Biomechanics, Inbreeding & Breakdowns

Understanding pedigrees, inbreeding, dosage, etc.

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xfactor fan
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Postby xfactor fan » Sat Jan 09, 2010 11:05 pm

This is from the link that Bill from WA posted earlier.
http://www.jwequine.com

Judy Wardrope has studied conformation for 30 years, and her observations are clear, she has a good understanding of Biomechanics, and more to the point can explain what she's seeing. And has examples so that a novice can see too.


http://www.jwequine.com/pdf/CTBA-Conf-Intro.pdf

This article goes into how the different bone lengths affect speed and aptitude.

Dave C
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Postby Dave C » Sun Jan 10, 2010 8:48 am

But are the different bone lengths a function of genetics or a product of the interplay of environmental factors with the genetics?

xfactor fan
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Postby xfactor fan » Sun Jan 10, 2010 3:37 pm

Of course the second.

The Genetics lay down the blueprint, that says "Under optimal conditions this is what will form" The environment modifies how the blueprint plays out.

Matchemforever
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Postby Matchemforever » Mon Jan 11, 2010 12:30 pm

http://www.donblazer.com/college/confor ... on_one.htm

Does not explain why:
“Short pasterns contribute to a harder ride, but also aid a horse’s speed.”

“A short gaskin is associated with high hocks, which generally means the horse will have inefficient movement, taking an extra long stride”

“A long gaskin is associated with low hocks which often puts the horse is a camped-out position. Horses which are camped-out behind lack power and smoothness. He can best be used as a trail horse or pleasure horse.
The gaskin length is best when it sets the hocks at the same level as the horse’s knees, for the horse will usually have both power and speed. When evaluating the potential of a horse which will be asked to work with speed and agility, look for hocks which are at the same level as the knees.”


“Sickle-hocked horses should not be considered for speed events, while post-legged horses--very straight hind legs--are particularly good at speed events, but little else.”

Some of this seems at variance with observations. I wish he had explained why his thinks short pasterns aid speed. I don’t believe a long gaskin, if the hocks and knees are pretty even with strong muscling and well let down stifle joint, necessarily make a horse week. And it certainly seems that post-legged seems to be selected for in a lot of TB’s these days, by accident or otherwise.

“Move to the horse’s side to evaluate the horse’s shoulder. An upright shoulder indicates the horse can work in sprint activities. The horse’s speed lies in his ability to gather and get into the next stride, not on the length of the stride. In other words, the more strides within a particular distance, the more speed. A horse increases speed by driving off the ground. His speed slows as he travels through the air”

“A long forearm favors speed and jumping ability. The horse with a short cannon will generally have speed, agility and foreleg soundness.”


Here is a link to other links on gaskins. Don’t have time to search to see if they are worth the time:

http://en.mimi.hu/horse/gaskin.html

You can also link to “pasterns” here. Again, have a feeling most of this stuff is from 4-H type sites where the generalities are given. Hard to find real explanations either by years of experience or scientific.

Matchemforever
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Postby Matchemforever » Mon Jan 11, 2010 1:22 pm

"Mumtaz Begum looks down right deformed, her gaskins and hind cannons are so long"


Viney, IMHO :wink: Mumtaz Begum's hind leg conformation shows pretty extreme post-legged. I don't see a lot of angulation anywhere, even from point of hip to stifle, in the picture. Look at how upright her hind pasterns are- and generally, the hind feet have a little more angulation. She only raced at two, according to the TB Heritage site. Not known why she didn't race more, trouble keeping her racing or rush to get her into the breeding shed. Another filly of Mumtaz Mahal didn't make it to the races, either.

http://www.allbreedpedigree.com/mumtaz+begum

(I know it's allbreed, the link I got when searching MB. Pictures are correct)

That kind of straight hind leg, in a brief comparison looking at horses in her pedigree where pictures exist (caveat), seems to be from The Tetrarch and his sire, Roi Herode. In that case, seems to have thrown back to third generation. Had that happen with size once, baby would have made all of 15.2 out of 16.1 and 16.3 parents. There was one grandsire who was short.....

Mumtaz Mahal, I think, had a lower placed, more angulated stifle, probably helped in that department by her dam, Lady Josephine.

More on stifles in the Judy Wardrobe site listed by xfactor fan.

I kind of wonder if Mumtaz Begum really was higher in the hind end than the front. The back feet in the picture do not seem to be on the same level as the front, but just slightly, so maybe the way she was stood up?

Shammy Davis
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Postby Shammy Davis » Mon Jan 11, 2010 2:16 pm

If you think about it, size and length may have more to do w/natural proportions than anything else. A horseman w/a good eye for conformation is an invaluable resource at a sale.

