Chronic Protein Deficiency In Horses

This is a very important article for all horse owners to read and understand.  I know that a lot of horse owners don’t have time to read this, but I promise you that reading and understanding this article will be life-altering for your horses. If your horses are lame, if their top line is melting away, if skin disease plagues them, ask yourself why. Then read and understand why I think that most horses have a chronic protein deficiency. Doc T

The Basics Of Protein

Look at this sentence. It is made up of words and each of those words is made up of letters. There are 26 letters from which all the words are made and all the written thoughts in the books of our world are ideas expressed by the combinations of these words. 26 letters, enormous vocabulary, and infinite written ideas.

Taking this one step further, look at the variety of books, magazines and newspapers in the world. All appear different and are made of different materials, yet all have sentences, words and letters. This is how all the things on this planet are made if you think about it – even you and your horse.

Books, magazines and newspapers are made up of a few basic parts: paper, cardboard, ink and glue or staples. Our body and the body of our horses are made up of 6 basic parts too: gas (air), water, minerals, carbohydrate (sugar), fat and protein. Of these, protein is the most interesting because all proteins are made up of only 20 building blocks called amino acids. Consider these letters. These amino acids make up all of the proteins of the body. Proteins are like words in a dictionary made of a finite number of letters, yet an enormous amount of information can still be expressed through unique sentences depending on how many words are used and where we place them.

Letters make words that in turn make sentences that create unlimited thoughts. Amino acids make proteins that in turn make structures that create unlimited living things on our planet.

Proteins basically provide the structure that makes us and every living animal we know into their unique shapes through the connective tissue of bones, ligaments, tendons, and muscles. They also make up a lot of other things in our bodies including defense mechanisms, sensors, and hair. I know this is basic, but I really want to get a few points across about protein in our horses.

Our alphabet is divided into two groups: the vowels (a e i o u) and the consonants (all the other letters). The amino acids in your horse are also divided into basically 2 types: non-essential amino acids (NEAA) and essential amino acids (EAA). This is VERY IMPORTANT. The difference between them is that NEAA’s can be made by the horse but the EAA’s need to be consumed pre-made in the meal. Imagine your book had only consonants (NEAA’s) but was missing some but not all of the vowels (EAA’s). The result would be a book that was hard to impossible to read.

If the diet of a horse doesn’t contain enough of the EAA’s then the horse will be deficient in many things such as connective tissue and immune function leading to lameness and skin conditions. Like a book missing some of the vowels, the horse may look like a horse but he will not work properly.

NEAAs can be made from carbon, hydrogen, oxygen, sulfur and nitrogen consumed in normal foods and the air we breathe. With this in mind, have you ever wondered why cattle can graze on poor land or be fed poor hay (”cow hay”) and still do well? Did you ever see a picture of a goat on top of a pile of garbage with a tin can in his mouth looking fat and happy? The answer is because ruminants like goats, cattle, sheep, and deer can manufacture almost all of their amino acids thus they have a low requirement for EAAs. In essence, they can build most of their proteins from the molecules they consume. Ruminants still need all the amino acids a horse does but can manufacture most of them (the NEAAs) while their need for consuming the EAAs is low.

However, you and your horse cannot manufacture about half of the amino acids we need to grow and maintain our bodies. These 10 or so amino acids need to be consumed in their complete form and are therefore essential to maintaining life.

Remember, the wall of our digestive tract (stomach and intestines) is solid to large molecules such as proteins. Every protein we eat is broken down into smaller amino acid building blocks or small groups of amino acids called peptides (like syllables of words) and these are absorbed through the intestines into the body. These amino acids and peptides are transported to individual cells and assembled into the proteins required by the cell. [As a side note, think of this the next time you buy an expensive joint supplement. What you are really feeding is a high-quality protein high in EAA’s that is broken down by digestion into the basic amino acids and peptides and reassembled into what the horse needs. It would be just as good to feed your horse a less expensive high-quality protein source.]

Here is an interesting fact about EAAs. This fact I am about to describe occurs in humans and horses and once understood, will change the way you look at protein in both you and your horses.

When the minimum amount required in daily intake of just one EAA is less than 100% of what is needed on a daily basis, then none of the other EAAs will be absorbed at 100% even when there is an abundance of the other EAAs. Another way to look at this is to say that if there are not enough of the individual amino acids to build the protein, that protein won’t be made.

For example, EAA #1 requires 100 units a day and EAA #2 requires 500 units and EAA #3 requires 1000 units and so forth for all of the 10 EAAs required by your horse in a day of eating. Pretend that your horse consumes 200 units of EAA #1, 500 units of EAA #2, and 800 units of EAA #3. In this example, the horse is consuming 200% of what he needs for EAA #1, 100% of EAA #2, and 80% of EAA #3.

At first glance, you would assume that your horse is deficient in only EAA #3. In reality, mammals have a system where if one EAA is at 80% of what they need, then ALL of the EAA’s are at 80%. In this example, because EAA #3 is only being consumed at 80%, then every EAA this horse consumes is at 80% effectiveness no matter how much is eaten.

Enough High-Quality Protein

It is important that your horse consumes enough protein, but it has to be of high quality (high in EAA’s) and it all needs to be absorbed from the gut into the body.

Crude protein is the absolute amount of protein in the feed. Unfortunately, some countries add urea to the feed to increase the crude protein value making the crude protein value suspect on any product. Many countries and the UN have started to use “True protein” or to list the individual amino acids as a way to see the protein content of food. This value does NOT tell you the quality or the availability of the protein for your horse. What is needed is the biological value of the protein which is the amount of protein that will be available for absorption past the wall of the intestines and used by the horse.

