Protein for Performance Horses

PROTEIN FOR HORSES : EQUINE ATHLETES NEED FOR PROTEIN

During hard training or competitive events, equine athletes damage muscle tissue as a result of the production of high levels of lactic acid and /or over exertion. These muscle tissues must be repaired rapidly in order to maintain improvement, ready your athlete for the next event, and alleviate stiff and sore muscles. While in hard training or before and after serious competition dietary programs must be chosen with care in order to maintain improvement, prepare his or her system for the coming event and impact quick recovery from that event. Diets chosen for your athlete must contain protein that is profiled properly ( amino acids) along will minerals, vitamins, fat and carbohydrates. High quality protein is essential for maximum performance of any equine athlete because of its amino acid profile and the availability of these amino acids. The interaction of these amino acids with vitamins and minerals are necessary interactions for improved muscle growth and repair, stronger supportive tissues, an improved carbohydrate metabolism, stronger bones and joints, thicker hoof walls and greater overall soundness.

PROTEIN

Protein can be defined as any substance which is made of amino acids in a peptide linkage. The word protein comes from the Greek word PROTOS or FIRST because protein is the basic constituent of all living cells. Protos may also be the root of the name proteus , a mythological figure who could change form. Food protein also changes form to become a body substance after being eaten. Protein makes up three - fourths of the dry weight of most living cells. Proteins are also involved in the biochemical structure of hormones, enzymes, nutrient carriers, antibodies and many other substances and functions essential to life.

AMINO ACIDS

Protein is a collection of amino acids tied together. Once the protein is consumed and digested the amino acids breakdown into single amino acids or in some cases , peptides, which are just a few amino acids tied together. Some amino acids are considered ESSENTIAL and some are considered NON ESSENTIAL. We often do not realize how much the horse needs amino acids, because we are not aware of how busy the equine system is. Every second the bone marrow makes millions of red blood cells - every four days most of the lining of the gastrointestinal tract and the blood Platelet are replaced. - Most of the white blood cells are replaced in ten days and the number of muscle cells replaced or created in horses that are training hard or performing can be staggering.

ESSENTIAL AMINO ACIDS

Essential amino acids are amino acids that cannot be synthesized by the system from other things such as vitamins or carbohydrates. These essential amino acids must be eaten every day. If not, consumed daily the horse will then borrow them from other parts of his system to provide them for his daily maintenance. Essential amino acids are extremely important to your horse. The exclusion of even one essential amino acid from the diet or the reduction of an essential amino acid in relation to its need will reduce the total protein synthesis in the system. In horses where everyday maintenance is necessary and improvement with training is required, the creation of new cells is your priority. The horse requires a precise amino acid profile. Amino acids are not just randomly joined together, but are assembled according to a detailed predetermined procedure whose sequencing is controlled by the D.N.A. In order for new cells to be synthesized, all of the amino acids in the D.N.A. profile must be available in adequate amounts. If just one amino acid in the profile is missing the creation of new cells stops. This is called first limiting amino acid.

SOURCES OF PROTEIN AND AMINO ACIDS

Horses receive protein from both their grain mix and the hay they receive. Alfalfa hay of course is very high in protein and grass hays are lower. Common sense would tell us that if you are feeding alfalfa hay, your grain mix should be lower in total protein. If you are feeding grass hay you should be feeding a grain mix that is higher in protein. Grain mixes come in all types, but in general they are a combination of pellets ,oats and corn. Corn and oats both contain protein but are low in the essential amino acid lysine. The pellets in your feed should contain additional protein sources. These sources could be and more then likely are plant protein products such as soy bean meal in combination with other of numerous processed grain by-products. Soybeans as well as processed grain by products must go through some sort of heat process. This heat can destroy some of the most important essential amino acids for the horse.. All amino acids have a different melting point. Cystine is destroyed at 175 degrees F . Lysine , which is a extremely important amino acid is destroyed at 224 degrees F.Proline is lost at 220 degrees F. Soy bean meal processors are never supposed to exceed 200 degrees F but when push comes to shove, you know what happens. Products like distillers grain or dried solubles are almost always heated at a very high temperature. This heat process destroys many valuable amino acids and makes the feed compound unbalanced to the horse causing him to not get the full value of his protein and also taxes his system excreting all those out of balance amino acids.

AMINO ACIDS AS AN ENERGY SOURCE

The horse can convert amino acids into energy. This pathway is not the most efficient method to obtain energy, but the system has many checks and balances. Amino acids that can be converted into sugars are called glycogenic. Amino acids that can be converted to fat are called ketogenic. A few amino acids can do both.( isoleucine - lysine - tyrosine ).

MAKING DECISIONS

Whether your horse is a champion racehorse or a backyard pony, the amount and quality of the protein you feed will affect him or her one way or another. Protein in general should never be fed in excess to any horse. Too much protein or protein with the wrong amino acid profile will tax the system of your horse and cause him or her to be less than he should be. This information should help you make good decisions for your horse so he or she can be all you hoped for. If you have been depending on your feed company to make all the right decisions for you -think again!.

Protein is a collection of amino acids. Every protein source is a different combination of amino acid types. Some of these combinations are very good and some are not so good. The horse’s system needs amino acids that match his needs. Total protein of your horse feed is a worthless term, unless you know the amino acid profile. Your feed tag might say 14% CRUDE PROTEIN but to the horse it might only be 8 or 9% usable protein. The more unusable protein the horse consumes the more he has to excrete. This over feeding of unusable protein stresses the horse`s system. Excess protein can contribute to higher heart and respiratory rates, higher rates of sweating and dehydration. Some studies have concluded that performance horses do not need additional protein for good performance. These studies however do not take in to account the quality of the protein and how it might contribute to the gradual weakening of supportive tissue, bone loss, muscle atrophy and the weakening of blood vessel walls that eventually lead to bleeding or breakdown.

To produce new cells the horse`s D.N.A. has a recipe for every different kind of cell in the horse. When you feed your horse, the protein he consumes is broken down into individual amino acids. The blood stream carries these amino acids to the site they are needed, much like a conveyer belt. Lets imagine that each new cell the horse needs that day is a cake. Millions of D.N.A. cooks are standing along the conveyer belt waiting for the raw materials to bake that cake. As the raw materials pass by the cooks start grabbing all the components of their cake. When all the materials have reached that cook he grabs a little energy to bake the cake and “ walla” a new cake or cell has been created. If for some reason in four hours the cook is still missing one ingredient, he must put every component he has gathered up until that point back on the conveyer belt and start all over again. If the cook is short just one ingredient or can find no energy to bake the cake, no new cake or cell can be created.

THE HORSES NEED FOR AMINO ACIDS

LYSINE - An essential amino acid & high percentage constituent of muscle. Usually the most limiting amino acid in grain diets. Precursor for acetyl coa ( a critical nutrient for carbohydrate metabolism ). Large percentage constituent of collagen. Precursor for carnitine. Normal metabolism requires RIBOFLAVIN-NIACIN - B6 - IRON.

METHIONINE - An important essential amino acid constituent of muscle. Possible link in endochondral ossification. Regulates cell metabolism & growth. Low methionine creates folic acid deficiencies. Normal metabolism requires B12 - FOLIC ACID - B6 - MAGNESIUM.

PHENYLALANINE - An essential amino acid constituent of muscle. Precursor for catecholamine - which are adrenalin like substances. - Can be an effective pain killer and may enhance acupuncture. Normal metabolism requires - IRON - B6 - & COPPER. Precursor for tyrosine.

CYSTEINE - Precursor for cystine, necessary component of glutathione & the production of mucopolysaccharides (joint fluids ). Maintains integrity of red blood cells and is involved in the production of red blood cell membrane. Important in energy metabolism. Has the ability to clear out lungs. As cystine, component of muscle & hormones. Protects against per oxidation & is a detoxifying agent. Normal metabolism requires MAGNESIUM & ZINC.

ARGININE - An important constituent of muscle. Precursor for high energy compounds such as CREATINE. Primary in the removal of the waste products of muscle work (urea cycle ). Precursor of PROLINE (main component of collagen ) Collagen is the supportive tissue of skin, tendons, cartilage & connective tissue.

GLYCINE - Required in high levels for optimum growth & healing. Required for the production of D.N.A. Raises blood sugar levels. normal metabolism requires COPPER & CHOLINE.

TYROSINE - A constituent of muscle. Precursor for dopamine, norepinephrine, & epinephrine ( adrenalin ). Stress increases requirement. Normal metabolism requires FOLIC ACID & COPPER.

TRYPTOPHAN - A low level but essential constituent of muscle. Regulates growth hormone. precursor for serotonin ( platelet clotting factor ). Pain killer- controls hypertension & anxiety. Raises blood sugar & increases zinc absorption. Normal metabolism requires - B6 & MAGNESIUM.

LEUCINE - An essential amino acid & high percentage constituent of muscle. Major metabolic regulator. Reduces muscle breakdown. Stimulates insulin release. Normal metabolism requires THIAMIN - RIBOFLAVIN - BIOTIN & COPPER.

CARNITINE - Speeds usage of fats. increases adenosine triphosphate levels -ATP Aids conversion of amino acids to fuel within the muscle. Improves stress & exercise tolerance.

HISTIDINE - An essential amino acid constituent of muscle. Aids copper transport within the system. Reduces the effects of arthritis. Precursor for histamine - an important neurotransmitter. Normal metabolism requires COPPER - ZINC & VITAMIN E.

TYROSINE - A constituent of muscle. Precursor for dopamine, norepinephrine, & epinephrine ( adrenalin ). Stress increases requirement. Normal metabolism requires FOLIC ACID & COPPER.

Ride Manager`s Checklist - Mickie Newman

(To help poor frazzled ride managers to remember what they need to explain at ride meetings!)

This list encompasses both Endurance, LD and CTR. You may need to adapt some of these itemso to your own organiztion`s rules.