I've always heard that the pastern should be no less than half the length of the cannon bone. I must tell you that I've never believed it, but I think it is as good a guideline as any other.

As a farrier, I learned that shorter pasterns made the hoof more upright with longer heels and that combination compounds the problems which lead to navicular disease, hoof wall cracks, and contracted heels. Whether short pasterns are an indicator speed, I don't know. I think the overall physical balance of horse as it pretains to a particular breed's work is what is most important to consider.

In a previous post someone provided the length of individual horse cannon bones. I'm not sure what that tells us, because we need to know what those measurements were in relationship to.

I think we all feel that the records set by a stout racehorse like SECRETARIAT over a distance of ground are phenomenal and they are. I've thought a great deal about his conformation, but I go back to the idea that he was able to store and use energy better than 99.9% of all other Thoroughbreds past and present. His may not have been the perfect conformation for the true classic runner. It may be that he was more efficient internally than he was physically and that was the difference. You don't get the burst of speed that he provided in the Belmont without the stores of energy being available.

And, finally, I know someone will say what about his stride? He could not have maintained that stride if he was becoming fatigued. That keeps me going back to his storage and use of energy.

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Postby Matchemforever » Mon Jan 11, 2010 2:32 pm

Shammy,

I think the ability to store energy is as sound an idea as any when it comes to the very few, phenomenal race horses.

Secretariat was a bull of a horse and just physically, shouldn't have been able to carry that mass the distances he did.

Man O' War is another case in point. Not built like Secretariat but not small. However, I think the incredible thing with MOW, in all accounts I read, was how much energy he used up before the barrier ever went up, how many false starts, etc. By all accounts, this is a horse that should have left his races at the barrier. Yet most accounts say he was never pushed, looked ready to go on, and his riders most often rode with a strangle hold on the horse.

I think MOW is another case in point about energy like Secretariat.

And I'm not sure that has to do so much with the heart factor, although it certainly can't hurt.

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Postby Dave C » Mon Jan 11, 2010 5:30 pm

I think judging conformation is far more an art than a science. Some people can just 'see' which horse is put together properly and as Shammy said 'they are an invaluable resource at a sale'. I also think there are a whole lot of people who promote themselves as conformation experts with very dubious credentials. This is also why I think it is very good that there are people out there who are trying to turn it into a science, where there is a objective formula for how a horse should be put together, a standard that anyone can apply and verify, so that you don't have to just trust that your 'expert' actually knows what they are talking about.

I'm not sure that I agree with the above quotes about speed in regards to the shoulder
“Move to the horse’s side to evaluate the horse’s shoulder. An upright shoulder indicates the horse can work in sprint activities. The horse’s speed lies in his ability to gather and get into the next stride, not on the length of the stride. In other words, the more strides within a particular distance, the more speed. A horse increases speed by driving off the ground. His speed slows as he travels through the air”
.
I've seen and ridden far too many TB's who generate their speed through extremely long strides rather than a high frequency of strides. TB's when they tire during a race very noticably shorten their strides. I think perhaps what the the author really means is quickness or acceleration, or explosiveness, as opposed to speed.

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Postby Shammy Davis » Mon Jan 11, 2010 6:33 pm

Matchemforever, there is very little known about the racing program conceived by Chris Chenery. He was able to take foals from fairly obscure overlooked mares that were useless racehorses that he bought for a few hundred $ and placed them well above what normal expectations might be. Remember, he was sending some his mares to Richard Hancock at Ellerslie near Charlottesville, because of proximity, not pedigree. It is apparent that he was looking for strong family lines, but that makes sense.

After forty years of looking at horses, I've come to the conclusion that for the most part, athletic horses look athletic and non-athletic horses are not too appealing. There are exceptions, of course and that is the rub. What did Chenery see that we are not?

There was something more to what was going on at Meadow Farm in Doswell, VA. I'm haven't a clue what. I've alluded to some horsemen having the eye for right horse. I believe that. It's a gift. I think Dave C is exactly right, it is art not science. Conformation flaws can be overcome with well thought out and sometimes imaginative training and care regimens. With the right feed and training even a nag can look like a winner in the post parade.

But, that being said, there is something more with Chenery. His biography is understated. He was an engineer and industrialist. But his heart was with the Thoroughbred. The shame for history is that Chenery was a quiet individual who did not seek out publicity or fame. It would have been nice if he had put some of his thought about TB on paper. Maybe, he did and the family has not released it. I don't know.

