Equine Nutrition & Feeding Time-Budgets Feral Horses Select highest fiber, lowest protein content 70% of its day foraging Stabled Horses 10% of their day feeding Meal fed Mastication •Jaw sweeps 60,000 times/day when grazing •Saliva contains little, if any amylase Left Side of Horse Right Side of Horse Digestion is organ specific 8% Starch digestion occurs in the stomach and small intestines Amino acids and fat digested and absorbed in small intestine 30% Vitamins/minerals absorbed in small intestine (Stomach: 15 min. Small intestine: 30-90 min.) 62% Fiber digestion occurs in the cecum/colon (48-72 hours) Stomach 9-15 liters Trickle feeders Transit time <2 hr Cardiac sphincter does not relax to allow regurgitation Small Intestine 30% of GIT, ~70 ft. long ~contains 24 gallons 3 Segments Duodenum Jejunum Ileum Starch digestion occurs in the stomach and small intestines Amino acids and fat digested and absorbed in small intestine Many Vitamins/minerals absorbed in small intestine α-Amylase – low & varies widely between horses Large Intestine Hindgut – 60% of digestive tract capacity Cecum – 25-35 liters Large muscular mixing vat Initiates fermentation Begins protein degradation & B vitamin synthesis Large Colon 50-60 liters Continuation & completion of microbial digestion, absorption of VFA, B vitamins Conservation of electrolytes (Na, Cl, K), absorption of P Small Colon 18-19 liters Primary function is to conserve water Fiber digesters most active pH of 6.2-6.8 Starch digesters prefer pH 5.2 – 6.0 Microbial Fermentation Volatile Fatty Acids Microbe Fibrous & Non-Fibrous Carbohydrate Gas Metabolized For Energy Wasted Energy B-vitamins & Vit. K Protein and Amino Acids? Aspects of The Foal GI Tract Small digestive tract The small intestine does not increase in length from 4 wks of age Cecum not fully functional until 15-24 mo of age The large intestine increases with age even up to 20 yrs Carbohydrate s Total CHO Non-Fiber Carbohydrates Nonstructural Carbohydrates Neutral Detergent Fiber Neutral Detergent Soluble Fiber Hemicellulose Acid Detergent Fiber Sugars Pectins Cellulose Starches Fructans Lignin β-Glucans How Hindgut Acidosis Can Occur In Hindgut And How It Can Be Attenuated High Grain or High Fructans Increase in VFA& Lactic Acid of Hindgut Time Released Buffer Minimal decrease in pH Optimal VFA absorption Optimal Energy for Working & Breeding Horses Significant decrease In pH Decrease in fiber fermenting Organisms Increase in lactate producing organisms Very low pH Bacterial lyses Release of endotoxins Laminitis Subclinical Acidosis Irritation & damage To intestinal mucosa Inhibition of fiber fermenting Organisms & lactate Utilizing organisms Off Feed Decreased fiber digestibility Colic Symptoms Stereotypic Behaviors Pagan, J. 2007. Feedstuffs Postprandial Cecal pH Change 7.6 7.4 7.2 Oats Corn Hay 7 6.8 6.6 2 3 4 5 6 7 Same DE in each sample, take a look at the amount of starch though! Corn 4.3# Oats 2.71# 5.0# 1.82# Starch Comparisons (what’s low, what’s high) Ingredient NSC % DM Sugar Starch Pectins Beta-Glucans -------------------------- % of NSC --------------------- Alfalfa hay 23.0 0.0 40.9 33.0 Grass hay 17.2 35.4 15.2 49.4 Barley 61.8 9.1 81.7 9.2 Corn 71.4 20.0 80.0 0.0 Oats 42.4 4.4 95.6 0.0 Wheat 73.8 8.9 80.2 10.9 Distillers 10.3 0.0 100.0 0.0 Corn gluten feed 24.7 3.7 71.2 25.1 Corn gluten meal 17.3 0.0 69.4 30.6 Soyhulls 14.1 18.8 18.8 62.4 Soybean meal, 44% 34.4 25.0 25.0 50.0 Wheat midds 31.2 10.0 90.0 0.0 Starch Digestion