Re:carbs and optimal growth

[K S Swigart <katswig@deltanet.com>]

On Thu, 2 Jul 1998, Mathew Pelletier wrote:

> Well Kat, I gotta hand it to you, your post stuffed my email box from
> the good Ridecampers who I have been emailing with regarding the latest
> and greatest in equine nutrition ;-).  I bet Susan's box is filled to
> the brim!  Lots of us prefer to lurk, I guess.
> 
> Anyway, many of us do not subscribe to Trailblazer (and I never have
> time to read it without sacrificing research papers), so forgive me if I
> make an attempt to clear up the confusion a bit regarding carbohydrates
> without referring to "x"'s article and so on.

You have said pretty much the same thing as what Kathleen Crandall said in
her article (and what I summaraized by quoting the opening paragraphs)
which is, in essence, mostly horses eat carbohydrates, but not all
carbohydrates are digested in the same way (she say "not all carbohydrates
are created equal").

So for Matthew Mackay-Smith to say "there is no feed more inimical to an
endurance horse than carbohydrates" is WAY off the mark.  That's like
saying virtually everything every horse eats is bad for endurance horses.
I can only assume that Matthew Mackay-Smith didn't really mean that when
he said that.

> Soluable, or "nonstructural" carbohydrates are formed by chains of
> simple sugars (glucose) linked to together by "alpha" bonds.  Amylase (a

It is my understanding that simple sugars (like glucose--and other
monosaccharides) are soluable (as in water soluable) and, in essence do
not neeed to be digested at all, but can be absorbed directly into the
bloodstream thorugh the intestinal wall, but that that nonsoluable variety
(polysaccharides) must be broken down by enzymes, primarily in the stomach
and small intestine.  And that both soluable and nonsoluable are
considered non-structural; as opposed to the structural carbohydrates
(i.e. found in the cell wall of the plant) which are the ones that must be
broken down by microbes in the colon and ceacum...and provide VFAs as a
"by product" of this break down.

> > p.s.  There is also and interesting article in _The Horse_ (July 1998) on
> > "the latest" in feeding horses.  It had some recommendations for feeding
> > young horses that I am NOT going to follow, but the article was
> > interesting just the same.  Not the least of reasons being that the
> > studies they used to determine the best way to feed young horses was based
> > on the premise that optimal growth was the goal.  This is not MY objective
> > when feeding youngsters.  

> Kat, I think the word "optimal" needs to be highlighted.  Optimal growth
> is NOT "maximal" growth.

I am fully aware of the difference between optimal and maximal, and didn't
consider that Dr. Ott was advocating a feeding program to encourage
maximal growth.  

There was, however, mention of feeding a concentrate:hay ratio of 70:30
and 60:40 (for weanlings and yearlings).  There is no way I am going to
feed my horses this way.  Not because I want to slow down growth for fear
of DOD, but rather because I don't want to subject my youngster's
digestive tracts to that kind of feeding regimine.

I feed my younsters what I think they need to stay healthy, and am totally
uncerned about growth rates.  If you will note my post from last week with
regards to the differences between how endurance horses are raised and how
race/show horses are raised, and the effect I have observed (granted, only
in the field and not in a controlled environment)...feeding young horses
for "optimal" growth leads to adult horses who are hard keepers.

Susan speculated that this might have to do with the overfeeding of grain
lowering the pH in the gut and destroying (permanantly???) the mucos
lining of the gut.

I just know what I have observed...in horses with virtually the same
breeding being raised on completely different feed programs and noticing
that those that were fed the way Dr. Ott appears to advocate have to be
fed twice as much for the rest of their lives.  WHile those that have been
raised primarily on forage stay sleek and fat on a handful of dirt.

I am not the only one who has noticed this.  Louis Bruhnke, who did the
"Ride Across the Americas" (from Tierra del Fuego to the North slope of
Alaska) had to abandon along the way "barn raised" horses because they
just couldn't hold their weight on the uncertain feed supplies that they
had for their trek.

I had the three horses that did make it to the end of the trip at my place
for 10 months; and there is no doubt about it these horses were EASY
keepers, and stayed sleek and fat on half the rations of horses that were
half their body weight.

I notice a huge difference between the "thriftiness" of all the horses on
my property and the single most defining difference between the easy
keepers and the hard keepers is the way that they were raised.  It is not
a function of breed, it is not a function of size, it is not a function of
age, it is not a function of workload.

So....you can keep "optimal growth."  I don't care how big or how fast my
younsters grow (I don't want to speed it up, I don't want to slow it
down); I will assume that their growth rates are suitable to their
environments and the amount of nutrients they are getting.  Does this mean
that they may not achieve their maximum growth?  Maybe.  Does this mean
that "growth spurts" may be bad for them?  Maybe.  But I'll tell you, I
would like to have a horse that can stay fat on a handful of
dirt...considering the energy demands that I plan to put on these horses
when they are adults (however big they get to be, whenever they get to be
that big:)).

kat
Orange County, Calif.