I don't believe that his children truly understood his grasp of the Thoroughbred. Penny was the only one who took an interest. We give Penny a great deal of credit, but she was the caboose on a very long and successful train ride designed by her father. She doesn't have a clue either or she would have had a successful stable concidering what she had to work with, so that makes me think, her father did not put his thoughts on paper or discuss it w/those around him.

I think SECRETARIAT, like MAN O'WAR, was an exceptional horse in stature. Physically, they were extraordinary to eye, but something more carried them to the overpowering wins that they exhibited. We know they could be beaten, but when they won they were incredible.

We are seeing that now with RACHEL ALEXANDRA and ZENYATTA. RUFFIAN is an example. There are more both male and female. What we need to know is what is the essence of their athleticism and why is it there. It can't all be conformation. We won't see it in the pedigree either.

I think it has to do w/muscle fibre and energy exchange within them. Maybe it is the balance between slow and fast twitch muscle. How the lactate acid is expelled is important. There maybe a psychological component. Somewhere in the foundation moments of a foal to weanling, there is compelling exercise or exercises that reinforces courage that is exhibited in the future. From that conclusion, I'm lost.

I am reminded of the great sprinter, Wilma Rudolph who suffered from polio as a child as well growing up in proverty. Physical flaws can be overcome by will and energy. EASY GOER and CITATION both had a club hoof. Anyway you look at that, there stride was to some extent shortened. I don't believe that it is totally the heart. There was something else. SHAM had a 19 lb heart. SECRETARIAT had a 22 pound heart. 34 length difference?

The answer to the great racehorse is not in conformation. It is in the utilization of energy and/or the training and nutrition regimen that supports it.

So, what was going on w/Big Red? Freak no longer applies.

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Postby xfactor fan » Mon Jan 11, 2010 7:37 pm

Sham vs Secretariat.

Sham is from family 9, Secretariat family 2. Which would indicate different types of mtDNA with different energy profiles.

The sport horse data base has a good conformation photo of Sham, who looks to be a long bodied horse with relatively short legs. In particular his forearms are not all that long, with medium to short cannons.

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Postby Shammy Davis » Mon Jan 11, 2010 8:49 pm

XXF, don't get me wrong, I don't believe that heart size is a reasonable comparison.

I was just trying to make the simple point that this subject is extremely complicated and if we were too only look at the physical aspects, our conclusions would be as varied as the racehorse body types.

If say I'm right about the balance of fast/slow twitch muscle fibre or the efficient use of energy, then MtDNA might play an exclusive role in the phenomenal racehorse. Certainly it plays a role in a successful racehorse. Conformation alone, though critical to proper movement and athletic ability, is not totally consequential to athletic results in a single event or a series of events. Conformation is more a long term prognosticator of soundness and utility. How the horse uses energy is the key and probably the difference between SECRETARIAT and SHAM, not conformation.

Think about it. 34 lengths? I don't recall many of the names, but besides SHAM, the foal crop in 1970 was a pretty healthy and athletic one. Remember, SHAM ran the second fastest Derby and I think he lost by a neck.

Using family lines helps to define the issues because we can conclude from SECRETARIAT's mare, there were other successful racehorses thrown by her. But not like SECRETARIAT. There were full siblings and half siblings, none that excelled like SECRETARIAT. Why?

Lastly, consider that Chenery raced homebreds.

I don't recall that SHAM had any siblings that were successful. That being said SHAM has always been my favorite. :wink:

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Postby Dave C » Tue Jan 12, 2010 8:07 am

The balance between the various types of muscle fibres is almost strictly a function of training not genetics. One type of Type II muscle cell can be converted to the other type of Type II fibre in 6 to 8 weeks of training. Genetics may only set the upper and lower limit for each type.

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Postby xfactor fan » Tue Jan 12, 2010 10:47 am

Shammy,

I didn't bring heart size into the conversation. Just pointed out that Sham and Secretariat likely had very different mtDNA, hence different energy profiles.

They also had different conformation. And different trainers, and different riders.

Anyone who claims that there is only one factor that makes a great racehorse is trying to sell you something.

Dave C. I think that there is genetic control over the percentage of slow twitch, fast twitch and multi-twitch (fibers that can go either way with training) As part of the breeding for speed, the TB may have been selected for a large percentage of multi twitch muscles.
If you look at yearlings, or broodmares for that matter, some are lean, some are bulky, some are intermediate. This should give a basic indication of the percentage of each type of muscle present --pre training, pre muscles converting from one type to another.

Shammy Davis
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Postby Shammy Davis » Tue Jan 12, 2010 11:06 am


Shammy Davis
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Postby Shammy Davis » Tue Jan 12, 2010 11:08 am