The Equine Practice Inc, Travels With Doc T

Grazing Not Browsing -Decomplexicating Equine Nutrition Part 1 of 12

Browsers are people who stand in front of the refrigerator with the door wide open looking for something – anything – to eat. Right?

Actually there is a difference between a grazer and a browser technically. Horses are grazers and ruminants (cattle, deer, sheep, goats, and many more) are browsers. Lets look at each.

A very long time ago every specie developed a way to feed themselves. The idea was to take things that surrounded them and eat them to create the needed energy to survive and reproduce. It is a simple concept and one I really can’t understand. Why can’t we just face the sun and drink some water? No, we must kill things and eat them. Thankfully most humans don’t worry about being eaten and in this country horses are somewhat safe. The cow, pig, sheep? Not so lucky. Same with the plants we eat which are also killed for consumption. So are the plant’s babies (seeds) but more on this later.

We all have a tube running through us that starts at the mouth and ends at our anus. You and me, the horse, the dog, – you get the idea. Every one of these tubes have developed in a distinct way to digest the foods around us. The ruminants have won the “best in class award” because they can eat woody things called lignin. This includes twigs, bark, saplings and other stiff plants. They can also make almost all of the proteins needed to survive and grow. This is why you can see ruminants living in the poorest conditions and survive and often thrive.

Horses on the other hand cannot digest lignin. What they are very good at is digesting cellulose which is like lignin but not as robust. Cellulose is found in the cell walls of all plants grown on land. It is made up of a sugar called glucose. Making up the sugar storage of the plant is starch. Without having to know organic chemistry, I want to tell you exactly what starch and cellulose are.

We need to start with one molecule of glucose, the most common sugar. Each molecule is made up of 3 different atoms: carbon, hydrogen and oxygen. We will call these C H and O in the future. Through the magic of chemical energy, C H and O connect together in a simple pattern of a 6 sided ring or hexagon based on 5 C atoms and 1 O atom. For a visual, think of a stop sign in the shape of an 8 sided ring or octagon and pretend it has 6 sides. Around this ring are 12 H and 5 O atoms, but don’t worry about this now. Just pretend you are looking at a 6 sided stop sign and think of this as one molecule of glucose. There are other variations and combinations of this structure that make up the other sugars such as lactose and fructose but we want to talk about starch and cellulose.

The Equine Practice Inc, glucose molecule

Take one “stop sign” or glucose molecule and attach it to another molecule of glucose using a bonding glue. Now your visualization looks like “stop-stop.” Keep going and add a thousand glucose molecules together. stop-stop-stop-stop-stop-stop-stop-stop-stop-stop-stop-stop-stop-stop- and so on for thousands of units. This is what starch is and you and your horse can digest starch using our enzymes breaking it down into the simple sugar glucose.

The Equine Practice Inc, starch molecule

Starch – the glucose molecules are strung together in the same position.

Now bond your glucose molecules so that every other glucose molecule is upside down. In the 6 sided stop sign it would look like this: stop-sʇod-stop-sʇod-stop-sʇod-stop-sʇod-stop-sʇod-stop-sʇod-stop-sʇod-stop-sʇod-stop-sʇod- and so on. This is cellulose and another word for this is fiber.

The Equine Practice Inc, cellulose molecule

Cellulose – the glucose molecules are connected with every other molecule upside down.

What is necessary to understand is that you and your horse can NOT break the bonds of cellulose using the enzymes we have. In fact no animal can digest cellulose. What we all have are bacteria in the colon (large bowel) that CAN break up cellulose into the individual glucose molecules. But because it is an inefficient way to get energy, the horse developed a very large hind gut and a set of teeth to continually harvest enough grass and other forms of cellulose to get the energy it needs to survive the day.

Ruminants on the other hand can eat both cellulose and lignin. Lignin is like cellulose with the addition of an alcohol unit which the rumen bacteria break down. The ruminant then pushed this mix back up into his mouth and re-chews the material (chews the cud) and swallows it again this time bypassing the rumen and heading back for the regular digestion that is similar to the horse.

The take home message is that horses developed specific anatomy for digesting cellulose and because of this, it is the primary way a horse should eat. Grass therefore is the ideal food along with other non-woody plants and leaves. This does NOT include seeds such as wheat, oats, barley, chia, sunflower, corn and any other seed you can think of. These seeds contain starch which is a simple sugar and not cellulose. The bacteria in the gut of the horse become unhappy when simple glucose is presented to them not in cellulose form. Other bacteria start to take over and can be considered “bad” bacteria because they are very efficient in taking the starch and converting it to sugar giving the horse a high sugar diet.

But wait! Don’t the “good” bacteria break down cellulose into glucose molecules too? Isn’t this also feeding the horse sugar? The answer is a solid NO!

