EQUINE NUTRITION
Horse Industry Feeding Problems
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Age of horses is increasing
Diversity of horses increasing
Economy increases
demand/value?
Willingness to experiment
Increase use of supplements
Minerals/Vitamins/Lubricants
Fats
Factors affecting requirements
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Size, body type and weight
Age
Work: production stage
Breed: temperament
Fat insulation
Environment: climatic conditions
External & internal parasites
Vices
Mouth
Mouth
• Initial breakdown
of feeds
• Salivary secretions
from Parotid gland
– Secrete saliva only
during eating, ~10
gal/day
Anatomy of Digestive Tract

Esophagus
–
Can’t vomit, strong
cardiac sphincter muscle
in stomach prevents
Digestive upset = Colic
–
Choke
–
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Obstruction within
esophagus
Fast eaters
Digestive Tract
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Stomach - small,
frequent, meals;
initiates digestion,
like non-ruminant
–
–
–
10% of tract
Limited digestion
Gastric ulcers
Digestive Tract
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Small Intestine -
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30% of tract
Digestion of
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Starch 65-75%
Protein, AA’s 60-70%
Fat 90%
Ca absorption 95-99%
Phosphorous 20-25%
Fast rate of passage
No gall bladder
Digestive Tract
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Large Colon
– Absorbs
– H 20
– VFA’s
– AA
– Phosphorus, 50%
– NaCl
Small Colon
– Absorption of H20
– Fecal ball formation
Comparisons of digestion
Human
Ruminant
Equine
Stomach
30%
70%
9-10%
Sm.
Intestine
33%
19%
30%
Cecum
7%
3%
16%
Lg.
Intestine
30%
7%
45%
Differences in rates of passage
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Equine
–
–
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rush through foregut
time delay in cecum
rush through rectum
Ruminant
–
Slow recycling flow of digesta
Water
Essential for all body functions
Temperature regulation
Feed digestion
Amount of water intake
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Level of exercise
Ambient temperature
Quality of feeds in ration
Proportion of diet that is forage
Minimum 1 gallon/100 lbs BW/day
GI Tract Health
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Forage
Concentrate – Grain
Supplements
Digestion of Feed
Stomach
Small Intestine
Large Intestine
Fermentable Fiber
Fat
Digestible Carbohydrate
Fatty Acids
Glucose
Fat
Glycogen
Volatile
Fatty Acids
Digestive Categories of Horses
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Maintenance - basic requirements of life
Growth - youngest has highest requirements
Gestation - last three months
Lactation - first three months
Work - depends on activity
–
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light, moderate, intense
Geriatric
Maintenance
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Size: body weight
Environment
Individual digestive &
metabolic efficiency
Dry matter intake: 1.5%
of the BW
Most - energy
requirements are met
with forage alone
GERIATRIC HORSES
Fiber digestion decreases
Ability to manufacture or absorb
certain vitamins decrease
B vitamins
Vitamin C
Decreased kidney function
Calcium stones may build
up
Decreased liver function
Jaundice, weight loss,
lethargy, loss of appetite,
intolerance for fat and
protein in diet
THE GERIATRIC HORSE
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Confinement? No! Turnout with a
friend.
Weight loss reasons: Poor dentition
Reduction in digestion - parasites,
microbial constituents, B Vits
Selection of Feed
– Highly palatable
– Easy to chew & swallow
– Clean & dust free
– Highly digestible pellets or
extruded feeds
– Contain enough high quality
fiber to aid digestion. High
quality hay – no alfalfa.
– Chopped hay, hay cubes or
pellets
Soaked feeds or mashes
Feeding The Athlete
Levels of Performance/Work
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Light - western and English
pleasure, trail riding,
equitation, hacking
Moderate - dressage, ranch
work, roping, cutting, barrel
racing, jumping
Intense - race training, polo,
cutting,
SOURCES OF ENERGY FOR THE PERFORMANCE HORSE
Muscle
Glycogen
Blood Glucose
Creatine
Phosphate
Anaerobic
Glycolysis
Lactate
ATP
Myokinase
and CPK
Reactions
Lipolysis
Free-Fatty
Acids
Pyruvate
Oxidative
Metabolism
Oxygen
CO2and
Water
Energy Sources
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Hydrolysable CHO
–
–
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Fermentable CHO
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–
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Beet pulp or soy hulls
↓ glycogen usage
Fat
–
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Sugars & starches
Create ↓ intestinal pH &  risk of
colic
3X the energy concentration of
CHO
Creates higher energy feed
Protein (minimal usage)
Required Energy
Activity
Examples
DE (Mcal/d)
Maintenance
Pasture
16
Light work
Pleasure riding
20
Moderate work
Reining, jumping
24
Intense work
Racing, endurance
32
FAT
SUPPLEMENTATION
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Why Use It For Performance
Horses?
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Energy from fat is 90% utilizable
Fat ↓ heat of fermentation
Fat  glycogen storage prior to race
Fat ↓ buildup of lactic acid during intense
exercise
Fat ↓ fatigue
Sources of Fat
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Natural horse diets contain < 3-4% fat
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“High Fat” sweet feeds contain 6-10% fat
Fat Supplements
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Vegetable Oil (most common 99% fat)
Rice Bran (very palatable 20% fat)
Animal tallow (not palatable)
Fat Guidelines
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No gall bladder
– Max ~20% in total diet
– 1100 lb horse can digest 17.5 oz
of fat (Just over 2 cups)
If adding fat to existing diet, need to
rebalance other nutrients
– (i.e. vitamin E (200 IU/cup of
added oil)
Add 6-10 weeks before
performance.