Not all proteins eaten are absorbed and used equally. Some have a tougher time breaking down and being absorbed ESPECIALLY if the intestines are inflamed by consuming inflammatory feed such as grain, grain byproducts, seeds and inflammatory oils. I have talked about gut inflation in some of my other blog articles. The percent of protein absorbed is sometimes called their biological value (BV). For example, egg whites are completely absorbed, whey protein is about 96%, soybeans about 80% and grass and hay is about 50% to 65%. Also, some sources of protein also have limited amounts of EAA’s making these proteins poor sources of protein for horses.

The quality of the protein is based on the amount of EAA’s in the protein. The more EAAs in the protein, the better quality it is.

The quality of protein can’t really be measured in hay or grass because every batch of hay has a different amount. In fact, the only way to measure the total protein being fed is to measure the actual protein of the animal consuming it (killing it). Unfortunately, this measurement is not a test you want to do on your horse. A rule of thumb holds though that the better the quality of hay or grass, the higher the quality of protein consumed and the reduced chance of a protein deficiency in your horse. The more stalk in the hay, the higher the fiber and the lower the available protein. Therefore, if your pasture and hay are of poor quality and your pasture and hay are limited in quantity, your horse is probably not getting enough good-quality protein. They ingest enough protein to live, but do not live well enough to become athletes.

The Simple Solution Is To Add High-Quality Protein To Your Horses’ Diet

Proteins in mammals don’t last long. The average life span of a protein is about 1 to 2 days. They degrade into parts and are recycled or destroyed and excreted. They can live for a while, such as through the winter, without consuming good quality protein but at some point, they need to replenish what has been lost. Otherwise, a chronic deficiency will occur which is the main thrust of my message here.

Horses in the wild consume a lot of good quality and live forage with good quality protein in the natural habitat during seasons when it is available. When winter comes and forage becomes dead or scarce or covered by snow then the recycled proteins are used. It holds them over until the spring grass returns. The protein shortage in the wild has a backup plan that gets them through tough times until good protein can return to the diet.

In my experience with horses kept by humans, they usually don’t have access to a lot of pasture. Worse, access to good quality hay is limited by many factors including the age of the hay, the way it was harvested, and the distance from the source. In fact, most barns have poor-quality hay and it gets worse in the spring just before the new harvest is cut. If the horse can’t get access to good quality sources of protein year after year, then your horse could be suffering from a chronic protein deficiency. Specifically a deficiency in the proteins requiring the EAAs.

It is a chronic deficiency because I have been with horses since 1973 and today I see more horses having so many medical issues that did not occur 40 plus years ago. Lame horses are at an epidemic level now followed by skin issues, insulin resistance and pituitary dysfunction (Cushing’s). While vets now have tests and diagnostic equipment for these issues, no one is looking deeply for an answer to why they are occurring in the first place. Only superficial answers are given such as the intense show schedule, poor footing, genetics of today’s horses, poor training, etc. While all of these may be a factor, I still believe there is a deeper underlying cause for chronic protein deficiency.

If the body is constantly breaking down protein just from the process of living (called entropy), it needs the building materials to repair itself. Add to entropy the additional wear and tear from movement and work such as jumping, galloping, collection, explosive starts and stops, endurance, and more. Where are the building blocks for repairing bones, ligaments, tendons, and muscles? Where are the proteins necessary for hormone and receptor creation, immune system charging, systems processing, and more? Proteins are essential for everything in you and your horse’s lives and if you don’t get enough protein and their EAA’s and the reserves are used up, my hypothesis is that the horse will become sick, lame or both.

Another analogy may help explain this. If I delivered to you all the lumber you need to build a house, what house would you be able to build if I didn’t supply the nails? In essence, every horse being used for work or sport is stressing the muscles and other connective tissue in the process. Building this stronger structure is called conditioning the horse but requires the horse to have the materials to repair and strengthen the muscles, tendons, and ligaments. This material requires all the amino acids and especially the EAAs.

My solution is simple and I would love to get everyone to start and then record their results. Add high-quality protein to the horse’s daily intake, record all your observations, and be patient. Adding protein will require between 4 and 6 months to see the beginning results with maximum results in a year or two. You are basically rebuilding every cell in your horse’s body. And by supplying the necessary building blocks in the EAAs, then everything will be repaired and strengthened.

An interesting fact here is that one bacteria cell has about 2 million proteins. A human has about 1 to 3 BILLION proteins in EACH CELL. A protein in a yeast cell is made of about 466 amino acids but some muscle proteins in humans are called titan proteins because they are made of almost 27,000 amino acids EACH. Next to water, proteins are the most abundant molecule in the body. Are you starting to see the enormity of the situation?

Is My Horse Consuming Enough High-Quality Protein?

The best indicator of good quality protein consumption is the topline because this is made of muscle only, which is almost all protein. There should be enough muscle on both sides of the spine to fill in the hollow otherwise seen in a poor top line. The Nutrena® company has created a “Topline Score” – TLS. The back is divided into 4 sections and labeled with the letters A, B, C and D. It is interesting to note that the loss of topline in a horse always starts at the withers and progresses towards the croup (hips). Conversely, the withers is the last area to be filled in after increasing protein consumption.

The TLS goes like this:

  • A – all the topline is filled with muscle.
  • B – All the topline is filled with muscle except for the withers.
  • C – The croup and loin is filled with muscle but the saddle area and withers are not.
  • D – Only the area over the hips has muscle and the rest of the top line is absent.

