Types of Vitamins in Horse Diets

There are two main classes of vitamins: fat-soluble and water-soluble.

Fat-Soluble Vitamins:

The fat-soluble vitamins are A, D, E, and K, and they are listed on horse feed tags as IU/lb. This stands for “International Units per Pound”. They are able to be built up and stored in the body fat and other tissues, and thus are not absolutely required on a daily basis, but should be considered an important part of your horses’ regular nutritional program.

Water-Soluble Vitamins:

Water soluble vitamins, which are the b-vitamins such a niacin, thiamine, folic acid, biotin and many others, are excreted from the body on a daily basis in the urine. All of the B-complex vitamins are essential to horses, but they are synthesized by bacteria in the cecum and colon from ingested feed. After microbes form the vitamins, they are absorbed through the intestinal wall and are available for use by the horse’s body cells. Bacteria in healthy adult horses generally produce adequate levels of the B-complex vitamins.

While none of the vitamins are required by law to be listed on a feed tag, more and more feed companies ARE guaranteeing the levels included in the feeds.  These are generally listed on the tag in either mg/kg or mg/lb, so it is important when comparing feeds or supplements to make sure you are comparing the same unit of measurement.

In coming blog posts, we will look at several of the vitamins individually to learn more about what they are each responsible for.

Calcium and Phosphorus Levels in Horse Diets

Where do calcium and phosphorus come from, and what can you as a horse owner do to balance the diet?

As always, first examine your hay source.  Legumes are better sources of calcium than are the grass hays, but neither legumes nor grass hays are very good sources of phosphorus.  Legumes tend to have a significantly higher Ca:P ratio, with many coming in at around 6:1.  Grass hays, however will have a Ca:P ratio that is about 1:1 and often are even shown to be slightly lower in calcium than phosphorus.  The best way to know what is in your hay is to have it tested.  Check with your local Extension Office for places to get your feed tested.

Next, take a look at your grain source.  For cereal grains (oats, corn, etc.) the reverse is true in terms of calcium and phosphorus relative to roughages. The cereal grains are poor sources of calcium, but are moderate sources of phosphorus.  Oil seed meals, by-product feedstuffs from the distilling and brewing industry, and protein concentrates are often low to moderate in calcium but are excellent sources of phosphorus.  Commercially available feeds should have levels and ratios in balance, but don’t forget to check any supplements you are using. If you are feeding a straight grain, such as oats, or if you are using feed from local grain elevator, which do not always guarantee calcium and phosphorus levels, it is a good idea to have your grain tested along with your hay.

From these two points, it is easy to see where a horse on a grass hay and oats diet – still one of the most common equine diets in use – could suddenly be suffering from an calcium and/or phosphorus deficiency.  Sadly, a deficiency of either of these two minerals is not something that will show up quickly in a manner that is visible to the horse owner.  Years of this imbalanced diet will lead to demineralization and weakening of the bone structure, which can result in increased susceptibility to lameness and injuries.

Calcium and Phosphorus in Horse Diets

Horses are more likely to suffer from a lack of calcium (Ca) and phosphorus (P) than of any other minerals.  Considering the detrimental effect on bone development that a deficiency of these two minerals can have, every horse owner should investigate where their horse’s diet is at in regards to them.

One of the first things any animal science student learns in their Animal Nutrition 101 course is that an animal must always supply calcium in a higher amount than phosphorus, no matter what the species.  The reason for this is that phosphorus will bind up calcium in the animal, making calcium unavailable for use in bones, teeth, and other areas it is needed for.  If there is more phosphorus than calcium available to the horse, then the phosphorus will start to pull calcium away from wherever in the body it can, including the all-important bone structure! 

The reverse situation has very little in the way of detrimental effects, however.  As long as there is more calcium than phosphorus, there is very little risk of getting in to a calcium toxicity situation.   In horses, the ideal ratio is to have between 1.2:1 and 2:1 Ca:P.  Studies have shown up to a 6:1 Ca:P ratio not having an ill effect on horses.

