'Research was conducted at Colorado State University
some years ago, in which some proud-cut geldings were
surgically examined. It was found to make little difference
in their behavior whether the epididymis had been removed or
not. It has been theorized that these animals have male
hormone production in their bodies from some sit other than
the testicles--perhaps from one of the other glands in the
endocrine system. Many of the geldings who "act like
stallions" after castration are those who were sexually
aggressive as stallions, and had considerable sexual
experience. They may still exhibit breeding behavior after
being gelded. This may be a constant problem, or it may
only be seen around mares or premises where they had
previously exhibited sexual behavior. There is little or no
cure for the gelding who remains "studdy" after he has been
castrated. There isn't anything else to remove, except
maybe his head!'
Ruth B. James, DVM in
_How to Be Your Own Veterinarian (sometimes)_
This is not the only source for this information, but it is
what I had readily to hand. For anybody who does not have
this book, I can highly recommend it.
My understanding (I could hunt down the source if anybody is
really interested) is that a major producer of testosterone
is the adrenal glands, but there are a bunch of other glands
in the body which may manufacture it (the ovaries, for
example), and the amount of testosterone produced varies
from individual to individual--just like in stallions.
Interestingly enough, there have been studies in humans
regarding the role of testosterone in sex drive and other
behavior patterns. I could hunt down those studies as well,
as some of the behavior patterns may be applicable to
horses.
kat
Orange County, California