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Wednesday, June 4, 2014

June 2014 - Metabolic rate and leptin resistance

Self-regulating forage intake is something that horses will naturally do, when given the chance of knowing that the hay is always available.  But, for some horses, it takes more time and this can be an issue if the horse is already overweight and is gaining far more than you can reasonably stand.

This horse, who eats and eats and eats non-stop, and doesn't appear to self-regulate is suffering from a very sluggish metabolic rate along with leptin resistance.  This is a cumulative result of many years of forage restriction which slows down the metabolic rate, resulting in easy weight gain once the horse has more to eat. We see this with people all the time -- go on a strict diet, lose weight, and gain it all back (and more!) once you start eating normally again. This is all because the metabolic rate has been damaged to become very slow.

Leptin is another issue.  This hormone is secreted from fat cells and when it rises, it normally tells the horse that he is satisfied and to stop eating. But, when body fat gets too high, the horse can become resistant to leptin, and no longer respond normally. So he continues to eat without ever getting the signal that he has had enough.

The solution?  Exercise!  Exercise not only burns calories, but more importantly, exercise causes the horse to become more sensitive to leptin and his appetite will be satisfied with less food.  Also, the metabolic rate increases. Furthermore, exercise makes cells more responsive to insulin, allowing insulin levels to normalize and fat to be burned (when insulin is high, it tells the body to store fat).

Another part of the solution is to use slow feeders.  I have an article on this topic coming up in my June/July issue of Forage for Thought.  Watch for it in your email -- it sometimes goes into your spam folder.  I will be sending it out today (June 4th).  If you do not currently get Forage for Thought, be sure to sign up by going to my homepage - www.gettyequinenutrition.com.

10 comments:

  1. Hi Dr. Getty,

    I've been feeding my mare free choice hay for about 3 months now, she is likely IR but I haven't had the test done for that. She seems to be eating way more than I would think she really needs... some days it's around 37 pounds (on days when I work her really hard), but usually more like 28! She's 16.1, Morgan/Warmblood, and approximately 1160lbs. I ride her usually 5 days a week for about an hour at a time. She only gets supplements in a small amount of beet pulp, and her hay is in small hole hay nets.

    Could the fact that I've gotten a new load of low sugar hay play any part in her over-eating recently? I feel like she was eating a bit less before, but this hay is still below 10% NSC. Do you have any suggestions for me? Is it reasonable to expect her to still slow down even though I've been doing this for 3 months, or could it be mostly because of the new load of hay?

    Thank you very much in advance for your help!
    Amanda Austin

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    1. Greetings Amanda,

      I can understand your concern, but actually, 28 lbs for a horse her size and with her exercise level is not out of line. It amounts to 2.4%, which is very typical for a horse who works five days a week. And I believe you are on target regarding her eating more of this new hay if the hay is less digestible than the previous hay she was eating. Take a look at the NDF value on your hay analysis report. Is it over 60%? The higher it is, the more indigestible fiber the hay contains and the horse will eat more to compensate.

      After 3 months, it is very reasonable for her to have self-regulated. The small hole size may be frustrating her, so be mindful of that. But, in her case, I believe the extra consumption has to do with her need for energy. Also look at the Digestible energy level of this new hay, compared to the older one. Let me know the difference if you have both reports available.

      Glad to help,

      Juliet Getty :)

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  2. Hi Dr. Getty,

    I've been feeding my mare free choice hay for about 3 months now, she is likely IR but I haven't had the test done for that. She seems to be eating way more than I would think she really needs... some days it's around 37 pounds (on days when I work her really hard), but usually more like 28! She's 16.1, Morgan/Warmblood, and approximately 1160lbs. I ride her usually 5 days a week for about an hour at a time. She only gets supplements in a small amount of beet pulp, and her hay is in small hole hay nets.

    Could the fact that I've gotten a new load of low sugar hay play any part in her over-eating recently? I feel like she was eating a bit less before, but this hay is still below 10% NSC. Do you have any suggestions for me? Is it reasonable to expect her to still slow down even though I've been doing this for 3 months, or could it be mostly because of the new load of hay?

    Thank you very much in advance for your help!
    Amanda Austin

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  3. Hi Dr. Getty,

    Thanks so much for getting back to me! The NDF on the new load of hay is actually less than the other one (45% compared to the previous 53%). The DE's are almost the same, (old hay .90/lb and new hay .88/lb).

    The reason I have put the hay into small hole hay nets is because she needs to loose a bit of weight, and I've been hoping this will slow her down and she will consume a bit less (though she seems to get plenty of food out no problem! I did introduce them slowly and she doesn't seem particularly irritated with them).

