Once a mare has become an adult at the age of three (3), she can be bred to a stallion. At this time you can only breed horses of the same breed.
When going to a mare's profile and selecting the "summary" tab there will be a heart-shaped icon with the text: "breed this mare". When clicked, the player will be brought to a new screen where they may select a stallion to breed to the selected mare.
In reality, only 80% of bred mares deliver a fully grown foal, while the remaining 20% mares will lose the embryo, fetus, or foal prematurely. In Horse Reality we implemented a 5% chance of pregnancies ending in a miscarriage. This is not affected by energy, training, health, or any other factors of the mare and will happen within the first 4 days of a pregnancy.
The semen quality of stallions also has been taken into account. The better the semen quality, the higher the success rate. Depending on what his stats are, the chance of a failed pregnancy can be greater.
At this moment, the quality of the stallion's semen cannot be tested.
These are the current stats:
- 80+ quality = chance +5%;
- 65+ quality = chance +10%;
- 50+ quality = chance +15%;
- 25+ quality = chance +20%;
- <25 quality = chance = 40%;
This means that if you would have a mare bred with a stallion that has good semen, the total chance of a failed pregnancy is 10% (you have always 5% chance + 5% extra because of his semen). This means you have a 90% chance of getting a healthy foal out of this combination, and it is still 10% lower than the official birth rate in equines.
A failed pregnancy happens when you breed with a horse with bad semen. Within 2 days of breeding, you will receive a message that your mare doesn't seem to be carrying an embryo and she isn't pregnant. After these days you can breed her again. Normally you find out in approximately 40-50 days if your mare is or isn't pregnant anymore, which is why you receive the message 2 days after the breeding.
A miscarriage happens due to that 5% chance we started with. This will happen within 4 days. It means that she started to have a foal, but she lost it after 4-5 months of her pregnancy.
Both issues result in the same notification for now. At a later stage, we will implement different notifications with the real explanation. For now, you will receive a message that states your mare doesn't seem to carry an embryo and that she isn't pregnant anymore.
Overo Lethal White Syndrome
Be aware that if two horses are bred with the OLW gene, there is a high chance the foal will get stillborn due to the Overo Lethal White Syndrome. A foal with the OLW syndrome cannot survive more than 3 days. Due to the syndrome being very painful for the foal, in Horse Reality, a foal with that particular syndrome will be euthanized upon birth.
Pregnancy takes between 13.5 and 17 REAL days. In the first 4 days, you'll see that the message says: "Covered X days ago by Stallion". It means that the breeding isn't definitive yet and there is still the possibility of a failed breeding, or an embryo loss. When the 4 days have passed and your mare is in the clear, the message will say: "Due in X days from Stallion. Then you'll know for sure that your mare will have a successful breeding and will give birth at the end. Once your mare gives birth, you'll receive a notification. Please note that there is a half-hour delay when mares are giving birth. This is normal and does not have to be posted as a bug in the forum.