Download Equine Nutrition and Feeding the Laminitic Horse

South Shore Equine Clinic
Client Seminar
Mark T. Reilly, DVM, Dipl. ABVP
Linda J. Cimetti, DVM
South Shore Equine Clinic &
Diagnostic Center
May 7, 2008
Equine Nutrition
and
Feeding the Endocrine Horse
South Shore Equine Clinic & Diagnostic Center
May 7, 2008
Martha’s Vineyard
Equine Nutrition 101:


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Horses are herbivores by design and foragers by nature
They have evolved to utilize grasses and other forage plants
as their primary source of nutrition
Site of digestion within the digestive tract important to overall nutrition
Equine Nutrition 101


Horses are happiest when they can graze or
nibble all day long
Though 24/7 turnout
in grassy pastures is not
always possible, one way
to satisfy their urge to
chew, and ensure health
of the hindgut is to provide quality hay
Meeting Nutritional Needs


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A mature horse will eat 2-2.5%
of its body weight per day
At LEAST half of this should
be provided as roughage
For an average 1,000 lb horse that should be at
LEAST 10 - 15lbs of hay per day or roughly 5-7
flakes
Feeding Forages



Forage (hay or pasture) should be the cornerstone of
your horse’s diet
The concentrate or grain
portion of your horse’s diet
is meant to supplement the
forage portion
The best way to formulate a diet for your horse is to
have a consistent supply of analyzed hay
Hay Basics

Hay generally falls into one of two classes,
grass or legume
Grass (Timothy) Hay
Legume (Alfalfa) Hay
Hay Basics

Hay’s nutritive value and palatability will depend
on several factors, such as:

Plant species

1st cut vs. 2nd cut

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Level of maturity at
harvest
Weed content
Which “cut” is better?

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In general the quality of hay increases with
cuttings
2nd cutting tends to be higher quality than 1st
cutting
However, it is more important
to assess the maturity of the
plant at the time of cutting
Hay Basics

Other variables that will affect nutrient content of hay
include:

Growing conditions
(rain, weather, insects, disease)

Curing and harvesting conditions

Soil conditions and fertility

Moisture content

Length and method of storage (do not want to store hay for > 1
year)
What is “High-Quality” Hay?
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High leaf to stem ratio (indicates less mature plants)
Small diameter stems (less mature plants)
Fresh smell and appearance
Cleanliness
Color (faded, yellow or brown color may indicate aged hay
or poor storage conditions)
Few seedhead (timothy) or blooms (alfalfa) means less
mature plants
Which Hay Should I Feed?

Ultimately depends on availability

Timothy hay – 2nd cutting quality timothy hay is
appropriate for most horses

Alfalfa generally higher in protein and calcium; early
maturity alfalfa may be low in fiber (ie; rich hay)
Hay Quality

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Ultimately hay needs to be ANALYZED in
order to actually know what you are feeding
Which sample was highest in protein?
Calcium? Potassium? Calories?
Which sample is most likely to make my
laminitic horse worse … better?
How to Analyze Hay

www.equi-analytical.com

Hay probe is necessary for core samples

Need to take representative samples from 15-20 bales

SSEC can come to your farm and sample hay for you with our hay
probe (you will need to submit it to the lab)
Chameleon Playing Ping-Pong
Formulating a Ration
Average 1,000lb
horse requires 16,000
calories/day for
maintenance

High performance athlete
(ie; 1,000lb racehorse)
may require up to
35,000 calories/day