# Thank everyone for coming.
# Give ride time (for competitive), start time(s) and whether or not there will be a wake- up call. policy for start (endurance and LD, shotgun or controlled; competitive, what intervals and if you are letting groups go as we have been doing).
# Introduce vets and any other judges, and have them give parameters and any other info they feel is needed.
# Policy for disposal of manure. some places want it piled, some scattered, some picked up. riders need to know what policy is for that location. also policy for trash, whether there are dumpsters ( and what to do if they are full) or if it`s pack-in- pack-out.
# If a rider decides to pull for any reason, please notify someone in management so that they are not sending out a search party.
# On competitive rides, there are NO PIT CREWS allowed. you may have someone hold your horse for you but that is it. no sponging, no walking, no saddling, etc. the committee realizes that carrying a muck tub alone is not feasible, so you may have someone help with that (riders frequently double up on this duty to help each other out) but not do it for you. juniors may have their tack checked by adults to ensure safety but still need to be responsible for their own mounts. also, on competitive rides there is no forward motion allowed while off the horse (you may get off to rest but must not progress. some rides/ vets require forward motion for the last mile or two; if so notify the riders of this.
# Trail: markings, signs, landmarks (especially what to look for if there is vandalism), hazards.
# Location of P/R areas and any special problems, regulations etc.
# Ask if there are any new riders and invite them to stay after for further explanations.
# Explain emergency proceedures. point out horse ambulance and remind people to make sure its path out stays clear. if 911 works in your area remind people that if they need to call their home phone will appear to the dispatcher so it`s especially necessary to be as specific as possible with your location.
# Encourage people to fill out their surveys, whether AHAO members or not. these are very helpful to management, giving them ideas on things to keep or improve in future years. NOVICES (in AHAO rules "novice" is first or 2nd year horse or rider; so this is more for a "newbie" clasification)
# Ask how many first-time riders are present and encourage them again to please ask questions if there`s anything you don`t cover or that they don`t understand.
# Explain the process for pulse checks, coming into set hold for competitive or gate-into-a-hold for LD. explain that each rider has the right to ask for an immediate recheck but that the second one counts.
# If you will be using monitors at any checks explain that AHAO rules state we may use either monitors or stethoscopes as long as it`s the same for everyone at a check. rechecks will be done by stethoscope.
# Rules state that riders have "any reasonable time" for completion. reasonable is determined by the ride management. this clause is in the rules to allow for extra time taken due to vandalism, weather setbacks, or other problems that may legitimately arise. we do not want you to hurt your horse, but we also do not want you to be having a picnic and have all of the staff waiting on you (this is CTR only; endurance has times set by AERC).
# For LD rides, make sure the riders know that finish is determined by when the horse pulses down to 60 (which must be done within 30 minutes of arrival), NOT by being first across the line. remind new riders of the signs of overriding and what to watch out for. if they are unfamiliar with taking pulses, explain the procedure and encourage them to try it. Even if they do not own a stethoscope, most experienced riders, pit crews or P/R staff (providing they are not occupied with duties at the time) are usually glad to give a demo. Explain (or have the vet do so) what metabolic parameters are looked at and why.
# Ride staff are volunteers. if there are any problems we of course do not want you to hesitate to bring them to our attention. but please remember that these people are doing this for very little compensation (usually just food and a completion award). be nice to them!

Tying Up - Exertional rhabdomyolysis - Susan Garlinghouse

contributed by Susan Garlinghouse

Exertional rhabdomyolysis -excruciatingly specific details of what`s happening at the cellular level.

The complete pathophysiology (Why It Happens) of exertional rhabdomyolysis (most commonly called "tying up") is still not completely understood. Currently, the conditions that are known to be factors in causing tying up are

# resting a conditioned horse on a full-grain diet, followed by exercise ("Monday morning disease");
# whole-body potassium depletion;
# selenium deficiency; an unaccustomed level of exercise;
# postviral infections, particularly rhino;
# intoxications with ionophores (a substance which increases cellular permeability to a specific ion, which would in turn disrupt the electrical potential of the cell), blister beetle, mercury, coffee bean (cassia) or gossypol from raw cottonseed.

Other factors which have been suggested as being contributory are hypothyroidism, some high-performance lines of horses, nervous horses, fillies, shock, laminitis, tetanus, neural injury, estrus, hyperestrogenism (resulting from possibly a granulosa cell tumor), cold damp weather, heavy muscling, and low-sodium rations. Electrolyte depletion, especially calcium, magnesium and chloride may also cause muscle cramps, which are sometimes referred to as slow-onset rhabdomyolysis; or synchronous diaphragmatic flutter, commonly called "thumps". These are related syndromes, but not exactly the same as the syndrome described here, which is most accurately described as acute rhabdomyolysis.

One of the current hypotheses is that when a conditioned horse is not worked and kept on full feed high in soluble carbohydrates (such as grain), the horse will accumulate carbohydrates in the muscles. If there is a sudden demand for work, the body cannot adequately remove the rapidly accumulating lactic acid in the muscles. This in turn causes vasospasms and ischemia---which means essentially that the surrounding blood vessels "clamp down" so that the lactic acid waste product cannot be removed. As a result, intracellular pH drops, the muscle cell is disrupted and you get the hard, crampy muscles you see when a horse ties up.

Other theories of the biochemical mechanism is that there is a deficiency of the high-energy phosphates in muscle cells following maximal, anaerobic exertion, and/or a depletion of muscle glycogen after prolonged, slow (endurance-type) exercise. High body temperatures and electrolyte imbalances/depletions are also probably contributing causes, and certainly major factors in endurance horses that tie up during competitions.

Unless you`re a biochemist, all of these different theories essentially boil down to the same net effect---the ion pumps (ie, sodium/potassium, calcium/magnesium and calcium/ATPase) in the membrane surrounding the muscle cell which move substrates in and out of the cell are disrupted, and so the interior environment of the muscle cells either cannot get rid of waste products of metabolism, OR has too much of a metabolic substrate to be able to function, OR can`t get enough of a metabolic substrate to be able to function. And so the muscle cell simply shuts down. When muscle cells shut down, they don`t do so in the relaxed position, they freeze up in the contracted position, which is why you get those rock-hard muscles. Biochemically, it`s not all that different from rigor mortis.

The effect on kidneys comes in when the connective tissue (the sarcolemma) surrounding and enclosing the muscle cell is disrupted, releasing the contents of the muscle cell into the bloodstream. There are lots of different proteins and substrates and whatnot in a muscle cell, but the important one for this particular discussion is myoglobin. Myoglobin is a protein pigment which is responsible for oxygen transport in the muscle cell. Hemoglobin transports oxygen in the bloodstream, myoglobin transports oxygen in the muscle cell. When myoglobin is released from a disrupted muscle cell into the bloodstream, it travels to the kidneys and is filtered out. In being filtered out of the bloodstream (and keep in mind, there`s probably a lot of it from the kidney`s point of view), it causes (or CAN cause) kidney damage or even total renal failure by overwhelming and clogging up the kidney tubules and restricting the blood (and therefore oxygen) supply to the kidney tissue. This effect will be worsened if the animal is hypovolemic, meaning he`s dehydrated and therefore has a decreased total plasma volume. A decreased plasma volume means that in turn the blood is thicker and that the heart must work harder to circulate. And this in turn means that less oxygen to delivered to the muscles and organs, fewer substrates, less waste product removed, and so on. A vicious cycle sort of thing.

So while myoglobin does not directly damage the kidneys, in great enough concentration it will cause damage indirectly by clogging them up and creating what is called myoglobinuric nephrosis and possibly renal failure. It`s also the myoglobin being filtered out that shows up as very dark urine. The dark urine itself is not what you have to worry about---what you DO have to worry about is the fact that myoglobin in the urine means that significant muscle disruption and damage has occurred in the system, and that the kidneys are being overwhelmed with a whole lot of waste product to try and get rid of. Needless to say, this is serious s**t from the physiological point of view. However, dark urine doesn`t always mean myoglobinuria. Dark urine can be caused by other things as well. But if your horse is dehydrated, won`t move and is standing there hunched up and miserable and the urine looks a lot like coffee---you`ve got problems.

Some of the other things a veterinarian will look for in a suspected tying-up horse are elevated enzymes in the blood plasma, specifically CK (creatinine kinase) and AST (aspartate aminotransferase). AST is also referred to as SGOT, but both refer to the same enzyme. There are other things the vet will look for as well, like creatinine, urea, electrolytes and so on, but enzyme levels are at the top of the list. CK and AST are both enzymes contained in the muscle cell (as well as other types of cells) which are released into the blood when the muscle cell is disrupted. Therefore, if the enzyme levels are elevated in the blood panel, it must mean that tissue cells somewhere are being (or were being) damaged. The tricky part in diagnosis is figuring out where tissue damage is occurring---AST occurs in both muscle and liver cells, so elevated levels could mean problems in either muscle OR liver (and for that matter, AST levels can also be elevated by certain drugs or toxins). CK levels will indicate muscle damage, while other elevated enzymes in the blood panel will indicate liver damage. And to make things even more confusing, there are various isoforms of yet another enzyme, LDH (lactate dehydrogenase) which will indicate whether muscle damage occurring is from skeletal or cardiac (heart) muscle.

The elevation in CK will be detectable within a few hours of the onset of clinical symptoms, peak within 24 hours and decline fairly quickly. CK`s half-life is six hours, meaning that half of the amount remaining is removed within six hours. Hence, 50% is gone within 6 hours, 75% is gone within 12 hrs, 87.5% is gone within 18 hrs, 93.75% is removed within 24 hrs, and so on. The concept of "half-lifes" doesn`t refer only to enzymes, by the way, the same general idea applies to drug half-lifes, isotope half-life, etc etc (just a little extra trivia for you)(I know, riveting.)

The rise in levels of AST will peak approximately 24 hours after the onset of the clinical signs of tying up, and decline much more slowly---AST has a half-life of about 14 days, so with significant muscle damage, it`ll be awhile before levels are really back to normal. The relative levels of these two enzymes, among other things, are what a DVM will look at in determining the extent of damage, whether damage is still occurring and how long ago the initial damage occurred. For example, if a horse transport company delivers a horse doing a good impersonation of a piece of granite, and swears the horse must have injured himself last week before they ever laid eyes on him...but the blood analysis shows screaming CK levels (indicating recent muscle damage) and relatively low AST levels (also indicating recent damage), then the transport companies arguments can be classified under the heading of I Don`t Think So Chuckles.

References:

Hodgson, DR, Rose, RJ (1994): The Athletic Horse. W.B. Saunders, Philadelphia. pg. 169-174.

Kobluk, CN, Ames, TR, Geor, RJ (ed)(1995): The Horse, Disease and Clinical Management. W.B. Saunders, Philadelphia. pg. 809-810, 1278-1279, 1317-1318.

Lewis, LD (1995): Equine Cliinical Nutrition, Feeding and Care. Williams & Wilkins, Baltimore. pg. 262-263.

Copyright 1998 Susan Evans Garlinghouse.

Electrolytes - Managing Heat Scientifically. Part I - Cooling - Abby Bloxsom

By Abby Bloxsom, courtesy of Eastern Competitive Trail Ride Association, www.ectra.org

A Little Background

No matter where you ride or what distance you ride at, no matter what your experience or how fit your horse is, heat and humidity make distance riding harder. The horse is an arctic adapted species – in a summer coat, its body is temperature-neutral between about 30 and 60 degrees Fahrenheit, meaning that it will not have to expend energy to either cool off or heat up within that temperature range. Humans are not set up that way. Our small, flat, mostly hairless bodies with blood vessels close to the surface evolved in tropical climates (until we learned to dress ourselves, at which point our territory expanded gradually over the globe). Naked, we get cold quite easily.

This means that while we prefer to ride and compete in the summer, the heat and humidity of that season places a strain on the horse’s system that we as humans may not feel. In addition to the heat of the human-preferred climate, the horse is constantly producing heat of his own. When he’s exercising, he produces it at an alarming rate. Your job as Heat Manager is to get the excess heat out of the horse’s body as quickly as possible. (On borderline coolish days – or even on a dry, breezy day when the temperature might still be fairly high – it’s also important to know when not to cool the horse. A minimum amount of heat is necessary in order to maintain the horse’s normal body temperature, but that’s a subject for another time.)

