B-Vitamins in Horse Diets

Water soluble vitamins, which are the b-vitamins such a niacin, thiamine, folic acid, and many others, are excreted from the body on a daily basis in the urine.  B-complex vitamins play an important part in allowing horses to metabolize the nutrients contained in feedstuffs, by facilitating carbohydrate, fat and protein utilization within body cells, providing the energy needed for growth, performance and reproduction. All of the B-complex vitamins are essential to horses, but they are synthesized by bacteria in the cecum and colon. 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.

Since bacteria in the horse’s digestive tract produce B vitamins, several factors influence the B vitamin status of horses. Changes that affect the bacterial population may change the synthesis and availability of B vitamins, and they include, but are not limited to:

• Drugs, which selectively kill certain species

• Horses going “off feed” thus reducing the availability of food for the bacteria

• Dietary changes which change the levels of fiber, carbohydrate and protein passing to the bacteria in the hindgut

In addition, situations that decrease the horse’s ability to absorb B vitamins have an effect on overall vitamin status include:

• Chronic or clinical diseases that interfere with efficient metabolism by the horse

• Parasitism, through ulceration of the mucosa and direct competition for vitamins in the feed, causes reduce availability

• Diarrhea bouts reduce B vitamins for the horse

• Moldy feed, especially hay contaminated by Streptomyces, makes biotin unavailable for horses

• Stress tends to decrease the horse’s ability to absorb B vitamins

• Anti-metabolites present in plants such as bracken fern, yellow star thistle or horsetail, interfere with thiamin utilization and transport

Finally, information on the B vitamin requirements and synthesis in young, growing horses and performance horses is limited. While there is much anecdotal evidence available about the effects of supplementing b-vitamins to horses, few actual research studies have been completed to determine the actual results of such supplementation, positive or negative.

Feeding Tips for Stall Rest

Regardless of the diagnosis, when stall rest is on the treatment list, adjusting your feeding program to match your horse’s lack of activity can improve the experience for both you and your horse.

Horse on stall rest
As a curious 2 year old, Toby injured himself and landed in stall rest-land.

Whether recovering from an injury, surgery, or other, stall rest is generally prescribed to limit the movement of your horse to aid in the body’s natural healing process.  Often times, when a horse’s activity level moves from work or competition to that of quiet stall rest, it takes a period of adjustment for him to settle into the new routine.

Altering his feeding program to match this now sedentary lifestyle will help him make the transition.  Please note: all feed and forage changes should be made gradually through a period of 5-7 days so as not to disrupt the digestive system.

For the horse sentenced to a period of stall rest, the name of the game is energy management.  If he is an athlete who is used to getting high calorie feed and plenty of exercise, transition him to a lower calorie feed or ration balancer, with a high quality grass forage.  Reducing the energy he receives from his feed will help manage his weight and behavior.

Selecting a feed that is balanced for amino acids will offer the body aid in the development and repair of tissues, especially muscle and connective tissue. Fortified, balanced levels of vitamins and minerals will aid in immune response as well as minimize bone density loss.  Feed that is fortified with prebiotics, such as yeast culture, and probiotics can aid in the balance of the gut bacteria, overall absorbtion of nutrients and supports the immune system. Omega 3 fatty acids in the feed can also provide support for the immune system as well as help manage inflammitory response in tissue.

Monitor his body condition score and weight throughout stall rest and make feed amount adjustments as needed.  If he begins to gain weight, reduce his feed amount to the lowest advised amount from the feed manufacturer.

If he drops too much weight, slowly increase the feed amount, making sure to stay within the feeding directions.  Increasing the amount of hay can also provide benefits, though keep watch that he doesn’t start wasting.  Health complications or hay quality concerns aside, uneaten hay is an indication that he is being fed too much per meal.

In addition to providing much needed fiber and calories, hay in the stall can also provide a distraction,  curbing destructive behavior such a cribbing, weaving and pawing.  Consider providing stall toys, such as a ball or treat roller to keep his mind occupied and prevent bad stall habits from forming.

Pending the doctor’s orders, hand walking is a common method of providing limited exercise while reducing the chances of further damaging the injury or wound.  Hand walking is also a great way to spend time with your horse, especially if stall rest has taken him away from his normal job.

Once the period of stall rest is completed and he goes back to ‘work’,  transitioning his feed back to the ‘normal’ energy levels should be done with even more caution than transitioning the energy down.  For advise on your specific situation, please discuss with a qualified feed consultant or your veterinarian.

Vitamin K in Horse Diets

Vitamin K is one of the fat-soluble vitamins, meaning it can be stored up in the body.

The main function of this vitamin is for blood clotting to occur, which we all know is critical to our accident-prone horses!

