Thursday, February 4, 2010

Feeding Horses and NSCs

Fritz's nervousness and digestive troubles have prompted me to learn more about feeds, and in particular NSCs - non-structural carbohydrates. We have a number of senior horses at our barn, and also a number who are insulin resistant, so I'm always trying to learn what works best for them from a nutritional point of view. I'm certainly no expert, but will try to summarize what I understand. NSCs consist of both sugars and starches and are the "quick-digest" carbohydrates that can raise blood glucose levels; structural carbohydrates are "slow-digest" carbohydrates that are digested in the hindgut. Here is a link to a good description of what NSCs are and how they function in the horse's diet, from Triple Crown feeds - read this first as it will help you, I hope, to better understand the rest of what I'm saying (I'm not endorsing Triple Crown, but their web site has excellent information). This link also has a good table of the NSCs for various feedstuffs.

I think the first think to remember is to look at the total picture - all the things your horse is eating - forage (grass and hay) and other feedstuffs as well as vitamins and minerals. It's important, I think, not to become so obsessed with one aspect that you lose sight of the total picture. And the information you have about what your horse is eating won't be perfect or complete, even if you regularly test your hay and grass, and get the best information you can about the other feedstuffs. All this means is that you can only do the best you can do, and it isn't necessary to be perfect.

I've asked Jason from Paradigm Farms (where our Lily and Norman are retired), who is an expert on these matters, to comment, and here's part of what he had to say (and check out the feeding and nutrition posts from Paradigm that are listed on my sidebar) - I've edited, so if you have corrections or comments, Jason, please add to this:

For most horses at most stages of their lives, a moderately high NSC feed MAY not be hurtful. However, if a horse has suffered ulcers or is prone to digestive upset it may be a wise idea to go the low NSC route. Too much NSC in the gut leads to acidosis which in turn is a stressor that leads to a predisposition for a whole bunch of maladies including ulcers, founder, laminae problems, colic, etc. Horses evolved to eat grass in small meals, many times per day. Even the lushest of grass pastures is generally lower in NSC's than most grains. Because of this, more often than not for horses in work I recommend an increase in the quality and quantity of hay before an increase in grain feeding. A "quality" horse hay in this instance would probably be a really soft grass mix containing moderate levels of protein (<=14%) and relatively low levels of fibre (ADF <=35 and NDF <=50). This sort of hay can be a trial to find . . . . Too much protein actually leads to a process called protein catabolization which steals energy away from where it is needed to break down the excess protein into nitrogen which is excreted as urea. It is not a healthy process; in humans it's why those who go on a very high protein diet DO lose weight and DO look terrible when they've accomplished it ! NSC's are basically carbohydrates which lack a fibre portion and which are rapidly available and rapidly digested in the gut. Their metabolic purpose is to provide a quick burst of energy while the structural CHO portion of the diet is digested and absorbed.

To simplify, most feeds are made up of a percentage of each of these: protein ingredients (soymeal, corn distillers grains, etc.); grain (starch) ingredients (corn, oats, barley, wheat, etc.); fibre ingredients (beet pulp, alfalfa meal, soyhulls, etc.) and mineral and vitamin ingredients. [T]he only real control we have in selecting a feed for older or IR horses is to select one that has a relatively small grain portion and which achieves much of its energy from fat.

One thing that is interesting to me is the table of feedstuffs contained in the Triple Crown link. I was surprised to learn that oats, corn and barley are the highest in NSCs, and therefore feeds that contain these in their top few ingredients are likely to be high in NSCs. Jason points out that the particle size is important too - whole grains are lower in NSCs than finely ground grains, but this aspect is hard to take into account when dealing with commercial grains.

And here's another table of various widely-available feeds and their NSC values, and another table that lists Purina feeds. I have not independently verified these NSC values, and some of them may be out of date - the best way to find the NSC value for a feed you are using is to call the manufacturer - many of these numbers are not otherwise available. But always keep in mind that it's the total picture that needs to be kept in mind - what are your horse's energy needs - how much work are they in and how old are they; what other foodstuffs are in your horse's diet; does your horse have any metabolic issues, like tying up or insulin resistance that might affect what you feed; and what are your alternatives.