How It Works

Before I talk about how you can help your horse to keep his cool in the summer heat, I want to review a little chapter from our high school science textbooks about heat in general. There are three basic heat transfer processes: conduction, convection, and radiation. Conduction is the way that heat travels through an opaque solid, as when the handle of a frying pan gets hot during cooking (I always forget about that). The speed of transfer – the amount of heat moved over time – depends on the difference in temperature between the warmer part and the cooler part of the solid. This is called the temperature gradient.

Convection is when heat is transferred from one solid, liquid, or gas to another, such as when a warm plate on a countertop warms up the surface of the counter, or when you put your jello in the refrigerator to chill it. Again, the speed of transfer depends on the temperature gradient.

Radiation is the process involved when a material transfers heat by electromagnetic energy. This process is unique in that objects need not be in contact with each other. All objects in our everyday world radiate heat because they are warmer than absolute zero, but the amount of heat given off depends solely on the temperature of the object. A glass of lemonade in the sun will warm up because it is absorbing more radiant heat (from the sun) than it emits (by virtue of its inherent "heat").

The problem with using any one of these processes to cool the body of a horse is that – especially on a hot, sunny day – they are way too slow compared to the amount of heat that his powerful engine is producing inside his body. The horse has a large body mass, especially compared to its surface area, so the transfer of heat from the muscles (where the horse is burning fuel and creating heat) outward to the surface by conduction is inefficient. He moves a little more heat by convection, as his blood is heated and then pumped through his blood vessels to the skin. The air around a dry horse is also heated by convection, which removes heat from the horse as long as it’s cooler than the horse itself (remember the temperature gradient?) This effect is reduced to nil, however, as the ambient temperature approaches the horse’s body temperature.

The warm body of the horse also radiates heat, in increasing amounts as he heats up. Still though, if he’s standing in the sun, he’s like my glass of lemonade in that he’s soaking up a lot more infrared radiation from the sun than he’s emitting. A dark horse – like a black rubber bucket – will soak up more solar radiation than a white horse, but he also radiates more, and he’s still going to be producing many times that amount of heat by virtue of the work that he’s doing. So keep him out of the sun when you can – but you should do that with any horse anyway.

Rest assured, though, that Mother Nature has also given us a supercharger to jack up the speed at which we can transfer heat, and that is the phase change. As water changes from solid (ice) to liquid (water) to gas (water vapor), it absorbs huge amounts of thermal energy. Firefighters take advantage of this when they cool a fire by spraying a fine mist of water over it. As the water vaporizes rapidly, it sucks the heat out of the fire, cooling it instantly. The speed of evaporation is limited by the ambient relative humidity– the amount of water vapor contained in the air relative to the maximum amount of vapor that it can possibly contain at that temperature. In the case of the fire, the relative humidity is effectively zero right before the hose comes on. Because the air is superheated from the fire, the maximum amount of vapor that can be contained is very high, so the cooling potential is very high. In the bathroom after a shower, the humidity approaches 100%, so evaporation and cooling potential are very low. This cooling supercharger – evaporation – is the best tool that we have for removing heat from a hot body. That’s why we sweat.

Putting It Together

Dry Weather: In a dry climate (or even in the humid Northeastern U.S. on a dry day, say below 40 or 50% relative humidity) the sweat produced by the glands on both equine and human skin will evaporate rapidly, sucking the heat out of the skin and the blood vessels just below it. The heart can then pump this cooled blood around through the body to cool the tissues in the core of the body. The evaporative process also occurs in the passages of the horse’s airway. He breathes in dry air, and the moist tissues in the nostrils, sinuses, trachea, and lungs are cooled by evaporation (and a little bit by convection).

Remember, though, that the horse’s sweat and the moisture in his airway contain water, electrolyte salts, and some proteins that come from inside him, from the tissues of his body. You can help preserve an enormous amount of your distance horse’s vital body fluids by putting plain old water on the outside of him. That’s the first reason that we sponge. On a day that will likely be warm at the outset, it doesn’t hurt to start right out in the morning by sponging a horse before starting a ride, and preventing those early fluid losses. Continued sponging during a ride will spare even more sweat, especially if you concentrate on the areas with the most blood vessels under the skin – the chest, neck, shoulders, belly, and upper legs.

When the humidity is very low, say below 25 or 30%, evaporation can happen so fast that you might think you and the horse are not even sweating – but you are. The more water you keep on the horse’s body the less he will have to replace from the inside (a notoriously slow process). Your horse will stay cooler, his pulse will be lower, and his recovery will be faster. SO just because it’s a dry day and the horse feels fairly dry and cool, don’t stop sponging! In this type of weather, the water used for sponging can be fairly warm, since the goal is for it to evaporate (it will feel cool anyway). In fact, if the water is too cold it might actually chill the horse by removing heat too quickly. If I were competing in very dry weather (which, face it, in New England I’m not!) I’d probably refrain from clipping my horse during the competitive season. I’d want to keep the water on the horse so that it will be able to cool him by evaporation. It can’t do that if it runs off onto the ground.

Hot Weather: As the ambient temperature approaches that of the horse (100-103 degrees F), remember that the effects of conduction through the body and convection to the air are both reduced (because they depend on the temperature gradient, right?). This means first that we must rely on a new principle: convection to water. The water that goes onto the horse must be cool, so that heat will be transferred from the body to the water. As the air becomes hotter, the water needs to be cooler so that the cooling process will be faster (remember the temperature gradient). Water sponged onto the horse must be scraped off immediately (it will feel warm) and replaced with more cool water.

High air temperatures also mean that radiation and evaporation (the supercharger) become more important. It’s essential to keep the horse in the shade to minimize the heating effect of solar radiation and maximize the effect of convection to the air (cooler air means a greater difference in temperature, hence faster cooling). Standing in a breezy spot or walking the horse about slowly will increase both the evaporation and the convection rates as the air passes over the horse’s heated body. In high heat with low humidity, this may be all that’s needed.

Humid Weather: As the ambient relative humidity approaches 100% and temperatures are in the "very hot day" range, however, we have an entirely different situation. Very humid air cannot absorb water from evaporation (the steamy bathroom effect), which means that the supercharger is now out of gas. The weakling coolers of conduction, convection and radiation can do the job, but not without a lot of effort on your part. As on the hundred-degree day, you will need to get a jump on the cooling by laying on the water heavy and early.

In oppressive weather, we depend on relatively slow heat transfer processes, but they are all notorious for being painfully slow for a horse with a chunky body. A loaf of bread fresh from the oven stays warm much longer than a pancake, even a stack of pancakes, because heat has to travel much farther from the core of the bread to the outside than it does in the flat pancake. This is why my riding partner’s chunky little horse – faster and fitter than my lanky mare – inverts and has trouble recovering in muggy weather. On a cool, dry day he can trot circles around her for 25 miles!

Clipping a horse before a ride can help with cooling in humid weather – it allows the convection heating of air and water over the body to happen faster, since even the summer coat is a decent insulator. It also allows the evaporative cooling to draw more heat because it takes place closer to the blood vessels below the surface. Keeping pads, ear nets, and hanging mane to a minimum will of course also help your horse keep his cool on a muggy day.

A horse with a fast, efficient gait can sometimes manage to cool himself out on the trail by using speed to his advantage: a convection oven cooks faster by virtue of the fact that circulating the air rapidly speeds up the convection process. My husband likes a fan in the summer for the same reason. If a horse is very fit (it would be counter-productive to try this with a horse who was not up to it) moving him along the trail at a good clip (in the shade, over easy going) can speed up both convection and evaporation, even if the temperature gradient and relative humidity are not in your favor.

When the rider dismounts at a hold or the end of a ride in hot, humid weather, the saddle should be pulled immediately. Huge amounts of the coldest water need to go on the horse’s body – everywhere, but especially on those big veins of the chest, neck, head, ears, belly, and upper legs. The water must be scraped off as quickly as possible and replaced with more cold water. In effect, you’re speeding up the convection to water by circulating the water over the horse’s body. You need to keep this up as long as it takes to make the water run cool off the horse’s body.

When the water does run off cool, you’re not done. Walking the horse slowly will maintain blood circulation from the core of his body until he’s both cool and dry. You may find though, especially in a horse with a blocky body type, that he seems to heat back up again later because the body core was not as cool as the surface was. The cooling/walking cycle needs to be repeated until the horse stays cool if allowed to rest after the walk.

In An Emergency

If all else fails, and the horse really does overheat (a temperature over 103 degrees that isn’t coming down) it’s essential for the horse’s health to get the heat out as fast as possible. At this point, a horse will have been withdrawn from an ECTRA ride, so the ride rules go out the window. To take advantage of the temperature gradient, you need ice – and lots of it – in your water bucket, and you need to get the very cold water onto the entire horse as quickly as possible. Again, as long as the water comes off warmer than it went on, keep scraping it off and putting more on. Use the shade, the breeze, and walking to your advantage, and use as many people as you can get to help cool the horse before he suffers medical complications.

The Human Factor

Of course, it does no good to discuss caring for the horse if I don’t also throw in two bits about caring for the rider. On an ECTRA ride, you have no crew available to look after the horse while you go off and lie down, sponge yourself, or eat and drink. DO NOT put the horse’s welfare in front of your own at all costs, since an under-fueled or dehydrated rider can quickly become weak, disoriented, and careless. By forgetting to care for him or herself, a rider can easily jeopardize the welfare and safety of the entire team. You can use the same physics to cool your own body that you use on your horse in extreme weather conditions. Now go out and ride.

Electrolytes- Commercial Products - Diane

The Trademarked product "Endura-Lyte" is manufactured for Life Science Products in St. Joseph, MO by an un-named producer. There are several distributors available including Roger Rittenhouse, Teddy Lancaster, Safe Haven Specialties, A.B.C. and others. Jeannie Waldron`s article is entitled "Electrolytes and the Competitive Trail Horse".

This formulation contains NO bicarbonates. The milliequivalents of selected cations necessary for electrolyte balance in the working equine includes Na @ 4968mg/oz, K @ 2652mg/oz, Ca @ 752mg/oz, Cl @ 9940mg/oz and Mg @ 600mg/oz.

Supplementing with Endura-Lyte at 6 doses, 1.5 oz/dose, during a 50 mile race will replace 49% Na, 38% K, 48% Cl, 100% Ca and 26% Mg. 100% replacement is unnecessary since hay, grain and other forage will make up a significant amount of the total required.

How the cations are available makes a significant difference in the bio-availability of each cation, e.g. Ca acetate is much more soluble than Ca phosphate (also Mg in a citrate is more soluble than a calcite--"dolomite"). These ions need to be highly soluble to work at all.

Make sure you read your labels and understand what the ingredients are. Avoid products like Stress Dex that are high in sugars.