Which is Your Horse?
Exercise
Category
Mean Heart ****Description****
Rate
Types of Events
Light
80
beats/min
1-3 hours per week;
40% walk
50% trot
10% canter
Recreational riding
Beginning of training
programs
Show horses (occasional)
90
beats/min
3-5 hours/week;
30% walk,
55% trot,
10% canter,
5% low jumping, cutting,
other skill work
School horses
Recreational riding
Beginning of
training/breaking
Show horses (frequent)
Polo
Ranch work
18,000
Cal/day
Medium
22,000
Cal/day
(Which is Your Horse? Cont.)
Exercise Mean
Description
Category Heart Rate
Types of Events
Heavy
110
beats/min
4-5 hours per week;
20% walk
50% trot
15% canter
15% gallop, jumping,
other skill work
Ranch work
Polo
Show horses (frequent,
strenuous events)
Low-medium level eventing
Race training (middle
stages)
110-150
beats/min
Various; ranges from
1 hour per week
speed work to 6-12
hours per week slow
work
Racing (Quarter Horse,
Thoroughbred,
Standardbred, Endurace)
Elite 3-day event
26,000
Cal/day
Very
Heavy
32,000
Cal/day
Body Condition Score (BCS)


In addition to workload of your horse, its
current and desired BCS should be taken
into consideration
Like a professional boxer, every horse has
an ―ideal fighting weight‖
VS
Body Condition Score (BCS)
BCS of 4-6/9 is ideal for most horses
Formulating a Ration

Forage is the cornerstone:

10-15 lbs 2nd cut timothy hay likely to provide 11,000 – 16,500
Calories/day and 10% protein

This may be enough for your horse!

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Vitamin/mineral supplement
Concentrates (grain) is supplemented to meet additional needs
What is in Grain?
Three sources of energy (Calories):

Carbohydrates:
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Protein:
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Sugars, Starches, Fiber
Stored as glycogen – used as ―quick‖ energy by the body
Made from various amino acids
Growth (young animals), builds muscle, muscle recovery/repair
Typically utilized by the body for energy only in severe muscle wasting
states (ie; starvation, advanced disease)
Fats:


Enters the body as free fatty acids/triglycerides
Utilized in longer-lasting, aerobic work
Carbohydrates

Starches and Sugars

Referred to as hydrolyzable carbohydrates

Converted to glucose in the small intestine, providing immediate
energy to the horse

If too many hydrolyzable carbohydrates enter the small intestine,
they will not be digested and will enter the large intestine

When hydrolyzable carbohydrates enter the large intestine they
are rapidly fermented by microorganisms to lactic acid and can
wreak havoc, resulting in colic and laminitis
Carbohydrates (cont.)

Starches and Sugars

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Glucose can be utilized immediately
or stored in the form of glycogen for
future ―quick punch‖ anaerobic energy
Stored glycogen is crucial for high-intensity, shortduration exercise, such as sprinting, jumping, barrel racing, etc.
Muscle glycogen stores can be almost completely depleted
during endurance exercise, such as a 50-70 mile or longer race
Carbohydrates (Cont.)

Fiber
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Fermentable fibers are also
carbohydrates, but they are
digested differently than starch and sugar
Digestible fiber is fermented by the microbes in the
horse’s hindgut into volatile fatty acids (VFA’s), which
are then absorbed
These VFA’s are a source of energy for less intense,
longer duration activity—aerobic activity
Carbohydrates

Fiber
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Rapidly fermentable fiber
includes pectin, fructans and some oligosaccharides;
produce lactate as a byproduct, contributes to colon
lactic acidosis
Slowly fermentable fiber
includes cellulose, hemicellulose, and ligno-cellulose;
metabolized into volatile fatty acids and promotes
large colon health
Carbohydrates

Fiber
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Non-structural (NSC)
internal component of the plant cell
(simple sugars, starches, oligosaccharides, fructans,
and soluble fiber)
Structural
originates from plant cell wall and make up insoluble
fiber in diet
(cellulose, hemicellulose, and ligno-cellulose)
These are metabolized into volatile fatty acids (VFAs)
and promote large colon health
Protein
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Proteins are composed of
amino acids (the building blocks
of protein) and will vary in amino
acid composition
Amino acids are not only essential for growth, but also
for rebuilding tissue damage resulting from vigorous
exercise
Essential amino acids, like lysine and methionine, cannot
be synthesized by the horse, so they must be supplied in
the diet
Protein
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Mature horses have a lower
protein requirement than young,
growing or pregnant/lactating horses
Horses in heavy exercise have slightly higher protein
requirements
Protein comes from both forage and concentrates
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Good quality legume hay can provide 14-18% protein
Good quality grass hay can provide 7-12% protein
Protein