Old horses often have a TLS of D with or without a sway back which I believe is predominately a chronic deficiency in protein. I am suspicious of the painful condition of kissing spine as a sequela of a poor and weak topline due to chronic protein deficiency and collapse of the spine tips upon one another.

I want to add a TLS of F often seen in very old horses.  The added sign of muscle loss is the absence of the masseter muscles (cheek muscles or jowls) leaving only the flat bone of the mandible.

The Body Condition Score – BCS – was created to judge the fat on horses. BCS 1 is a walking skeleton and BCS 9 is fat enough to float in water. A BCS of 5 is ideal but is not descriptive enough. For example, if a pasture horse has a BCS of 5 and a TLS of C, the owner would be told by others that the horse is underfed and encouraged to add weight (body fat). But a racehorse with a BCS of 5 AND a TLS of A would be called an athlete just like our human counterparts.

Most trainers exercise the horse to improve the TLS but think again of the barn building analogy. The lumber is there (the horse) and there are plenty of carpenters ready to pound nails and build the barn (a training or conditioning system). But without the nails (EAAs), no barn is built (the horse breaks down).

If excessive poor quality protein (without the EAAs) is consumed, then the production of required protein in the body is curtailed. However, the protein not used in the diet is then consumed for energy creating urea, a byproduct of the nitrogen loss in all the amino acids being converted into glucose (gluconeogenesis). If you smell ammonia in the urine, it is because your horse is consuming excessive amounts of poor quality protein, is inadequately making the proteins necessary for body maintenance and growth, has a poor hair coat and hoof, has a poor TLS, may be lame, may have skin conditions or is unthrifty and the urine and barn smell like ammonia.

Where Do Horses Get High-Quality Protein And What Exactly Should They Be Eating?

Horses in the wild consume a variety of forage (grass, leaves, and other vegetation) and they consume it throughout the day. This is not the case with horses in captivity on poor or little pasture and suspect quality hay. With this in mind, I want to go deeper into the discussion of amino acids because there is more to understand before you can help your horses. Stay with me.

I said that there are about 10 EAAs but you might say so what? Horses in the wild must get them so why not just turn them out in a big field? You might also say that your horses basically look good and are performing well enough. In essence, you would be right – for most horses. Because of the sub-clinical effect of chronic protein deficiency, you often won’t see its effect until it is too late (lameness) or the horse ages and the topline is lost. Because this deficiency is possible in most horses fed by humans, it is necessary to learn about the 3 “Limiting Amino Acids” (LAAs).

The LAAs are the EAAs that are found in limited supplies in nature. They are lysine, methionine and threonine. Looking at the 3 limiting EAAs and what they do in the horse will help you understand why it is important to give enough high-quality protein to your horses every day.

  • Lysine – promotes bone growth in foals and maintenance of the connective tissue (bones, joints, tendons, ligaments, etc) in mature horses. A deficiency may cause a variety of developmental orthopedic diseases in the legs of young horses and in adults may cause the breakdown of suspensory ligaments, tendons, joints and other structural components.
  • Methionine – growth and maintenance of hair coat and hoof structures. A deficiency often causes a poor hair coat and poor hoof quality (cracks, crumbles). See more below.
  • Threonine – overall growth, muscle mass maintenance, production of adrenaline and other important hormones. A deficiency often causes poor body condition, poor TLS and lack of energy.

You might recognize methionine because it is often added to hoof supplements. It is one of 2 EAAs that have sulfur in it. Sulfur has the ability to attach to the sulfur of another amino acid with a sulfur molecule and this is called a disulfide bond. This bond causes the amino acid to fold upon itself and become structurally stronger.

Now that I told you this, let me say that methionine doesn’t create disulfide bonds. Confusing I know, however, the methionine is converted into cysteine and then cystine not only has strengthening provided by the disulfide bonds but makes up about 24% of the protein in the hoof. Without methionine, cystine cannot be made and cystine is the biggest player in hoof integrity. It is considered by some that the inflammation in the laminae (laminitis) causes the breakdown of the disulfide bonds which causes the coffin bone to separate from the hoof wall. Another hypothesis would suggest that providing enough protein, specifically methionine, would help prevent laminitis as well as hoof cracks and poor hoof quality. This is why methionine is added to hoof supplements. However, to be effective, there must be enough of all the EAAs to create, maintain and repair all the proteins of the hoof. Remember that while 24% of keratin is cystine, the remaining 76% is still protein. However, with a deficiency in the limiting amino acid methionine in the natural diet, and subsequent deficiency in cystine available with their disulfide bonds PLUS the deficiency in other EAA’s, the hoof will struggle to maintain itself against the rigors of shoeing and training.

A sidenote – when a farrier applies a hot shoe to the hoof, the stink made is from the release of sulfur.

If your horse is prone to laminitis or has poor-quality hooves, it may be valuable to add a high-quality protein source. While I can see no downside, it must be remembered that it takes a year to grow a new hoof so adding protein won’t fix a deficiency right away. But the sooner you start, the sooner the horse will have a solid hoof.

Lysine is critical for almost every protein in the horse (and you) because it helps to make the other proteins available for use. Without lysine, the remaining amino acids and proteins just aren’t as abundant to do their jobs. Lysine is the number 1 limiting EAA and it is often not available in large enough quantities in grass and hay. Lysine is the FIRST key to unlocking protein efficiency and supplementation and is essential for horses kept in our care today.

What Protein Should I Feed And How Much?

The simple answer is from ½ to 1 gram of protein per pound of body weight depending on the needs of the horse (1 to 2g per kg).

