Nutrition
for Maximum Performance
HOW TO TAKE THE COURSE
Hello, and welcome to your online
course: Nutrition for Maximum Performance.
Your instructor for this course is Eleanor Richards.
You can reach her by e-mail at: elrichards@thewayofhorses.com
You are now on a special link which
allows you to view, save or download the lesson. At the end of the lesson you will take a
little quiz. You can complete the quiz
online and simply click “submit” to send your quiz to
your instructor.
To achieve the best results, read each
lesson at least twice. If you have a
specific question, or you don’t understand the material, contact your
instructor for clarification. Don’t let your
questions go unanswered; one of the advantages of online courses is that your
instructor can work with you one-on-one to be sure you understand the
information being presented.
This course does not require that you
work with a horse, but after reading some of the lesson, it is a good idea to
go out and observe a horse or horses and practice the techniques you are
learning—if that is possible. Try to see
the things being discussed, and how they work.
Observation is one of the greatest keys to success whether training,
trading, feeding, or examining for general health. Look and work with your horse and look at
other horses—but when watching them perform, see more than the surface—see the
movements, see the personality, see the strengths and weaknesses of each
individual. And then try to apply some
of the things you have just been reading to the horse with which you are
working. This is the best way to
reinforce your understanding and assure your success.
Your instructor will grade your quiz
and send an e-mail to you with comments and suggestions. You will not receive the link for the next
lesson until your instructor is satisfied you have mastered the preceding
lesson.
When you receive your next lesson
link, study that lesson just as you have the preceding lesson.
You may or may not be working toward a
Professional Designation in Horse Training, but when each course is completed,
you will receive a certificate of recognition.
All Success Is Easy course instructors are experts in their field. They are proud of their accomplishments and
their reputations, so they are demanding of you. They want to assure your success by making
certain you have as good an education as possible. They want to be as proud of you as you will
be of yourself.
When you receive your certificate or
Professional Designation you will know that you have the knowledge which
empowers success. You can be certain
that your work with horses will be of benefit both to the horses and to other
horsemen.
Nutrition
for Maximum Performance
By Eleanor Richards
Copyright © 2003
LESSON ONE
UNDERSTANDING THE EQUINE DIGESTIVE
SYSTEM
The equine digestive system is like a
disassembly plant. It takes feed
(forage, concentrates, supplements, water) and breaks them down into a form the
body can utilize.
There are two methods of
processing: mechanical and chemical. The
equipment used are the organs that make up the
digestive tract.
Mechanical processing starts
in the horse’s mouth as he uses his lips to sort and choose the desired
feed. While grazing he will use his
incisor teeth to bite off the grass. The
tongue then moves the material back to the molar teeth where it is chewed and swallowed. The stomach continues to break down food with
a churning action.
Chemical processing is present
through out the digestive tract. It
starts with the salvia in the horse’s mouth and ends in the large
intestine. Bacteria, enzymes, and other
substances are used to release the
nutrients needed by the horse.
Horses
are non-ruminant herbivores – they eat plants, but do not have a rumen. Animals with a rumen (cows, sheep, and goats)
swallow the feed directly into a fermentation vat, the rumen, where it is
broken down by bacteria. It is then
regurgitated and chewed again before being re-swallowed. But, horses are hindgut fermenters. The feed a horse eats goes through the
chemical and enzyme process before it is fermented in the hindgut. Horses do not chew a cud. This method of digestion is the reason horses
need plenty of good quality fiber.
The best way to learn about
the equine digestive system is to follow a meal, as it is broke down and
processed.
SALIVA
Once the horse has gathered
the food into his mouth he begins to chew.
The chewing action stimulates three pairs of salivary glands – the
parotid, the submaxillary, and the sublingual.
A horse will produce 5 to 10 gallons of saliva per day.
If a horse does not get enough
chew-time the feed is not moistened sufficiently. Senior horses or horses that bolt their feed
can have problems with the feed causing an obstruction in the esophagus
(choke).
TEETH
The teeth are very important
to the health of the horse. Many
nutrition problems start here, so an understanding of the healthy equine mouth
is important.
By the time a foal is a week
old he will have 4 incisor teeth – 2 on the top and 2 on the bottom, these will
be in the center. In another week the second
set of incisors will come in and by 6 months of age the corner incisors will be
in. Also, the pre-molars will be coming
in at about the age of 2 weeks. There
will be 6 pre-molars top and bottom. So, by the time the foal is 6 months of
age he will have all his baby teeth, a total of 24 teeth.
The baby teeth, or caps, will
start to shed by the age of 2 ˝ years.
The erupting permanent teeth will shove the caps out of the way. You may find them in the feed box. There are times when the caps will not be
pushed out and this can lead to problems.
An equine dentist or veterinarian will need to remove the cap, so the
permanent tooth will come in properly.
Most adult mares will have 36
teeth and males can have 38 to 40. The
extra teeth males have are called canine teeth.
Mares do not usually get them and if they do they will be very
small. Canine teeth will not erupt until
4 to 5 years of age.
