Thursday, March 15, 2018

Why your horse needs vitamin E

An equine diet based solely on hay may be lacking in this essential nutrient.

Hay is almost the perfect food for horses---most varieties offer the right balance of protein, fiber, nutrients and energy to keep the average horse healthy.

The key word there is “almost.” One nutrient that hay may not provide in sufficient quantity is vitamin E. This essential nutrient is present in fresh pasture but begins to degrade as soon as grass and legume plants are harvested. And the longer the hay is stored before it is consumed, the more of its vitamin E is lost.

So for horses whose forage comes primarily from hay, with little or no grazing, vitamin E deficiency is a possibility. And it’s even more likely for horses who are in training with limited turnout because exertion increases the need for this valuable antioxidant. Vitamin E requirements are also higher for aging horses, those who are ill and those with certain health issues.

Vitamin E helps keep a horse’s muscles, nerves and all his internal workings functioning smoothly. And if he’s not getting it naturally in a green pasture, then you’ll need to find a way to add it to his diet. Here’s a look at what vitamin E does and what you can do to make sure your horse gets enough---but not too much.

Vitamin E in nature

“Vitamin E” is a collective name for a group of eight naturally occurring compounds that all have distinctive antioxidant activity. There are four tocopherols and four tocotrienols. Each is designated with an alpha-, beta-, gamma- or delta-.

“The most biologically available form is alpha- tocopherol, and this is why we can measure this one in the blood,” says Tania Cubitt, PhD, an equine nutritionist with Performance Horse Nutrition, a consulting firm in Middleburg, Virginia.

Vitamin E is fat-soluble, which means it’s handled quite differently by the body compared to water-soluble vitamins, such as vitamin C, which are not stored and are eliminated in urine if too much is consumed. Fat-soluble vitamins can be stored in the liver and the body’s fatty tissues. This means the horse can keep a supply of the nutrient when it is abundant, and access it when it isn’t. And that’s exactly what he does in nature. Vitamin E is abundant in fresh, green grass, but the amounts diminish as grass matures and dies. Horses who spend the winter foraging on dried grasses will draw on their stored vitamin E; then they will replenish their supplies of the nutrient when the green plants start growing in the spring.

All of which means that a domesticated horse’s lifestyle can work against his receiving enough vitamin E. “The normal horse under natural conditions is able to cope with seasonal fluctuations,” says Cubitt. “We have thwarted this, however, by putting our horses in an artificial environment. About 30 to 80 percent of the vitamin E in hay can be dissipated during the drying for harvest and during storage. If horses are stuck in a stall and not on pasture, they are relying on us to supply most of their vitamin E. I have seen a lot of horses that are actually deficient in vitamin E because of the way they are managed. So today we see a lot of horses being supplemented with vitamin E.”

What Vitamin E does

Vitamin E plays a role in many functions throughout the body, but it is known primarily as a potent antioxidant, meaning it binds with and limits the damage caused by free radicals, which are atoms or molecules with an odd number of electrons. Because they have an unstable electrical charge, free radicals tend to “steal” electrons from other molecules to become stable. But when the original molecule loses its electron, it becomes unstable and in turn tries to steal another electron from somewhere else. All this activity not only damages the molecules that have their electrons stolen, it may inhibit their ability to do their jobs within the body. If there are too many free radicals present in the tissue, this chain reaction can run out of control and injure cell walls, DNA and other vital structures.

Free radicals are a natural byproduct of the utilization of fats, carbohydrates and proteins as fuel. They do have beneficial functions; they can help neutralize bacterial or viral threats, for example. But when the number of free radicals in the tissues climbs too high---such as in the muscles after a horse exercises---the body deploys antioxidants to bind with them, breaking the cascade.

In the case of vitamin E, action centers on the fats that form the structure of cell membranes, where the nutrient remains ready to bind with free radicals that might otherwise damage the cell walls. “It helps protect the cells,” says Carey Williams, PhD, an equine extension specialist with Rutgers, the State University of New Jersey. “The vitamin E incorporates itself into cell membranes and protects them from oxidative damage.”

A shortage of vitamin E might mean more oxidative damage occurs in cells throughout the body, including those in muscles, nerves and immune cells. In the case of a hardworking horse, outward signs of oxidative injury might be muscle soreness and a slower-than-expected recovery from exercise. And so, when a horse’s workload increases, his need for antioxidants, including vitamin E, also goes up.

