34 CIRCULAR 824, U. S. DEPT. OF AGRICULTURE 
of fatigue and that the association between speed and fatigue was not 
significant indicates that the test did not satisfactorily differentiate 
endurance between the horses. The differences between riders 
(environmental factors) were also associated with speed to a greater 
extent than on the shorter tests. This fact may in part account for 
the correlations between time on the cross-country test and on the 
shorter tests not being higher. 
On the average, horses with short, level backs made the best time 
on the cross-country test. This may have been due to the association 
between top line of back and length of stride at the trot, or it may 
have been a coincidental association. Canfield’s offspring, on the 
average, had relatively short backs and were also the fastest. 
The riders liked a fast walk with good action and were able to 
recognize it, as indicated by the fact that in general they gave the 
best scores for performance at the walk to horses with the fastest time, 
longest stride, and best action. They were not, however, so consistent 
in scoring performance at the trot, indicating that they did not all 
prefer the fast trot with a long stride or that they did not recognize 
it. However, in scoring performance, they liked a straight, snappy 
action at the trot. Just why good action at the walk should have been 
associated with ease of trot to the rider when good action at the trot 
was not, is not clear to the authors. Many horsemen believe slope of 
shoulder is associated with ease of riding. It did not appear to be 
in this study. 
According to Steele (71) the need for progeny testing has already 
been recognized by some light-horse breeders but more need to practice 
it. He says, in effect, that performance and meritorious production 
should be made the basis of selection and retention rather than the 
current use of lengthy pedigrees. 
SUMMARY 
This circular presents results of performance tests for speed, 
endurance, and ease of riding under saddle of 68 three-year-old 
Morgan horses raised and trained at the United States Morgan Horse 
Farm, Middlebury, Vt. These horses were by 8 sires and ranged 
from 2 to 25 offspring per sire. Tests consisted of 1 mile under saddle 
at the walk and 1 mile at the trot and an 11.35-mile cross-country 
ride at the walk, trot, and canter. On the 1-mile tests records were 
made of the time required for the test and the length of stride. On 
the 11.35-mile test records were taken of the time required; fatigue 
at the end of the test; and riders’ scores on each horse for ease of 
handling at each gait, performance of gait, and ease of gait to the 
riders. Other measurements and scores were made on each horse. 
Horses with a fast walk, on the average, had a long stride, straight 
snappy action, and a medium slope of shoulder. Slow horses had 
either a short or a long stride. None of the sires produced all progeny 
with both a fast walk and a long stride. Canfield had the best record, 
69 percent of his progeny being in this group. 
Horses with a fast trot had a relatively long stride and in general 
had a medium score on general conformation. Differences between 
the offspring of the different sires were not on the average significant 
when the sex of the progeny was considered. 
