WHAT ARE ANATOMICAL PROPORTIONAL RATIOS ?
Anatomical Proportional Ratios are comparisons of the anatomy of a horse which enables a horseman to select a confirmation that is desirable for a specific use. Typically, the term "form to function" is commonly used by horseman, however I refer to the comparisons of anatomy as "conformational ratios".
With understanding comes knowledge, and with knowledge comes great opportunity. When we understand the differences of individuals, the differences become assets instead of liabilities. Anatomical Proportional Ratios are about consciously respecting the differences and defining those differences as tools to learn from and tools to utilize.
Often during my trip, I collected eighteen measurements when I photographed a horse. After measuring hundreds of horses, I designed computer programs to compare this data. When the data is sorted by specific criteria and then compared with information from another group, one can become knowledgeable about specific conformation traits.
By utilizing this method of comparison, one can observe the expression of any trait in an individual horse's ancestors and determine the degree of heritablity of this trait and how close that individual is to the average of his ancestors. I discovered that when I combined conformational ratio reports with the video tape information, additional insights became evident. For example, color related inherited characteristics are common in family lines and can be easily observed by grouping the video tapes of the bay, gray, or chestnut colored horses of a family.
The following are examples of reports which will enable you to better understand the value of Anatomical Proportional Ratios and demonstrate the depth and scope of the Arabian Horse Legacy's library and Database.
This is a portion the form I used to record the measurements of each horse
I am going to begin by focusing on only two of the nine traits that generally all world class performance horses of any breed have.
ANATOMICAL PROPORTIONAL RATIOS OF WORLD CLASS ARABIAN RACE HORSES
WITH 10 OR MORE 1ST OR SECOND PLACE WINS
Forearm to cannon bone ratio is 1.7 to 2.3 to 1
The depth of body when compared to the length of the forearm and cannon bone combined is nearly always greater than and averages 114% .
This trait is highly inheritable and has been documented in several family lines.
This trait varies within the breed from 85 to 136%.
The forearm to cannon bone ratio varies within the breed from 1.36 to 2.29 to 1.
The top 1% of the population in this trait varies from 1.95 to 2.29 to 1.
Now that we have isolated a couple of common conformation traits in flat track race horses, lets look at why they are important.
EXAMPLES OF TRAITS THAT LENGTHEN STRIDE
1. Length in the forearm and gaskin leads to long strides.
2. A long shoulder at about 45" angle.
3. Because of its function as a weight on a lever, there is an interaction between head size and weight, neck length and the ability to elevate the hindquarters.
4. High, muscular withers sloping smoothly into the back and accompanied by long sloping shoulder muscles allow greater extension of the forelimbs and freer movement.
5. The shoulder's main function is to help move the forelegs. Since shoulder muscles extend the forearm, their length and slope will determine the length of the forearm swing.
When long sloping shoulders allow greater extension of the forelegs and lengthen the stride, the result is less frequent ground strikes than a straight-shouldered horse would experience and effects any impact related hoof stress problems.
6. The hindquarters are for propulsion and should be long and well muscled. Generally, a steeply sloped croup restricts a horse to a shorter stride.
7. Long forearms are accompanied by long muscles and short cannon bones which can increase the length of stride.
8. A long muscular gaskin provides greater distance between the hock and the hip. The longer muscles exert more pull, lengthen the stride and increase hindleg swing action.
9. The angle of the hock will effect the power and length of the stride to some extent. An almost straight hock, accompanied by a long straight gaskin and short cannon bone give a running horse his lengthy stride. They allow full extension of his hindlegs and, consequently, full use of the power in his hindquarters.
10. Generally, horses with sickle hock's are not as fast as horses with straighter legs. They stand under too far, put excessive strain on their rear ligaments and are more likely to develop a "curb" abnormality.
Conformation ratios (racing). Generally, a stayer will have a long stride and easy action and is usually taller than he is long, a long neck, long forearms, a short croup and a long pelvis.
A sprint horse has a shorter back, is longer than they are tall, longer in the croup, strong loin, powerful hindquarters, shorter more upright pasterns and straighter in the shoulder than stayers or distance horses.
Expert horse people know that Conformation is important, However Attitude, Aptitude, and Environment will impact a horses performance, and must be carefully considered in the selection process.
It is also important to know when selecting breeding stock and when making breeding decisions, the expression of a trait in the individuals close ancestors. Throughout the world this is the most valued, widely accepted and understood method practiced by most horse owners. This heritablity estimate reveals how closely the phenotype(what the horse physically looks like) resembles its genotype(the gene types that an individual inherits from both parents).