“When you damage muscle, for any reason, you have some oxidative stress,” says Paul Siciliano, PhD, of North Carolina State University. “In the cell, when metabolism is taking place, some pro-oxidants are produced. You could equate it to a campfire out in the woods. The fire is producing heat energy and it might send up sparks in the process. As long as the sparks get put out, things are fine. But if one of them starts another fire and it grows, you could have a problem. Vitamin E attaches to the cell membranes and quenches those little fires and keeps things working properly.”

Oxidative damage is most likely to occur in tissues in the immune system, nerves and muscles, because they are more highly metabolic---that is, they “burn” energy faster. “Thus they produce a greater proportion of these pro-oxidants just as a cost of doing business,” Siciliano says. “There is higher likelihood to have a problem in those areas if horses are short on vitamin E.”

How much vitamin E does a horse need?

A horse’s requirements for vitamin E have not been well established. “We have defined these requirements only because we know that horses consuming it at a certain level haven’t had any deficiency symptoms,” Siciliano says. Guidelines in the Nutrient Requirements of Horses from the National Research Council (NRC), last revised in 2007, recommend about 500 IU (international units) daily as a maintenance level for an 1,100-pound horse in light work.

“This isn’t a lot, so if a horse has access to pasture, that horse has plenty of vitamin E, since green pasture is the best source,” says Williams. “Just like your parents always told you to eat your vegetables---because they contain lots of vitamins ---our horses that are out on pasture will have those vitamin needs met.”

The NRC recommendations are higher for hardworking horses and for breeding mares and stallions. “Working horses might need up to 1,000 IU per day,” says Williams. “These figures are the minimums, however. There have been many studies, including some I have done, that have shown that more vitamin E is even better. Most of the studies I did looked at supplementing 5,000 IU per day for the average-size horse on a hay diet and not on pasture. These horses had lower levels of muscle enzymes in their blood, which means less muscle membrane permeability or leakage of material into circulation.”

Higher levels of vitamin E may also be recommended for horses with certain health issues. “The categories that the NRC does not touch on, but which we have anecdotal evidence and research looking at, are guidelines for disease-state horses---horses with allergies, tying up, metabolic0 syndrome, or those that are suffering from or recovering from illness,” says Cubitt. “In horses with allergies, we know that potent antioxidants are effective. One guideline that has been suggested is about 5,000 IU per day. Horses who tie up and have muscle problems can also benefit from 5,000 IU per day. Horses with metabolic syndrome, insulin0 resistance and laminitis should also receive that higher level. Horses recovering from surgery, illness or stress may need 1,500 to 5,000 IU per day, depending on the severity of the illness/stress.”

Given that vitamin E is stored in fat, it’s not surprising that severely underweight horses may also have deficiencies. “These horses have no fat, so they can’t store it, so we have to feed them more vitamin E than the normal requirement; they need about 1,500 to 2,000 IU per day,” Cubitt says.

But it is possible to give a horse too much vitamin E. “A person needs to be careful with high doses of vitamin E, because vitamin E and beta carotene [the building block for vitamin A] have the same absorption pathway,” says Williams. “We found that high levels of vitamin E can actually decrease the level of beta carotene in the body. In one study, 10,000 IU of vitamin E was fed daily, and there was some interference with uptake of vitamin A. You are inhibiting one vitamin by overfeeding another.”

Horses on pasture would probably be getting adequate amounts of vitamin A, because beta carotene is also abundant in green grass. “If they are in stalls being fed hay, however, receiving too much vitamin E could become a problem,” Cubitt says.

Your horse’s vitamin E status

Your horse’s turnout schedule and activity level can provide clues to whether he’s taking in enough vitamin E, but a blood test is the best way to determine with some certainty.

“If your veterinarian tests plasma or serum concentrations for alpha-tocopherol, greater than 2 micrograms per milliliter is considered adequate, 1.5 to 2 micrograms would be considered marginal and less than 1.5 would be considered deficient,” Cubitt says. “If we were able to examine horses in the wild and measure their blood levels seasonally, by the end of winter they might be marginal, but that level would soon increase once the spring grass starts growing.”

If your veterinarian suggests that you increase the amount of vitamin E in your horse’s diet, you have several options. Obviously increasing his access to fresh grass will help---assuming this won’t put him at risk of laminitis or obesity. Grass contains somewhere between 30 to 100 IU of vitamin E per kilogram of dry matter.