One other note of interest in regards to calcium: it is also essential for proper tubule formation and cell attachment in the hoof wall of the horse. These parts of the hoof wall provide resiliency to the hoof and attach the wall to the sole of the foot, and inadequate calcium or poor calcium-to-phosphorus ratios can cause brittle hooves or tenderness on one or more feet. Proper balance of calcium and the addition of protein to horse rations can help produce strong hooves with well-defined tubules.

Hoof Health and Nutrition

If your horse has ever had issues with his/her feet, the old adage, ‘no hoof, no horse’ could not ring truer.  When considering hoof health, multiple factors influence the state of your horse’s feet including nutrition, conformation, environment, use and overall management and care.  When assessing your nutrition program in relation to hoof health, there are many key components that need to be present for healthy hoof maintenance and growth. 

  1. Water is the most important nutrient for horses overall.  Specifically for feet, adequate amounts of water provide tissue hydration and promotes the circulation needed to deliver nutrients to the living hoof tissues.
  2. Balanced energy in the diet is important to support metabolic activity, the growth and function across the entire body system, including the feet. 
  3. Balanced proteins (aka amino acids) provide structural strength and function for hoof tissues. Lysine, Methionine and Threonine are the three most commonly associated with hoof growth.  It is imperative that amino acids be present in balanced levels along with key minerals and vitamins.  The ability for the body to absorb these critical nutrients is dependant on the delicate balance of them and too much of one or another can disrupt the utilization of these key nutrients.
  4. Macro minerals include calcium, phosphorus, sodium, potassium and sulfur.  The appropriate balance of macro minerals play a key role in skeletal development and maintenance, blood clotting, muscle contraction, temperature regulation, enzyme activity regulation, glandular secretion and cell membrane integrity. 
  5. Micro minerals (aka trace minerals) include zinc, copper, manganese, cobalt, selenium and more. Trace minerals help with the synthesis of proteins, immune system activity, synthesis and maintenance of elastic connective tissues, the integrity of skeletal bone tissue, antioxidant activity and much more.
  6. Vitamins, both fat and water soluble, play a key role in the formation, maintenance and repair of hoof tissues. Vitamin A,D and E aid in bone and muscle growth, maintenance of healthy epithelial tissue, calcium metabolism control, immune response and activity.  Vitamins C and B-biotin, both water-soluble vitamins, aid in antioxidant activity, lipid metabolism, as well as growth and maintenance of tissues. Biotin aids in the cell-to-cell adhesion in the outer hoof layer.

If you are feeding a commercially produced complete feed, check the guaranteed analysis for these nutrients.  It is also important to check that you are following the feeding directions so the proper levels of nutrients are making it in your horse.  Feed companies formulate the nutrient density and balance based on their feeding directions.  Feeding less than recommended amount means your horse is likely not getting enough of the balanced nutrients he needs.

Hoof supplements are widely available and varied.  If you are feeding a complete feed from a commercial manufacturer that guarentees levels of the nutrients listed above,  you likely do not need to supplement for hoof quality. However, special cases require additional nutrient supplementation.  It is best to work with your vet, farrier and a qualified nutrition consultant to determine the best feed and supplementation program for your horse.

Feeding a horse that has established foot issues such as laminitis takes special care,  as he needs the nutrients in feed but likely not the energy provided.  Excessive levels of starch and sugar per meal increase spikes in glucose and insulin which may have a negative impact on feet.  A low calorie feed or ration balancer  fully fortified with vitamins, minerals and amino acids is your best bet for these special cases. 

Finally, if you have specific questions about your feeding program, check with a qualified nutrition consultant for more information.  A combination of regular hoof care , the right nutrition and proper management for your horse will go a long way in keeping him or her sound for years to come.

Laminitis in Horses – What can you do?

Many times when our animals are sick it can be hard to know what to do - how to feed them, how to help them, and how to make them feel better. With laminitis, the main thing you can do as a horse owner is to take steps to prevent it from happening. But if your horse does fall victim to this disease, knowing the appropriate diet and way to feed will help with the healing process.

