Lon Lewis quotes and my final reply tto ti

[RALSTON@AESOP.RUTGERS.EDU]

At 06:48 PM 6/24/98 EDT, you wrote:

>2-3 gallons is not small--be very difficult to fill with grain.

2-4 gallons is small when you consider that the small intestine holds 10 - 12 
gallons and the cecum and large colons together can hold up to 24 gallons!
It is easily filled, especially if ABNORMAL fermentation of highly fermentable 
grain occurs there, adding gas to the equation. 

>
>According to Lon Lewis, a good portion of carbohydrate digestion occurs in the
>stomach.
>
I quote from Lon Lewis's 1995 textbook, Equine Clinical Nutrition, page 4:
"Although solid particles are partially broken down in the stomach by acid and 
protein by pepsin, both of which it secretes, little digestion occurs in the 
stomach. In addition, in contrast to most animals, the horse can not vomit or 
regurgitate material from the stomach. Most of the feed dry matter ingested 
passes as particulate matter to the small intestine" and "Much of the fat and 
protein , and about 50-70% of the soluble carbohydrate... are digested in the 
small intestine....Nearly all of the crude fiber or cellulose and much (over 
50%) of the soluble carbohydrate in feeds passes through the small intestine 
into the cecum". 
And, from page 187 of the same text:

"Although horses may be gradually adapted to a diet consisting of cereal grain, 
the greater the proprtion of grain in the diet, the greater the risk of 
diarrhea, colic, acute laminitis or founder, exertion myopathy, hyperactivity, 
and obesity"

I highly recommend you get his UPDATED version of his text!

>What stays in the stomach overlong are hard to digest feedstuffs.

Yes, under normal circumstamces the larger particles pass more slowly, but over 
fermentation is not a problem under these conditions...

>What do you consider a large amount of grain? 3 lbs? 5 lbs? Where is the data
>that says that 5 lbs of grain given in a meal will, or has, killed any horse
>or has resulted in any of the negatives you've listed? 

I did not say over 5 lbs would kill a horse, just reduce the efficiency of 
digestion. Since you seem to like Lon Lewis, again I quote from my friend's 
book, from Page 188-189:
"To prevent digestion dysfunction (excessive gas production, colic, laminitis, 
impaired fiber fermentation) resulting from starch overload to the small 
intestine, starch (which constitutes about 80% of a cereal grain) intake in the 
horse fed 2 to 3 meals daily should be limited to approximately 0.4% of body 
weight per feeding which would be equivalent to about 0.5 lb of grain/100 lbs 
body weight...per feeding. When grain and therefore starch ingestion exceeds 
these amounts, there is a dramatic increase in the amount of starch that 
escapes digestion and absorption from the small intestine" All of these 
statements are referenced.

>> Hay and grass are not as fermentable and do not pose the same risk
> in a tired, stressed horse...plus they can eat them as fast as grains so
> the danger of overload is less.>
>
>For half the nutritional value and impaction in a dehydrated horse.

Grass is 70% water and does not pose a threat of impaction. If the horse is 
dehydrated for more than, say, 12 hours, yes, dry hay might compound the 
problem, but hopefully we quickly try to rehydrate such horses!

Re; Ulcers: 
>It's up around 85%--and all these animals are buted to death. 

My, my-what a lovely statement-can't train or run these poor critters with out 
major pain killers....

> I recommend that
>my trainers feed five times a day, with free choice hay and water available at
>all times. I assume something like that's your feeding schedule as well??
>
well-since you are pouring the grain to the poor beasties, it appears that you 
are already following my recommendations of no more than 5 lbs of grain per 
feeding! I also would add free access to salt....
>  
>3 lbs of long chain corn sugar is a little more that I would recommend (4 oz
>at a time). However, one trainer was having difficulty measuring the glycogen
>loader and I told him to just feed a coffee cup morning and night. He called
>back complaining that his horse ran "sleepy". In the conversation it came out
>that he was feeding a coffee CAN morning and night and had used 4 races worth
>of the stuff before raceday. No founder, though.

He was lucky.  

>I can't argue with 4 lbs at a time--that's fine. And gradually increasing the
>ration goes right along with my thoughts.

Alleluiah-we have reached an agreement!

>  
>Whoops--your misinterpretion of what I had given--a couple dozen folks
>actually got it right. Your aversion to carbohydrate led you off on a tangent.

No, my dear. You just did not give details as to amounts until much later and 
had started off bragging about feeding over 20 lbs of grain to your racehorses.

>Then read my post on Lon Lewis' views.

When I find it-I hope you haven't misquoted my friend again...

>I confess that I'm just a horseman, not an academic. But I read the literature
>as much as anyone on this list. In our discussion last time on this subject I
>provided about 30 papers for your review. 

Most of them on human exercise physiology...which I did pursue...
I prepared a similar (though admittedly shorter, since there unfortunately not 
as many studies equine exercise physiology to choose from) reference list, this 
time on HORSES, for you, that, in the chaos of grading final exams and papers 
and getting ready to move to Ithaca I never sent. I'll send it to you but not 
clutter up ridecamp any more unless asked to do so.

> Tunnel vision is a severe form of ignorance.

Amen-I totally agree.

>Potter's was the first paper. Everybody was using a couple of ounces of corn
>oil a day before that paper was written.

Potter's paper was published in 1990. I know of endurance riders that were 
supplementing with more than a couple of ounces in the '80's! Ginger Rich's 
1977 paper on fat digestion (published under her maiden name, Bowman) was one 
of the "first".

> As far as heartrate monitors are
>concerned, I was in on the early development of these, working with Matthew,
>George Maylin and Fred Fregin--see early issues of EQUUS. 

Good for you! But I don't see many race horse trainers, at least on the east 
coast, using them...Matthew is one of the great grandfathers of Endurance 
riding!!!

>I find the group interesting, full of intelligent people. And I'm always
>seeking new information. I just hate to see authoritive voices quacking about
>incorrect concepts due to a limited range of experience.

I agree totally which is why I have taken the time to correct some of your 
statements!

>It's been fun.
>
>ti

Yep-now back to my data....
 
> Sarah Ralston, VMD, PhD, dACVN
> 

PS: I found ti's lon lewis post-He was quoting from the 1970's version of 
Feeding and care of horses. The second edition, published in 1995, is TOTALLY 
different-Lon's learned a lot in the past 30 years, as we all have.
The Clinical Nutrition text I am quoting here is virtually the same as the
"lay" second edition, except it lists his references at the end of each 
chapter. (over 150 for most 
chapters!). The lay version is only about 30 dollars and EXCELLENT-I highly 
recommend it!