The one use that most people will ever personally see Vitamin K administered for, is if the family dog happens to ingest rat poison, at which point the dog will receive an injection of Vitamin K from the vet. Rat poison functions by limiting the clotting ability of the blood, thus basically causing internal bleeding and eventual death of the animal. Vitamin K injections help restore the clotting ability, hopefully in time to reverse any damage.

In horses, forage sources and the bacterial activity in the gut upon ingestion of adequate forage produces enough Vitamin K, and thus it is not generally supplemented in the diet. Toxicities and deficiencies can occur, but are very rare.

How to Transition a Horse’s Feed

You may be thinking your horse might be in need of a senior diet, or perhaps there is a new feed available that you believe is even better for your horse.  Maybe you are no longer happy with your current feed.  Or, your dealer no longer carries the product you were using.  Whatever the reason, switching your horse to a new feed is a change that requires care and know-how. 

Changes to feed, pasture or hay in general should be made over a 7 day period, gradually increasing the new and decreasing the old.  For example:

Day 1: 80% of old feed / 20% of new feed

Day 2: 70% of old feed / 30% of new feed

Day 3: 60% of old feed / 40% of new feed

Day 4: 50% of each

Day 5: 40% of old feed / 60% of new feed

Day 6: 30% of old feed / 70% of new feed

Day 7: 20% of old feed / 80% of new feed

Moving from a feed higher in Non-Structural Carbohydrates (NSC) to one that is lower can be done relatively easily by following the instructions above.  If you are moving your horse from a ‘low’ NSC feed to one that is higher in NSC, feed changes should happen over at least the 7 days recommended above, if not longer. 

Research has indicated that horses fed pre and probiotics are better able to handle changes in diet than horses that are not. 

Changes in hay, though generally not given much consideration, can have as much of an impact if not more than changes in feed. If possible, try to follow the same steps as above when transitioning your hay.  Hay that is harvested from the same field, but in different cuttings will likely vary in nutritional content. Hay testing is available from many University Extension offices.  Check with your area extension office for more information.

Balanced Mineral Supplements for Horses

I had stopped at one of my large training barns to check on their horses diets, as they had just returned from a recent show circuit. The owner said the horses were doing well, but he was going to tweak their diets just a little. He had purchased a bag of selenium from a local milling company and just wanted to top dress a little extra.

Mineral Interactions in Horses

Unfortunately for him, the truth is that more is not always better. I explained how vitamins and minerals need to be kept in certain ratios and levels in order to keep horses healthy, and random adding of supplements can endanger their health.  For example, copper and zinc must be kept in a 3:1 t 4:1 ratio for proper bone growth, development and maintenance. In young growing horses, having this ratio out of balance could lead to Developmental Orthopedic Diseases. I also noted that not all are horse feed supplements are created equal.  In the case of minerals, organic complexed trace minerals (minerals that are tied to an amino acid) have increased bioavailability over the oxide or sulfate forms.  

Horses have mineral requirements which are broken down into Micro and Macro. Macro minerals include calcium, phosphorus, sodium, chloride, potassium, magnesium and sulfur. These are required in gram amounts in the diet. Micro, or trace, minerals include copper, cobalt, manganese, zinc, iron and selenium. These are required in much smaller quantities in the diet, and are measured in “parts per million”, or ppm. A part per million is equivalent to one drop of water diluted into 50 liters (roughly the fuel tank capacity of a compact car). Micro and macro minerals play an important role in bone development, muscle, hair coat , appetite, as well as skin and hoof integrity. The key is that they must be balanced in the horses diet.

Vitamin E in Horse Diets

Vitamin E is one of the fat-soluble vitamins, meaning it can be stored up in the body, and is of significant interest in horse nutrition. It is thought to be involved in muscular efficiency and may play a role as an antioxidant.  In growing horses vitamin E plays a key role in nerve and muscle development and function. Foals less than six months of age generally show gait in-coordination, with hind limbs more severely affected than fore limbs. Older foals and yearlings may show decreased muscular reflexes in the neck and trunk area along with muscle in-coordination (equine degenerative myeloencephalopathy).

Mares have an increased requirement for vitamin E due to rapid tissue synthesis by the foal in the last 2-3 months of gestation. About 60% of the foal’s body weight is deposited from months 9 through 11. Vitamin E is involved in muscle fiber formation in skeletal and cardiac muscle. Foals born to vitamin E-deficient mares tend to be stiff and weak and may be unable to rise. Often the tongue muscle is affected, leading to poor nursing ability.

Foal RestingVitamin E, together with selenium, functions within the immune system of the horse to protect cell membranes and enzymes from oxidation. One result of this function may be increased resistance to disease or stress. Because vitamin E levels are highest in fresh forages, horses show seasonal trends in serum vitamin E levels. Once horses are confined and have limited access to green pastures, vitamin E stored in adipose tissues, liver and skeletal muscles begins to be depleted. Daily supplementation of vitamin E through the feed helps maintain a constant vitamin E level in serum of horses.