Let’s do some math. If you are feeding a pound of grain with 10% crude protein in it then how much protein is your horse getting? 1 pound = 454 grams. 10% of 454g is 45.4g of protein. Because this is crude protein, we need to determine the true protein source. If it is alfalfa meal, oat hulls, and other assorted vegetable protein sources (read “by-products”), then we need to divide 45.4 by 2 (50% availability) which equals about 23g. Even with this knowledge, if you can’t determine exactly what amino acids are in this, then this 23g could be deficient in the LAAs and other EAAs.

Your 1000-pound horse is also consuming protein in the hay and pasture, but how much and of what quality? If a horse eats about ½ of a 40-pound bale of grass hay a day, then he is consuming 20 pounds or 9080g. Good quality grass hay has about 10% to 16% crude protein – let’s use 16%. 16% of 9080g is 1453g. Now crude protein needs to be digested and the biological value of grass hay is about 50%, so half of 1453g is about 725g. If the goal is to consume 0.5g to 1g of protein per pound of horse per day (500g to 1000g per 1000 pound horse), then you are right in the middle at 725g from hay plus 23g from the pound of grain (748g).

But are you really? Remember the 3 limiting EAAs that are often missing in a natural diet – lysine, threonine, and methionine. Add to this that you are using your horse for athletic purposes requiring conditioning that is building connective tissue. Then is 748g of suspect quality protein enough? In my mind, every horse needs to have added to this diet an additional source of high-quality protein that is found in soybean meal and whey protein isolate because they add the missing EAAs, and specifically the LAAs.

Continuing with this horse, let’s increase his requirement to 1g of protein per pound so we want 1000g of protein. He is about 250g shy which can be achieved by adding 266g (0.59 pound) of whey protein isolate (94% absorbed). You will need 312g (0.69 pounds) of soybean meal at 80% availability to also achieve this goal. From this additional protein, you should have enough EAAs and LAAs to prevent the consumption of fed protein for energy (urea production) and to build the proteins necessary to prevent the problems of chronic protein deficiency.

There are several commercial products containing soybean meal or whey protein isolate in combination with minerals, vitamins and a carrier base. Be careful of the carrier base as it is often corn and byproducts. When I started working with horses in the early 1970s, we had a bag of straight soybean meal and we added a scoop (I can’t remember how big but maybe a quarter cup) once a day.  I recommend only using the ingredient of soybean meal or other high-quality protein but I do NOT recommend any of the complete feeds of soybean meal mixed with grains and grain by products, vitamins or minerals.  These mixes will actually cause gut inflammation in most horses and will prevent the horse from using the high-quality protein in the mix.  Again, there are many protein mixes and “balancers” but beware because most of these products have “various vegetable proteins” as a source combined with soybean oil (inflammatory and added as a machine lubricant), corn (inflammatory) and molasses (unnecessary and inflammatory).

Summary

First of all, I am not affiliated with any company nor do I sell any supplements or protein products. I only want to create a conversation and develop thoughts that will inspire you to think and start making better decisions in keeping your horses.

Second, if your horse has any health issues then consult with your veterinarian first.

My recommendation is to 1) stop feeding sugar (grain, grain byproducts and all supplements including treats, carrots, sugar cubes, apples etc.), 2) increase pasture and good quality hay (grass and some legume) consumption, and 3) add 1.0 pound of soybean meal to the daily intake for your horses weighing  1200 pounds (545 kg) (1000 to 1400 pounds or 454 – 636 kg).  Have unlimited access to water and mined salt (rock salt or Himalayan). Further, I highly recommend starting a diary to record every possible observation and commit to this diet and chart for a year. If you want, after a year, write a summary of your observations and send it to me with permission to post and help me get the message out.

Remember, if you don’t like the results you are getting you can always return to your original diet. No harm was done.

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  1. Progressive is a progressive product. Nutrena is a nutrena product. BOTH companies are owned by Cargill. Btw…Pro add ultimate is FANTASTIC!!!!!

  2. I am interested in your news letter and I see it is under construction. The horses advocate . It says I need a password to access the site. Can you send a password for access. Is there a fee for access? If so how much?

    1. Thanks Chrystal – The site will be going through some major changes this summer and as time goes on, it will look worse! My plan is to soon announce an alternative for people like you who want to sign up before construction is complete. Until then, please go to https://theequinepractice.com/equine-practice-rounds/ and fill in the form to receive any announcements from me about this.

      There will be free content as well as more in-depth content that can be purchased either one topic at a time or a module filled with relavent topics (like a song or an album). In addition, I also will have some courses that will include Horsemanship Is Leadership™, The basics of owning a horse, advanced horse ownership and more for those who want to be held accountable as well as interact with me as a mentor.

      Hope to see you there! Doc T

  3. Hi Doc Tucker! I was so relieved to read this article, as I had experienced something similar to your poster above, Nichole Steele. Not in just 1 horse tho…. in all of mine (6 at one point). You were right… lack of protein in the diet was a major issue here. I do believe that this is partly what causes metabolic syndrome in the first place. Much oxidative stress on the body when it is in a catabolic state. Take this issue X years and at some point metabolic disease and or endocrine issues … or both will raise their ugly head. Not to mention trashed feet. I know this from personal experience as I have a genetic predisposition to metabolic syndrome, and all of my organic acids testing consistently showed a lack of protein. For years I did not eat right since I was always battling my weight. Sounds familiar when all the vets I know tell you to take your fatso horse off grass and feed him crappy hay. I am here to say that skinny horse does NOT equal no metabolic syndrome!

