Hey! What's in that hay??

We know hay is the main part of the equine diet... or at least it should be. Some say up to 50% of the diet can be substitued with grain. I disagree completely. I realize race horses burn up more calories, but calories can be given in the form of fat and simple grains at the rate of 4-5lbs/day instead of 10-15lbs of yuck "fortified feeds" if you use high quality vitamins and minerals.

Back to hay! 

Since forage is the biggest part of the diet, we need to make sure it is clean, healthy for the horse and has the right nutrients.

The hay test to the right is a great example of what we want to see for our horses, but it also has it's probolems as well. Finding perfect hay is really hard. In this hay the moisture is low which means less chance of the hay molding. Protein is at 10%. This is perfect! I'll explain more later... ADF and NDF are high, but this hay was visibly more mature, so these figures were expected. WSC, ESC and Starch gives us the sugar content. ESC+Starch in this hay gives us 5.2%, which means this is a low sugar hay. WSC is 5.8%, both values are well below the recommended amount for IR or sugar/starch senstive horses which is 10%.

Calcium:phosphorus ratio is 1.2:1 = PERFECT! Lastly, the iron content is very high, and very common in the midwest and other regions of the US, and copper and zinc are pretty low.

Here's an example of what a hay sample should contain if it were perfect. Dr. Kellon Cheat Sheet

Moisture Content

We want to look for hay that is low in moisture, but not too low. If it dries out too much before it is baled, the hay will fall apart and become dusty and crumbly when we try to pull bales apart. These small particles are not only annoying and a waste of money, but also can cause respiratory problems in the horses breathing them in. Too wet and we get moldy hay. Hay that is too wet when put up in barns can also start fires while they undergo the curing process. 

---------------> Look for hay that tests from 8-15% moisture, some types of hay may be higher moisture and that's ok. To tell without a test, take a small handfull of the hay and grab the ends with each hand and make a fist facing down. With the hay in each hand a small bridge of hay between your two hands, bike pedal the hay keeping the hay inbetween the hands taught. The hay should break within 3-5 pedals. If it breaks sooner, it is too dry or too young. If it breaks after more than 5 pedals, it is too wet or too mature. Another way to test it to pick up a bale. If it feels extremely heavy, it may be too wet. Cut the bale open and feel for any heat or moisture. Smell for mold. There is a very big difference between good hay and moldy hay. Usually you can see the mold, and if you break the bale apart and pull the suspect area out, you should be able to see whitish dust coming off the hay. This is mold.

Protein Content

Protein is a widely debated topic for horses. Some claim feeding horses high protein hay is fine, causes no problems and makes colts "blossom." Yet another thing I completely disagree with. Protein is the most expensive basic nutrient to supplement a diet. Both carbs and fat are less expensive. Protein is also the hardest for the body to use as fuel/energy. If the body is malnourished, yes a little extra high quality protein will not hurt. Actually making sure lysine is in adequate amounts will do more good than adding a lot of protein. Horses (and any animal) never needs more protein in the diet than what is found in the mother's milk. For horses, that is 12%. When we consider alfalfa hay, at it's best can be over 20%. What's wrong with feeding this? Well, if you're feeding young horses, they will grow too quickly. This may seem good that they are big and "strong" as a two year old, marketing them as broke, trail ridden and started on patterns by 2.5 years. They look like an adult horse. But they aren't. They are a two year old. A baby. They are not done growing until they are 5 and sometimes older. So basically their bodies are forced to grow too fast, actually weakening their bones, ligaments and tendons. This is why we see so many horses with hock issues, joint problems and arthritis at such young ages. Feeding high protein is not the way to go. Feeding high quality protein is.

---------------> Look for hay that tests from 8-12% protein depending on what the age and work of the horse is. The more work and younger they are the more towards 12 it can be. Pasture puffs and trail horses rarely need hay this high or high protein feed. Typically alfalfa and coastal bermuda are high protein. Leave this to the cows unless you are feeding 20% or less with grass hay that is lower protein. Certain medical conditions may require more protein in a diet, but again, look into a supplement that has added lysine and methionine as well as high quality vitamins and minerals. These will get you further than high protein. Try to get mixed grass hay or grass/alfalfa mixes that are 20% or less of alfalfa. Don't get me wrong, alfalfa is a great source of quality protein, but just because it's good doesn't mean more is better.   Protein Praises and Woes

ADF and NDF 

ADF stands for acid detergent fiber. It measures cellulose and lignin and other poorly digested components. The lower the ADF, the more digestible the nutrients in the hay are. Hays over 45% have little nutritional value and those lower than 31% are excellent. NDF stands for neutral detergent fiber. It measures hemicellulose, cellulose and lignin. The higher the NDF the less the horse will consume, usually. Hays lower than 40% are excellent and those above 65% will likely not be consumed by most horses. Horses will benefit from hays they can get the most nutrients from, but some horses need higher fiber and lower protein and sugars than others. It's hard to get the perfect combo so sometimes we have to sacrifice one value for another. With hays like the one above that test higher in ADF and NDF I just make sure they are supplemented with a high quality, highly available vitamins and minerals to make up for what is lost in the hay. Purdue Forage Info.