Buckeye Feeds has produced an excellent product called "Perform `N Win" with outstanding solubility and bio-availability. This product appears to be "less harsh" and prompts an almost immediate drinking response. It is also highly palatable to most horses. Recommended doses range from 3/4-1.0 oz. per application (your individual needs may vary).

Ride-Rite electrolytes, made by A.B.C. contains Jeannie Waldron`s formulation with additional K citrate, Ca sulfate, amino acetic acid, Mg sulfate, Na sulfate, Si dioxide, etc. These additional ingredients act as "buffers" to the highly acidic chlorides and acetates. A.B.C. recommends feeding these electrolytes in conjunction with Pro-Bi to maintain gut sounds and deter appetite suppression.

Acculytes are designed to be fed daily as a topical dressing. It is not very soluble at all. I personally do not recommend using this as an oral dose via syringe.

Apple Dex is a very palatable electrolyte with sugars. It works best as an additive to the water bucket for free choice application.

Jeannie Waldron`s and Perforn `N Win electrolytes have been extensively field tested on horses doing what YOU do--endurance racing and CTR`s. These products merit your careful consideration for addition to your conditioning/racing program.

Diane
nelsonde@ttown.apci.com

Electrolytes - Content Comparison

Karen Chaton`s Electrolyte Table: Here

South Africa - Gauteng Multi Distance Endurance Ride – 13-15 October - Kristine Smuts

On the weekend of 13 – 15 October, four Gauteng endurance clubs hosted the new Gauteng Multi Distance Endurance Ride which was held in “The Cradle of Humankind” at the Rhino and Lion Nature Reserve, Krugersdorp.

The four clubs involved were Premier, Rand, Randfontein and Weermag Perdesport. Each had their own duties to perform and without the dedication of all those involved, this ride would not have been the success it was. It is hoped that this ride will become one of the best endurance rides in the world!

On Thursday morning the 12th, the course designers were notified that due to the storm the night before, the low-water bridge which was on the 160km and 110km route, was under water. Johannie Geldenhuys, who was part of the course design team, had to hastily work out an alternate route should it rain again before the ride on Saturday morning. Well, it didn’t rain again so there was relief all around – not least from the riders!

Riders and their entourage started arriving on Thursday afternoon and the grounds slowly filled up with the general festive air that goes with “Hi! Glad to see you again, how have you been?” being shouted across the camping ground. Old friends re-united for a chin-wag about the one subject everybody has in common – horses. Genuine interest was expressed about the progress of horses since the last time everybody was together; the new horse that was there for his first ride; the horse that had an inexplicable lameness during the season.

During Friday the air started becoming tense as the longer distance riders fretted over their horses, their tack, their grooms – “Did you remember the sponges?”, “Where are my chaps!?”, “Where did you put the spare numnah?”. Eventually it was time to present to the vets which seemed to calm the nerves somewhat as this was a familiar routine that people could hold onto.

The course discussion took place at 9pm when the riders found out what lay in store for them. As it was the first time this course was being presented, nobody, except for the course designers, knew what the terrain was like. Places where it was hard going was emphasised and an uncomfortable silence fell over the audience. An even more uncomfortable atmosphere prevailed when it was mentioned that all riders would have to pass the lion enclosure! However, the mood lifted when it became clear that all distances were based on the “clover leaf”, meaning that you start and finish at one point. Grooms let out a collective sigh of relief when they realised that they could stay in camp and wait for their riders and not have to travel to designated points along the route.

The weather played along with a bright, full moon seeing the 160km and 110km riders off at 1am the next morning for the first leg of 40kms which was marked out by fluorescent arrows and glow sticks. The shorter distances – 80, 60 and 30kms – were set off at 5 minute intervals from 5:30. Horses were coming and going all through the morning with grooms nervously checking their watches and keeping an eye on the road for sight of their riders. Some grooms, notably the newbies, were caught napping when their riders arrived well ahead of their previously discussed time.

By lunch time the shorter distance riders had arrived back at base camp. During the course of the afternoon, the longer distance riders started arriving, clearly relieved that they could finally relax. Some riders were visibly at the end of their tether, but surprisingly there were individuals who looked as if they had just come from the beauty parlour – undoubtedly the veterans!

Many people departed during the afternoon and the camp site looked like an old lady with some teeth missing – only the stalwarts remained (maybe because they couldn’t do much else!). Party plans for Saturday evening were discussed among friends but by 8pm very few people were around and silence fell over the site – a clear case of egos writing cheques that their bodies definitely couldn’t cash!

On Sunday morning, those who remained were treated to a champagne breakfast where the certificates and prizes were handed out. Janita Doyer received Best Condition award and she also won the 160km first prize. Only one of the three international riders completed the course, but she had a slightly unfair advantage as she regularly competes in South Africa, whereas the other two ladies, one from America and one from Britain, were unfamiliar with our conditions – especially as we had a heat wave that weekend!

Some riders were noticeably unhappy with the course and the rules, but the majority of people, including Janita, said that it was the best ride they had ever been on. A good testament to the organisers and not least to the Nature Reserve.

Surprisingly, the horses were not overly spooked by the many antelope, rhino and ostriches they encountered on the course. There were reports of one or two horses spooking badly at the lions, who had a grand time making sure the horses and riders could see them pulling menacing faces on the other side of the fence!

It was such an incredible privilege to be able to host this ride at the Rhino and Lion Nature Reserve. The co-operation we received from the officials at the Reserve was overwhelming, especially as it came from people who were “non-horsey” people. The Spioenkop Disaster Management team were falling over themselves with enthusiasm at being part of the organisation – a good lesson to those actually involved with the sport who do not show the same amount of enthusiasm for their own sport!

Special thanks need to go to our sponsors, property owners and benefactors : Mr Leebman, Mark Reed, Rebecca Waddell, Willie Joubert, Nkwe Ngunis, Blikkies Auret, Danielsrust Horse Trails, ABSA Private Bank, Conserv Tours, Wondercave Kromdraai, Kromdraai Conservancy, Healthtech Laboratories, TackOnline.co.za, Jozami Arabians, Randburg Motorlink, Rhino and Lion Nature Reserve.

There were numerous people involved from an organising point of view as well as the ground crew who were on duty for more than 24 hours – these are too many to mention by name, but particular reference should be made to the veterinary staff, the time-keepers, the weigh master, the grooms, the gatekeepers – husbands, wives, children and domestic staff, opening and closing gates and providing refreshments for the riders along the route from the first rider to the last rider who came in at 11:40 on Saturday evening and who still cleaned up all the bottles and other debris left along the route!

Lastly, thanks should go to especially the riders, without whom there would be no event to host.

What is always amazing is the dedication to the sport exhibited by those volunteers who work hard for weeks before and after an event, spending their own private money and time, sharing their knowledge, using talents and contacts to make an event successful and who want no more than a thank you from their fellow volunteers. The success of this event was a true reflection of this kind of dedication exhibited by those involved and I am privileged and humbled to be in the company of those people.

For more information on endurance riding in South Africa, please go to the ERASA web site www.erasa.co.za, or contact Kristene at ksmuts@sarcc.co.za

Beating the Metabolic Pull. Part I - Hydration - Susan Garlinghouse

Reprinted from Endurance News, June 2000
Susan Garlinghouse, MS

My belief has always been that if a rider understands some of the why in nutrition and physiology, then it is much easier to understand the how in making well-informed decisions during and between rides. This article is the first in a three-part series explaining a little about the way things work in an exercising horse, along with suggestions on how to apply this knowledge for better metabolic integrity and performance.

Whether your goal is to race at FEI levels, top ten or just get back into base camp before the barbecue is all gone, the common denominator is that first you have to finish with a horse that is fit to continue. You do not need an advanced degree to recognize the metabolically fit horse---he has good gut sounds, is eating, drinking, is well hydrated, bright and alert. Most of us have also seen the other end of the scale---the deflated horse with an IV running into his neck, that the treatment vet is hovering over, that is on his way to a clinic. The difference between the fit to continue horse and the treated horse depends largely on three primary metabolic factors---hydration, gut motility and energy balance. The first two are so closely related as to be almost the same issue and are by far the most critical factors in maintaining metabolic integrity. The third factor, energy balance, has become a hot topic and can certainly make the difference between a win and a middle of the pack finish. However, the amount of rocket fuel on board is not going to help if your horse is dehydrated, colicking and already in trouble. If you remember anything from these articles, remember the order of priorities---hydration and motility first, and then energy balance. Assuming your horse is conditioned for the job at hand, and you have paid attention to maintaining hydration and motility during every stage of the ride, you will find your horse has better performance, recoveries and stamina, long before you start considering, "how do I increase his energy?"

This first article covers hydration, which is much more involved than just letting the horse drink at every water stop, and remembering to carry a sponge. What exactly does water do in the body, anyway? For the endurance horse, one of the most critical roles is the removal of excess heat during exercise. During a fifty-mile ride in ambient temperatures, the average horse will produce enough heat to melt a 150-pound block of ice, and then bring that water to a boil. If that heat is not removed, the internal body temperature will quickly rise high enough to literally cook the entire body. Evaporative cooling via sweat production and respiration accounts for the majority of heat dissipation during exercise. Horses that are dehydrated progressively lose their ability to produce sweat, a condition called anhidrosis, resulting in loss of cooling and a concurrent rise in body temperatures. As the body dehydrates and blood loses plasma volume and fluidity, the cardiovascular system becomes less efficient at transporting oxygen and other resources throughout the body. The heart rate increases to compensate, so that a horse that canters easily at 130 beats per minute when fully hydrated may have a heart rate of 20-30 beats higher when dehydrated, simply due to the extra work of pumping less fluid blood. Not only does this result in slower recoveries, but it also has a significant effect on the efficiency of muscle function. To maintain the same intensity of work, the horse will rely more and more heavily on anaerobic metabolism, contributing to faster fatigue and greater incidence of metabolic disease, such as colic or tying-up. As effort increases and efficiency decreases, the body responds as though to an emergency (which, in fact, it is), and begins to shunt blood flow away from less-vital organs, such as the gastroin testinal tract, in order to maintain maximum circulation to heart, lungs, muscles and central nervous system. As blood flow decreases to the digestive tract, gut motility slows and may stop entirely, leading to colic until blood flow and motility are restored.

Progressive dehydration also affects the normal functioning of the "thirst center" in the central nervous system. Thus, dehydrated horses badly in need of fluids may entirely lose interest in drinking voluntarily. If you know your horse has been working and sweating hard throughout the day, and yet is not drinking, do not assume he doesn`t need water. In fact, he may be approaching a metabolic crisis if not resolved quickly. Don`t make the mistake of thinking, "he knows best what he needs"---use your head to make the right decisions on his behalf.

