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  Discussion on Research Study: The effect of weight loss on glucose tolerance
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Moderator:
DrO

Posted on Monday, Jan 19, 2009 - 12:05 pm:

Ponies are usually insulin resistant and fat ponies even more so. Knowing that fat releases hormones which adversely effect insulin sensitivity in humans, this is not surprising finding. But it is always good to get confirmation. A surprising finding was how hard they had to work to get some of these ponies to loose weight. They had to reduce the feed to supply 1/3 of calculated energy requirements at their ideal weight. I suspect strongly that such calculations for horses would not apply well to ponies who are known to be very energy efficient but I did not know how efficient.
DrO

J Anim Physiol Anim Nutr (Berl). 2008 Oct;92(5):538-45.
The effect of weight loss by energy restriction on metabolic profile and glucose tolerance in ponies.

Van Weyenberg S, Hesta M, Buyse J, Janssens GP.

Laboratory of Animal Nutrition, Ghent University, Merelbeke, Belgium. stephanie.vanweyenberg@ugent.be

In nine initially obese ponies, a weekly weight loss according to 1% of their ideal body weight was evaluated for its impact on insulin sensitivity and metabolic profile. Weight loss was obtained solely through energy restriction, initially at 70% of maintenance energy requirements, but to maintain constant weight loss, feed amount had to be decreased to 50% and 35% of maintenance energy requirement during the course of the trial. An oral glucose tolerance test (OGTT) was performed at weeks 0, 10 and 17. Fasted blood samples were taken on weeks 0, 3, 10, 17 for analysis of triglycerides (TG), non-esterified fatty acids (NEFA), creatine phosphokinase (CPK), lactate dehyDrOgenase (LDH), T(3), T(4) and leptin. Total average weight loss was 18.2%. When the OGTT was performed at weeks 0, 10 and 17, ponies had lost 0.22%, 9.9% and 16.3% of their initial weight respectively. Weight loss was associated with a decreased AUC for glucose and insulin. Moreover, greater % weight loss was associated with a significantly lower glucose peak and a lower area under the curve (AUC glucose). The lower glucose response after an OGTT in lean ponies was not the result of an increased insulin secretion, but an improved insulin sensitivity. Restricted feeding led to mobilization of TG and NEFA and to a reduced basal metabolism, with lower LDH, CPK, T(3) and leptin. In conclusion: in obese Shetland ponies, weight loss at a rate of 1% of ideal body weight per week through restricted energy intake, ameliorated insulin sensitivity.
Member:
mrose

Posted on Monday, Jan 19, 2009 - 8:20 pm:

Dr.O, I'm not surprised at how much the feed had to be reduced, just because of my limited experience with Arabians, who, for the most part, are also very fuel efficient. I have one mare that to keep from getting fat, I can feed no more than 12# of good hay/day plus a handfull of Eq. Senior with her vitamins/mineral supplements. On the other hand, I have a middle aged QH mare, about the same size, who easily eats 3x as much to keep looking good with the same amount of exercise. I've only owned one pony, a Welsh-Shetland cross, and I swear he could gain weight standing on asphalt!
Member:
ekaufman

Posted on Monday, Jan 19, 2009 - 8:53 pm:



I only eat 6 lbs of grass hay/day and check out my pony butt!
Member:
scooter

Posted on Monday, Jan 19, 2009 - 9:43 pm:

Doesn't really surprise me either, as you know Hank lives on air. To loose weight he has to be kept at 1% of his BW or less. He is considered a horse by measurement standards...15.1 hh but does have 1/4 welsh pony in his breeding.

What does surprise me is with the seemingly proper hay...stemmy, over ripe he isn't gaining weight free choice. When given good quality grass hay 8 lbs. is the most he can have without gaining weight.