Prevention of Laminitis
I’m sure you’ve heard the phrase “The best offense is a good defense.” That is certainly true with the hoof disease laminitis - here are some simple steps to improve your defense and help prevent this disease:

  • Keep concentrate meals at 5 lbs. or less to avoid overwhelming the capacity of the upper GI tract (prevent starch leakage to the hind-gut)
  • Restrict turn out time for those not used to spring grasses. This helps control intake of grasses that are high in sugar.
  • Sugar content (fructans) in grasses may be higher mid day & afternoon. Time turnout in the evening, nighttime and early morning hours

Closely monitor ponies and older horses, as they are often more prone to acute and/or chronic laminitis:

  • Restrict turn out time
  • Utilize a grazing muzzle when appropriate

Feeding the Laminitic Horse
For horses that are prone to bouts of  laminitis or  who are recovering from an episode with the disease, the overall diet is very important.

1. Feed a low-calorie, controlled carbohydrate feed

Turning horses out to pasture at the right time of day may help prevent laminitis

2. Feed smaller meals on a more frequent schedule

3. To aid in damaged hoof repair and growth, look for feeds that also contain guaranteed levels of:

For the laminitic horse, balance is key – once tissue damage has occurred it is imperative to provide a well balanced diet to encourage repair and healing. While it is important to manage calories closely, particularly calories from starches and sugar, we also have to strive to balance the overall diet for the best result.  Understanding the nutrient content of the hay your horse is eating is important to determine the nutrient content of the total overall diet (hay plus concentrate). It is a great idea to consider having your hay tested and factoring those results into your feeding program.

Understanding Laminitis

If you suspect laminitis, call your vet immediately!

Spring is upon us and hopefully warmer weather has arrived where you are! Many of our horses will soon begin to receive a substantial amount of their daily nutrients from new growth pasture.

While it can be a relief to turn horses out on green pasture after a long winter (for both the horse and the owner), these horses can be faced with a challenge that strikes terror in the hearts of horse owners everywhere: Laminitis.

Laminitis is a specific disease of the foot, which is characterized by damage or inflammation at the junction between the sensitive and insensitive laminae. This important area allows for the attachment of the hoof wall to the coffin bone within the hoof. Laminae become inflamed when an accumulation of toxins and lack of blood flow is found in the hoof. Although laminitis can be caused by a myriad of different things, we classify it in two ways:

  1. Metabolic laminitis
  2. Mechanical laminitis

Metabolic laminitis is more common of the two types and often coincides with some sort of toxemia in the body. It has been reported that approximately 45% of laminitis cases were triggered by lush, green growing pasture. While lush grass is one known cause, laminitis can also be caused by grain-overload (think feeding meals that are way too large, or your horse breaking into the feed room) or even by a retained placenta in a broodmare.

It can be hard to make the connection between something that the horse eats to a hoof disease, so let’s walk through an example: Your horse has been turned out on lush spring pasture that he hasn’t had access to all winter. He over consumes the rich grass which in turn overwhelms the upper digestive tract, and leaks into the hind-gut (cecum/large colon). Certain microorganisms in this part of the GI tract rapidly ferment the starches and sugars that leaked into the hind-gut resulting in an alteration in the pH. This change in the pH level kills off critical populations of cecal and colonic bacteria (good bugs) that help in the digestion process. Not only is the digestion process inhibited, but these dead bacteria release endotoxins which get into the horses blood. The endotoxins in the blood restrict blood flow to the hoof, damage those delicate laminae tissues and result in laminitis.

The second type, mechanical laminitis, is usually trauma induced. Overload on a horse’s foot from excessive body weight, riding on a hard-surface, or where the horse is trying to lessen the pain from a separate injury by shifting more weight to the good leg can all be causes of mechanical laminitis. A well known example of mechanical laminitis is Barbaro, the 2006 Kentucky Derby Winner.

In either metabolic or mechanical situations laminitis can happen in any foot, but most commonly it will occur in the front feet of horses on pasture. They will have a tender footed stance and act like they are “walking on egg shells”. A close inspection may show that the horse is shifting their weight—maybe backwards or even from side to side in an effort to compensate for the pain that they are experiencing in their affected leg or legs. If you find your horse in this situation, or suspect laminitis for any reason, contact your veterinarian immediately!