WSC, ESC and Starch

WSC stands for water soluble carbs. ESC stands for ethanol soluble carbs. These are important to test for when we want to reduce fat or manage Insulin Resistant/Metabolic/Cushings horses. Katy Watts suggests going by these three values rather than NFC or NSC. They are more easily calculated and have well known definitions whereas NFC and NSC can be confusing as they are used interchangeably but have different tests. Katy Watts suggests using ESC+Starch to find sugar values in the hay. WSC can also be important, but your horse will tell you what he/she is ok with or not ok with.  Testing for Sugar.

----------->Look for hay with less than 10% ESC+starch and WSC less than 12% for obese, horses not being worked, IR, Cushings or Metabolic horses. Most of the horses I see in my day to day travels can stand to lose a couple hundred pounds easily. So low sugar hay really should be considered for most horses, even for trail riders unless the horse becomes too thin. Even then adding healthy fat (not corn oil) is better than adding sugar for energy.

Calcium:Phosphorus Ratio

Calcium and Phosphorus must be in certain ratios in order for the body to absorb and use these minerals in the tissues and bones. Grass hays are usually within the appropriate ranges of 1:1-2:1, but other hays like alfalfa and brome for example can be in excess of calcium by 12:1!! When this happens the body cannot use the calcium that is being ingested. This causes the body to pull calcium from the bones to buffer the blood and also help with muscle contractions. Weak bones are the result. When this type of diet is fed to growing horses and pregnant mares we see increased incidence of thumps, OCD's, epipysitits, contracted and lax tendons in foals and weanlings into yearlings. 

------------> Look for hays balanced in Calcium and Phosphorus within 1:1-2:1. If the hay tests higher, a ration balancer will need to be given especially for the skewed mineral profile or mix with more appropriate hay. Flexural Deformities.

Iron, Copper and Zinc

Across most of the US, iron contents tend to be pretty high in hay, feeds and even water. This is why it's so important to filter water to remove excess iron that is in the incorrect form to be used within the body. When this form, iron oxide, is taken into the body it gets lodged in tissues and also blocks receptor sites for the good forms of iron. These receptor sites are copper and zinc, both known for hoof building capabilites as well as bringing out beautiful coat colors and supporting a healthy, strong immune system. It's best to test hays to see if the iron is high, but if you can't we can usually assume it is. Filtering the water will remove excess iron and other harmful metals that leach into the water from pipes as well as chloride that is not good for our health. Once we do this, it is important not to stop there. The diet now needs to be supplemented with copper and zinc to bring those levels up within the tissues to support the immune system, hair, coat and hooves. When there is an extreme amount of iron in the diet the tissues can hold onto it and build up as toxins within the body and overwhelm the immune system and cleansing organs (liver and kidneys). So what do we do?  

  • Remove excess iron when possible in water and supplements.
  • Only feed supplements without added iron.
  • We can also help this process by doing a simple detox to remove excess heavy metals and toxins that have overwhelmed the liver and kidneys.
  • Then add back the Copper and Zinc the body so desperately needs with good supplements

-------------> Test hay to see levels of iron. Filter water no matter what. I use a Nikken shower filter and the difference shows in the horses. They actually choose that water over unfiltered water. Get a high quality supplement that has no added iron as well as chelates of copper and zinc to ensure the body is not being suppressed and is getting all the nutrition needed to be healthy, happy and robust. Dr. Eleanor Kellon recommends an iron:copper:zinc:manganese ratio between 10:1:3:3 to 4:1:3:3 the latter being for IR horses. Here's an interesting article by Pete Ramey discussing the issue of too much IRON  in the diet and how it has been linked to causing insulin resistance High Iron Diets.


Magnesium needs to be in the correct ratio with calcium to be absorbed. This ratio is  2Ca:1Mg. In times of stress, high calcium diets (alfalfa, lucerne, clover) and spring and fall our horses may require a higher amount to deal with the lower amounts in the grass or overall diet. It is a great and inexpensive addition to the diet that may cure many behavioral problems as well as tense muscles, ulcers and touchiness/moodiness. Check out these great sources of info to learn more! Gravel Proof,  Mineral HeroThe Naturally Healthy Horse