    In my case poor digestion has hindered my progress, and I do believe that our horses have this issue as well…. look at all the ulcer horses out there and every one (them and us) on Prilosec. Whey, soy and other novel proteins have been very helpful here including alfalfa pellets in small amounts. I am still tweaking things, but have been at it now for over 2 years. Things MUCH better but not fixed yet. And by the way, I have not fed grain since 2004.

    Meanwhile, I thought I would throw out there that lack of dietary folate (which is not FOLIC ACID btw) may be putting a stick in the spokes. As you mentioned in your article, many horses out there do not have access to decent pasture. Most are being kept on nubs, often due to insulin resistance. In the summer I am still stuck in this mess here too, even tho I have decent pasture available. Nubs are the worst of the worst of course. But, getting back to folate, it is a critical player in the methionine cycle (methylation). Wild horses would not have a ton of access to methionine directly, but they WOULD have continual access to reasonable amounts of folate, even during most of the winter months. When folate is adequate, methionine gets recycled, so probably in a natural setting requirements for methionine would be lower. This is just a guess… I have genetics which cause a hiccup in methylation (many people do) and the bypass for this is methylfolate, the active form of folate. BTW, I cannot even convert the folate in food very well, again, those genetics. Folic acid will actually make the problem worse as conversion to usable folate requires many enzymatic steps and uses up many methyl donors. Often it gets stored an un-metabolized folic acid so blood tests for folate will be adequate or even high. This is VERY taxing on the body. The answer for me was…. you guessed it…. good sources of COMPLETE PROTEIN along with methylfolate. I am much better and so are my horses.

    I mention this because I could only find 1 person, an equine nutritionist who did her dissertation on the possibility of a similar genetic issues in horses. She found that folic acid was not only not helpful in most horses’ diets, but actually made certain matters worse when combined with certain meds. I know this is a little off topic… but it might be the next thing we should all be looking into to try to get our buddies back on track. Meanwhile I have seen some benefit here by adding active forms of all B vitamins including methylfolate and methylcobalamin, and things such as TMG to help keep homocysteine levels in check. Don’t really know the impact from a blood work standpoint tho. No one really looks at this in horses.

    ANYWAY…. I am so grateful for what you have taught in this article. It IS critical info, and I am so sick of the mainstream (including those who work up the NRC guidelines – my neighbor with her PhD is one) telling me that a healthy horse can be maintained on hay. The best timothy hay I have ever tested (and I have tested a lot) came in at 9% protein, and that was stellar first cutting. Best teff hay was more like 12%. The horses do like it better. But with these low numbers for crude protein, and the ability of most horses to only be able to stuff in about 20-25 pounds if that, it is easy to see how they can come up WAY SHORT on protein.

    Thanks again! I will be sticking with your site for more good info!
    Hugs! Kim C 🙂

  4. I’ll make a very long journey very short. I had a appy with chronic founder for three years. He would founder same day every year(summer solstice) three years in a row. It would take him a year to recover and then bam. He had all the ir/cushings signs. Cresty neck fat pockets. Older in his 20’s. He was on a diet of grass hay only. After foundering we did all the things vets say to for his condition. Supplements geared towards insulin resistance ect. I started to do a lot of research after the third bout and realized we were starving him of nutrients. Protein being a main one. He needed protein cause those are the building blocks of amino acids and he desperately needed them. Out of desperation one day I tossed him a flake of alfalfa thinking if we were going to lose him because he was in so much pain it can’t hurt. I did that in the am and by that evening he was walking great. Strutting his stuff. That was more than ten years ago and he’s never had another founder episode. Adding protein to his diet is exactly what he needed. Thank you for this article!

    1. Thanks for this story. Alfalfa is a legume that has nitrogen that is important in the formation of all the non-essential amino acids as well as it has some of the essential amino acids. I always recommend several sources of protein (hay, legume hay, a mixed pasture, soy beans, whey, and others such as flax and dried egg whites) to help provide all of the essential amino acids.

      The hoof is made of one protein called keratin and 26% of this is just one amino acid. It is cystine and the horse actually converts methionine into cystine. Unique to these are the sulfur molecules which in cystine can actually join together creating a folding of the amino acid creating a stronger protein. These are called disulfide bonds and are extremely important in the connection of the horny tissue of the hoof with the sensitive laminae. It is this connection that breaks down in laminitis (inflammation of the laminae) and I suggest that while insulin resistance is part of the breakdown process, horses with an abundant supply of all amino acids but especially methionine have a better chance of resisting and even avoiding laminitis.

      One more thing. There are 3 “limiting” amino acids in the horse meaning that these AA’s are hard to find in the wild. They are Lysine, Threonine, and (you guessed it) Methionine.

      Lets all try to prevent laminitis. Stop feeding grain and start feeding a variety of protein sources aiming for 1 gram of protein per pound of body weight.

  5. I started my horse on the Pro-Add supplement after doing a lot of research on thrush. My horse had knee surgery and after being on stall rest and only being let out in a small paddock with no grazing, his coat had gotten dull, tail rubbing, thrush, his top line had disappeared and he had chronic problems with lameness. He is also on very little grain due to the fact that he gains weight easily. After being on the Pro-Add supplement, all of these problems have disappeared. He is doing great and looks great. He has been on the supplement for about two months now. No more thrush.

    1. This is music to my ears. Please everyone – read this comment and try it yourself. Chronic protein deficiency is real and easily corrected in all horses.