During a hot and strenuous ride, horses can lose from 1.5 - 4 gallons of water per hour in the form of sweat. Over the course of a 50-mile ride, this can often add up to ten (or more) gallons of fluid lost solely through sweat production. Research conducted by Gary Carlson at UC Davis indicates that the average Tevis horse experiences a net loss of almost five gallons of fluid between the start and finish (equivalent to approximately 4% of body weight in a 900 - 1000 pound horse). Losses of over 12 gallons have been measured, representing 10% of the body weight. Keep in mind these numbers represent the fluids that remain unreplenished in the equine body, after the horse has presumably had ample opportunity to drink throughout the day. These results indicate that even under ideal circumstances, horses may not be able to drink enough water to replenish the fluids lost through sweat production, resulting in progressive dehydration.

It has been estimated that dehydration losses of as little as 3-4% (that is, 3-4% of body weight has been lost in the form of fluid) have an adverse effect on performance, even though outward clinical signs may not be readily apparent. Horses experiencing an 8% dehydration have a capillary refill time of 2-3 seconds, poor skin tenting, dry mucous membranes, dry feces (and, therefore, are at greater risk of colic) and generally a high, hanging heart rate. A horse at 10% dehydration is in serious trouble, requiring extreme veterinary intervention, and at 12%, the horse is close to imminent death. Skin tenting alone is a relatively inaccurate method of determining extent of dehydration, and often lags behind changes in true hydration status. Therefore, along with the ride veterinarian, you must consider all metabolic factors in evaluating your horse, including mucous membranes, gut motility, heart rate, capillary refill time, attitude and way of going.

What is the difference between a clinically normal horse with 4% dehydration and one in metabolic distress at 8% dehydration? Less than five gallons of fluid in the body can make the difference between completion and a metabolic crisis. So--- your horse is already drinking at every puddle and bucket, you have finally mastered that flying sponge trick, your crew is waiting with plenty of cool water for washing, and you dutifully clip his winter hair every year. What else can you do to improve his hydration status?

One of the easiest ways to prepare for good hydration on Saturday is to maximize forage intake the week before. Forages take several days to reach the hindgut, so that Thursday`s hay is in the cecum and large colon on Saturday. For reference, the foregut consists of (in order) the stomach and small intestine, while the hindgut consists of the cecum, colon and rectum. Fiber both encourages water intake and absorbs and holds water as it moves through the digestive tract. Although 90% of the water will have already been absorbed prior to reaching the hindgut, several gallons are still present and available as the hay moves through the system on Saturday. This provides a significant extra reservoir of fluid and electrolytes to draw upon during exercise-induced dehydration. Recent research has indicated that feeding one of the soluble "super-fibers", such as soaked beet pulp, along with hay, further increases this fluid reservoir. This extra water alone may make all the difference between Completion and Trouble. Make sure that the horse has hay available during the trailer ride to base camp, as well as immediately upon arriving and unloading. Adequate fiber intake the night before, as well as a dose of electrolytes, will trigger thirst responses and drinking throughout the night to ensure the horse starts fully hydrated.

The timing of meals fed before and during a ride also has an effect on hydration. Many horses are still provided with a large "breakfast" before the start, little or nothing until the lunch stop when another large meal is provided, and then little or nothing again until the finish. Studies have demonstrated that such feeding practices (more than 4-5 pounds of any type of feed, spaced more than 2-3 hours apart) results in a large fluid shift from the plasma volume (the fluid portion of blood) into the digestive tract. These fluids are used to provide saliva and other gastric juices needed to process the large meal. In a 1000-pound horse, these fluid shifts may equal 4-5 gallons of fluid, resulting in a 15-24% decrease in total plasma volume. Don`t worry about the exact numbers, just think which is easier for the heart to circulate---thin, fluid blood, or thick "sludge"? While this fluid moves back into the plasma volume within a few hours, the net result is a transient dehydration that can significantly affect performance until the condition corrects itself. In a backyard horse standing around doing nothing, the effect is relatively unimportant---to an endurance horse that covers many miles in those few hours, the effect can make a significant difference.

To avoid this fluid shift, simply avoid feeding large meals only at vet checks---help your horse be a "nibbler" instead of a "feast-eater" during endurance rides. The same amount of food, fed in small, frequent meals every hour or two---instead of intermittent feasts--- avoids these fluid shifts entirely, and yet still provides the same total nutrition. Make an effort to provide small amounts of food in between vet checks---a baggie of hay or grain in a cantle bag, or a few minutes of grazing along the trail. If you know you will be doing some footwork in the next few miles out of a vet check, carry along a thin flake of hay and hand it out as you jog along. Practicing eating along the trail at home will make it easier for your horse to do so during a ride---and there are few tricks your horse will learn faster than that you want him to eat along the trail! Although opportunity differs for every rider depending on the goals for the day, the point is to examine your riding plan and make an effort to provide small, frequent meals whenever possible, avoiding the intermittent feast. Those few extra minutes spent along the trail will be worth the effort in metabolic health and performance.

The rule of "small and frequent" also applies to anything provided in an oral syringe. While fluid shifts are not as large or dramatic, any concentrated source of salt or sugar draws fluid inward until the diluted solution is reabsorbed into the bloodstream a relatively short time later. To minimize the effect, any oral syringing should be broken up into smaller doses---better eight 2-ounce doses than two eight-ounce doses! Make every effort to only syringe after the horse has already had a drink (preferably immediately afterwards), as the less dilution required from plasma volume, the better. Not only will plasma volume be spared, but also absorption of the electrolytes into the system will be more efficient and thus more available during exercise. Pre-loading electrolytes several hours before the start and throughout the day not only avoids progressive electrolyte depletion, but also triggers a complex endocrine response in the kidneys and central nervous system to encourage early drinking. Once absorbed, the body does not store excess electrolytes, so pre-loading should be limited to the night before and several hours before the start. Pre-loading for days and days before a ride does no harm, but is simply a waste, as the kidneys have long since flushed the excess out in the urine as soon as current needs have been met. While salt does trigger a thirst response, and can be used to encourage drinking during a ride, the response is not an immediate one. Use this as an early strategy to maintain a metabolic edge throughout the day---if you wait until the horse is already dehydrated and in a crisis state, the best you can hope for is damage control. Recognize the difference between a horse that is not drinking because he doesn`t like what is being offered, and one in a metabolic emergency. In many instances, all the horse may need is a few extra minutes to recover, eat some green grass, hay or mash, and then will drink normally. If the horse is not drinking when you know he should be, is uninterested in food, recovering poorly, acts dull or colicky, or is otherwise exhibiting signs of exhausted horse syndrome, do not attempt to magically fix the situation with a large oral dose of electrolytes alone. At this point, it`s entirely possible to make the situation worse instead of better. Realize that the horse is in a crisis and seek veterinary help immediately---although correcting the electrolyte imbalance is an immediate priority, administration with fluids via intravenous or nasogastric tube into the stomach, rather than oral syringing, may be required to prevent further deterioration of the situation.

Although not as prevalent as in past years, it is still common to see endurance horses being fed rations which are well in excess of protein requirements, especially in the West, where good alfalfa is cheap and plentiful. While many horses have and do compete successfully on high-alfalfa rations, this too has an effect on hydration status and should be a consideration in your metabolic strategy plan. Horses that compete well on high-alfalfa rations are most likely doing well in spite of the high dietary protein, not because of it---undoubtedly a testament to the many other management, conditioning and riding factors that a smart owner puts into a successful ride. For every horse that wins a ride while consuming a high-alfalfa ration, there are undoubtedly many others that could have finished, placed higher, or earned better vet scores by simply decreasing the dietary protein consumed. This conclusion is supported by Dr. Sarah Ralston`s work at Rutgers University, which suggests the incidence of metabolic pulls increase as dietary protein levels significantly exceed requirements.

Mature performance horses only require 8-10% crude protein in their diet, and these needs do not significantly increase with the demands of endurance conditioning. Good-quality grass hay or pasture easily provides these protein requirements regardless of the level of performance. If you are in doubt about the quality of forage, a few pounds of a 12-14% grain mix from a reputable company ensures adequate protein without supplying excess. Supplying "extra" in the form of alfalfa or high-protein supplements, such as Calf-Manna, to "support muscle development", is neither required nor beneficial.

A high protein ration`s effect on hydration is based upon its inherent nitrogen content. Once protein requirements have been met, the body utilizes excess protein for energy production. The amino acid molecule is snipped apart and the carbon backbone sent into energy-producing pathways, while the remaining nitrogen atom is discarded. Nitrogen is first degraded to ammonia and then to urea, which is subsequently filtered out by the kidneys and excreted in the urine. Both ammonia and urea are toxic substances, therefore urine production to remove them from circulation takes priority over water conserving responses during exercise. The net effect is that horses consuming high-protein rations have increased urine production and higher water requirements simply to clear the body of an avoidable waste product. In horses living in box stalls (not uncommon in highly developed urban areas), the increased ammonia and urine production can lead to greater incidence of upper respiratory irritation, as well as poorer hoof wall and sole quality. During a ride, when water intake may already not be enough to keep up with loss, the additional loss of water through increased urination is an added contribution to potential dehydration.

While excess protein does contribute to energy production, the pathway is a relatively inefficient one, as protein metabolism produces 3-6 times more waste heat than does the utilization of an equivalent amount of carbohydrates or fat. In cold climates, this heat production from excess protein can be used to help maintain body temperature, especially during the off-season. However, during hot weather and prolonged exercise, this excess heat must be removed from the body via the same cooling mechanisms as heat from exercising muscles---sweat production and respiration. During intense exercise in hot or humid conditions, the net effect is a greater heat load to dissipate, increased fluid and electrolyte losses, and yet another contributing factor to potential dehydration. Does this mean you should not feed alfalfa at all during endurance rides? Not necessarily. Alfalfa contains high levels of both calcium and potassium, and small amounts throughout a ride can help offset electrolyte deficits. However, a few pounds at vet checks are sufficient, especially if you are otherwise providing electrolyte supplementation, and more alfalfa is not necessarily better! If your horse is being picky at a stop, and refuses anything but alfalfa at vet checks, better to let him eat more alfalfa than he really needs than to not eat anything at all. Ideally, however, provide limited amounts of alfalfa, while offering other lower protein feeds such as grass hay, beet pulp or grain-based mash. At home (if alfalfa is fed at all), limit intake to 25% of the forage ration, and never more than 50%. Again, while many horses continue to compete successfully on high-alfalfa rations, its effects on hydration status should be a consideration in your management plan.

To summarize the main strategies included in this article:

# Maximize forage intake for several days before the ride, including the use of "super fibers", such as beet pulp.
# Pre-load with electrolytes the night before and several hours prior to the start.
# Provide small, frequent meals every hour or two along the trail by carrying along a few pounds of feed, or by intermittent grazing.
# Anything provided in a syringe should be provided in small doses at frequent intervals, preferably after a drink.
# Provide a ration adequate, but not excessive, in dietary protein by limiting alfalfa and other high protein feeds.

Beating the Metabolic Pull. Part III - Energy Balance - Susan Garlinghouse

In this final article in the series, we`ll discuss the possible ways to increase energy during a ride without jeopardizing the overall health of the horse. At the risk of becoming tiresome, remember the order of priorities in protecting metabolic integrity--- hydration, gut motility; and only then, look to increase energy balance. Luckily, these issues are often so closely interrelated that attending to one issue often benefits all three.

