How does Minecraft horse breeding work?
Once you have two horses and at least two golden foods, you're ready to breed. Get your horses near each other and feed a Golden Apple or Carrot to each of them. Hearts will appear above their heads, and in a few moments, a baby horse will appear. The baby horse (or "foal") will follow its parents wherever they go.
Pasture mating, hand mating and artificial insemination are the three methods used, with variations of each. Breed registry regulations vary regarding the use of artificial insemination.
You can't breed wild horses in Minecraft. You can only breed tamed horses and both horses need to be tame to breed properly. So make sure you have tamed both horses.
By extension, without two perfect horses, a perfect horse cannot be bred. After 3.13 blocks jump, 11 hearts, or 9.71 blocks/second speed, any future breeding will have a higher chance of producing a worse child than a better one.
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The maximum speed of horses varies between 4.74 and 14.23 blocks/second. The fastest horses in Minecraft move at 14.57 m/s, but the average one goes at 9.71 m/s.
All it requires is a Potion of Swiftness or a Potion of Leaping (or both). If a player throws the potions on two different horses and gets them to breed while the effects are still active, their offspring will retain the boosted stats of their parents.
Health: Well, black pegasuses are the best and the fastest Minecraft horses. You will get a black Pegasus horse with 50 hearts in the Minecraft game. Working speed: You will find Black Pegasus with maximum working speed. The speed of Black Pegasus is nearly 1.3 blocks per second in Minecraft world.
The most likely reason that mares lie down after mating is because they are overwhelmed and need to rest to bring their heart rate back down to normal levels. Stallions can be aggressive and hyperactive when courting and mating, and horses are socially sensitive creatures.
Can a horse mate a donkey?
You're right, a horse and a donkey can have babies together. A male horse and a female donkey have a hinny. A female horse and a male donkey have a mule. But hinnies and mules can't have babies of their own.
Unlike other passive mobs, skeleton horses slowly regenerate health evident by their health bar while the player rides it. This is the same case for normal horses. However, they cannot be bred or fed.

While most can be commonly found in almost any biome, the skeleton horse is arguably the rarest type of horse in the game. It is an undead horse that has certain special abilities as opposed to normal ones. These mysterious magical creatures do not commonly spawn in the world.
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So as far as I know the fastest horses in the game are 139 speed and the slowest is 48, however, the horse nerf made Minecraft's techinchal highest speed now 135, so when breeding you can't breed 139s because the averaging can be max 139+139+135/3.
This horse needs to be fed warped fungi to be tamed.
Though speed can vary, white horses offer the best chance to be the fastest. They are typically faster than their counterparts who might jump higher or have a lot more health.
When breeding horses, the speed stat (along with some other stats) can be increased with splash potions of speed, and as a result, the baby will come out very fast. This can be done over and over, and will eventually result in some extremely fast horses.
No, a horse's base health cannot exceed 15 hearts.
But even in vanilla Minecraft, it's theoretically possible to raise a horse's health above the maximum: The Health Boost and Absorption Status Effects.
Does breeding horses with speed potions still work?
Apparently, horse breeding causes the child to inherit the final value of the parents' speed attributes, instead of the base value. As a result, parents with the speed potion effect produce offspring that are naturally faster than both. This process can be repeated indefinitely.
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Unlike other passive mobs, zombie horses slowly regenerate health. Zombie horses, in common with other undead mobs, take damage when affected by a Potion of Healing and are healed by a Potion of Harming.
They should not, no.
They occur when a horse is struck by lightning within a certain distance of an active player. Zombie horses don't occur naturally and must be summoned or spawned by the player. The skeleton horse is also a bit faster than the zombie horse, which makes sense given that zombies are notoriously slow.