Here in America, we almost never keep a stallion unless they are being used
for breeding. If your stallion is not covering mares or being used for
collecting semen, there is really no need for him to be a stallion.
Stallions are a very definite liability when it comes to management.
However, gelding a stallion at a more advanced age may not solve your
nervousness problem at this point in time. I have observed geldings who
were gelded at an older age, say 6-7 years, and still exhibited the same
characteristics of nervousness and non-recovery as you have described.
My guess is that if you can make it through the qualifying stages of your
lower distances, and start doing longer distances with this horse he will
probably settle down and start to work, whether you geld him or not.
Another observation I've made, and confirmed by interviewing people who
ride stallions in endurance, is that stallions seem to be less "honest"
than mares and geldings. My "honest" I mean they will not give you their
best effort, but they save some energy for themselves. They keep some
energy in reserve.
Just my two-cents on stallions.
Linda Van Ceylon
lvanceylon@vines.colostate.edu
phone: 970-491-1428