Protein requirements are
absolutes (grams of protein)
rather than a percentage
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―Protein‖ requirement is really amino acid requirements,
so protein quality can make a difference (lysine)

Can be estimated by using overall percentage of diet
with the following guidelines
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Under 2 years old 14-16%
>2 years old, but not yet ―senior‖ 8-12%
Senior horses likely similar to those under 2 years old
Protein
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Horses fed a protein deficient
diet will lose weight even if
sufficient caloric intake is
provided
Over-supplementation of protein is costly, but
likely does not have major negative health
consequences

May cause increased urination – monitor protein
content of diet in animals with renal disease
Fats
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Fats/oils are generally used in
equine diets to increase energy
density and reduce the amount of
hydrolyzable or rapidly fermentable
fiber found in grain
Dietary fats are necessary for absorption of fat soluble
vitamins (vitamins A, E, D, K)
Digested fats provide over 2.25 times more utilizable
energy than an equal weight of digested carbohydrate or
protein
Fats
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Vegetable oils are more palatable
to horse than animal oils
Fat supplementation may have
―glycogen-sparing‖ effects, but
will not replace glycogen

Omega-3 fatty acids found in flaxseed may modify
allergic diseases (hives, ―sweet itch,‖ COPD)

Takes a minimum of 3-5 weeks for a horse to become
metabolically adapted to a high-fat diet
The Endocrine Horse
Role of Insulin
Insulin
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Produced in pancreas

Metabolism of sugars and starches(CHOs)
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Responds to elevations of blood glucose
Insulin
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INCREASED when food high in CHOs is
eaten
DECREASED amounts needed during
xercise and physical activity
e
Role of Insulin

Function of Insulin
= Glucose entry
into cells
Endocrine Disorders

Equine Cushing’s Disease (ECD) or
Pituitary Pars Intermedia Dysfunction (PPID)
 Pituitary dysfunction
 Excess secretion of ACTH & other hormones
 Older or aged horses and ponies
 Delayed shedding or patchy hair coat
 Excess drinking and urination (PU/PD)
Cushing’s Disease

PPID
Cushing’s Disease
 Coat
changes
Cushing’s Disease

Associated with
IR because GCs
decrease glucose
uptake into cells.
Metabolic Syndrome or Insulin
Resistance

Equine Metabolic Syndrome (EMS)
 Typically
young
 ―Easy keepers‖ - obese
 Morgans, Arabs, Paso Finos
 Pronounced fat deposits
Insulin Resistance
Fat deposits remain
-Neck or crest
-Shoulders
-Buttocks
Insulin Resistance
Fat deposits
-Neck or crest
-Shoulders
-Buttocks
Insulin Resistance
Due to impaired tissue responses to
circulating insulin
-Insulin Receptors
-Insulin-signaling pathways
-Glucose transport systems
Insulin Resistance

Similar to Type
2 Diabetes
Insulin Resistance

Similar to Type
2 Diabetes
Insulin Resistance and Obesity
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Cells become less sensitive to Insulin
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Compensate by secreting more insulin = making things
worse
Fat (lipid) accumulation within fat and muscle
Leads to OBESITY
OBESITY

INSULIN RESISTANCE
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OBESITY interferes with Insulin signals
>>>>>>>>
Insulin Resistance
Insulin Resistance and Obesity

Either EMS or ECD
One, Both, Neither
Insulin Resistance and Obesity
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Obese and Insulin
Resistant
Insulin Resistance and Obesity
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Obese and NOT
Insulin Resistant
Insulin Resistance and Obesity

Either EMS or ECD
Other Species
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INSULIN RESISTANCE
Other Species
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INSULIN RESISTANCE
Crested Neck
Feeding Endocrine Disorders

OBESE HORSE

Induce weight loss
Feeding Endocrine Disorders

OBESE HORSE
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Induce weight loss