General Guidelines For Feeding
Working Horses
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Hay requirement
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Exercising horses do not need high levels of protein
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Feed at least 50% of total ration as forage (pasture &/or
hay)
Preferably high quality grass hay or alfalfa/grass mix
More important – quality of protein
Horses should be fed to meet their immediate needs
–
I.e. cut grain on rest days
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If stalled, overfeeding can  stocking up or colic
The Growing Horse
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Goals
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Maximize genetic
potential for growth
Sound
musculoskeletal
system
•Nutrient balance is important
•Requires higher quality feeds
•Growth rate & age determines requirements
•Growing till reach 30 months
Percent of Mature Body Weight
vs... Months of Age
Light Horse
Draft
100
80
%
60
40
Percent of Mature Height
vs.. Months of Age
20
0
6
12
18
24
Months of Age
30
36
98
96
94
92
90
88
86
84
82
80
78
6
12
18
Months of Age
24
Weanlings
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Minimize stress
Minimize post-weanling slump.
1.5-2.5 lbs grain/100 lbs body wt
0.75-1.0 lb hay/100 lb body wt
Ca > P
Monitor feed & water intake
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As foals get older, the
ration should be
increased by adding
more good quality hay,
leaving the grain mix
relatively constant.
Feeding Yearlings
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Sales/show
–
Forage
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High quality
.75-1.0 lb/100 lb body
wt.
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Turnout
–
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Concentrate
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Formulated for growth
1.0-2.0 lb/100 lb body
wt.
Forage
–
High to moderate
quality
2-2.5 lbs./100 lbs.
body wt.
Forage balancer
Monitoring The
Growth Process
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Daily Intakes
Body Weight
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Average daily gain
Signs of Skeletal
Abnormalities
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Physitis
Joint effusion
Lameness
Nutrition of The Broodmare
Lactation
0-3 months
4+ months
Months 0-8
Months 9-11
Gestation
Gestation: Nutritional Concerns
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Provision of nutrients
for:
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Other products of
conception
Fetal growth &
development
Foal
10%
Other
5%
85%
•Last 3 month of gestation: 60 % foals’ weight
•Mare needs to gain 0.3 – 0.8 lb/d
Average daily milk
production in mares
Daily Milk Production (lbs)
28
27
26
25
24
23
22
21
15
30
45
60
Time (days)
90
120
150
Feed Consumption (% BW)
Mare status
Forage
Concentrate
Total
Early pregnancy
1.5-2.0
0-0.5
1.5-2.0
Late pregnancy
1.0-1.5
0.5-1.0
1.5-2.0
Early lactation
1.0-2.0
1.0-2.0
2.0-3.0
Late lactation
1.0-2.0
0.5-1.5
2.0-2.5
•Adding concentrate to late pregnancy mares accounts for limited energy &
acclimates microbes
•Allow 1 wk to 10 d for mares to adjust to intake changes
•Heavy milkers may require as much as 1.75-2.0% of BW in concentrate
feed/day
Nutrition of the Breeding Stallion
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Primary Concern
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Maintenance of Body
Condition
Non-breeding
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Forage + vitamin/mineral
supplement
Breeding
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0.5% concentrate
1.75-2% hay
Body Condition Score
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Maximum Reproductive Efficiency
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Moderately fleshy to fat mares can be expected to
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Cycle earlier in the year
Have fewer cycles per conception
Have a higher pregnancy rate
Maintain pregnancy more easily
Mare prior to breeding should have a BCS of 6 or greater
and fed to maintain weight.
BCS of 5.0 is marginal especially for lactating mare.
FEEDING MANAGEMENT
GUIDELINES
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Feed By Class
Feed According to
Body Weight
FEEDING MANAGEMENT
GUIDELINES
Feed to Condition Scores
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1-3 Poor-Thin
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4 Can see ribs, vertebra
ridge evident
5 Back flat, can’t see
ribs, but can feel them
6 Crease down back, fat
deposits
7-9 Fleshy - Extremely fat
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Time & Additional Grain
Required To Improve BCS
by 1 level
Improving 1 Condition Score
Days Needed
Daily Gain
60
0.75 lbs/day
Additional Grain
Needed
4.5 lbs/day
90
0.50 lbs/day
3.0 lbs/day
120
0.40 lbs/day
2.3 lbs/day
FEEDING MANAGEMENT
GUIDELINES
Feed Adequate Long-Stemmed Roughage
 Feed Hay From Well-Designed Mangers
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FEEDING MANAGEMENT
GUIDELINES
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Recognize Feeding-Related Behavior Problems
Group Feeding Should Account for Dominance
Hierarchies
Encourage Aggressive Horses To Eat Slowly
Protect Trees From Bark-Chewing Horses
FEEDING MANAGEMENT
GUIDELINES
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Never Feed More Than
0.75% of BW
(concentrate) at any One
Feeding
Multiple Feedings
Set Feeding Times
FEEDING MANAGEMENT
GUIDELINES
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Check for Refusals
Change type and
amount of feed
gradually. 7-10 d period
Provide Salt