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 – Starch65-75% – 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 – H 2 0 – VFA’s – AA – Phosphorus, 50% – NaCl Small Colon – Absorption of H 2 0 – Fecal ball formation Digestive Tract

Comparisons of digestion HumanRuminantEquine Stomach30%70%9-10% Sm. Intestine 33%19%30% Cecum7%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 Acids Glucose Fatty Acids Fat Glycogen Digestible Carbohydrate Fermentable Fiber StomachSmall IntestineLarge 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 Glycogen Blood Glucose Anaerobic Glycolysis Oxidative Metabolism Pyruvate Lactate ATP Free-Fatty Acids Creatine Phosphate Myokinase and CPK Reactions CO 2 and 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 ActivityExamplesDE (Mcal/d) MaintenancePasture16 Light workPleasure riding20 Moderate workReining, jumping24 Intense workRacing, endurance32

FAT SUPPLEMENTATION l Why Use It For Performance Horses? l Energy from fat is 90% utilizable l Fat ↓ heat of fermentation l Fat  glycogen storage prior to race l Fat ↓ buildup of lactic acid during intense exercise l Fat ↓ fatigue

Sources of Fat l Natural horse diets contain < 3-4% fat l “High Fat” sweet feeds contain 6-10% fat l Fat Supplements l Vegetable Oil (most common 99% fat) l Rice Bran (very palatable 20% fat) l 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 Months of Age % Percent of Mature Height vs.. Months of Age Months of Age

Weanlings Minimize stress Minimize post-weanling slump lbs grain/100 lbs body wt 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 lb/100 lb body wt. – Concentrate Formulated for growth lb/100 lb body wt. Turnout – Forage High to moderate quality 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 months4+ months Months 0-8Months 9-11 Lactation Gestation Nutrition of The Broodmare

Gestation: Nutritional Concerns Provision of nutrients for: – Fetal growth & development Other products of conception 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

Feed Consumption (% BW) Mare statusForageConcentrateTotal Early pregnancy Late pregnancy Early lactation Late lactation 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 % 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 – % 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 u Feed By Class u 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 NeededDaily GainAdditional Grain Needed lbs/day4.5 lbs/day lbs/day3.0 lbs/day lbs/day2.3 lbs/day

FEEDING MANAGEMENT GUIDELINES u Feed Adequate Long-Stemmed Roughage u Feed Hay From Well-Designed Mangers

FEEDING MANAGEMENT GUIDELINES u Recognize Feeding-Related Behavior Problems u Group Feeding Should Account for Dominance Hierarchies u Encourage Aggressive Horses To Eat Slowly u Protect Trees From Bark-Chewing Horses

FEEDING MANAGEMENT GUIDELINES u Never Feed More Than 0.75% of BW (concentrate) at any One Feeding u Multiple Feedings u Set Feeding Times

FEEDING MANAGEMENT GUIDELINES u Check for Refusals u Change type and amount of feed gradually d period u Provide Salt