Critical capacity for hydrolysable carbohydrate overload ~0.4% of BW Maximizing starch digestion in small intestine Properties of the starch granule Grain processing Plant cell walls Transit time through the small intestine Availability & concentration of enzymes Cuddeford, D. 1999; Harris et al. 1999 Comparison of Small Intestinal Starch Digestibility of Processed Corn Whole corn Crushed corn Ground corn Popped corn Starch intake 1.9:1.0 (g/kg BW/meal) Morning:eveni ng 1.9:1.1 2.1:2.0 1.3:1.5 Preileal starch 28.9 digestibility (%) 29.9 45.6 90.1 Processing affects the site of starch digestion. REMEMBER! “The number one cause of deaths from colic is from starch overload due to feeding mismanagement.” Dr. John Reagor, PhD Chief of Toxicology Texas Veterinary Medical Diagnostic Laboratory Building a Horse Ration Start with horse needs Maximize forage Add energy if needed Add protein & minerals if needed Consider adding vitamins & supplements Consistency is key to good feeding practices Feed concentrate that makes-up the difference between nutrients needed & nutrients in roughage 1. Know What & How Much Your Horse is Eating Grain Hay Supplement Pasture 2. Know Your Horse & Provide Feed Based on: Class Weight Body Condition Score Stage of production Age Activity level Growth Nutrient Requirement Varies With Class of Horse Adult (no work) Working Light exercise Moderate exercise Heavy exercise Very heavy exercise Stallions Pregnant Mares < 5 mo 5th, 6th, 7th, 8th, 9th, 10th, 11th mo Lactation 1st, 2nd, 3rd, 4th, 5th, 6th mo Growing 4, 6, 12 mo 18 mo Light exercise Moderate exercise 24 mo Light exercise Moderate exercise Heavy exercise Very heavy exercise 3. Feed According to Body Wt. Feed intake usually expressed as % of Body Weight Lbs feed/100 lbs body weight Free Choice Forages Provide fiber & energy At least 1% of body weight (dm basis) Concentrates Provide energy Supplements Provide protein, minerals and vitamins How Much Hay & Grain Should an 800 lb. Yearling Foal Receive? Total Intake: Forage Intake: Concentrate Intake: How Much Hay & Grain (800 lb. Yearling)? Total Intake: 20 pounds 800 x .02 = 16 pounds 800 x .03 = 24 pounds Forage Intake: 10 pounds 800 x .01 = 8 pounds 800 x .015 = 12 pounds Concentrate: 10 pounds (20 total–10 forage) 800 x .01 = 8 pounds 800 x .02 = 16 pounds 4. Know Your Forage Forage quality depends on: Pasture vs hay Legume vs grass Cool vs warm season species Plant maturity Growing conditions Harvest conditions Forages are the Foundation Pasture, Hay Grass Bromegrass Orchardgrass Tall Fescue Timothy Grain Hay Oat Hay Wheat hay Straw Legume Alfalfa Birds Foot trefoil Clovers Lespedeza 5. Maximize Pasture Production Fertilize grasses Overseed Frostseed Interseed Rotationally graze Control weeds Avoid overgrazing Correct stocking density 6. Evaluate Hay Quality Visually Stage of Harvest Leafiness Color Odor Softness Penalties 7. Match Hay Quality to the Horse 8. Evaluate Hay Substitutes Handout: Hay Substitutes Note: Fed as sole part of diet? Advantages and disadvantages Special comments Compare on cost per pound of Digestible Energy (DE) Hay Substitutes Hay cubes Haylage Beet pulp Rice bran Wheat barn By-products from grain harvest Straw Complete Feed with >15% 9. Control Loss by Method of Storing Hay Square Bales 1. Barn or some kind of permanent structure 2. Tarp with hay stacked off the ground 1. 2. 3. 4. 5. 