Questions about genetics and height, also sport medicine boots?

Question

I have a few questions. I know when breeding two horses, the foal will usually mature to a height that falls somewhere between the sire and d**n, but how much of that is nutrition verses genetics? My reason for asking this is I have a foal out of my 15hh mare. She was bred to a Thoroughbred/Dutch Warmblood, who is barely 15hh as well. When we purchased this stud, we actually bought his dam at auction. She was close to emaciated when we got her, and pregnant. The mare is a TB, and she is about 15.2hh, and I am thinking that the stud that she was bred to, being a Warmblood should be around the 16hh mark, and yet they produced a tiny colt. Could this have been due to the mares poor state of health? And is it possible that my colt might get more height from further back in his bloodlines? I hope that makes sense.

My second question is, can anyone tell me the differences or pros/cons between Professionals Choice Sport Meds II, 3, and Elites? Thanks!

Answer 1

Sometimes it is better to look at the grandparents. The size of the colt at birth doesn't reflect how big he will be when mature. Nutrition as well as genetics can play a part in height. Poor nutrition for the mare can affect a colts birth weight, but this can be overcome with the colt getting a real good nutritional diet.

Sorry I can't help you on the boots.

Answer 2

The colt's small birth size doesn't mean too much.  When my mare was born, she was tiny!  Now as a four year old, she is 15.2 and close to 1,200 lbs.  She is a TANK!  

I agree that you don't just have to look at the parents for size.  If you can, go back and look at the parents pedigrees to see how tall some of the horses in their parentage were.  My mare has Poco Beuno on her papers, and a lot of those foals are born small and continue to grow until the age of 4 or even 5.  You never know, your horse might be like that, too.  

It really seems like height is a bit of a random thing with horses.  You can never seem to base it completely off the parents.  Your colt may just grow slowly, or maybe he will be one of those babies that just shoots up in a couple of months.  Just give it time.  Once he starts growing, look to see if his butt is level with his withers.  Once he has started to level off, you will know that he is close to his full height.  

Answer 3

From my experience, it is safe to say that a foal will NOT necessarily mature to a height half way between that of its parents.  Far too often I've seen this to not be the case.

My first TB broodmare was 15.2hh herself and had already bred several racing foals before I purchased her.  I bred her twice to the same stallion; a 16.3hh TB. Foal number 1, a colt matured at 14.3hh and the second foal, a filly matured to 15.1hh. All horses were kept in superb condition, fed correct stud diets and were under the constant supervision of a stud vet. Genetics alone must have determined their size.

I kept the above filly and bred her for the first time to a 16.2hh Polish Warmblood stallion.  She produced me a filly from this covering in 2007, which at 14 months old now stands at 15.2hh already!  They say a first foal is supposed to be small. Hmmmm.... if that's so, goodness knows what next Springs foal is going to grow to!!!!!

Another case as example, we have a 17.3hh TB gelding on our yard, bred by his present owner. I asked how big his dam and sire had been.  It turns out the year before his owner had bred a full sister to him, as well. The dam of this big horse was 16.0hh and the sire 16.1hh.  His full sister grew to 16.1hh, so where the 17.3hh gene came from, no one knows!!

Good feeding in the early stages of life does influence how quickly a horse grows initially, but several studies have shown that malnourished young horses, subsequently given correct feeding, can catch up to their genetically determined  height if caught in time and not suffering the often associated complication of neglect, irreversable worm damage.

With regard to your question about the Prof Choice SMB, I'd recommend the SMB II as they fit better than the SMB I's do.  But today I have invested in a set of the Elite boots. Compared with the regular SMB's they are supposed to be lighter, better fitting and support the leg better. Blurb suggests they can reduce stress to upper limbs by <26%. I've a yearling filly with bench knees who is under going remedial farriery.  I am going to use the Professionals Choice Elite boots in front, to help support her front legs as she develops.

Answer 4

Well, I know at least in my case this isn't always the rule.  My broodmare is barely 14hh, and when I bought her she was bred to a 15hh stallion.  I figured I would have a smallish foal.  My filly is currently 2 1/2 months old, and is only 3 hands shy of her mom.  She's large enough that I actually called the woman I bought the broodmare from to double check parentage, and the vet tested her for growth disorders.  But she's nice and healthy.

Vet says she should round out about 16.1 or 2, possibly larger if she keeps growing like she has.  I searched both parents pedigrees and found out that her grandsire on her sire's side was over 17hh, and he was the only tall one in either parent's pedigrees all the way back to the foundation sires.

I'm of the opinion it's the luck of the draw.  There might be that one ancestor that effects height, whether to the short or the tall.  But it could just be in my case.

Answer 5

Height is a combination of genetics and nutrition. My stallion is short, but regardless of the mares he's bred to, he throws babies that grow taller than he is. Yes, it is possible the foal is smaller due to poor nutrition during gestation. Just remember, don't feed your foal to push growth. Feed a healthy diet not too high in protein. Too much protein can cause metabolic bone disease, ephisitis, physitis, (pardon my misspelling) etc. The foal will grow to it's genetic potential with proper feeding, so don't rush it.

I prefer Professionals Choice products in general. I haven't used the Elites.