Re: RC: Breeds

[CMKSAGEHIL@aol.com]

In a message dated 6/14/00 6:52:07 AM Pacific Daylight Time, 
truman.prevatt@netsrq.com writes:

<< Heidi,
 
 I think you hit the nail on the head in that what you get at a ride is not 
the
 true resting rate. Check in a mare and depending on where she is in her cycle
 the check in rate can vary 20 bpm where as the resting rate is pretty
 constant.  Same thing with a stallion.>>

Actually, Truman, there is another factor here, and one that I think IS very 
important.  Some horses seem to be able to "uncouple" themselves from the 
excitement and DO check in at or near their actual resting rates, where 
others are not capable of doing this.  And in my experience, it has virtually 
nothing to do with hormones--some of the coolest customers I've had have been 
stallions (some of my own included) who can be at least moderately interested 
in what is going on around them but still not reflect it in their HR's.  
(I've seen my share of geldings check in at 80, too!)  I think it has to do 
more with an equine equivalent of a "Type A" personality--where the horse is 
giving himself adrenaline and hyping himself up--and I don't think that is a 
good thing in this sport.  That constant "revving of the engine" (pardon the 
vehicular analogy) depletes all manner of things--lytes, energy, etc.--and 
"washes the horse out" before he ever hits the trail.  I would far rather 
have a horse with a "true" resting pulse of 36 that STAYS at 36 at check-in 
than one with a "true" resting pulse of 24 that also checks in at 36...  
Furthermore, I'd be leery of keeping a stallion in my breeding program whose 
pulse elevated significantly just due to the hubbub around him--he is not 
able to separate that from his "fight or flight" instinct and save his energy 
for the task at hand, and I don't care to perpetuate that flaw.  (And yes, 
the WORST ones I see for consistently being "up" at checkin are frequently 
akin to the modern show horses--where that "hopped up" look and attitude HAVE 
been quite actively selected for--just as conformational flaws detrimental to 
athletic performance have likewise been selected as the "style...")

Heidi
 
 Given that the heart is devlivering O2 and and carrying away waste products, 
in
 a volumn of blood then the faster it has to beat to deliver the necessary
 volumn implies that it is delivering less volumn per beat. Which either means
 the heart is small or inefficient. In the extreme, neither case is 
desirable. >>