6. Round Bales Barn Tarp Sleeves or bonnets Plastic wrap Net wrap Twine wrapped, outside Round Bale, Hay Storage Losses Storage Conditions Approximate Dry Matter Losses, % Outside, on ground, without cover 13-30+ Outside, on ground, plastic or tarp cover 8-9 Outside, on drained surface, without cover 7-8 Outside, on ground, net wrapped 6-7 Outside, on ground, full plastic ‘sleeve’ 5-6 Outside, drained surface, plastic or tarp cover 5-6 Inside bale storage 5 10. Control Hay Loss in Feeding Method of Feeding % Loss Unprotected round bales fed free choice on the ground Protected round bales fed in a feeder 25 Square bales fed on the ground 25 Square bales fed in a feeder 5 5 Control Hay Loss in Feeding Use a container for hay Hay feeder Feed bunk Hay net Limit the amount of time to access round bales Feeders should be no higher than shoulder level 11. Feed by Weight NOT Volume Weights vary by: Feed type Processing method So, the amount of energy provided varies Calculating Nutrients 3-lb coffee can full of 32 lb/bushel oats = 2 1/2 lbs 34 lb/bushel oats = 4 lbs corn or pellets = 5 lbs Oats = 1.46 Mcal/lb Corn = 1.76 Mcal/lb 2.5 * 1.46 = 3.65 Mcal 5 * 1.76 = 8.8 Mcal Hay Bale 40-130 lbs 10 flakes/bale Avg 4” flake alfalfa 5 lbs Avg 4” flake grass 3 lbs Alfalfa = 1.10 Mcal/lb Grass = .99 Mcal/lb 5 lbs * 1.10 = 5.5 Mcal 3 lbs * .99 = 2.97 Mcal Forage Isn’t Everything Most do not have all the minerals &/or vitamins a horse requires. Four ways to add these. 1. Add 1 to 4 oz mineral or mineral/vitamin supplement per day or 2. Add 1 to 2 lbs ration balancer (mineral plus protein) per day or 3. Feed 5 to 7 lbs fortified grain per day or 4. Feed 12 – 14 lbs complete feed (forage & grain) 12. Evaluate Your Mixed Feed Relative quality of the ingredients Amount of crude fiber & energy Price – Cost/pound Cost/pound of nutrient Grain Intake Comparison Energy Sources - Grains Oats Barley variable crimped vs. whole Corn cracked, steam rolled Sorghum & wheat less than 30% rolled, cracked, flaked, Fat/Fatty Acids • No gall bladder Horses can be safely fed up to 20% fat in the total diet Energy from fat is 90% utilizable Often used to supplement calories for hard-working horses and hard keepers Reduction in DM intake & bowel weight Calmer temperament Protein Muscle & bone growth, milk production, fetal growth, normal metabolism Requirements can be met with good quality hay or pasture forage Low requirements for maintenance Quality = amino acid balance Very important for young horses Lysine, methionine, tryptophan most limiting for growth & milk production Minerals Content in the diet Determined by soil & water Quality of feed & proportion of grain to hay Macro-minerals Ca & P - quality forages usually provide adequate amount This ratio is very important: 1.5:1 to 2:1 Grains are rich in P and low in Ca NaCl (Salt) Salt block will meet many horse’s needs If horses sweat a lot - need salt in the ration Trace Minerals Look for iron, zinc, copper, selenium Minerals Macro-minerals – – – Ca & P - quality forages usually provide adequate amount This ratio is very important: 1.5:1 to 2:1 Grains are rich in P and low in Ca NaCl (Salt) Salt block will meet many horse’s needs If horses sweat a lot - need salt in the ration Trace Minerals Look for iron, zinc, copper, selenium A guide to the recommended concentrations of trace elements in the diet, mg/kg dry matter. (Modified from the NRC 2007). These will need to be adjusted to suit individual circumstances, growth rate and appetite etc. Vitamins Fat soluble: - stored in body - A, D, E, K - Toxicity’s can occur if fed in excess Water soluble: - must be continuously supplied - B-complex; niacin, thiamin, riboflavin •High quality fresh forages = maintenance for mature horses •Hay is poor in Vit A, supplement Vit A in the ration •Exposure to sunlight provides Vit D •Supplement Vitamin E Guide to recommended levels of Fat-soluble vitamins (need to be adjusted according to individual circumstances). 