I'm still in the process of digesting (so to speak!) all of this and thinking about whether I'll recommend any long-term changes in Fritz's diet to his owner or whether I'll be making any changes to the feeds we use.


  1. Thank you for all that great information and fabulous links! Horse digestions is quite complex. Probably the hardest part of having our backyard horse is figuring out what to feed them!

  2. I should put half as much thought into what I feed myself as I do the horses. Never once have I thought about trying to balance my vitamins and minerals, measure the NSC's in my diet, or anything else, but I think about it for the horses constantly. Priorities and all . . .

  3. The feed situation is complicated. My Boys are on a high fat feed--so far so good--but I have to further check some of the other values.

    Right too that the hay is important. But what is really important is that the horse have some kind of food--preferably grass or hay to nibble on almost all the time. Perfection would be a good, not too rich, pasture. The key is for them to be able to "graze" all the time.

  4. Kate;

    Nothing to add except perhaps a few things which MAY help clarify the process for some of your readers.

    A balanced ration takes into consideration the WHOLE picture, as you have correctly and wisely mentioned. The whole picture ALWAYS starts with forages, and MAY include additional energy sources (starches, fats), protein ingredients, and vitamin/mineral mixes as needed AFTER forages are tested.

    The very best we can do is to take a "snapshot" of what a given horse consumes on a given day and make adjustments from there.

    Forages come FIRST ! Improving or changing the quality of the forage at hand should ALWAYS be the first option, though for practical purposes it often isn't.

    Additional supplementation with complete feeds, grains, protein ingredients and vitamin/mineral premixes needs to come AFTER the forages have been changed if possible.

    Hope this is helpful. For those with the inclination for a deeper understanding, I highly recommend the book "NRC Nutrient Requirements for Horses, 2007" .

  5. Thanks for the information. More stuff I didn't know.

  6. Kate, I highly recommend Eleanor Kellon's online equine nutrition course, NRC PLUS, for anyone who wishes to get very knowledgeable about feeding issues.

    Since taking her course (plus two more, Nutrition as a Therapy and Comprehensive Care of the Senior Horse) I've seen wonderful changes in my herd's health. None of them were suffering in any significant way on processed feed, but now that I have our hay tested and supplement what is missing, correctly, I've seen many subtle things improve. The most change is in my senior mare, who is now on a complete senior diet, but one that *I* mix with whole ingredients. The vet, who had previously been slightly concerned about my intention to take over the nutritional balancing for my horses, couldn't believe how wonderful she looks.

    And I'm actually saving money!

    It's a lot of work and not for everyone, but from your posts it sounds like these classes would be right up your alley.

  7. Billie, I've taken Dr. Kellon's courses as well. I agree they are a great learning tool and I learned a lot, although I had already been exposed to most of the knowledge from Jason. However, I would caution that they are still just touching the tip of the iceberg, and are far from providing a truly comprehensive education in equine nutrition. Obviously anyone who takes her courses will have a lot more equine nutrition knowledge to use in making informed choices for their horse.

  8. Melissa, I wasn't suggesting that the one course was completely comprehensive - I don't see how any course COULD be. But I do feel she does a wonderful job of putting the information in a coherent form, offers support for questions and assistance getting familiar with forage testing and balancing, and her grads list (free to anyone who has taken the NRC PLUS class) offers a forum for folks to continue growing and learning as they put the info into practice, and to keep current on new information.

    If you follow up the NRC PLUS class with any that apply to your individual horses, (Equine Cushings, Insulin Resistance, EPSM/PSSM, etc.) you get another in-depth layer of information that is extremely useful.

    Not trying to be a commercial for her classes - but offering something from my experience that has been very useful to me personally.

    An aside: I am new here and haven't read all the posts, much less the comments - but I don't know who Jason is... ?

  9. Wouldn't it be nice to have a blog where all of these informative articles could be put together in a newspaper fashion? Maybe once a month... And all of the horse people out here would know to go there to learn given to the authors with a link to their sites.

    Kate, you do a great job educating us.

  10. Billie - Jason and Melissa together run an excellent facility for retired horses in Tennessee. Two of mine are there - Lily and Norman. Jason has a background in the feed industry and is very knowledgeable about equine nutrition - see the posts on the sidebar.

  11. Thanks for the info and links Kate, very interesting. I know only too well how complex the horses digestive process can be.


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