      Thank you so much for sharing this!! Doc T

  6. Good profound article, thanks, and I found something that includes all recommendations : Life Data Labs “Barn Bag” available through vets

    1. Many horse owners ask this questions. It comes from their beliefs of what they have been taught. And often these beliefs are hard to overcome. This is why I call it a “2 week no-grain challenge.” If in 2 weeks you don’t see a difference, then just go back to what you were feeding. With the exception of weight loss in older horses, no other horse has had an adverse reaction to removing inflammatory grain from the diet. Please read again thoroughly this article and watch the HorseTalk webcast on the no grain challenge as well as all the material on chronic protein deficiency. After this, if you have some questions, please ask it here. Thanks, Doc T

  7. I would like your opinion of Soy being very oestrogenic and not good for hormonal issues (IR etc).
    Also, the fact that most Soy is also GM and has been sprayed with roundup which can cause leaky gut etc?…

    1. This question is asked a lot. So far there are no reports of feminization of horses on soy, but I have one client who said she has had one horse get enlarged mammary glands.

      My premise is that horses are chronically low in protein. Insulin Resistance (IR) has an unclear cause and I don’t think soy has an effect because horses with IR are not being fed soy (or enough protein of any source).

      Genetic modification has occurred in every plant and animal on the planet with some naturally occurring and some created artificially. There are many sources of protein and if you are concerned with a GM soy, look for other sources. Remember, the more sources of protein, the better distribution of amino acids leading to a decreased deficiency of an amino acid. This said, we have a surplus of soy beans in America now and the cost is very low. With 80% absorption, soy becomes an economical and efficient source of protein for horses.

      In light of most horses I know receiving half of their protein requirements and that source is usually of one source (forage), it makes sense to supplement with any other source to meet the requirements of horses to maintain, build and thrive.

  8. Wouldn’t lupins be a better source of protein? I have a horse that suffers from ulcers & I avoid feeding grains. I feed a fibre based diet, so have been adding lupins to supplement his protein uptake, especially as recently he has lost his topline. How much would you suggest I feed of lupins? Thanks

    1. All legumes are good sources of protein. But it is more complicated. All horses should receive a variety of amino acids. The broader the sources of protein the better the chance that more amino acids will be available. However, the absorption of legume protein is not as good as whey or soy. I’m glad you are grain free. I suspect that the inflammation from grain may also prevent the full absorption of protein.

      The feeding of lupins is something I don’t know about so I am unable to comment specifically, but horses in the wild will pick around the environment and sample diverse forages including lichen on rocks.

    1. I believe that a lot of health issues in horses can be related to a chronic deficiency in protein intake. However with Polysaccharide storage myopathy (PSSM) a defect in the genetic code has been identified as the cause that can be traced back to the Crusades era when horses were bred with muscles to carry the armored knights. I look forward to getting the basic information on protein out to horse owners, but there is a lot more to discuss and identify.

  9. Very interesting. Appreciate all the info. I do think one of the main causes of so many previously unseen health issues in horses is the use of vaccines. Same with dogs and cats.

    If horses have a good topline and coat, is it safe to assume they are not protein deficient?

    1. Vaccinations are getting a lot of bad press and there are a lot of questions about over-vaccination. Remember, always vaccinate for diseases that will kill your horses – rabies and tetanus. These are horrible deaths and I have seen both personally (even given post rabies exposure protocol).

      Thanks for your thoughts.

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  10. Thank you for the article about protein for horses. I board my horses so controlling food is an issue. We are not athletes. Just ride for fun. Trot at most. My horse’s topline fell apart last Spring. It had been a cold winter so I wasn’t exercising him much either. I didn’t know if it was my fault or poor feed. He was not happy and I realized my saddle was pressing on his withers so I was riding him less and less which didn’t help. I started feeding him Cadence Ultra and doing ground work instead of riding which wouldn’t hurt his back. Then I discovered Intrinzen and started doing that a bit. I bought a new saddle too. We went to Icefarm for a month and I rode him almost daily. He and his back have really come along now and I am riding him regularly. I wonder about soy – I thought we humans were to limit soy consumption. Also I would like to figure out how to improve my own diet in relation to the information in your article. I also have a question that is not horse related. When you said that poor quality food causes the urine and barn smell like ammonia, my first thought was pig farms and the complaints about odor. Also when farmers are fertilizing fields, we often smell ammonia. Is this related? Are pigs fed poor quality feed as well? I am not a pig owner but I still want to know…everything about everything apparently. Thank you.

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  11. Honestly, I’ve found that the toplines of my horses suffer when on no-grain, high protein and high fat diets. They simply get fat with no topline. My hay, which is tested, is low carb, moderate protein and higher than average fat. In my experience with this hay, adding oats is what puts the topline on. Sometimes I wonder if certain (non-diseased) horses have a higher muscle glycogen requirement and rob the horse of prorein to make it.

    What were people feeding 40 years ago?

    1. We fed oats and soybean along with great pasture and great hay 40 years ago. All animals need some sugar along with their protein. Protein is the materials and sugar is the energy needed to put them together. I did not advocate a high fat diet. I recommend no grain but only recommend low starch hay and pasture with insulin resistant horses.

      Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  12. What kind of whey/ soy do i need to feed? Just get it in a ‘human’ groceryshop?
    Just buy whey in a fitness shop ??
    Feed her soms eggs trough the mash? (It becomes scrambles eggs for sure)

    What exact available product can i feed my horse?

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  13. Love your article. For extra protein I add 3/4 cup of hemp meal 17% protein , to my ration as well as 30mls of lysine . Would it wise to add the other two amino acids if so how much?

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  14. Very interesting article. What about the age, I think that feed with excessive amount of protein a foal or a young horse mainly , also a adult, can be very dangerour.the amount between 0,25 to 0,75 pounds of whey/soy looks inaccurate and therefore dangerous.

