Why was Eight Belles such a big filly for 3 years old

Question

Why was Eight Belles such a big filly for 3 years old

Answer 1

She was too tall for her age and gender because of inbreeding and because she was undoubtedly overfed to make her look good for the sales ring as a yearling. This is a common practice on the farms, because the breeders know that fat sells- but it has some terrible consequences for the horses. Overfeeding can lead to overgrowth, and it's obvious to anyone with half an eye that this filly was way overgrown. It also can lead to the development of conditions such as epiphysitis, which in turn weakens the bones and makes them much more likely to break under stress. Ruffian, the filly who raced 30 years ago, was also a victim of this practice, and her trainer spent many months during her first year with him just trying to get the baby fat off of her so she could race as a two year old. To do otherwise would have been to risk her getting hurt before her career even properly started.  Add this to poor genetics, and you have a recipe for a disaster.

Answer 2

Horses, like people, grow to different heights.  Fillies develop before colts so the fact that you see a filly who's bigger than the colts early in their 3 year old year doesn't completely surprise me.  Eight Belles's sire was something like 18 hands... so she could have just inherited genes that would make her grow tall.  However, overfeeding young horses is a common practice and it is a problem.  I can't personally say that any single factor made her grow tall.  I don't know how much she was fed or if she would have grown that tall naturally.  I don't think anyone can say exactly which reason, but those are the factors that went into making her such a massive filly.  Ruffian was the same way.  Ruffian was bigger than Foolish Pleasure in every way except for one... her shoe size.  She was taller, rounder, heavier... and all of that came down on a smaller hoof.