    In the last month or so she's gained a bit of weight and is now closer to 1180 than 1160 and I would like to get her back down to the 1160lbs. I think part of the reason she gained weight was because she wasn't very willing to eat her supplements and so I kept adding little bits of different low sugar carriers to make it more appetizing, and I think I just went a bit overboard in my attempt to get her to eat it! Now I've tried a couple different brands of supplement that she seems to be liking more and I've greatly reduced the carriers I used for her supplements (beet pulp and hay cubes). I hope this will result in weight loss along with the exercise.

    Feeding her free choice low sugar hay shouldn't be a problem because she is likely IR, correct? When you caution about the haynets being frustrating, do you think she might consume less if the hay was available to her loose, or in the large holed hay nets, or does this likely not have anything to do with the amount she is consuming?

    Thank you again for all your help, I greatly appreciate it!
    Amanda Austin

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    1. Hi Amanda,
      Congratulations on your excellent investigative work in figuring out what may be contributing to her weight gain! I believe you are on the right track. This new hay is also more appropriate to feed free choice since the DE is lower (fewer calories).

      Yes, you may feed this hay to an IR horse since the NSC is in line. I assume if the NSC is less than 10%, that the ESC + Starch is even better, which is the measurement we look at to determine how much of an insulin response it will take.

      Continue with the slow feeders. Horses do eat more slowly than they would if the hay were loose on the ground. And the smaller the opening, the slower they feed. But, as we know, this has to be balanced with the amount of frustration a smaller-holed net would induce. So, if she is calm about it, you can feed using a small hole hay net. And place as many as possible in her area to encourage her to move and relieve boredom.

      Please keep me posted. :)

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  4. I would also like to ask you if there's a point at which you would say my mare is eating too much food - like the day she ate 17kg of hay after a hard ride through the park (11km loop with hills and plenty of trotting and galloping up hills) - that seems like so much food, but should I simply assume that's ok if that's what she needed to eat that day, that she must have just burned that many calories?

    Thank you for answering all of my questions!
    Amanda Austin

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  5. Hi Dr. Getty,

    Okay so my mare seems to have lost a bit of weight with the continued reduction of low NSC carriers to get her to eat her supplements. My vet was out a couple of weeks ago and thought her weight looked pretty good. YAY!

    I got in a new load of hay which should last me the next 4 months, and the results of the analysis are good, protein 11.8, NDF 53.8, Starch 1.1, WSC 9.2 and ESC 4.5, the DE is .82 Mcal/lb.

    I am continuing to give her free choice hay in small hole hay nets, however about a month ago I went away for a week and when I got back she ate like crazy the first 24 hrs (I assume she ran out of hay at some point during the time I was gone...) then she seemed to drop down to closer to her normal amount, but now I've been back for a month and she is still eating much more than she was before I left for my trip. Before I left she was consistently eating about 13-14kg a day, and now since I've been back (mid september) she has been eating around 17-18kg of hay a day, and more if I've ridden her a bit harder... and that's with her hay being in small hole hay nets (a combination of 1.5" and 1"). She has never once run out of hay in the last month since I've been back, although she always seems particularly excited about her hay when I bring out a freshly packed hay net... I suppose it easier for her to get the hay out of when they're full, could this have an effect on her concept of hay being available all the time? She doesn't seem stressed by the hay nets and will leave the majority of hay that falls onto the ground and choose to pick it out of the hay net instead of eating what has fallen to the ground. I'm stumped as to why she's suddenly eating 3-4 kg more than before....

    I have a couple of questions as to why this may be:
    1) Could it be because of the drop in temperatures? I have her in Langley, BC, Canada and have started putting a rain sheet on her overnight since I got back because it was getting pretty chilly overnight. However she's currently eating just under 40lbs of hay in a 24hr period, and weighs about 1180lbs, and I haven't been working her particularly hard recently as I've been busy with work being done around the barn, school and work.

    2) Could she be eating more hay in an attempt to fill a nutritional gap - ex. if her micro-minerals aren't properly balanced? This hay analysis doesn't show the zinc/copper/manganese etc. levels so I don't know for sure if these are properly balanced. I am thinking about getting another analysis done with these levels included. Could this have anything to do with her over-eating?

    Does it seem reasonable for her to have increased her forage intake so drastically (about 10lbs more a day) because of weather changes, and/or her getting in her winter coat, and should I expect it to drop back down at some point once her winter coat is somewhat established? Or do you think there is another reason that she is now eating so much more? And if so do you have any suggestions for me?