13. Control Waste in Feeding Grains & Mixes Use a storage container Buy a monthly supply Feed in a container Trough Pan Bucket 14. Do the “Little Things” Feed smaller amounts more often Feed individually if possible De-worm regularly Float the teeth Provide shelter and bedding Always have fresh, clean water 15. Formulate the Total Ration REINS Work with a consulting nutritionist 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 Maintenance Dry matter intake: 1.5-2.0% of the BW Feed selection Good quality grass hay → 0.8-0.9 Mcal DE/lb Alfalfa → 0.9-1.2 Mcal DE/lb Traditional concentrates (3-3.5% fat) → 1.25 Mcal DE/lb Fat added (6% Fat) → 1.45 Mcal DE/lb Maintenance Physiological Maintenance 2007 NRC Low Maintenance DE req. = 30.3 kcal/kg * BW (kg) CP req. = 1.08 * BW Average Maintenance DE req. = 33.3 kcal/kg * BW (kg) CP req. = 1.26 * BW High Maintenance DE req. = 36.3 kcal/kg * BW (kg) CP req. = 1.44 * BW Recommended Daily Feed Intakes as % of Body Weights Class Forage Concentrate Total Example 1,000 lb horse Mature (Idle) 1.5 - 2.0 0.0 - 0.5 1.5 - 2.0 15-20 lb Geriatric 0.8 – 2.0 0.5 – 2.0 1.5 – 3.0 15-30 lb Geriatric Horses Nutrient Considerations Reduced salivation CF digestibility ↓ Total fiber < 30% CP digestibility ↓ 12-14% CP Energy: Increase soluble carbohydrates, fats, & oils Caloric Restrictions Supplement minerals & vitamins including vitamin C Typical Nutrient Content of some Senior-type Feeds Crude Protein 12-14% Crude fat Not less than 5% Crude fiber Not less than 16% Lysine 0.6-0.7% Ca 0.6-1.2% P 0.4-0.8% Mg 0.15-0.30% S 0.15-0.30% Cu 26-55 ppm Zn 100-220 ppm Vit A 1500-3000 IU/lb Vit E 40-80 IU/lb Biotin 0.4-0.5 mg/lb Vitamin B1 (Thiamine) 2.2-2.6 mg/lb Vitamin C 5-10 g/day SELECTION OF FEED FOR THE GERIATRIC HORSE Hay cubes, ground hay, wet down hay Soft Multiform feed Moderate fat level - 5% fat Highly digestible fiber sources Guaranteed amino acid levels- rebuild muscles Direct fed microbials & Yeast Cultures Stabilized high fat rice bran, ground flaxseed, beet pulp Organic trace mineral complexes – avoid stress from excess mineral intake Feeding The Athlete Levels of Performance/Work Light – Recreational riding, beginning of training programs, Show horses (occasional) Moderate – School horses, Recreational riding, Show horses (frequent), Polo, Ranch Heavy– Ranch, Polo, Show horses (frequent, strenuous events), Low-medium eventing, Race training (middle stages) Very Heavy – Racing, Elite 3-day event Aerobic and Anaerobic Metabolism During exercise, ATP is generated from breakdown of: Glucose Fatty acids Amino acids ATP low in muscles; essentially no storage Continuous ATP production vital for athletes Simplified Energy for Muscle Contraction Blood Glucose Free Fatty Acids Lipolysis Muscle Glycogen Lactate Creatine Phosphate Pyruvate ATP Oxidative Metabolism CO2and Water O2 Energy Predict substrate used based on type of exercise performed Endurance Long term exercise utilizes fatty acids as primary energy source Needs muscle glycogen as well Racehorse Predominately uses muscle glycogen stores Work ENERGY, ENERGY, ENERGY Electrolytes & water muscle function and