A type of tooth that may cause
problems is a wolf tooth. They are found
in front of the molars. Wolf teeth do
not serve any purpose. They may
interfere with the bit. Many equine
dentists and veterinarians re-commend they be removed. They have short roots and are easily
extracted. Wolf teeth usually erupt
between the age of 12 and 18 months.
The upper jaw is wider than
the lower jaw and at rest the back teeth do not meet. As a horse chews his lower jaw moves side to
side and this action causes the teeth to grind together. This grinding action causes the teeth to wear
away. Below the surface of the gum-line
is almost 4 inches of tooth, which erupts continuously as the exposed surface
wears away. So, by the time a horse is
in his twenties the amount of tooth left to erupt is a lot less than a horse
that is 4 years old.
Routine dental examination is
important to how well a horse will utilize his feed. If all works well the teeth will wear away
evenly, but that is rarely the case.
Malocclusion, a term used to describe when teeth do not meet properly
can occur.
Overtime, points (sharp edges)
can develop on the inside of the lower teeth and the outside of the upper
teeth. These sharp edges inhibit the
side-to-side movement of the lower jaw and 
soon the horse has lost the full range
of the chewing action. These points are
also very sharp and can lacerate the inside of the mouth and side of the
tongue. Horses will pack material
between the teeth and cheek to try to pad the sore area. An equine dentist or veterinarian will
“float” or file off these points. This
procedure does not hurt, because the adult equine tooth does not have nerves or
blood supply.
A missing tooth can also cause
problems. The corresponding tooth
continues to erupt, but is not being wore off. Soon it is sticking above the
rest of the arcade of teeth and the horse cannot chew properly. This tooth will
need to be filed on a regular basis to prevent malocclusion.
The type of feed the horse
eats will also affect the wear of his teeth.
A horse that has a diet of only pellets or complete feed without any
long stem fiber will have uneven wear of teeth. A horse that eats this type of diet or only
hay will also develop long incisors.
Because he is not nipping grass off with his incisors they can become
long, which prevents the molars from grinding the feed properly.
Malocclusion can also be a
genetic problem. Horses with inherited
tooth problems will need to be monitored regularly and offered feed they can
utilize.
Once the food has been chewed
and softened with salvia the horse swallows.
ESOPHAGUS
The esophagus is a muscular tube that
leads to the stomach. The length is
about 50 inches for an average sized horse.
Choke, an obstruction of the
esophagus, is a feed related concern. A
horse that bolts his grain or does not have enough salvia to soften the feed
can get the dry material stuck in his esophagus. Also, a horse that has tried to swallow a
corncob or other large object can develop this problem. As the horse continues to eat the feed cannot
pass by the obstruction and the material builds up in the esophageal tube.
The symptoms of a horse choking are frequent attempts to swallow,
stretching out of the neck, excessive salivation, and feed material mixed with
saliva coming out of the nose. A veterinarian
should be called immediately as severe damage to the esophagus can result. Unlike humans, horses can still breathe while
choking, but immediate care is still needed.
Choke can be avoided. A horse
that bolts his feed should have several large rocks placed in his feeder. He
will need to move them around to eat his ration. A horse that has an inflamed
esophagus or does not have enough moisture to break down the feed should be
provided with a feed that can be pre-soaked.
This will aid in the passage of the feed to the stomach. Soaking the feed should also be done for
seniors or horses that have tooth problems which result in them not being able
to chew properly. Avoid feeding horses large pieces of apples, carrots, cubes, and other
items.
A unique feature of the equine esophagus is
the very strong cardiac sphincter valve.
This valve is located where the esophagus joins the stomach and prevents
food from being regurgitated. It also prevents horses from burping. The horse’s stomach will usually rupture
before this valve allows the material to be regurgitated. This results in death and is why feed must be
of the quality and quantity the horse can handle.
STOMACH
The stomach of the horse is
very small in relationship to the size of the horse. It only makes up 8-10% of the capacity of the
digestive system. The average horse’s
stomach will only hold about 4 ˝ gallons and is about the size of a football. The stomach breaks food down mechanically
and chemically.
There are four sections to the
equine stomach: the esophageal section, the cardiac section, the fundic
section, and the pyloric section. The
oesophageal is basically a storage area and no digestive action takes place
here. The cardiac section produces
mucous used to coat the stomach and protect it from acidic secretions. The pyloric section produces pepsin enzymes,
gastric lipase enzymes, and hydrochloric acid.
The stomach has an overall low pH level, but the pyloric section is
highly acidic.
Most of the digestion, which
occurs in the stomach, takes place in the pyloric section. Pepsin breaks down protein into amino acids,
which can then be utilized by the horse.
The feed is also mixed with hydrochloric acid and bacteria that produces
lactic acid. These stomach secretions do not break down fiber, so very little
forage is digested in the stomach.
The muscles in the stomach
uses rhythmic contractions called peristalsis.
This mechanical action helps break down feed into smaller particles.
The design of the equine
stomach is such that a horse needs small frequent meals. It fills quickly and empties quickly. Feed usually only remains in the stomach for
about 20 minutes. Ulcers can result if
the stomach is allowed to become empty.