Before discussing specific strategies, it`s helpful to have a brief review of the energy substrates available to endurance horses (or any other equine athlete). There are essentially three "fuels" utilized during exercise; phosphocreatine, glucose and fats. All three function via different pathways to produce the same end product, adenosine triphosphate (ATP), the actual energy source that drives muscular contraction.

Of these three fuels, phosphocreatine is of the least importance to the endurance horse, and only worthy of brief mention. Think of PC as the "starter fuel" in the muscle cell---it is what will provide immediate energy for the first few seconds of exercise, until other fuel sources arrive in greater quantities for long-term exercise demands.

Glucose is intermediate in both its supply and speed of response during exercise. When molecules of readily-available glucose are stored in plant material, it is referred to as starch, and when stored in the animal body, as glycogen. Because the storage of glycogen in the body requires both water and space, relatively little is stored in the body. Fats, on the other hand, are far more efficiently stored and so can be accumulated almost without limit (as some of us have discovered after the holidays). The advantage of utilizing glucose as an energy source is that it is more quickly available than are fats, and while it is most efficiently metabolized in the presence of oxygen, it does not require oxygen to produce energy. During intense exercise, the cardiovascular system of heart and lungs may be unable to supply sufficient oxygen to individual muscle cells. Under those circumstances, energy can continue to be produced for a short period by utilizing those pathways that do not require oxygen. These pathways are referred to as anaerobic, and utilizing them during exercise is referred to as passing an anaerobic threshold. Utilizing these pathways results in the accumulation of the metabolic by-product lactic acid, and thus, the "burn" felt in overworked muscles. This pathway is not meant for long-term exercise, as the accumulation of lactic acid and rapid depletion of cellular glucose stores quickly contributes to muscular fatigue. Therefore, the primary advantage to glucose as an energy source is its versatility in either the presence or absence of oxygen, and its speed in being quickly available on demand.

Fats are the fuel of greatest importance to the endurance athlete. While their utilization absolutely requires the presence of oxygen, and is not as quickly available as glucose or phosphocreatine, its supply within the body is almost unlimited in any horse in reasonable body condition. It has been calculated that the average 1100 pound horse has only 45 calories available within body stores in the form of phosphocreatine; approximately 18,000 calories available in the form of glycogen; and approximately 153,000 in the form of fats. When you consider that an average horse carrying a lightweight rider will utilize more than 19,000 calories during a flat fifty-mile ride at an average speed of 8 mph, it becomes apparent that body stores of glycogen alone are insufficient to fuel the exercise demands of the day.

The disadvantages of fats as a fuel source are that they absolutely require the ongoing presence of oxygen within the cells to produce energy, and they are the slowest of the three sources to become available after the onset of exercise. A third feature, which may at times become a distinct disadvantage, is that while glycogen may be utilized by itself without any other substrate, fats require a small but critical amount of glycogen to produce energy---hence the saying, "fats burn on the flame of glycogen". To use an old analogy---think of glycogen as a smallish pile of fast-burning kindling, and fats as heavy, thick logs. While the logs will supply far more total heat, they cannot burn well without kindling. On the other hand, while kindling will burn rapidly and well, its relatively small supply will soon run out, leaving you without the wherewithal to burn the logs. Therefore, the key element in energy management is to rely on fats as the primary fuel source, and to conserve the limited supply of glycogen for "kindling" and for carefully planned spurts of anaerobic activity which may be necessary to reach your riding goals for the day.

Complex system that it is, the body is well adapted to utilizing the fuel most suited to the exercise at hand. At rest and during moderate exercise, with plenty of oxygen available, the body will utilize primarily fats, the fuel in greatest supply, with just enough glycogen being used as kindling to produce energy at its highest efficiency. As the intensity of exercise increases, as during a tough hill climb or a prolonged sprint, oxygen supplies may become insufficient and energy utilization shifts from the oxygen-using pathways, to those which do not require oxygen. Fats are utilized less and less, while glycogen becomes more and more important---so that at maximum intensity, the reliance on glycogen is approaching 100%. At this intensity of exercise, glycogen stores are rapidly depleted, and the accumulation of lactic acid greatly increased. As complete glycogen repletion may take several days, as well as the complete removal of accumulated lactic acid, an extreme exercise bout of this intensity is best left for either the flat-track racehorses, or if necessary, at the very end of an endurance ride. Once the system is pushed to this level of exhaustion, you had better be close to packing it in for the day!

Given the energetics of endurance horse metabolism, how do we put this to use during the riding season? One of the first ways is to utilize a high-fat diet. Although still the subject of research and heated debate, studies in exercising horses have demonstrated several clear metabolic benefits for endurance horses. Its most obvious benefit is that fats are the most concentrated source of calories available, and therefore of the most use in adding calories to an existing ration. Up to several cups of any type of good-quality vegetable oil (with the exception of linseed), or crystallized fat supplements such as FatPak, provide enough additional calories for most horses to maintain a good body condition.

Fats in the diet also have the benefit of decreasing heat production during digestion, thus lowering the heat which must be dissipated through sweat production by as much as 14%. Remember that proteins produce from 3-6 times the amount of metabolic waste heat as do carbohydrates or fats. By supplying calories in the form of fat, instead of protein, the amount of metabolic heat that must be dissipated is decreased, thereby helping to product hydration throughout the day.

A further benefit is that horses adapted to a high-fat ration over an eleven week period (and it appears to take this long to reap the full effect) demonstrate a glycogen-sparing effect. Essentially, the body becomes more efficient at utilizing the fuel source in greatest supply (fats), and therefore is able to conserve the fuel supply most likely to run out (glucose). By doing so, horses under laboratory conditions were able to exercise for a longer period of time at a lower heart rate, with less lactic acid accumulation, than did horses maintained on a strictly high-grain or high-protein ration.

Does this mean that fats should be fed during an endurance ride? Common sense would say yes, but in reality, the answer is no. Remember that a horse in good body condition---ribs easily felt but not seen, and without jutting hip or pinbones---already has a plentiful supply of body fats onboard to fuel the day`s work, even during 100-mile or multi-day rides. Remember also from lprevious discussions in this series that protecting gut motility is a higher priority than is energy balance, and providing bulkier feeds will maintain blood flow to the gut far better than will fats. Therefore, while adapting horses to a high fat ration between rides is an excellent strategy, withdraw the fats the night before in order to encourage forage intake. Utilize rice bran (which has a 20% fat content) as a condiment in mashes to increase palatability, rather than the majority of the meal. After the ride is over, return to including fats in the regular ration. Skipping fats for a few days during a multi-day will not put you back at ground zero in that eleven week adaptation period---simply start the fats again once you arrive back home.

Bottom line---strategies to maintain energy during a ride should be aimed towards protecting and maintaining an ample supply of glycogen, the kindling to burn all those available fats. At the risk of sounding preachy, one of the most obvious elements of your plan is to arrive with a well-conditioned horse. A large part of the physiological response to conditioning is the increase in efficiency of the muscular and cardiovascular system--- not only at delivering oxygen, but also storing glycogen and removing waste products. A horse with borderline conditioning is much more likely to slip over the anaerobic threshold, and use up available glycogen much more quickly than if he were truly fit for the job at hand.

In order to help protect glycogen stores, the first strategy is to start with a full load onboard. "Glycogen loading" has been explored and utilized in human marathon athletes, but seems to be relatively ineffective (and at times, risky) in horses, possibly because they are already evolved to store relatively large amounts of glycogen in muscle and liver tissue, compared to the inferior human athlete. Simply making sure that the glycogen stores are full, without attempting to overfill, is more than adequate. This can be done by slightly increasing the grain ration several days before the ride---an extra two or three pounds spread over several days is sufficient. If your horse is already consuming significant quantities of grain as part of his regular diet, then adding more is probably unnecessary. Decreasing the intensity of exercise for a day or two before the ride, as normally happens anyway, is enough. If it is part of your normal routine to go for a short ride after arriving at base camp, you can certainly continue to do so, but now is not the time to go haring off across the wilderness in a five mile sprint. An easy ride to loosen muscles will keep the glycogen stores where they belong in preparation for tomorrow.

Offering one more moderate meal of grain the evening before the start, along with plenty of free-choice hay and ideally, soaked beet pulp, will "top up" the onboard glycogen stores. Again, just a pound or two of grain will suffice---in order to protect hydration and motility first, the consumption of plenty of hay during the night will do more to produce a successful ride than will "just a little extra" grain.

Many riders are in the habit of providing a grain meal to their horses first thing in the morning, in order to have "plenty of energy during the day". Remember that wheat bran counts more as a grain than as a forage, although less so than do oats, corn or barley. The theory in feeding "breakfast" is that by maintaining high plasma glucose levels, glycogen stores will be spared for use later in the day. Again, common sense would say this is a good thing to do, but in reality, grain in the morning works against the production of energy. The starch content within grain is quickly broken down to simple sugars in the small intestine prior to absorption. As blood glucose rises, insulin is released from the pancreas to regulate and move the glucose into storage. The steeper the rise in glucose, the greater the insulin release and the more quickly glucose is moved from circulation and into storage. Plasma glucose levels quickly drop, not only back to baseline, but below previous levels. The net effect is that for several hours after a grain meal of several pounds or more, plasma glucose levels will quickly spike, and then decrease sharply, making glucose relatively unavailable as a fuel source until the system stabilizes. This phenomenon is called the hypoglycemic rebound effect.

At the same time, high plasma glucose and insulin levels have the effect of decreasing fat utilization, so that not only is glucose relatively unavailable, but so are fats. The result is a decrease in endurance and speed for several hours, directly opposite to the desired effect. By feeding the last grain meal no sooner than four to five hours before exercise begins, you are giving the body a chance to digest, absorb and stabilize glucose and insulin levels well before exercise demands begin. Not only will glucose be available in ample quantities, but so will fats very soon thereafter. Remember that excitement releases adrenaline, and adrenaline releases glucose. Most endurance horses will have no trouble whatsoever generating sufficient glucose during the first loop!

Can this hypoglycemic rebound effect occur during the ride as well? Absolutely. Research has indicated that any grain-based meal of several pounds or more, whether the grain consists of corn, barley, oats or sweet feed, has the same effect. Remember also from previous articles that large meals, spaced more than a few hours apart, also has a detrimental effect on fluid balance---a second reason to avoid large, sporadically spaced meals during ride day.

To avoid these effects, remember the rule of small and frequent---rather than grain only at vet checks, carry a small baggie or two of grain between vet checks to offer every hour or so. This not only will avoid swings in insulin and fluid balance, but will also provide a small, steady source of glucose throughout the day without decreasing the utilization of fats. The net effect is increased energy and better performance without jeopardizing the overall metabolic health of the horse. Remember that providing bulk as well throughout the day is the higher priority in maintaining hydration and motility, so include fresh green grass, hay or soaked beet pulp mash as well throughout the day as your ride plan allows.