fluid balance Forage is not enough for 1+ hour/d moderate work. Starch is necessary for replacing glycogen stores. Required Energy Activity Maintenance DE (Mcal/d) 16 Light 20.0 Moderate 23.3 Heavy 26.6 Very Heavy 34.5 • Non-Structural CHO’s •Sugars & starches •↓ intestinal pH & risk of colic •Fiber •Beet pulp or soy hulls •↓ glycogen usage •Fat •Protein (minimal usage) Feeding Guidelines for Performance Horses Starch is necessary for replacing glycogen stores. Hay 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 Cut grain on rest days Feeding Guidelines for Performance 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 Cut grain on rest days FAT SUPPLEMENTATION • No gall bladder Max ~20% in total diet Energy from fat is 90% utilizable Reduction in DM intake & bowel weight ↓ metabolic heat production Improvement of acidemia during high-intensity exercise Calmer temperament FAT SUPPLEMENTATION Enhanced stamina capacity for uptake & oxidation of fatty acids in muscle Dose dependent in activity of lipoprotein lipase & skeletal muscle citrate synthase & β-hydroxy acyl-coA dehydrogenase Concomitant decrease in use of endogenous carbohydrate stores Muscle glycogen sparing Min. 3 weeks for response Add 6-10 weeks before performance Breeding Animals Open Mare Maiden mare Barren mare Gestating mare Lactating mare Stallion Open & Barren Mares Flushing- Increasing energy intake 20-25% ~3 wks prior to breeding. Maintain optimum body condition Late Pregnancy Last 3 months - Unborn foal growth averages 1 lb/day During the 10th month, the largest amount of mineral retention occurs in the unborn foal “In the last trimester of pregnancy, the mare should be on a ‘growth- type’ feed formula,” A balanced feed will decrease severity of orthopedic problems in foals 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 •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 Lactating Mare Lactating Mare 28 Daily Milk Production (lbs) Mares produce average of 24 lbs (3 gallons) milk/day High producing mares give as much as 32 lbs (4 gallons) milk/day Low producing mares often produce 21 lbs (2.5 gallons) 27 26 25 24 23 22 21 15 30 45 60 90 Time (days) Y = a x (d0.0953)x c(-0.0043d) Y= daily milk yield in kg; a=0.0274287x mature wt in kg & d = day of lactation 120 150 Feed Consumption (% BW) Mare status Forage Concentrate Total 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 Heavy milkers may require as much as 1.75-2.0% (17.5-20 lbs for a 1000 lb mare) of BW in concentrate feed/day Approximate Amounts of Grain (lb) Needed with Hay for Broodmares 1100 lb mare 1300 lb mare DE Req (per lb of feed) Mcal Avg Hay lb Good Hay lb Avg Hay Lb Good Hay Lb Barren Mare & 1st 2/3 of pregnancy (maintenance) 1.00 3.0 - 4.0 - Pregnancy (last 90 days) 1.10 7.0 5.0 8.0 5.0 Lactation (1st 3 months) 1.20 14.0 12.0 16.0 14.0 Lactation (3 months to weaning) 1.10 9.0 6.0 10.0 6.0 Nutrition of the Broodmare. KY Cooperative Extension Body Condition Score Reason: Standardized scale for estimating and comparing body fat Developed in 1983 by Dr. Don Henneke System for assessing subcutaneous fat Nine levels of body condition Six body areas of fat storage Uses Research Feed management Health management Body Condition Scoring 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 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 Economic Optimum Mares with scores of 5.5-7.5 Spend fewer days at the breeding farm Less time open Body Condition Affects Reproductive Performance Mare managers