I leave you hanging on that because it leads into the next article. But simply put, starch is broken down into simple sugars killing the good bacteria and causing lots of problems in the horse including insulin resistance. Cellulose is NOT broken down into a simple sugar but into something you will not believe (hint: it makes energy). Stay tuned!

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Comments 17

  1. Here, where I live in the southwest there is no grass. There used to be real good prairie grasses, but when the white man came ,he wanted to starve out the indigenious peoples here & totally destroyed the fragile native grasses through over-grazing, & burning. Hay is substituted, but anothet problem w/ that is, all so-called pastures, & hay fields here are flood -irrigated. That’s the worst way to water plants, for when the water recedes, all the silt,& sand is left on the leaves, & stalks. Which leads me to my 2nd. pet-peave: Alfalfa hay. Cattle can barely handle it, & horses scour even worse on it. Good pastures are great, but don’t forget about the worms! Because, most people won’t clean-up manure on a daily basis, now worms are resistant to ALL current anthelmintics. So the point of my rantings is grass is good if you know how to properly care for it. Unless of course, you want to feed worms!

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      Remember that the worms need to climb up the grass shaft. And the best parasite control is what our parents did with us. They cleaned the environment (septic system), washed our hands and made us use forks. Preventing the lips from touching the feces is the BEST parasite control with anthelmintics a poor second.

  2. It’s difficult to wait for the next pics of the puzzle!! But, question… I know my hay analysis shows the amount of lignin, however I’ve don’t think I’ve noticed cellulose on it.

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  3. Hi Doc T, I feel terrible. I’ve been feeding 2 cups of black sunflower seeds, 2 cups of Renew and 2 cups of Enrich Plus ( balancer ) per day to a mare that has chronic Lyme disease and a history of founder, cresty neck etc… She has horrible shaped front hooves that curve shortly after it grows out of the coronary band and has flat soles and high heels. I’m assuming you suggest that I test the hay that I feed also. The last batch that I acquired was 2nd cut timothy. A vet that I used years ago said second cut orchard grass is good for her but no one sells it where I live. Also, I’m wondering if you recommend any farriers in north east PA? I will not euthanize unless she has no hope and I believe that she does. Thank you for your articles!

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  4. Another great post explaining the “why” I should be feeding my horses forage. Your chemistry lessons make so much more sense than the school textbooks. Based on your postings, we removed the grain from our horses feedings and now give them forage and hay — they are calmer since we have done that. I do have a question – is beet pulp considered cellulose? We have a 28 yo that is a hard to keep weight on him and it was suggested to feed him beet pulp. Keep up the great work!

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  5. I am a green owner of an Arab 25 and pony 12. I started your grain free challenge and haven’t gone back. My equine have energy for playing and great looking poop. No coughing. They are moved between 2 areas for forage and a pasture were working on. They get orchard grass hay too. You’ve helped affirm my instincts where my horse and pony are concerned. Thank you!! They are steadily svelt and have remained so all winter. They drink fresh water from heated buckets. Saved the Arab from a colic last winter because I didn’t know about cold water…he survived and I still have no vet. Just a fan Farrier.

  6. Greetings Doc T – all three of my boys are thriving mentally and physically on “no grain” feeding program. We are beginning week 5.

    The TB is almost – and I stress almost – docile to ride. The older WB (22) who had recurring, runny stools no longer has the issue. The other WB could eat rocks and he would be unaffected.

    Keep ‘feeding’ us good science in ‘digestible’ bits.

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  7. So are you saying we should give our horses Chia seed. There has been so much written and products for horses stating that Chia seed is better than flax seed as an omega 3.

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      I’m not sure where you thought I said any seeds were OK for horses. I also have not discussed oils such as omega fats. What I am saying is that cellulose is converted into short chain fatty acids as explained in part 2. What those become is interesting.

      The primary source of energy in horses is cellulose. In addition, all the fats and vitamins start here. The biggest problem for all horses (and all humans) is a continuous year round supply of carbohydrates. Understanding this principle is essential for the health of horses (and humans). Stay tuned for more.

      1. Sorry, what I meant to say is we should not give our horses chia seeds then? I have been giving my horse ground flax seeds but I have also read that chia seeds were a good source of omega 3’s for horses.

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          Chia has the good 3’s and are low in the bad 6’s – in humans. Not absolutely sure about horses but keep in mind that removing inflammatory feed far outweighs the addition of supplemental things. Also remember that if the horse’s good gut bacteria are restored and fed correctly then they will produce the short chain fatty acids needed to create the required fats to reduce inflammation and increase energy. Lastly, removing the constant work load of daily overdose of carbohydrates will help to restore healthy mitochondria – more on this in a bit….

Your thoughts are important for all to hear and may help others to learn from your experiences. Take the time to add to the discussion. However due to time limitations I will probably not answer direct questions to me. Thanks, Doc T

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