A recent and controversial innovation is the use of carbohydrate supplements that can be syringed at intervals during a ride as a replacement or supplement for grain. To date, no published research studies have thoroughly investigated its use or effects on the endurance horse, and the only existing information is anecdotal. The theory behind its use is the same as that for grain, and the same caveats apply. Too much of any carbohydrate source at any one time can cause fluid shifts, hypoglycemic rebound, as well as the potential for colic or laminitis if greatly overused in a metabolically stressed horse. Poor results are by far most likely to result if carbohydrates are used as a replacement for proper and long-term conditioning, or in an effort to obtain performance beyond the current capabilities of the horse. Carbohydrates of any type will not only will not turn an exhausted, dehydrated horse into a winner, it can potentially turn a possible completion into a metabolic disaster if every other detail discussed in this series hasn`t first been seen to. Those who have done their conditioning homework and use carbohydrates thoughtfully in conjunction with a realistic and sensible ride plan, are by far to be most likely to garner a demonstrable benefit as "icing on the cake" without risk to the metabolic whole.

To summarize the main strategies in this article:

# Remember that glycogen is the fuel in shortest supply, and plan your ride strategy to conserve glycogen, staying primarily below the anaerobic threshold, while relying on fats as the primary fuel.
# Maintain your horse on a high-fat ration in between rides, but avoid feeding fats on ride day.
# Provide a "full tank" of glycogen by increasing the grain ration slightly for several days before the ride, with the last meal being no closer than 4-5 hours before the start.
# Provide small, frequent amounts of grain along the trail every hour or two, avoiding large, sporadic meals, along with bulkier forages.
# If used at all, utilize carbohydrate supplements as "icing on the cake", never as a replacement for doing your homework.

Beating the Metabolic Pull. Part II - Gut Motility - Susan Garlinghouse

Reprinted from Endurance News, July 2000
Susan Garlinghouse, MS

In the second article of this series, factors affecting gut motility and how they help maintain metabolic integrity will be discussed. Remember that last month`s article introduced a list of priorities in avoiding a metabolic crisis during an endurance ride---first, pay attention to hydration; second, to gut motility, a very closely related issue; and as a distant third, attend to maintaining energy balance. Maintaining the first two factors exerts such a positive effect on the metabolic whole that overall performance and recovery will be improved even before energy balance is addressed. Later strategies to increase energy throughout the ride then become icing on the cake, while still maintaining strong metabolic scores during vet checks.

The term "gut motility" refers to the normal sounds of digestion audible via stethoscope through the abdominal wall, and provides a good indication of the stress level being experienced by the horse. Under normal circumstances, the gastrointestinal tract of the horse generally maintains a slow, constant churning (or peristalsis) as food is digested and moves through the system. Horses and other herbivores evolved to a diet of forages maintain this churning action not only after a meal, but continuously over hours and days as the high fiber portions are fermented and slowly broken down and absorbed into the bloodstream. Control of the digestive process is maintained by circulating hormones, and is subject to a priority system when the body is under stress, as during strenous exercise. As the exertion level increases beyond that which is easily maintained, the body assumes that the animal is under attack and is fleeing for its life---physiologically, it does not make the distinction between a life-threatening emergency and simply a prolonged, over-enthusiastic gallop. Complex hormonal signals adjust the distribution of blood flow to maximally support the cardiovascular and muscular systems to continue its "escape"; maintain support to the vital organs such as heart and brain; and temporarily diverts blood flow away from those systems uninvolved in the "fight or flight" response, such as the digestive tract. As a result, blood flow to the hind gut gradually decreases as stress and the intensity of exercise increases, and motility concurrently slows or stops. If motility is decreased for long enough, colic eventually results as gas and fluids begin to accumulate, causing distention and pain. Although there are many causes of colic, slow gut sounds at a vet check are almost always related to decreased blood flow to the intestinal tract, which in turn is almost always related to the body being pushed beyond it current capacity and into a state of physiological emergency.

Remember from the previous article that dehydration has a profound effect on efficiency of the cardiovascular system. As plasma volume decreases, blood thickens and becomes less fluid, requiring the heart to work harder to transport oxygen and other resources throughout the body. Likewise, as plasma electrolyte supplies become depleted, the efficiency of cellular function, including muscle, also decreases. The net result is that a dehydrated horse`s body more readily goes into a physiological state of emergency, diverting blood flow away from the digestive tract, than does one that is fully hydrated. A vicious cycle is created in that dehydration and electrolyte imbalance directly causes a decrease in intestinal motility, while the loss in motility impairs the horse`s ability to absorb the fluid and electrolytes needed to correct the situation. A critical point to understand that even though a ride`s terrain, temperature and speed may not differ greatly from training rides at home, minor variations in conditions can cause a cascade of physiological effects that have a significant impact on the metabolic well-being of the horse. Never make the mistake of thinking that because your horse easily exercises at a certain speed at home without turning a hair, that he will automatically do just as well at that speed during competition. He might, but then he might not! Sometimes even such minor details as level of excitement (of both horse and rider) can affect the body`s response to fatigue and stress. Especially in relatively inexperienced endurance horses, continually assess your horse and adjust to meet the change.

As with many other issues in endurance riding, there are many shades of gray in determining the degree of metabolic trouble. Few riders take the time to check gut sounds out on the trail, but carrying a stethoscope just in case is always a good idea. Changes in attitude, lack of interest in eating or drinking and signs of dehydration warrant a quick check in all four quadrants on both sides. While fully accurate interpretation of gut sounds is not easily learned without veterinary training, simply being familiar with your horse`s normal frequency and characteristics will help you identify brewing trouble out on the trail if a veterinarian is not readily available.

What to do if faced with potential colic either at or between vet checks? Recognize that poor gut sounds are an indication that the horse is exercising beyond his current capacity, creating a progressive state of physiological stress. If you are out on the trail and moving towards a vet check, the obvious first answer is to slow down. Decreasing the demand on the cardiovascular and muscular systems will allow the body to recover and reduce the emergency status it is responding to. As the body moves back towards recovery, blood diversion away from the digestive tract will eventually begin to reverse itself and intestinal activity will improve as blood flow returns. Helping the horse to recover does not necessarily mean stopping entirely to rest. In fact, gut activity will be improved if you keep moving steadily. Research has indicated that blood flow to the digestive system, and therefore maximum efficiency of the digestive process, occurs when the horse is exercising at approximately 20% of his maximum aerobic capacity. For most fit horses carrying a rider, this is usually somewhere between a brisk walk and an easy jog. As an added bonus, continuing low-level exercise flushes waste products such as lactic acid from the muscles more efficiently than occurs at rest, so the entire body benefits and recovers more quickly, while still maintaining forward progress towards a check and veterinary help.

By adding bulk to a slow digestive tract, additional hormonal signals are released that move the digestive tract higher on the priority list in line for blood flow, thereby increasing intestinal activity. While the GI system `s demands will not displace those of the cardiovascular or muscular system during strenuous exercise, once the body recovers from emergency status, blood flow and motility will more rapidly return if feed is in the stomach. The bulkier the food item, the more the stomach walls are stretched, and the more motilin (a hormone which triggers peristalsis) is released. Therefore, whether at a check or out on the trail, encourage continuous eating, preferably of moist, bulky forages such as green grass, wet hay or soaked beet pulp. Avoid concentrates such as grain, which can exacerbate colic and laminitis if the problem persists beyond a temporary situation. Remember from last month that even before a crisis state is reached, allowing for small, frequent meals along the trail benefits hydration status as well. Since gut motility is so closely related to hydration, continuous nibbling along the trail therefore provide advantages in both areas.

It is a common misconception that wheat bran mashes possess laxative qualities to provide bulk and avoid impaction during endurance rides. They do---for the rider! Humans and horses have vastly different digestive systems and while bran (of any type) is poorly digested by the monogastric species such as humans, dogs and pigs, thereby providing bulk as it passes through the GI tract, this is not the case with herbivores, such as horse, cattle or sheep. Horses are able to easily digest the fiber in bran via microbial fermentation in the cecum and large colon, and thus little or no additional bulk is produced to promote motility. Clinical research has demonstrated that horses fed almost 50% of their total ration in the form of wheat bran did not produce greater quantities of fecal material, or produce feces of greater moisture content. So while sloppy bran mashes are an acceptable feed at rides, and a good way to introduce electrolytes, additional moisture and other feeds during a stop, they should be viewed as a grain product, not as a significant source of fiber to promote motility.

In the interest of providing feed with maximum bulk to promote motility, pay attention to particle size of ride-day forages. Remember that motility factors are triggered as the result of stretching stomach walls, and that maximum stretch yields maximum motility. A pound of long-stem hay yields the same total nutrition as a pound of pelleted hay, but the volume of long-stem hay is significantly greater and therefore it`s potential ability to stretch stomach walls, even after chewing. Even if you normally feed pelleted hay at home (and it is recommended that at least 50% of the hay ration be in the form of pasture or long-stem hay to maintain gut integrity), always provide long-stem hay at rides. Due to the relatively slow digestive process of horses, always provide plenty of hay for several days before the ride, including free-choice hay throughout the night before. If you provide wet mashes at stops, consider soaked beet pulp mashes instead of wheat bran. Beet pulp absorbs tremendous amounts of water during soaking and provides significant moisture as well as bulk. Additional grain products such as wheat bran, sweet feed or other concoctions can be added to increase palatability and provide additional energy.

Although added fat as an energy source seems like a good common-sense idea during rides, you`re probably better off not providing significant fats on ride day. Fats do indeed provide the primary source of energy during endurance exercise, but if the horse is in reasonable body condition---fit and muscular without staring ribs or hipbones---then he already has sufficient body fats on board to provide sufficient fatty acids throughout the day. Adding additional fats during the ride, therefore, is providing a fuel source already in good supply, at the expense of attending to other critical issues. Because fat is such a concentrated energy source, a meal high in fats tends to decrease total intake, thereby decreasing the total bulk needed to maintain gut motility. For this reason, vegetable oil should not be added to ride-day mashes, and any added rice bran to increase palatability should be provided as a condiment, rather than the majority of the meal. Focus on green grass, long-stem hay and well-soaked beet pulp to provide bulk throughout the day, with additional grain sources to provide energy only if motility is being maintained.

To summarize the main strategies in this article:

Recognize that poor motility is an indication of blood flow diversion away from the digestive tract as the result of stress, and reduce the intensity of exercise to allow blood flow to return. Maximum blood flow to the GI tract occurs at approximately 20% of maximum aerobic capacity. Remember the strong relationship between hydration and motility, and maintain the latter by protecting the former. Move the GI tract higher on the blood flow priority list by adding bulk to the stomach to trigger release of endocrine motility factors and promote peristalsis. Utilize long-stem hays, green grass and soaked beet pulp rather than wheat bran or high-fat feeds to maintain intestinal activity.