So wouldn't the quality of the "feed" come into play in this equation?
Moderator:
DrO

Posted on Tuesday, Jan 20, 2009 - 8:53 am:

You are calculating feeding based on percentage of bodyweight. The experiment based the amount fed based on measured usable energy levels of the feed and adjusted against a calculated energy need of the ponies. As such they automatically take quality into account as better forage will have more usable energy.
DrO
Member:
erika

Posted on Tuesday, Jan 20, 2009 - 11:40 am:

No wonder I can't lose weight in winter. I have pony metabolism in a horse body!!
Member:
ajudson1

Posted on Tuesday, Jan 20, 2009 - 12:23 pm:

Erika, me too!
Member:
pattyb

Posted on Tuesday, Jan 20, 2009 - 9:08 pm:

Thank you for the best laugh I've had alllll day!

I wanted to add something here that I haven't had time to post elsewhere:

After much experimenting with feed this, don't feed that, pulling my own hair out in exasperation, I finally found what was setting off my Arabian/Paint.....inspite of a normal fasting insulin test. Actually, I must give the credit to a PhD who listened to my story wholeheartedly. After taking what he said and testing his theory, it appears that I have one of a very few insulin resistant horses who reacts in a very negative way when he gets too much grass, even dead winter grass, because it affects his insulin levels. One day he can be fine, the next day, ornery as a hungry bear.

Ziggy had been doing fairly well emotionally until I upped his pasture time, considering I was safe with dead winter grass. In a day to day experiment, I found that Dr. PhD was right. If Ziggy got enough dead grass to flip the proverbial switch, he came in ornery and most importantly and telltalingly...starving. Cut him back the next day and he was much calmer....and not so starved.

When I talked with Dr. PhD, I told him that I was flabbergasted, I was not able to figure out why my horse almost seemed bipolar. When I told him the mood always matched the "starvation," he told me that his moods were apparently connected to his insulin level. To test the theory, play with his turnout time, changing nothing else. I did so, not expecting the connection to be nearly so obvious....but it was.

Right now, my horse gets less than 1% of his BW in hay, supplemented with Triple Crown Lite for his vitamin and mineral needs. I also have him on Quiessence, experimenting with that as I go along. Today, even the farrier noticed the difference....Ziggy stood with ears forward, not his usual ears back. He had other plans for today...lol....but he was a good boy and seems to be responding well. Whatever flips that switch, if I avoid it, he does much better. I just find it to be very interesting how different he can be, one day to the next, just by influencing his insulin levels. If it were simply too much energy food, he wouldn't have the IR starvation thing going. Prevent the starvation, cure the orneriness.

With the info here, I can also see how his Arabness is also coming into play and may well explain why I can't feed him the normal rec. of 1.5% bw in hay. He has to have, like Diane's Hank, course hay of medium to medium low quality. Interesting, it's all very interesting.
Member:
scooter

Posted on Wednesday, Jan 21, 2009 - 7:29 am:

Patty I find that interesting too, but isn't it well known that ir horses should have minimal grass even in the winter?

I noticed one year when we didn't have much snow the horses were able to graze in the dead of winter and they got VERY fat. According to safegrass even grass in the winter can and does have high sugar levels UNLESS the grass is completely brown. Even here in the frigid midwest I have noticed this doesn't happen, seems the grass has green at least at the bottom. Hank actually had a bout of laminitis that winter, and until I figured out that "winter grass" isn't safe either he didn't improve. Another good thing about snow!!! We have enough now tho so it can stop anytime
Member:
pattyb

Posted on Wednesday, Jan 21, 2009 - 10:12 am:

Good morning Diane...and thanks for commenting.

The safety of dead winter grass seems to be fodder for much debate on the Internet so, I proceeded carefully. What really floored me was how intertwined it was with his mood swings. Any time the starvation switch was turned on, he was awful. It didn't matter if it were grass, dead grass or more hay, once the switched was flipped, it was alllll down hill from there. And to complicate the situation, how do you then put him further on a diet without setting him up for an ulcer? He's actually getting less than 1% bw in hay, a few hours of limited pasture and just enough TC Lite to be sure he gets his vitamins, minerals and supplements.

Th PhD I spoke with recently also said things similar to the title of this thread---> As I get the weight off of him (50#'s), I should see less "starvation" and better attitude, since with him, they are, without a doubt, connected. Sigh....after 6 years with a Cushings horse, I thought things would get easier now that I am down to just 2 horses. It's almost like one was preparing me for the other.................
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