Should I breed my mare?

Having a foal can be a big undertaking and much thought should go into what it involves before starting to prepare your mare for breeding. 

Conformation, temperament, age and physical fitness should be taken into consideration. Be mindful that some traits are passed on, so try to have an objective look at your mare and consider what she might pass on to her offspring.

Plan your budget and stick to it, breeding can be costly and you are also adding to your herd.

It is important to consider that there are a few risks involved, complications can arise during pregnancy and around foaling, It is important to have a basic range of facilities to handle and manage your mare and foal.

Once you have made the decision to go ahead, its time to call Sydney Equine Practice to organise a pre-breeding check and for more advice on natural service, AI and ET. 

What is the oestrous cycle?

The oestrous cycle is generally 21 days long (+/- 2-3 days) and can be divided into two phases, the follicular phase and the luteal phase. The follicular phase (oestrus) is when the mare is displaying signs of being 'in season' which lasts for 4-7 days. The luteal  phase, also known as dioestrus begins once the mare ovulates. The mare will no longer stand with tail to side, urinate at the sight of a stallion or teaser.

Is my mare too old to breed from?

Mares can become pregnant and carry a foal into their late teens and some into their twenties, but with age comes more risk to both mare and foal. The mare may need much more care throughout her pregnancy than other younger mares. It may also be wise to consider the unborn foal may fit into a higher risk category where it may need more attention once it is born.

Frequently sport horse mares start their breeding careers after their athletic careers are over. The result is that we are presented with the 'older maiden mare', with a collection of issues which can be a challenge to the stud vet. Frequently these mares have had a long period of time on altrenogest which can result in a uterus with less muscular tone and a fibrous cervix. It is common for these mares to develop intra-uterine fluid post-insemination with a pronounced inflammatory response which is difficult to clear due to the fibrous cervix. These mares are challenging and need much more treatment and attention during breeding to produce a pregnancy.

Another hurdle is the decline in egg (oocyte) quality which can lead to a decrease in conception rate and an increased risk of early embryonic death. Therefore it is best to be aware that the pregnancy rate is lower for older mares.

Mares will stop cycling in their mid-twenties but some will enter into 'menopause' earlier. This can be ruled out during the pre-breeding exam ultrasound examination of the ovaries.

The optimal age for breeding is 3-10 years old, but this is often their busiest time of their athletic careers. Embryo transfer should be considered for these mares so they can continue working while producing offspring. 

When should I get a pre-breeding check done?

The natural breeding season of the mare is spring and summer. The mare has a period of cyclic inactivity (anoestrous) when she cannot be bred during the winter. There are two transitional periods between when the mare is cycling  (spring/summer) and the anoestrous period; these transitional periods take place in autumn and early spring. During the transitional periods mares can be unpredictable and erratic; they will develop follicles but not ovulate.

A pre-breeding check can be carried out during springtime to identify any reproductive abnormalities and establish whether the mare is still in transition or has had a first ovulation of the breeding year.