You may also want to see if you can get hay that has been cut earlier---grasses cut for hay while young and growing will have higher levels of vitamin E. Exactly how much of the vitamin hay loses, and how quickly, depends on several factors, including the conditions of harvest and the amount of sunlight it is exposed to when drying (sunlight denatures all vitamins). One study found that fresh alfalfa hay lost as much as 73 percent of its vitamin E after just 12 weeks in storage. In addition, some grains, such as corn, oats or barley, contain some naturally occurring vitamin E but only about 20 to 30 IU per kilogram of dry matter. Grains also lose some of their vitamin E over time in storage; dry, dark storage is best for all feedstuffs.

To avoid uncertainty and ensure that their horses receive what they need, many owners opt for supplements, balancer rations and commercial feeds formulated to provide the nutrients required by average horses or those at specific life stages or activity levels.

“Most commercial feed products are fortified with vitamins and minerals,” says Williams. “They usually provide about 100 to 150 IU of vitamin E per pound. So if a horse is eating two or three pounds of grain daily, this will be adequate if at maintenance or light work.” Vitamin E is included in a wide range of supplements, both as the primary ingredient and as an addition to products for joint health, digestive support and other formulas. However, if the goal is for a level of 5,000 IU per day, make sure you are feeding a sole concentrated source of vitamin E. Otherwise there is a risk of over- supplementing the other nutrients in the product to get to that level of E.

When it comes to keeping a horse healthy, often the best approach is the “natural” way---mimicking as closely as possible the way he would live in the wild---despite stalls, trailers and training schedules. When it comes to an essential nutrient like vitamin E, that means letting him graze as much pasture as possible during the warmer months. But when that’s not feasible, taking steps to make sure your horse gets enough of this essential nutrient will help to keep him healthy.


Synthetic and natural Vitamin E

Vitamin E can be provided to horses in both natural and synthetic forms.

“Synthetic vitamin E is what we see added to many horse feeds and supplements because it is less expensive,” says Tania Cubitt, PhD, an equine nutritionist with Performance Horse Nutrition, a consulting firm in Middleburg, Virginia. “When you see synthetic vitamin E listed on a label, it will be ‘dl-alpha-tocopherol,’ or some variation starting with a ‘dl.’ Natural vitamin E will be listed as d-alpha-tocopherol or the tocotrienols, without the ‘l.’”

There are differences in how the horse’s body absorbs the two forms. “Specific transport proteins in the liver seem to bind better to the natural form, allowing it to be transported to other tissues,” says Cubitt. “Synthetic forms are excreted faster than the natural form, and they don’t have as much time to get into the tissues where they are needed.” In other words, the horse has to consume more of the synthetic form to achieve the same levels in the bloodstream as the natural form.

However, the natural form costs more. “The natural products are expensive—usually about twice that of a synthetic product, or more,” says Carey Williams, PhD, of Rutgers. “Your choice depends on what you want to do: If you want to feed twice as much of the synthetic product at the cheaper price, you will be getting about the same effect. You can feed less of the natural product or a little more of the synthetic product. In terms of cost, it would end up very similar.”

Other effects are also likely to be about the same, according to Williams. “There’s been a huge debate regarding whether to use the natural or the synthetic products. There are a lot of people who swear by one or the other. I’ve done research with both types, but most of my research has been with the synthetic product, and we got antioxidant benefits.”

With either form, absorption can be improved by adding fat to a horse’s ration. The fats bind with the vitamin E and help to carry it across the intestinal wall and into the bloodstream. Researchers have also explored other methods to improve the absorption. Some products contain “micellized vitamin E,” which means it has been chemically changed to improve absorption. Another approach is called nanodispersion, which separates the vitamin E into tiny droplets that disperse across a wider range of intestinal wall. Both of these methods have been shown to aid absorption.


Diseases of vitamin E deficiency

Several neuromuscular disorders have been linked to vitamin E deficiency:

- Equine motor neuron disease (EMND) is caused by the degeneration of the motor neurons, which control the movement of the large muscles. “This affects the motor neurons and therefore the skeletal muscles,” says Paul Siciliano, PhD, of North Carolina State University. “In a horse with this problem, you’ll see great appetite—eating very well—but these horses waste away, losing muscle mass, and may die without intervention.

“I observed this problem firsthand in a group of blood donor horses maintained at a veterinary hospital,” Siciliano adds. “They were fed the leftover hay from the prior year. It was good hay, not moldy, but it had been stored a long time. Over time, the hay gradually loses the compound that has vitamin E activity. The horses became vitamin deficient and eventually developed motor neuron disease.”