Vitamin D for Horses

Vitamin D is one of the fat-soluble vitamins, meaning it can be stored up in the body.  It is often referred to as the “Sunshine Vitamin”, since the easiest way for both you and your horse to get your daily dose is a little time in the sun.  Horses receiving a few hours a day of sunlight will meet their needs easily, and they also receive a dose from eating hay that has not been stored for more than six months.

It is fairly common to see a small amount of Vitamin D added to horse feeds, mainly to help those horses who are stabled and receive little or no turnout time and are often fed hay that has been stored for a lengthy period of time.

Vitamin D plays a role in helping calcium to be absorbed. Deficiency may result in rickets and weak bones.  However, excessive Vitamin D may be toxic and may cause abnormal calcium deposits, which could contribute to conditions like spavins, ringbone and sidebones.

Feeding Tips for Horses with Laminitis

Laminitis in short, is the inflammation of soft tissue in the hoof causing damage to or death of the laminar cells, resulting in the loss of the foot’s mechanical integrity.  The severity of damage is unique to each case with the worst damage resulting in founder which is the sinking of the coffin bone.

Overall management and feeding of horses with laminitis requires special care, since factors such as body weight, starch intake, mineral and energy balance, as well as metabolic function can have a profound effect on the fragile environment of the damaged tissue of the hoof.  If you are managing a horse currently being treated for laminitis or one with a history of laminitis, the most important element of overall care is staying connected to your vet and farrier.  When it comes to feeding, here are some nutrition tips to help you along the way.

  • Weight: weight control and regular exercise help any horse physically and mentally, but the laminitic horse in particular.  Excess weight and stagnation add unneeded stress to an already fragile situation. Once the acute phase has passed, regular turn out and exercise provide essential blood flow to the foot, which provides the nutrients for tissue repair.  Activity is also helpful in managing weight.
  • Pasture:  Lush pasture access should be limited by a grazing muzzle for horses prone to laminitis or those currently being treated for it.  If a grazing muzzle is not available, the horse should be limited to access later in the day when plant sugar (fructans) levels in grass are lower, or be kept on a dry lot.
  • Forage: High quality grass hay is the ideal forage for a horse prone to laminitis.
  • Feed: A product specially formulated for metabolic issues or a ration balancer are the best bet to feed your laminitic horse.  Micro nutrients such as vitamins and minerals are essential for tissue repair, so be sure to check that the feed is balanced for these as well as the essential amino acids.   Avoid feeds which provide high levels of starch per meal as these horses tend to be sensitive to increases in blood sugar and insulin.
  • Supplements: Horses with laminitis may benefit from supplemental magnesium and chromium, both of which assist in sensitivity to insulin.
  • Water: Often overlooked as a nutrient, water is one of the best allies in the defense of laminitis in your horse.  Fresh, clean tepid water is a key to overall health as well as circulation of nutrient rich blood.

Following these guidelines for feeding and management, as well as working closely with your veterinarian and farrier should provide you with the tools you need to manage laminitis in your horse.  With extra care and help from the trusted professionals in your life, your horse with laminitis can live a happy, balanced life.

Vitamin A for horses

Vitamin A is one of the fat-soluble vitamins, meaning it is stored up in the body. It is potentially the most commonly deficient vitamin for horses that do not receive commercial feeds or do not have access to green forage.

Roughages that are green, leafy and not too old will contain carotene, which can be converted to vitamin A by the horse, but roughages that are bleached, or have been weathered and are dark and dusty will not contain sufficient vitamin content to be considered. If good green forage is available, the horse will generally have sufficient Vitamin A to meet its needs. However, if a horse is fed poor quality roughage, supplemental Vitamin A is needed.

Since so many horses are fed hay that is stored for many months, most all commercially prepared grains contain Vitamin A to help combat this deficiency. It is important to remember that horses can develop a toxicity situation with Vitamin A, if high-potency vitamin supplements are fed on top of an already well-fortified grain base.

Total Dietary (ie. Hay + Grain) Requirements for 1100lb horse, According to 2007 NRC Guidelines:

  • 15,000 IU per day for maintenance horses
  • 22,500 IU per day for moderately active horses
  • 30,000 IU per day for pregnant/lactating mares

Times that are especially critical for additional Vitamin A are the last 90 days of pregnancy and during lactation. High performance horses and weanlings also need additional Vitamin A.

The most common signs of Vitamin A deficiency are dry, scurfy skin and hair coat, and runny eyes and night blindness are other symptoms. A few studies have been done that have shown night blindness can actually be induced by depriving the horse of Vitamin A and then fixed by adding sufficient Vitamin A back in to the diet. Hooves may be dry and scaly. There’s also a slower resistance to respiratory infections, stress and diarrhea. Toxicity symptoms can include dry hair, anemia, and increased bone size.

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.