    About a week ago I got to the barn and her neck felt much harder than it has in a long time, so I'm on extra high alert and am worried about her. What ratio of magnesium:calcium would you recommend for her, and are there any other supplements in particular you would recommend that would help with metabolism and insulin levels? She gets ground flaxseed, Vitamin D, B-Plex (by HorseTech), Focus HF, magnesium, Remission and salt.

    I'm terribly sorry for how long of a comment this is and how many parts to my question there are here! I love my horse and am trying to do the best for her and love your work - I have your main book and several of your spotlight books, I really believe in what you advocate with free choice feeding. I wish I could do a consultation with you, but sadly at the moment I cannot afford it, being in school and working to support my horse and myself, money is tight. So any and all advice you could give me would be greatly appreciated!!

    Thank you so much,
    Amanda Austin

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    1. Okay one slight amendment to my above post, my mare is probably around the same weight, although I was thinking she may have lost a bit because I can feel her ribs easier now and her girth is a bit easier to do up, however the weight tape today is still saying about the same - but regardless my vet was out a couple of weeks ago and did think she looked quite good!

      Thank you again for all of your help Dr. Getty,
      Amanda Austin :)

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    2. Hi Amanda,

      Let me first commend you. Your hard work is paying off and I congratulate you for doing an excellent job!

      It is very possible that she regressed while you were away and is having to "relearn" her self-regulating, so be patient. But what also occurs to me is that this new hay is higher in NDF than the other one. The higher the NDF, the more indigestible fiber it contains. Therefore, the horse needs to eat more of it in order to get the same amount of calories and other nutrients.

      I've also addressed your questions below.

      My very best wishes,

      Juliet Getty :)

      1) Could it be because of the drop in temperatures? I have her in Langley, BC, Canada and have started putting a rain sheet on her overnight since I got back because it was getting pretty chilly overnight. However she's currently eating just under 40lbs of hay in a 24hr period, and weighs about 1180lbs, and I haven't been working her particularly hard recently as I've been busy with work being done around the barn, school and work.

      *** Yes, as the outside temperatures get colder, it does take more calories for her to maintain her internal body temperature. Therefore, she will consume more hay.

      2) Could she be eating more hay in an attempt to fill a nutritional gap - ex. if her micro-minerals aren't properly balanced? This hay analysis doesn't show the zinc/copper/manganese etc. levels so I don't know for sure if these are properly balanced. I am thinking about getting another analysis done with these levels included. Could this have anything to do with her over-eating?

      *** This is a possibility especially if the hay is deficient. I recommend sending in a sample (clumps of hay from 15 to 20 bales) to Equi-Analytical Labs and order their Equi-Tech test (I believe it is $28) to get a full report, including trace minerals.

      Does it seem reasonable for her to have increased her forage intake so drastically (about 10lbs more a day) because of weather changes, and/or her getting in her winter coat, and should I expect it to drop back down at some point once her winter coat is somewhat established? Or do you think there is another reason that she is now eating so much more? And if so do you have any suggestions for me?

      *** Yes, putting on a winter coat also takes energy and this new hay is lower in calories, so she needs to eat more than before. And as I mentioned earlier, this hay is higher in lignin (an indigestible fiber) which accounts for her higher intake.

      About a week ago I got to the barn and her neck felt much harder than it has in a long time, so I'm on extra high alert and am worried about her. What ratio of magnesium:calcium would you recommend for her, and are there any other supplements in particular you would recommend that would help with metabolism and insulin levels? She gets ground flaxseed, Vitamin D, B-Plex (by HorseTech), Focus HF, magnesium, Remission and salt.

      *** I recommend feeding her 10,000 mg of magnesium each day along with 3/4 cup of ground flaxseed to offer omega 3s. Ideally, there should be 2:1 calcium to magnesium, and even as much as 1:1. Check to see if Remission contains iron. If it does, I would not feed it since iron increases insulin resistance.

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  6. Hi Dr. Getty,

    Thank you so much for all of your help - I really appreciate both your suggestions and reassurances that this is not something to be overly concerned about - I have to admit when she first started eating around 40lbs of hay a day I was freaking out a little bit... this was when she was still eating the last bath of hay which was lower NDF and slightly higher calories than what she has right now. Since changing over to this newer hay, her consumption has stayed the same even though there are those differences which would make you think she would eat more of the new hay?

    I'm wondering, if she is eating more because she needs the extra calories, would it make sense for me to mix in a second hay that is similarly low sugar but higher in calories? This thought is unfortunately coming from more of a financial standpoint - I can get a higher calorie hay that is still low in sugar for about the same price and am thinking if I offer her some of the higher calorie/low sugar hay in addition to the low calorie/low sugar hay, she might need to eat less pounds total in a day. Does this reasoning make sense, or am I going astray with this thought process?

    Thank you again for all your help!
    Amanda

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