Same horse!!
OBESITY
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Athletes can be overweight
too!
Exercise helps IR
Feeding Endocrine Disorders
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GOOD BODY CONDITION
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Maintain weight
Improve Insulin Sensitivity
Feel ribs under the skin
No visible fat areas
Feeding Endocrine Disorders
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THIN BODY CONDITION
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Gain weight
Improve Insulin Sensitivity
Laminitis
Laminitis
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CENTURIES
SEASONALLY
DIETARY
CHANGES
Laminitis
Laminitis

Basement Membrane

Inflammation

ICE ICE ICE
Laminitis
Laminitis
Laminitis
Laminitis
Laminitis
Laminitis
Laminitis
Laminitis

Growth rings
Heel > Toe
WEIGHT LOSS
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Eliminate ALL grain

Restrict access to pasture to < 2 hours

AVOID Starch (NSCs) and Fructans!!
WEIGHT LOSS
EXERCISE!!!
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Decreases blood glucose levels
(and therefore Insulin levels)
Exercise and Diet Changes are NOT
mutually exclusive!
WEIGHT LOSS
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Grazing Muzzle
Weight-watchers
Paddocks
Weight tape
WEIGHT LOSS
Avoid DYNAMIC grass growth
 After
 New
drought – SPRING and FALL
grass has HIGH amounts of
CHOs
WEIGHT LOSS

Soaking hay for 30 minutes prior to feeding
Lowers sugar content 30%
 Analyze and select for low CHOs

NSC (Oats = 44; Corn = 73)
 HAY varies !!! (11% - 31%)

WEIGHT LOSS

FAT HORSE
Feed 2% body weight in hay plus basic
vitamin/mineral supplement
 Then lower to 1.5% of current body weight
 Then lower to 1.5% of IDEAL body weight
 8 - 10% Protein is ideal = add alfalfa or
soybean meal
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= 15 pounds of hay to 1000 pound horse
MAINTENANCE DIET

Optimal Body Score
MAINTENANCE DIET

Optimal Body Score
MAINTENANCE DIET

Optimal Body Score
MAINTENANCE DIET

Optimal Body Score
MAINTENANCE DIET

Predominantly HAY
< 12% NSC
 Approx 2% body weight
 Vitamins/minerals and Protein as needed

MAINTENANCE DIET

Avoid High Glycemic Feeds
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NO Sweet Feed with molasses
 Makes Insulin Resistance worse!
Feed small amounts more frequently
(lesser amounts of carbs fermenting at
one time)
MAINTENANCE DIET

Avoid Sudden Changes in Feed
 Bacterial
Flora needs to adjust gradually
MAINTENANCE DIET
MONITORING
 BODY
SCORE CONDITION
Assess every 2 –4 weeks
 BLOOD
INSULIN LEVELS
Measure at least every 6 months
MAINTENANCE DIET

Optimal Body Score
WEIGHT GAIN DIET
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Free choice hay (soaked)
Molasses-free beet pulp
Rice bran
Corn oil
WEIGHT GAIN DIET

Soaked Molasses-free Beet Pulp
Mostly digested in large intestine
 ONE CUP = ¼ POUND (Presoaked)
 Start with ¼ pound of pre-soaked BP
 Feed twice daily
 Increase gradually to 1 (one) pound daily
 RINSE in warm water, then SOAK 10-30
minutes in warm water before feeding

WEIGHT GAIN DIET

Low-NSC Pelleted Feed
Ease of feeding
 Lower sugar contents
 Palatability

Goals of Management
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Decrease body fat mass (obese)
Avoid feeds that exacerbate IR (NSC)
Minimize risk of laminitis
Avoid sudden diet changes (i.e. changes
in bacterial flora of gut --> laminitis)
Questions???
South Shore Equine Clinic
& Diagnostic Center
151 Palmer Road
Plympton, MA 02367
781-585-2611
www.ssequineclinic.com
Mark T. Reilly, DVM, Dipl ABVP
Linda J. Cimetti, DVM
Suzanne P. Shaw, MVB