    1. Most problems with foals or young horses is from the sugar of grain causing the developmental orthopedic diseases associated with very rapid growth. Excess protein when used as the source of energy will be converted to urea and excreted in the urine (ammonia smell). However, a chronic deficiency in protein has other dangerous problems such as lameness, hoof deformity, and poor performance leading to fatigue related injuries. The National Research Council recommends these values.

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  15. Where would I find whey and soy. A lot of soy is genetically modified. I give my older Paint nonGMO alfalfa cubes soaked in water. He is also fed Nutrena Pro force senior feed. Thanks Jolly

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  16. I cannot find it now, but in the 70’s it was available, whey powder. And it may be a regional availability product.

    Closest I can find in Florida is calf or goat milk replacer (non medicated).

    I feed this as a protein / fat supplement.

    I also feed one pound of soaked split green peas(for protein and lysine) to my now 31 year old sound, former distance, Arab mare.

    Her base feed consists of soaked: beet pulp, bran, alfalfa pellets, black oil sun flower seeds, split peas and corn oil. No molasses anywhere.

    Her forage consists of peanut hay, orchard grass hay and scrub florida pasture.

    I do grate four carrots and one apple daily for her, but she has no carb issues.

    2 ounces daily of Red Cell.

    I enjoyed your article, very informative, written in easy to understand style. Just would add that poorly fitted tack and bad riding will also influence a horse’s topline, especially behind the withers area.

  17. I have a couple of problems with your proposed solutions to protein deficiency. First, let’s talk “species appropriate” diets. This entails feeding an animal foods appropriate for their species. You feed dogs and cats meat. If you put them on a vegetarian diet, it will literally kill them. You don’t like meat? Don’t keep animals that require it. Horses are not carnivores nor are they omnivores. Whey is a by-product of milk. Milk is an animal-sourced food. This is not species-appropriate for horses. I therefore will not consider feeding my horse whey. Second, although soy is a plant and therefore more species-appropriate, more than 90% of soy crops today are genetically modified and just as bad, sprayed with the toxic and recognized as a carcinogen, weed killer glyphosate. You could use an organically-grown soy instead, yes, but soy also has phyto-estrogens which can cause a serious hormonal imbalance. I had my mare on a supplement for a short time that contained soy and she developed a hormonal imbalance rather quickly. When I realized the source I took her off the supplement and she became hormonally balanced again. So I thought about alfalfa, which is a high-protein hay, however, just as the soy it is now being genetically modified and sprayed with glyphosate. Of course an organically-grown alfalfa would work in that case, buy my mare gets more hyper when I feed her alfalfa so that leaves that out as well. Peanut-hay seems to be a good balance overall and she loves it, so that’s a better option. But that leaves out the higher requirements you recommend. What would be a better substitute than species-inappropriate whey and toxic dirty soy?

    1. The point of this article is that horses are having a chronic protein deficiency especially when they are used for athletic purposes. I suggest 0.5 to 1.0 gram of protein per pound of body weight. How that is done is open to the owner, but it needs to be addressed. A variety is better than one source.

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

    2. I, too, was questioning this same thing regarding whey and soy. More and more horses are soy intolerant, which I believe is connected to the chemicals as well as the hormone disrupting properties of the phyto-estrogens. It would be very helpful to have some other options of protein sources in this topic for those with horses that cannot tolerate soy.

      1. Where do you find that horses are “more and more intolerant” to soy beans? I haven’t seen that. There has been no reported effects of estrogens on horses with soy bean meal use and it has been used for decades in horses. If there is a report then the results should be compared to the feminization of all stallions through castration.

        Soy beans are a legume and are not recommended for humans (lectin damage to the gut lining) but in horses, their digestive tract is fine with all legumes (soy bean, alfalfa, clover, peanuts).

        Chemicals are used in all non-organic foods but you can find organic soy beans that have been de-hulled and oil removed (solvent extracted leaves no residual chemicals).

        There are other sources of broad spectrum amino acids and you can use them. I recommend soy bean meal because of its high bioavailability and low cost. 1 pound a day (normal size horse) of soy bean meal with a flake of alfalfa fed every day over 4 to 6 months will replace the chronically lost protein. Once the horse has recovered their amino acid deficit then the amounts can be reduced.

        We must remember that the REAL problem in almost ALL horses is the chronic protein deficiency due to the carbohydrate dependency brought about by feeding carbohydrates every day for years. No horse will have ill effects from feeding SBM for 6 months. After that the gut inflammation is eliminated and the amino acid reserves are restored. Then reduce the SBM or replace the protein source to something else.

  18. How do you fees whey protein to a horse. I’m what form does it come. Can you recommend best hay supplements..ect…..

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  19. Could really use some suggestions. I moved to Texas in 07 and have struggled with maintaining weight on our barrel and rope horses. Have tried numerous expensive, popular feeds.. some folks well others not so much. Have gone back and fourth on different hay, have pastures but I know quality is not like back home. I’m spending a fortune and not very happy with results. Where do I find whey or soy in bulk?

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  20. I have a question for you..I have an appy mare that has health issues and cannot get a vet to diagnose her. Symptoms are , bloated belly but very underweight, does not get a winter coat, sweats profusely in the heat or under saddle, freezes if wet or weather gets chilly .In cold weather , i have to double up on blankets and keep her stalled and feed her warm mash and water . Any ideas?

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  21. Your article is very interesting and well written. I completely agree with your findings and hope you keep putting out these high quality articles. They are quite beneficial to everyone who love their horses.