For the horse person who needs to apply more sophisticated genetic selection procedures there are many new and great resources available today.
For those of you who use or want to use heritablity estimates as a tool in your selection procedures the following studies demonstrate the value.
In this study of a well known Arabian Stallion I focused on his fore arm to cannon bone ratio and compared twenty of his close ancestors to his expression of the trait. It is interesting to note that if one used his sire and dam alone for heritablity estimates the expectations would have been quite different.
This horse identified as GET inherited the trait from his grandparents and great grandparents. If this was a trait you were selecting for in your herd, It would make sense to select a mare that had parents and grand parents expressing the trait of this stallions grandparents.
In this study I analyzed a different horse and a different trait. I compared the depth of body to the length of the forearm and cannon bone combined. This individual expressed this trait in the middle range of his close ancestors. It is common when studying several traits in one horse to discover they inherit the average expression of their ancestors in some and favor the grouped close ancestors in others.
Here is another example of a different trait and the Get expressing this trait near the average of the close ancestors.
In this study I selected only *Morafic sons and daughters and two traits.The Comp M1 list is forearm to cannon bone ratio and the Comp B2 list is length of back compared to total body length. The purpose of studies such as this is enable one to select the individual from a family that has the strongest expression of a given trait to those that compare favorably with the intended use.
The *Morafic progeny studied here ranged from 1.4 to 1.9 to 1 (forearm is nearly 1.5 to 2 times longer than the cannon bone) in forearm to cannon bone ratio. The length of back ranged from 38.4% to 46.2% of total body length.
This study looked for three highly desirable flat track racing conformational ratios which where expressed in any individual. There were twenty seven horses in the data base which met the criteria and this is a list of the top 3%
The following studies are examples of how raw data and information can become knowledge. It is possible to generate 51 different Anatomical Proportional Ratio reports on every horse in the data base.
EXAMPLES OF CONFORMATIONAL RATIOS REPORT:
Reg. No. 951200
Name Alaa El Din
Sire Nazeer
Dam Kateefa
Forearm to cannon bone ratio is 1.4 to 1
Forearm is 5% longer than rear cannon bone
The back length is 43% of this horses overall body length
Depth of body is 15% greater than forearm and cannon bone
The neck is 50% of the length of the overall body length
62% of this horses head length is below the eye.
ãCopyright 1985 , Ferman Ansel. All rights reserved. No part of this material may be reproduced in any form or by any electronic or mechanical means, including information storage and retrieval systems without the written permission from the author.
EXAMPLE OF CONFORMATIONAL RATIOS REPORT.
Reg. No 32342
Name Ansata Ibn Sudan
Sire Ansata Ibn Halima
Dam Ansata Bint Mabrouka
This horses length of back is 40% of overall body length
This horses parents' Average length of back is 41.8%
This horses grandparents' average length of back is 42.9%
The average length of back of his first 31 ancestors is 44.8%
The get of Ansata Ibn Halima, this horse's sire vary from 38% to 47% in length of back. 20 offspring sampled at random.
The get of Nazeer, a grandparent on both sides vary from 37% to 51% in length of back. 78 offspring sampled at random.
This Stallions length of forearm to cannon bone ratio is 1.60 to 1 (his forearm is more than one and one half times longer than his cannon bone).
This Horses body depth (measured from the middle of the wither to bottom of the belly) is 140 % more than the combined length of his forearm and cannon bone.
This horses rear cannon bone is 107 % longer than his forearm. These traits contribute to reach, push and length of stride performance. 52 % of the 400 horses in this study group are the same length, 19 % were shorter and 29 % were longer.
The length of his shoulder is 1.38 time longer than his forearm, and his shoulder is the same length as his forearm. His shoulder is 40 % of his total body length.
44 % of his body length is in the back.
His neck is 46 % of the length of his body, and when you combine the head and neck lengths they are 79.5 % as long as his body length.
61 % of this horses head length is below the eye, and his head is three fourths as long as his shoulder.
These few examples are from fifty one proportional ratios compared on this horse.
Here is some more information on ratios for you to use.
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Ó 1997 Arabian Horse Legacy Inc.
ãCopyright 1985 & 1998, Ferman Ansel. All rights reserved. No part of this material may be reproduced in any form or by any electronic or mechanical means, including information storage and retrieval systems without the written permission from the author.