EMND does not develop quickly. “When studies tried to replicate this in an experimental setting—to make horses deficient—it took nearly two years of feeding a low vitamin E diet before any signs occurred,” says Siciliano. “When people see a problem, they immediately wonder what they’ve done to cause this change, but the reality is that the problem occurred because they didn’t change anything—the horse stayed on a deficient diet for a long period of time.”

- Equine degenerative myeloencephalopathy (EDM) is caused by damage to the nerves in the spinal cord and parts of the brain. It typically develops in younger horses, those who are less than 2 years old, and it causes ataxia (incoordination) and loss of proprioception (the sense of where their body and limbs are located).

EDM seems to run in families, which suggests that the cause is genetic. However, the disease is also characterized by low levels of vitamin E, and supplementing with this nutrient helps horses improve. While low levels of vitamin E do not appear to be a direct cause of EDM, it’s possible that a vitamin deficiency could produce the signs in a horse who is also genetically predisposed to the disease.

- White muscle disease, a degeneration of the skeletal muscles, is caused by a deficiency of selenium, another potent antioxidant. But low levels of vitamin E also seem to play a role in the disease. “Selenium and vitamin E are both important for muscle function and work as antioxidants, but with slightly different jobs,” Siciliano says. Higher levels of one nutrient can help compensate for lower levels of the other, and signs of deficiency are more likely to occur in horses with low levels of both.

- Sporadic exertional rhabdomyolysis (“tying up”) is a severe, painful cramping of the large muscles that can occur during or just after exercise. “Exertional rhabdomyolysis has many causes, but one thought is that it can be caused by inadequate levels of vitamin E,” says Carey Williams, PhD, an equine extension specialist with Rutgers, the State University of New Jersey. “During research trials in my lab, we had a few horses that were marginal in terms of plasma vitamin E levels. They had more of a tendency to tie up during or after the exercise, or at least be very muscle sore with higher levels of creatine kinase [a muscle enzyme that is abnormally high in the blood when horses tie up]. Many people who have horses who suffer from tying up problems are feeding 5,000 IU of vitamin E, and that does seem to help.”

Why your horse needs vitamin E - Three Runs Plantation Equestrian Blog. Re-published article from EQUUS Magazine.

Saturday, March 3, 2018

We’ve All Been There …

… wondering why we struggle with riding skills. Jim has the secret for getting from THERE to HERE

We’ve all been there, dejectedly sitting in the bleachers after yet another disastrous round as the star du jour rides by, using invisible aids while sitting motionless in the saddle.

“Why is this so HARD?” you ask yourself. The bad news is that riding well is hard to learn. The good news is that every good rider, at one time or another, has been right there with you in the bleachers. The important thing to know is that you can be a better rider—you just have to decide to get better.

First of all, riding well is hard to learn because it is not all about you—your horse is part of it, and probably the main part. If you want to learn how to ride well, you need to understand horses—how they think, how they react to certain situations and how they move underneath you. I say, “learn,” but it’s not like memorizing the multiplication tables from 1 through 12. When it comes to horses, your learning curve will trend upward for as long as you live—that’s the fun part. And while we are busy having fun, I thought I would pass along some of the things I learned the hard way so that you don’t have to repeat my mistakes.

Think Like a Horse

One of the hardest things to learn, especially for redheaded boys (like I was), is that horses don’t wake up in the morning and decide to ruin your day. Horse logic is not always the same as rider logic. As a prey animal, horses are always alert for danger and easily—squirrel!!—distracted. Once you look at the world from their point of view, you can understand why they react the way they do and teach them that you are there to keep them safe.

Their reaction to liverpools and ditches is understandable if you think about it—again, from their point of view. To you, it is a simple ditch, 24 inches wide and 12 inches deep, but to them it is the China Syndrome. Thousands of years ago, one of their potential ancestors was not careful about where he stepped and took himself out of the gene pool. Horses are spooky for a reason: Saber-toothed tigers ate the non-spooky ones a long time ago. Horses are quick to react. You and I may know something is not a threat, but your horse says, “Why take a chance? That plastic bag snagged in the bushes could be about to pounce.”

Once you understand this and learn to think like a horse, it changes your actions when your horse reacts violently to things. If you punish your horse for spooking at a sun spot in an indoor arena, you confirm in his mind that sun spots are something to be afraid of. If you allow him time to look at it in a nonconfrontational way, he will decide that he was wasting his time spooking at it and be willing to accept sun spots as part of his environment.

