lease. Surprisingly enough, there are quite a few horse owners who will lease you a broodmare. Provided that the leasing fee is not too high, this can allow you to try breeding without making the commitment of buying a horse.
  • Borrow. Occassionally, a horse owner may want to reduce their horse population temporarily (e.g. to make room for other horses) and be willing to loan you a broodmare. Alternatively, you may be able to do a deal, such as breeding two foals, you keep one and give the other to the owner of the broodmare for loaning you the mare.

One needs to look at the associated costs and commitment to determine which of these make the most sense for you. If you are leasing or borrowing, keep in mind that you need the broodmare not only for the duration of the siring and pregnancy (average about 11 months) but also for the duration the foal is nursing (typically 4-6 months), which gives you a total of 15 to 17 months.

Breeding Facts

With horses, the average pregnancy lasts about 11 months, although on occassion it can be as little as 10 months or as long as a year. So, if a mare is mated in May, the probabilty is that the foal to be born in April of the following year, although it could be as early as March or as late as May.

When breeding, one normally controls when the foal is conceived by putting it together with a stallion only at the best time. The ideal time depends on:

  • Climate. One normally wants a foal to be born in Spring, so that it has time to grow and gain weight before the difficult winter. However, one does not want it born too early, when the temperature is too cold for a foal (unless it is being kept in a heated area). Depending on the local climate, around April is a good time to be born (no longer very cold but lots of time before the next winter) which would suggest a mating in May. Of course, in hot countries the timing is not as important, while south of the equator (e.g. Australia) the time would be reversed.
  • Competition. In a number of sports, only horses of the same age (e.g. 2-year olds, 3-year olds) can compete against each other. With such sports, all foals are considered to have been born on January 1st of the year in which they are born. Consequently, a foal born in February would be considered the same age as a foal born in August of the same year, but the foal born in February will have more growing time before the first competition and thus a competitive advantages. To maximise this advantage, some breeders will use artificial stable lighting to bring their breeding mares into season early in the year, aiming for them to foal as soon after January 1st as possible.

After birth, the foal will normally suckle for 4-6 months, at which point it is usual for the owner to separate the foal and mother in order to wean the foal off suckling milk. In the wild, a mare may allow a foal to suckle up to a year. With domesticated horses, if the foal is not seperated from the mare and the mare does not become pregnant again, the foal may continue to suckle for years (which is not a natural situation and should not be allowed to happen).

Once the foal is separated from its dam, it can take some weeks for the mother to completely stop milk production and the foal needs to be kept separated from the mother until the mother completely 'dries up' as otherwise the mother will resume milk production. During the start of the 'drying up' period, the mother can continue to produce milk which can build up and put pressure on the breasts, sometimes resulting in injuries. Consequently, one should carefully monitor the breasts during this period to make sure all is well. If the mare has a history of trouble during weaning, one may consult with a veterinarian about 'drying up' medication to minimise risks.