Steph and Khruschev`s 2000 WEC Experience - Steph Teeter

Khruschev and I were part of the 2000 World Endurance Championship event, representing the US in Compiegne, France. Two years of focus and preparation, all for ONE ride! I enjoyed every minute of the process and have no regrets, only thanks - to friends and family that helped along the way, and tolerated the obsession without complaint. Our story isn`t one of glory or tremendous success, but of persistance and teamwork. We didn`t do the race I had hoped for and trained for, but we had an amazing ride - the USET support staff gave 100% and was first class. We finished 32nd out of 150 starters - respectable, but not reflective of Khruschev`s ability and level of training. But this story is not about placement, it is about teamwork, and about finishing. My crew - my friends and family - were unbelievable, I can never thank them enough, and we couldn`t have done it without them. And Khruschev is a one-in-a-million horse.

As I write this, I`m flying over the Pacific Ocean, headed home. Khruschev is also in the air, on a different plane. I wonder if he`s thinking about the past few weeks, replaying the events, re-riding the course. Horse memories. Most likely he`s just munching his hay, exchanging occasional reassurances with his travelling buddies, Sam and Ramsz, and thinking about his next meal. The `here and now` of being a horse.

We had our share of challenges during the past few weeks. None of the challenges we faced were what we had trained for, what we had anticipated. But Every one of the challenges taught me some valuable lessons - stay flexible, stay tough, trust your horse (he will always give you everything he has), count on your family and true friends (they will always be there for you) and never ever give up. It ain`t over `till it`s over!

Khruschev caught a nasty cold while being shipped to California and developed a persistent cough. With the help of Nancy Elliot (USET team vet) and the constant support and concern of the friends I made during our stay he got through it. He was back to normal and the cough finally subsided in time for shipping. Hang in there. Then the trail gave out from under us during a training ride in the steep hills of coastal California. Khruschev slid down the ravine while I managed to bail off over his head. He waited for me at the bottom, and beyond odds managed to scramble and lunge back up the wash and onto the trail. His left hind and left front legs were bloody but there was no serious damage. The timing wasn`t too good though - USET was doing a final soundness evaluation the following day, only sound horses would be shipped over seas. The next day his hind leg was bruised and hot to the touch where he had scraped it. He was trotted straight out of his pen without a warm up - perfectly sound, out, back, circles left, circles right. Hang in there ... we`re still in the game.

We arrived in France on Saturday and settled in at the stables north of Compiegne. Beautiful old barn tucked in the Compiegne Forest, full of gorgeous Celle Francais and Spanish Warmblood horses, and friendly and helpful folks. We spent the first few days hand walking the horses, settling into a routine, grazing them in the field out back. There were paddocks available for turn-out, but the ground was wet and soggy from the unseasonal rains and we were afraid of what it would do to their feet going from dry to wet in such a short time so we tried to limit their time outside. The long days confined to stalls were hard on some of the horses. Khruschev is pretty much `ok` wherever he is though - just keeps eating and drinking and being a horse. But there was trouble brewing with his feet. We had our first formal trot-out evaluation on Tuesday (Aug9). The first few steps he took were off. My heart sank, and you could hear a pin drop. Uh oh. (Hang in there)The next 17 days were a constant emotional roller coaster. We pulled his shoes the next day, his feet had become extremely soft from time in the soggy pasture, the soles had turned crumbly, he had a deep corn in the left inside heel, a bruise near the toe. Both feet seemed sore, but he was most uncomfortable with the left front. Nancy pared the feet down and dug out the corn which was starting to abcess. She packed his feet and we gave him 24 hours with his feet packed and wrapped. Our farriers weren`t due to arrive for another 10 days. Darolyn and Cowboy said the Brazilians were somewhere in Compiegne with their farrier so the search began. The following evening we took the packing off of his feet and the Brazilian farrier trimmed them (btw - the Brazilians were great!!) - Cowboy had extra easyboots and we were thinking these could get us by until the farriers arrived. This plan backfired big time. The easyboots were not quite large enough and we had to really crank to get them on - the result was that the next day Khruschev was lamer, sorer than before. Now his heel bulbs were bruised and sore too! His feet had become so soft and sensitive that they bruised from the easyboot straps. I felt so bad for him - it was beginning to feel like the harder I tried, the worse it got. (hang in there)

By now John and Destry had arrived, and Susie and Lari were coming soon so I had plenty of moral support and also help keeping his feet iced, trying to ease the discomfort. everybody at the barn - riders, crew,support staff- was incredibly supportive and helpful.) The saga continued for the next two weeks, we tried three different shoings (thanks Ernie, Jaye, Brazilians) - one day he seemed better, the next day sore again. (hang in there) It was a fairly consitent pattern - the first few steps were the worst, but once he took more steps and warmed up he was better. He felt good when I rode him, but after he stood for a while, the first few steps were uncomfortable - better again once he warmed into it. We tried to keep a minimum level of fitness with longing and walking, but the best thing for him was rest and time (something that was running out).

Friday (Aug 25) arrived and all of the US horses were evaluated that morning for soundness before the official vetting in. Khruschev wasn`t perfect, but Rick gave me the ok to give it a try. So we presented to the officials - After the first trot-out there was some mumbling and head shaking and we were sent to another lane for further evaluation. Another trot - still some inconsistency. One more time .... about the same, but they gave us a thumbs up to start. The official smiled at me as we walked out - "maybe he`ll warm out of it - good luck Khruschev". It was a wonderful, friendly gesture. Hang in there.

We went back to the barn, I felt like we had been given a gift just being able to start, and yet another chance. And I knew that it wasn`t time to give up yet. I started looking for Jaye Perry (one of the USET team farriers), somehow hoping there was still something he could do to make Khruschev comfortable. Jaye was not to be found, but I was told he had left earlier in the day, searching for a farrier supply store. We spent the afternoon getting ready for the ride - John, Destry, Suzie, Lari and Carol worked non-stop preparing everything we would need for the ride. They kept the spirits high and acted like everything was going to be fine. I was the most dejected I had felt during the past two weeks. My wonderful horse was not himself, we might get through the first loop, at least we could start the race, but this was the 11th hour and I was running out of optimisim. Jaye showed up at the barn around 7pm that evening. I asked him if there was anything else he could do - any more rabbits to pull out of his hat? He smiled and said "where do you think I`ve been all this time?" Over an hour later Khruschev had his final (4th) shoing since we had arrived. We walked him around. Jaye looked satisfied and said just put him in his stall, he`ll be fine. Hang in there. I didn`t even trot him out, had no idea if he would trot sound then, or even in the morning. But I couldn`t bring myself to find out at that point.

That night during dinner and into the next morning I felt incredibly calm - almost numb. During all the excitement of getting ready in the dark, the electricity and anticipation that others were feeling, I was calm and quiet. I had already received one `gift`, just being able to start and at least do the first 20 mile loop. Nothing more could be done now in preparation. My crew was totally prepared and I knew they would take care of everything. The only thing I had left to do was ride our best ride - mile by mile. I knew this was not the race we had trained for - our challenge was not the sand, the speed, the heat and humidity. I had to keep him sound and comfortable. We joined the other 150 riders in the warm up area - just climbing on his back I could feel the transormation in his attitude - he was ready for a race! But I still hadn`t trotted him! We walked for about 15 minutes and I finally mustered the courage to trot - perfect!! He felt solid and absolutely wonderful. As soon as the race started I could feel Khruschev go `yes! finally! now let`s go do our job!`. He flew out into the dark with the others, even threw in a few good bucks - it was exhillarating and very emotional.

My plan was to ride mile by mile constantly gauging our progress by his comfort level. Cruise when the footing was soft and take it easy on pavement and cobbles. I felt it was best to start cooling him down a mile from the vet check - have him pulsed down and ready to present as soon as we got there - no standing around, just keep him moving. We got to the first hold just as the other US riders were leaving. I had walked him in the last mile - trotting intermittently - he seemed great. He was down as soon as we got in, went right to the vet. John and Suzie took him and I lost them in the crowd - we had started, we had gone 20 miles, more than I had expected during the last 2 weeks. Would we do another loop??? Yes! He passed - CRI was 52/48 and he got an A on gait! Whoop and holler... and then down to business. Next task - loop 2. Let`s see if we can squeeze in 14 more miles.

And so it went.... all day long. Each loop was a gift. Each hold was a joyous occasion. Khruschev`s crew (John & Destry (my son) , Suzie Hayes, Lari Shea, Carol Andrews & Linda Voigt) was excellent - fast, efficient, encouraging, and Fun! They worked non-stop, feeding, icing Khruschev`s feet, preparing electrolytes, making sure I was eating and drinking and laughing. And Khruschev was the model horse to crew for - was pulsed down when he arrived, never stopped eating, drank well, allowed himself to be fussed over and was just plain ol` happy.

We rode steady all day. Fast trot and canter in the woods and soft trails, easy easy on the rocky stuff. It got incredibly humid during the afternoon - hot and stifling. We rode alone all day (after the first wild loop) and he never asked to quit. I slowed somewhat during the worst of the heat, but he handled it well. There were zillions of US volunteers out on the trail at the crew points. Friendly, willing, ready to do whatever we needed - pour water, give electrolytes, mash, whatever. It was a great boost to our spirits to have them out there.

The final hold was at Pierrefonds, with the castle looming in the background. It was magical for us. By then the only other US rider left was Connie, and she and Smoke were doing great. We only had a 30 minute hold (at 88 miles) and they had all the horses do an exit CRI. I was pretty anxious ... 12 miles to go, is he still ok? I was too anxious to eat much during the hold - but we still managed to spend the time laughing and having fun. Final CRI and trot out - 60/52 and A for gait - unbelievable!! We left the last hold with everybody hooting and hollering - a real boost for our spirits. The sun was setting as we rode through the Pierrefonde Castle - . , the stones and turrets were glowing orange from the sun, the windows reflecting the sunset. I imagined Khruschev in armor, and horses of another era..

One more loop - Khruschev felt incredibly strong and I was tempted to let him pick up the pace and to move up in our placing - many tired horses had left before us. But I played it safe - with only one other US completion, I felt that it was too great a risk to change our mode of caution. We rode the last 6 miles in the dark - trotting when we could, being extra cautious in the rocks, and steadily moving on. We reached the final pit crew area, one mile before the finish, and the enthusiasm and hollering as we left were more than we could resist. We flew in the last mile - and came to the finish in a huge extended trot - the stand was full of cheering spectators and as far as Khruschev knew, we had won! (I never told him otherwise.)

The human spirit is indomitable. After the Fort Howes ride in Montana this year, we were having breakfast, sharing the table with the joyful, dancing Canadians. One of them had just finished his first 100 miler, he finished last, just before cut-off time but from the look on his face that morning you knew for certain that he was a winner, his excitement and enthusiam were radiant and infectious. We were laughing about the trials of the trail, being out all night with the coyotes and he grinned - "well you know, AERC`s motto is `To finish is to Win` - I`m a winner, eh?- go motto!"

Steph Teeter