Staying With the Motion

Being quadrupeds, horses have certain gaits and produce certain sensations when we are (however precariously) trying to remain attached to them. Most of the horses we ride have four gaits with four distinct rhythms: the walk with four beats, the trot with two beats, the canter with three beats and the gallop, a fast canter, with four beats. My point in this is that your horse takes different actions with his body to produce each of his gaits and his actions will change how you perceive his motions and how your body needs to react in order to look as if you’re sitting motionlessly.

Here is one of my favorite examples of this: When your horse trots, his shoulders remain level but his hips move up and down and he swings one hind leg under his body while the other hind leg pushes back to propel his body forward. Ever wonder why sitting the trot smoothly is more difficult to learn than sitting the walk or the canter? This is why: At the walk and the canter, your seat moves back and forth in rhythm with your horse, but at the sitting trot your hips must move alternately up and down in order to follow your horse’s motion correctly. If you understand your horse and his movement better, then the actions you must take with your body to stay with his motion become more understandable.

Your Leg, THEN Your Hand

Improved understanding will lead to better riding. Once you can follow your horse’s movement correctly, you can apply your aids with much more precision. BUT, once again, before you start to apply aids, you need to understand what you are trying to achieve with those aids.

Basically, you use your aids to put your horse’s forces at your disposal—to enable you to move faster than you can run on your own, to jump higher than you can jump and to eventually feel that, in general, the law of gravity no longer applies to you. Like anything else worthwhile, this does not happen easily, nor should it. Beverly Sills, the legendary opera diva, said, “There are no shortcuts to any place worth going.” I wouldn’t have it any other way.

As you continue to progress along your learning curve, you will discover that much of riding is counterintuitive. By now, you probably understand that for your horse to strengthen and improve his dressage work, he needs to lower his head slightly, relax the muscles of his back and become stronger and more energetic with his hind legs. However, you are doomed to failure until you also understand this simple rule: You don’t pull your horse’s head down. You push it down.

Once you understand this rule, you have been handed the keys to the kingdom of the horse. The first time you feel your horse step from your inside leg to your outside rein is a supremely important moment in your development as a horseman. Your first experience of this response will usually be at the trot on a circle. Make the circle about 10 meters in diameter. Now increase the size of the circle by closing your inside leg and pushing your horse toward your outside hand. Instead of speeding up, your horse accepts your leg, responds by stepping farther under his body with his inside leg and seeks a connection with your outside hand. In simplistic terms, you now have your horse balanced between the accelerator and the brake. From this point on, you know how to ride from your leg to your hand rather than the other way around. At first intermittently, then consistently and finally, generously, your horse will put his strength at your disposal.

Let Your Horse Do the Jumping

Learning to ride well over obstacles is equally as hard as learning to ride well on the flat. Just as with dressage, I have one very simple rule for you. To illustrate it, during my lessons and clinics and after a few warm-up jumps, I ask riders, especially young teenagers or older riders who are so terrified that they have regressed, the following question: “How many jumps have you jumped today?” The responses will vary widely in numbers and accuracy. Once students have expressed their opinion, I will say, “No, you haven’t jumped any.” You see, that’s my rule—“Your horse does the jumping!” You are just along for the ride. Most horses like to jump, especially if they are unencumbered by the rider’s hands. If a horse truly does not like to jump, there are other jobs he can do, and it is up to us to steer him down the correct career path.

Once we have a horse who likes to jump, we need to stay attached to his motion and ride him in a rhythm. My reasoning is this: It is difficult to ride well—and for him to jump well—if we are continually either left behind the jumping motion or topple forward on landing. Time spent in perfecting your position is never wasted. I have written numerous books and articles on the correct jumping position and you can find a list of some at the end of this article, but my short version is to adjust your stirrups so that you have approximately a 90-degree angle behind your knee when seated. Over small obstacles, your jumping position is the same as the top of your posting trot. Your stirrup leather should form a vertical line and there should be a straight line between your elbow and your horse’s mouth. Remember to follow your horse’s mouth with your elbows, not by closing your hip angle.

Once your position is secure and independent, then ride your horse in a rhythm before, over and after the jump. To help keep the rhythm in the approach, count out loud until your horse leaves the ground. You can tell yourself you had a good jump when you have approached, jumped, landed and departed in the same rhythm. Your rhythm is important because when we hear the rhythm, we hear the balance. When your horse is balanced, he jumps to the best of his ability.

Simple, just not easy. But if it were easy, everyone would do it—and you want to be the one in the saddle someday, riding past while younger, less experienced riders look at how easily you and your horse perform. This time someone new is in the bleachers, saying, “Why is this so HARD? She makes it look so easy!”