should monitor body condition on a regular basis Mares should be optimum condition for breeding Body Condition Score Reproductive performance of mares in varying body condition Body Condition Cycles per Conception Conception Rate (%) <4.5 2.8 71 5.0-6.5 1.4 93 >7.0 1.4 96 From Nutrition & Feeding Management of Broodmares Body Condition Score Condition score of 5 or less in milking mares - do not have enough stored fat to support efficient reproductive performance Mares with BCS of 5 or less More likely to skip a breeding season Incidence of embryo loss increase Body Condition Score Weight loss by pregnant mares does not affect foal’s birth weight, but may decrease mare’s colostrum and milk production. Body Condition Score Maximize 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. Lactating Mares Early lactation weight loss in mares that foal in thin condition lengthen rebreeding time lower conception rates threaten the subsequent pregnancy Body Condition Score Excess obesity (BCS 8 or <) doesn’t appear to affect pregnancy, foaling ease, foal’s birth weight, or reproductive efficiency. May decrease milk production Feeding The Growing Horse Goals 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 Average Daily Gain 3.5 3 2.5 2 1.5 1 0.5 0 0 2 4 6 8 10 12 14 16 18 20 22 24 Month of Age Nutritional Strategies Aimed at Minimizing DOD Rations should be balanced to promote a consistent growth curve Requires periodic updating of the ration www.Foalcare.com Size Matters at the Sales Amount of Feed Recommended for Growing Horses Lb grain mix/day/mo of age Horse Age (mo) Grain mix % in total diet Lb Grain Ponies Mix/100 lbs body wt/d Others Nursing foals 0-4 100 0.5-0.75 .25 1.0 Weanlings 4-12 70 1.7-2.0 0.5 1.5 Yearlings 12-18 60 1.3-1.7 Long Yearlings 18-24 50 1.0-1.25 Two-year olds 24-36 50 1.0-1.25 For all age horses feed grain only up to a max. of 0.9 lb/100 lb of anticipated mature wt/day Nutritional Strategies Aimed at Minimizing DOD Feed selection High quality forage is a must Grain mix concentrates formulated specifically for growing horses Improper use of supplements Feed amounts Forage Minimum of 1 lb / 100 lb BW / d Fed to appetite is best Concentrate ~ 1 lb / 100 lb BW / d Max. 8 to 10 lbs /d Monitor The Growth Process Daily Intakes Body Weight Average daily gain Signs of Skeletal Abnormalities Physitis Joint effusion Lameness Feeding Guidelines & Strategies To Minimize Risk Of Hind Gut Dysfunction Consider.. Body condition Stage of production Quality of feeds available Feeding Guidelines & Strategies To Minimize Risk Of Hind Gut Dysfunction Check for Refusals Change type & amount of feed gradually. 7-10 d period Provide Salt Feeding Guidelines & Strategies To Minimize Risk Of Hind Gut Dysfunction Control amount of NSC (sugar, starch & fructan) the horse consumes. Minimize the flow of fermentable polysaccharide to the large intestine Feed starch sources little and often i.e., less than 5g oats/(2g starch)/kg body weight/meal Pre-feed forages Feeding Guidelines & Strategies To Minimize Risk Of Hind Gut Dysfunction Minimize the flow of fermentable polysaccharide to the large intestine Limit rate of concentrate intake through physical obstruction Maximize substrate (glucose) availability to the performance horse Ensure good occlusion of teeth through regular dentistry Feeding Guidelines & Strategies To Minimize Risk Of Hind Gut Dysfunction Group Feeding Should Account for Dominance Hierarchies Recognize Feeding-Related Behavior Problems