1. Managing Carbohydrates for Performance Horses Bill Vandergrift, PhD EquiVision, Inc. EV Farm, LLC

2. Outline Understand the basic carbohydrate groups What their primary sources are What they are converted to in the horse’s body What their primary function is in terms of fueling stamina, power or both Understand how to feed different carbohydrate sources to achieve peak performance Understand how other dietary components affect carbohydrate metabolism

3. Evaluating Dietary Response Adequate Stamina Temperament Ability to focus on task at hand Soundness Hoof and hair coat quality Body condition

4. “Carb” Classification Structural Carbohydrates: Fibers Non-Structural Carbohydrates: Starches, Sugars, Fructans

5. Fiber Classification Structural fiber: Cellulose (glucose polymer) Hemicellulose (xylans and mannose) Lignin (insoluble) (Major source – forage) Soluble fiber: Pectin (beet pulp) Pentosans (soy hulls)

6. Fiber Measurements Crude Fiber (feed tag) Crude Fiber (feed tag) Most of cellulose but only part of lignin Most of cellulose but only part of lignin Since grain is low in lignin can and is still used on grain feed tags Since grain is low in lignin can and is still used on grain feed tags Neutral Detergent Fiber (NDF) Neutral Detergent Fiber (NDF) Hemicellulose, cellulose and lignin Hemicellulose, cellulose and lignin Higher NDF = lower intake Higher NDF = lower intake Acid Detergent Fiber (ADF) Acid Detergent Fiber (ADF) Cellulose and lignin Cellulose and lignin Higher ADF = lower digestibility Higher ADF = lower digestibility

7. Fiber Measurements Acid Insoluble Lignin (AIL), Acid Digestible Lignin (ADL) or just plain Lignin Acid Insoluble Lignin (AIL), Acid Digestible Lignin (ADL) or just plain Lignin Lignin Lignin Higher lignin = lower intake and lower digestibility Higher lignin = lower intake and lower digestibility NDF – ADF = Hemicellulose ADF – Lignin = Cellulose Lignin = Lignin

8. Non-Fiber Carbohydrate Measurements Water Soluble Carbohydrates (WSC) Water Soluble Carbohydrates (WSC) Sugar, some starch, fructan Sugar, some starch, fructan Ethanol Soluble Carbohydrates (ESC) Ethanol Soluble Carbohydrates (ESC) Sugars, some starch Sugars, some starch Non-Fiber Carbohydrates (NFC) Non-Fiber Carbohydrates (NFC) Sugar, starch, pectin, fermentable acids Sugar, starch, pectin, fermentable acids Calculated: = 100% - (CP% + NDF% + Fat% + Ash%) Calculated: = 100% - (CP% + NDF% + Fat% + Ash%)

9. Non-Fiber Carbohydrate Measurements WSC + Starch = WSC + Starch = Non-Structural Carbohydrate (NSC) WSC – ESC = Fructan WSC – ESC = Fructan High fructan = bad for laminitic horses High fructan = bad for laminitic horses High ESC = high sugar High ESC = high sugar high glycemic response high glycemic response Bad for insulin resistance Bad for insulin resistance

10. Carbohydrate Fractions in Common Feeds Fed to Horses Feed Water Soluble Carbohydrate (%) Ethanol Soluble Carbohydrate (%) Starch (%) Non-Structural Carbohydrate (%) Molasses 53.352.11.059.7 Oats 3.23.044.348.7 Corn, Steam Flaked 1.92.572.673.8 Rice Bran 10.19.519.429.5 Legume Hay 9.07.32.111.0 Cool-Season Grass Hay (Timothy, Orchard, etc) 10.77.82.412.9 Bermuda Grass Hay (Coastal, Tifton) 7.58.45.813.2 Fresh Cool-season grass pasture 10.44.42.613.1 Fresh Bahiagrass pasture 5.34.80.35.6 Beet Pulp 10.210.61.411.8 Soybean hulls 3.61.51.75.1

11. Hoffman et al, 2001

12. Fermentation vs Digestion  Sugars and starches are digested in small intestine  Increases blood glucose  Fiber and pectins are fermented in large intestine  Converted into fatty acids

13. Stamina vs Power All equine performance activities require some stamina and some power (aerobic vs anaerobic) Some require proportionately more stamina (endurance) Some require proportionately more power (jumping) Some require equal amounts of both (eventing)

14. Maximum Performance In most cases, it is not the fastest or strongest horse that wins – It is the horse that tires out the least! Maximum Performance = Maximum Stamina

15. Right Fuel for the Job Burn fat for stamina Fatty acids from fiber fermentation fat from feed Burn glucose for power Starches and sugars from small intestine digestion of non- structural carbohydrates

16. Optimize Glucose Metabolism to Maximize Performance Ensure glucose is available at cellular level when it is needed Dietary sources Some grain is often required Complimentary dietary ingredients Glucose sparing effect of fat Dietary fat and fermented fiber Proper Conditioning “Turn On” the enzymes!

17. Feeding Guidelines to Maximize Glucose Metabolism Feed at least 1.0 – 1.5% or more of horse’s body weight in forage per day Feed at least 1.0 – 1.5% or more of horse’s body weight in forage per day Feed smallest amount of grain needed for desired body condition and temperament Feed smallest amount of grain needed for desired body condition and temperament High quality forage, fermentable fiber, added fat help reduce amount of grain needed High quality forage, fermentable fiber, added fat help reduce amount of grain needed If less than 6 pounds per day you will need supplemental minerals and vitamins! If less than 6 pounds per day you will need supplemental minerals and vitamins!

18. Feeding Guidelines to Maximize Glucose Metabolism Do not feed more than 5 pounds of grain at a time Do not feed more than 5 pounds of grain at a time Optimizes enzymatic digestion of starch Optimizes enzymatic digestion of starch Do not feed more grain than forage Do not feed more grain than forage Prevents digestive acidosis Prevents digestive acidosis

19. Feeding Guidelines to Maximize Glucose Metabolism Do not work hard between 1 and 4 hours after grain feeding Do not work hard between 1 and 4 hours after grain feeding Facilitates normalization of blood glucose and metabolic hormone levels Facilitates normalization of blood glucose and metabolic hormone levels Prevents “running out of gas on a full tank” Prevents “running out of gas on a full tank”

20. Troubleshoot Too Hyper, Too Dull Too Hyper, Too Dull Evaluate grain intake level Evaluate grain intake level Evaluate mineral and vitamin intakes Evaluate mineral and vitamin intakes Evaluate digestive health (ulcers, acidosis?) Evaluate digestive health (ulcers, acidosis?)

21. Troubleshoot No Stamina No Stamina Feeding enough forage, grain and/or fat? Feeding enough forage, grain and/or fat? Evaluate electrolyte intake Evaluate electrolyte intake Evaluate mineral intake Evaluate mineral intake Evaluate actual condition level Evaluate actual condition level Heart rate monitor (V 200 ) Heart rate monitor (V 200 ) Evaluate physical limitations Evaluate physical limitations

22. Summary Understand the basic carbohydrate groups What their primary sources are What they are converted to in the horse’s body What their primary function is in terms of fueling stamina, power or both Understand how to feed different carbohydrate sources to achieve peak performance Understand how other dietary components affect carbohydrate metabolism

23. Thank you and God Bless!