EQUINE NUTRITION

Horse Industry Feeding Problems

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

Size, body type and weight Age Work: production stage Breed: temperament Fat insulation Environment: climatic conditions External & internal parasites Vices Mouth

• Initial breakdown of feeds

• Salivary secretions from Parotid gland– Secrete saliva only

during eating, ~10 gal/day

Mouth

Anatomy of Digestive Tract

Esophagus– Can’t vomit, strong

cardiac sphincter muscle in stomach prevents

– Digestive upset = Colic

– Choke Obstruction within

esophagus Fast eaters

Stomach - small, frequent, meals; initiates digestion, like non-ruminant– 10% of tract– Limited digestion– Gastric ulcers

Digestive Tract

Small Intestine - 30% of tract

Digestion of– 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

Large Colon– Absorbs– H20– VFA’s– AA– Phosphorus, 50%– NaCl

Small Colon– Absorption of H20– Fecal ball formation

Digestive Tract

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

Equine– 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

– 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

Forage Concentrate – Grain Supplements

Volatile Fatty AcidsGlucose

Fatty Acids

Fat

Glycogen

Digestible Carbohydrate

Fermentable Fiber

Stomach Small Intestine Large Intestine

Fat

Digestion of Feed

Digestive Categories of Horses

Maintenance - basic requirements of life Growth - youngest has highest requirements Gestation - last three months Lactation - first three months Work - depends on activity

– light, moderate, intense

Geriatric

Maintenance

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

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

Light - western and English pleasure, trail riding, equitation, hacking

Moderate - dressage, ranch work, roping, cutting, barrel racing, jumping

Intense - race training, polo, cutting,

Muscle GlycogenBlood Glucose

Anaerobic Glycolysis

OxidativeMetabolism

Pyruvate Lactate

ATP

Free-Fatty Acids

CreatinePhosphate

Myokinaseand CPKReactions

CO2and Water

Lipolysis

Oxygen

SOURCES OF ENERGY FOR THE PERFORMANCE HORSE

Energy Sources

Hydrolysable CHO– Sugars & starches– Create ↓ intestinal pH & risk of

colic Fermentable CHO

– Beet pulp or soy hulls– ↓ glycogen usage

Fat– 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

Why Use It For Performance Horses? 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

Natural horse diets contain < 3-4% fat “High Fat” sweet feeds contain 6-10% fat

Fat Supplements Vegetable Oil (most common 99% fat) Rice Bran (very palatable 20% fat) Animal tallow (not palatable)

Fat Guidelines

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

Hay requirement– Feed at least 50% of total ration as forage (pasture &/or

hay)– Preferably high quality grass hay or alfalfa/grass mix

Exercising horses do not need high levels of protein– More important – quality of protein

Horses should be fed to meet their immediate needs– I.e. cut grain on rest days

If stalled, overfeeding can stocking up or colic

The Growing Horse

Goals– Maximize genetic

potential for growth– Sound

musculoskeletal system

•Nutrient balance is importantNutrient balance is important•Requires higher quality feedsRequires higher quality feeds•Growth rate & age determines requirementsGrowth rate & age determines requirements•Growing till reach 30 monthsGrowing till reach 30 months

Percent of Mature Body Weight vs... Months of Age

0

20

40

60

80

100

6 12 18 24 30 36

Light Horse Draft

Months of Age

%

7880

82

84

8688

90

92

94

9698

6 12 18 24

Percent of Mature Height vs.. Months of Age

Months of Age

Weanlings

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

As foals get older, the ration should be increased by adding more good quality hay, leaving the grain mix relatively constant.

Feeding Yearlings

Sales/show– Forage

High quality .75-1.0 lb/100 lb body

wt.

– Concentrate Formulated for growth 1.0-2.0 lb/100 lb body

wt.

Turnout– Forage

High to moderate quality

2-2.5 lbs./100 lbs. body wt.

– Forage balancer

Monitoring The Growth Process

Daily Intakes Body Weight

– Average daily gain

Signs of Skeletal Abnormalities– Physitis– Joint effusion– Lameness

0-3 months 4+ months

Months 0-8 Months 9-11

Lactation

Gestation

Nutrition of The Broodmare

Gestation: Nutritional Concerns

Provision of nutrients for:

– Fetal growth & development

Other products of conception

Foal10%

Other5%

85%

•Last 3 month of gestation: 60 % foals’ weightLast 3 month of gestation: 60 % foals’ weight•Mare needs to gain 0.3 – 0.8 lb/dMare needs to gain 0.3 – 0.8 lb/d

Average daily milk production in mares

21

22

23

24

25

26

27

28

15 30 45 60 90 120 150

Time (days)

Da

ily

Mil

k P

rod

uct

ion

(lb

s)

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 changesAllow 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

Primary Concern– Maintenance of Body

Condition

Non-breeding– Forage + vitamin/mineral

supplement

Breeding– 0.5% concentrate– 1.75-2% hay

Body Condition Score

Maximum Reproductive Efficiency– Moderately fleshy to fat mares can be expected to

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

Feed By Class Feed According to

Body Weight

Feed to Condition Scores 1-3 Poor-Thin 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

FEEDING MANAGEMENT GUIDELINES

Time & Additional Grain Required To Improve BCS by 1 level

Improving 1 Condition Score

Days Needed Daily Gain Additional Grain Needed

60 0.75 lbs/day 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

FEEDING MANAGEMENT GUIDELINES

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

Never Feed More Than 0.75% of BW (concentrate) at any One Feeding

Multiple Feedings Set Feeding Times

FEEDING MANAGEMENT GUIDELINES

Check for Refusals Change type and

amount of feed gradually. 7-10 d period

Provide Salt