Feeding a horse too much grain
at one feeding causes the excess to be pushed into the small intestine before
the digestive juices have a chance to break it down. Colic will be the result.
The pyloric sphincter is
located where the stomach joins the small intestine. Once the meal is broken down the valve
relaxes and the feed passes through to the small intestine.
SMALL
INTESTINE
The small intestine is a tube that
measures about 70 feet in an average sized horse. Its capacity is approximately 15
gallons. Most of the nutrients from the
grain portion of the diet are absorbed in the small intestine.
The breakdown of these
nutrients relies on chemicals secreted by the pancreas, liver, and intestinal
mucosa. Pancreatic enzymes help digest
the feed. Because the horse has no
gallbladder, bile is constantly flowing in from the liver. Bile breaks down fat. The available nutrients are then absorbed
through the walls of the intestines.
Feed passes very quickly
through the small intestine. In as little
as an hour some types of feed will have moved through. However, it usually takes up to 8 hours for
most of the feed to reach the end of the small intestine. It is very important to the health of the
horse that soluble carbohydrates are absorbed in the small intestine. If they reach the large intestine
fermentation can occur which will result in gas and colic. To avoid overloading the small intestine
small frequent meals are strongly recommended.
Starch, complex sugars,
protein from the grain portion of the diet, fat, fat-soluble vitamins (A, D,
and E), and most minerals are absorbed in the small intestine. Protein from roughage, fiber, and phosphorus
is not digested well in the small intestine.
The small intestine consists
of three sections: the duodenum, the jejunum, and the ileum.
The duodenum prepares the food
for absorption by mixing it with enzymes and chemicals. Very little of the
nutrients are utilized here.
The jejunum is the longest
portion of the small intestine. Most of
the nutrients from the grain part of the diet are absorbed in the jejunum. Lining the inside of the intestinal wall are
tiny projections called villi. The villi
absorb the nutrients, which are now molecules and allow them to be utilized by
the horse.
The ileum is the last section
of the small intestine. The absorption
of water and water-soluble vitamins takes place here.
The insoluble carbohydrates
(fiber), any starch, or other material that was not utilized in the small
intestine now moves on to the large intestine.
LARGE
INTESTINE
The large intestine is 25 to
30 feet long in an average sized horse.
It has the largest capacity of the equine digestive system at
approximately 20 to 30 gallons. Feed
will remain in the large intestine for about 48 to 65 hours.
Digestion of insoluble
carbohydrates takes place in the large intestine. Protein from the fiber portion of the diet is
utilized. Phosphorus is absorbed. Any starch that was not digested in the small
intestine will be worked on by microbes – which can cause gas and colic. Some B vitamins and vitamin K will be
synthesized in the large intestine. (Definition of synthesis: the combining of
parts to form a whole.)
There are five sections that
make up the large intestine: the cecum, the large colon, the transverse colon,
the descending colon (small colon), and the rectum.
The cecum is a fermentation
vat. It has been described as a comma
shaped organ. The cecum is about 4 feet in length and has a normal capacity of
approximately 8 gallons. The size can
vary according to the quality of roughage being fed to the horse. The entrance and exit openings are both
located at the top of the cecum. This
can cause problems resulting in colic if the organ becomes compacted with
non-digested material. Most feed remains
in the cecum for about 7 hours.
Within the cecum are microbes
that aid in the digestion of cellulose, fiber, and any remaining soluble
carbohydrates. These microbes are
somewhat specific as to what they digest.
If a drastic feed change occurs the balance of the bacteria and protozoa
is disrupted and colic can result. Any
change of feed (concentrates or forage) must be made over a period of about 3
weeks, so the microbe population can adjust.
A horse that has a hay belly
is the result of an expanded cecum. Poor
quality fiber has accumulated in the cecum and can remain there for up to 72
hours. Switching to less mature hay will
be more beneficial to the horse and prevent a hay belly from developing.
The cecum then leads to the large colon.
The opening leading from the cecum to the large colon is about a 3-4 cm
hole. It is a prime spot for blockages
to occur.
The large colon is
approximately 20 feet long and is shaped like a horseshoe. Microbial digestion continues in the large
colon. Any remaining vitamins, fatty
acids, and water are absorbed.
The large colon is made up of
5 segments (listed in the order in which the feed travels): the right ventral
colon, the left ventral colon, the pelvic flexure, the left dorsal colon, and
the right dorsal colon. The large colon
folds back on itself several times and is held in
place by the bulk, which it contains. At
several points the colon narrows and blockages can occur in these narrow passageways.
The design of the large
intestine requires plenty of good quality forage
be available to the horse.
If the colon becomes empty the chances of it becoming twisted increases.
The remaining material then
travels through the transverse colon and into the descending colon (small
colon). The transverse colon is a very
narrow tube and another primary spot for blockages.
The descending colon uses
contractions (peristalsis) which results in fecal balls forming. Any remaining moisture is also extracted in
the small colon. It measures about 12
feet long and is very narrow at about 3-4 inches in diameter. The small colon is also free to move and can
become twisted.
The descending colon then
leads to the rectum. The rectum is a short
straight tube and acts as a storage area for the fecal balls until the horse
expels them.
