Recently we looked at the mare’s reproductive physiology and how it can impact when you breed her (link to Reproductive Physiology article). This article takes into account all mares – those who haven’t been bred before (maidens) and those who have but are not pregnant (empty). It was also referring to the mare with a foal at foot (the wet mare).
When you are choosing to rebreed a mare that is currently nursing a foal, there are other factors to consider, however. These include:
- the mare’s condition
- foal heat
- signs of oestrus
The Broodmare has a lot of Demands Placed on her Body
The Mare’s Condition
Because she is feeding a foal, the broodmare is already using up a lot of energy. Did you know that a lactating mare uses up as much energy as a racehorse in full work? This is worth considering if we are going to ask her to cycle properly, conceive and go on to produce another foal whilst she is still feeding one.
This is the reason that some owners choose to breed their mare every other year, or give her one in three years off. The choice is yours and ultimately should be based on the mare’s condition and your finances. You may find that you choose to breed her, but she doesn’t conceive. This could be her body’s way of stating that she cannot maintain a pregnancy at this stage.
Keeping the broodmare in good body condition will help to ensure that her condition isn’t the factor affecting her chances of conceiving. This would come in the form of a body score of 3 in Australian terms and 6 in US terms.
Your desired outcome will affect when you need to breed the mare. All mares with a foal at foot have a foal heat. This is the first cycle or period of receptivity and then ovulation after giving birth. This happens as early as 7 – 12 days post foaling.
If you are limited by time – the thoroughbred industry strives for early breeding that results in an early foal the following year – then you may desire to breed your mare on her foal heat.
If the mare is to be bred at this stage, then it is important that she is physically ok. This would require that she didn’t have a difficult foaling and that her uterus is clean and the vulva isn’t swollen. Some vets encourage owners to breed only on the foal heat if the mare is young, looks like she is going to ovulate later (12 days) rather than sooner and she hasn’t had a difficult foaling.
It is between you, the stud manager and the veterinarian to determine when you feel is the best time to breed your mare. If the foal heat isn’t a possibility, the she will be in the same position in her cycle 21 days later (30 days post foaling). Alternatively, she can be given a shot of prostaglandin at a time deemed appropriate by the vet after she has ovulated. She will then come back into season quicker.
Signs of Oestrus
Some mares display different signs of oestrus when they have a foal at foot to when they don’t. They may be termed ‘foal proud’. Although your mare may show really well when she is interested in a stallion and she has no foal, this doesn’t guarantee the same for when she has a foal.
Her focus can be completely on her foal’s safety. She may see a stallion as a threat to this and act accordingly. Wet mares when brought near to a stallion may be physiologically ready to breed. They have a mature follicle that is close to ovulation. Their uterus is showing the right amount of tone and inflammation.
They should be showing signs of being in season:
- tail up
- winking the lips of the vulva
- straddling the hind legs
- leaning into the stallion
Instead, they show signs of not being receptive:
- not wanting to be near the stallion
This doesn’t necessarily mean that the mare isn’t in season. It could mean that she is so focused on her foal that she is reacting for its safety.
Whoever is managing the mare should know how to counteract this. They may need to leave the mare and foal in a yard next door to the stallion so that she can become accustomed to his presence. If she doesn’t feel pressured, then she may approach him of her own volition and show signs of being receptive.
It may be that another day is needed for her to develop a little further in her cycle. Or it may be that she needs to be encouraged another way.
Initial signs of resistance don’t automatically mean that the wet mare cannot be bred. It just means that she needs to be managed differently. It is important for horse owners and managers to recognise this unique side of breeding the mare.
Thankfully once the mare’s condition and her foal at foot are taken into consideration, it is often possible to breed the wet mare quickly and effectively. When breeding of horses is carried out for an income, it is important that the process is able to be done efficiently. This is best able to be achieved when issues that may arise are understood, recognised and able to be acted upon.
Because the mare’s gestation is 345 days in length (11 months plus a week), and she comes into heat so quickly after giving birth, it is feasible to think that she could conceive and produce a foal each year. This doesn’t mean however that it is imperative that all broodmares are bred every year. When breeding horses, it is always worth considering how important it is to get a foal from a mare each year. How early this foal needs to be born the following year should also be considered when determining when to rebreed the wet mare.