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  22. I have a cushings mare age 21. she is on a low starch low sugar diet, would calf manna be appropriate for her. 35 years ago fed calf manna to youngsters and show horses for growth and coat condition

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  23. Wow! I absolutely loved reading your article. It was enlightening for me and I am definitely going to be changing up my horses feeding program, and reading more product labels. Thank You for taking the time to write this.

  24. I have been working with my OTTB for 2 years to improve his TL . He gets access to good quality hay 24/7 as well as forage from paddock paradise . In addition I feed him soaked alfalfa hay cubes soaked beet pulp with added mineral mix as well as salt ground flax yeasaac chia seeds pumpkin seeds and turmeric paste . Would you consider this to be enough protein. He gets this mixture 2x day. His TL has improved about 50% in the last year but as you indicated his withers are still lacking in muscle.

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  25. Excellent article and after my horse has been treated for 3 years for lameness in his coffin joint with joint meds and IRAP and NSAIDs, work ups, x rays (shows he has 3 close spines), I have taken advice on his diet as I could never get enough topline on him. My vet did not advise me about protein but your article is spot on. I have taken advice from a nutritionist and a new farrier who is trimming my barefoot horse. He is almost sound and is beginning to put on muscle on the right diet given that has been diagnosed by PPID.

    1. It depends on the need of your horse and the amount of protein already being fed. Goal is 0.5 to 1.0 grams per pound of body weight.

    1. These add variety. Be sure to add the total amount of protein in terms of grams per pound of body weight.

  26. Hi, and thank you. I have had Libby on Calf Manna several months and it has helped a lot! She had trouble getting up and is much better. Carolyn

  27. This was very interesting. I bought a horse July 2015, he was a little obese. We do not have a lot of pasture. By Dec 2015 he had lost his top line and looked horrible. In Mar 2016 I consulted with a Nutrena rep. She suggested their 10/10 pellet and Pro Ad. Nothing to lose so we gave it a try. Here we are Oct 2016, he looks so much better but he is still lacking right behind the withers. After reading this and that it may take up to a year and that area is the last to recover, I’m going to keep him on the pellet and pro ad and see how he is until the year mark. I was getting lax on the pro ad because we weren’t seeing any more improvement, but after reading this I have hope he’ll continue to improve. Thanks!!

    1. And you can add more – remember to calculate the grams of protein. Goal is about 1 gram per pound of body weight.

        1. Give 1 pound a day of any whey/soy protein supplement if the product label says 40% protein.

          40% of 454g (1 pound) = 182g

          Bioavailability for whey plus soy is on average 85%. 85% of 182g = 155g

          155g in addition to the hay and pasture is safe. More importantly, 1) whey and soy give a variety of amino acids many of which are missing in the diet and 2) eliminating the gut inflammation caused by grain is increasing the net absorption of all proteins.

  28. I could not find this on the Nutrena website. Nutrena’s ProAdd Ultimate without corn. Since Windy is on renu gold she needs minerals especially because her hay gets soaked.

  29. So thrilled to read this!! About two weeks ago I started mine on a plan very similar to what you have outlined. We have 12 horses altogether with different ages, breeds, uses etc and while struggling with their body issues the one thing I keep coming back to is the same thing; lack of proper protein and the amino acids needed. My issue has been with the topline in particular though I have questioned other small things as well. I got so excited to see this article and already I am keeping a journal of what we are doing. Thank you so much for valuable information!

    1. An alternative or addition – gives variety.

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  30. This the best article I have ever seen on this topic. It is explained so well and apparently there is no monetary or social axe grinding in it either!

  31. Right now I feed Nutrena’s Safe Choice Original twice a day and the graze 3 times a week on grass.
    Do I add Manna Pro Calf Manna or Nutrena’s Pro Add Ultimate to the Safe Choice or do I just feed grass/hay and either Manna Pro Calf/Nutrena’s Pro Add Ultimate?

    1. Thanks

      I am being overwhelmed with questions about protein and don’t have time to reply to them all. I will add your question to the list of questions to answer on the webcast on Sunday November 6 at 7pm eastern.

      You can register or watch the replay on my website TheHorsesAdvocate.com/HorseTalk

      Thank you for reading my thoughts about chronic protein deficiency. I hope you can attend the webcast.

  32. So my first thought after reading this is: Why don’t I just give a Lysine, Methionine, Threonine supplement? So I went looking for that, but the only one I can find is Tri-Amino – which contains synthetic methionine! And does not list carrier substrate, additives etc. on the label. Which I know is considered “normal” (incomplete disclosure on labels) for equine supplements but still bugs the heck out of me!

    Then I think: Wait a minute! And I go check the ingredient list of the Horse Tech High Point pellets I’m already feeding (Dr. Juliet Getty’s recommendation) and yes, it does contain these 3 needed aminos (amounts not disclosed), but again, the methionine is in synthetic form. GAH.

    1. I have been feeding Tri-Amino for years to my TB and it is one of the few supplements that I can say I honestly feel like it makes a difference to her topline. Synthetic or not, I believe it helps.

  33. Great article. I immediately went out and collected the ingredient tags from the three feeds I use. All three have lycine and methionine, but only the senior and the mare and foal feed has threonine. I asked hubby to pick up the recommended calf manna, and discovered that tag also does NOT list threonine. ???

  34. I enjoyed your article. Since we spoke last year when my horses had been with a trainer and getting grain from him, I have kept them on pasture plus peanut hay and a very small amount of grain a couple of times a week. We have had no health problems at all and they seem great. Pretty calm, also. I will switch to the manna-pro or Nutrena instead of the feed we have.