Nutrient requirment of racing horses

1. Nutrient requirements of
racing horses
ALI AFSAR

2. Horse
 The value of a horse depends on his ability to perform
work.
 Nutrition is one of the most important aspects of overall
development and management of horses.
 The biggest cost of keeping race-bred prospects and
racehorses is nutrition.

3. Digestive System
 Non-ruminant (post gastric fermentation; hindgut fermenter).
 Mono gastric with a functioning cecum.
 The cecum with its large amount of microbial digestion is very
similar to the rumen.
 The muscles of the esophagus (cardiac sphincter) are so strong
where they meet the stomach that vomiting or belching is
almost impossible for a horse.

5. FOREGUT:
 Mouth
 Stomach
 Esophagus
 Small Intestine
HINDGUT:
 Cecum
 Large Colon
 Small Colon
 Rectum

6. Nutrients
Site of: Digestion Absorption
Water ------- Colon
Protein Stomach & SI SI
Lipid SI SI
CHO's
Simple SI SI
Complex
Starch SI SI
Structural LI LI

7. Racing horse

8. How to ensure that racehorses can perform
at optimum levels?
Trainers need to pay close attention to
Nutrition
Providing the appropriate amounts and forms of
• energy
• protein
• vitamins and minerals
for young prospects as well as for racehorses
in training.

10. Race bred prospects
To produce and maintain a successful horse,
we must begin with
 Proper feeding
 Early development of young prospects
Two goals are to achieve
 To promote early growth
 Sound skeletal formation

11. Race bred prospects
If these goals are to be achieved:
 Weanlings cannot be fed the same rations
as yearlings.
 Long yearlings in training must be given
nutrient mixes that are different from those
fed to yearlings not being exercised.

12. Weanling Yearling

13. Diet proportions for race-bred of varying ages

14. Recommendations for weanlings
 Weanlings and yearlings should not be fed identical rations.
 To develop properly, race-bred weanlings must be given a
concentrate feed (14% CP) that provides at least 0.7% lysine.
 Need at least 0.7% calcium and 0.5% phosphorus .
 In feeds containing no more than 1.4 megacalories of DE/lb.
 A well-formulated balanced feed almost always eliminates
the need for any supplements because the nutrient mix is
balanced.

15. Recommendations for yearlings
 The digestive tract of a yearling can process
more roughage than that of a weanling.
 Fed a concentrate with at least 14% CP
 0.6% lysine
 0.6% calcium &
 0.4% phosphorus
 In a feed that contains 7% or more fiber and not more
than 1.4 megacalories of DE/lb.

19. Feeding Prior to Performance (or exercise)
To be, or not to be
 It depends on what the horse will eat and how it will be exercised.
 A grain meal, either with or without hay, fed two hours prior to an
exercise bout similar to the endurance and speed phase of a three-
day event decreased free fatty acid availability and plasma glucose
concentration.
 Grain meals fed three hours prior to exercise also decreased plasma
glucose and free fatty acid concentrations, which serve as fuels for
the horse.

20.  Feeding a grain meal two hours prior to exercise, and ad libitum hay,
resulted in decreased plasma volume and elevated body weights,
making the blood thicker and the horses heavier. This also could be a
detriment to peak performance.
 Feeding hay alone did not decrease free fatty acid and glucose
availability; therefore, performance will not be limited by the
decreased fuels as seen with grain meals prior to exercise.
 The hay alone may produce a decrease in plasma volume and
elevated body weights, similar to the grain meals.
 However, feeding hay in small amounts may reduce the effects, and
the consequences of withholding hay to stalled horses (ulcers, vices)
may outweigh the effects.

21.  Not only does a grain meal affect fuel availability, but it also may
affect heart rate. Higher heart rates during the first five minutes of
exercise were found in ponies that had consumed grain meals at 0.7%
of their body weight prior to exercise.
 However, horses that were fed less than 0.5% of their body weight in
grain did not have higher heart rates during an exercise bout.
 Higher heart rates at a given speed could have an undesirable effect
on performance, as the heart would be working at a faster rate than it
should.
 Even though research results are inconclusive, the potential for
increased heart rate should be avoided by giving the horse forage only
(ad libitum or up to 1% of body weight) prior to competition.

22.  If a competition starts early in the morning, it is best to give the
horse a last grain meal the previous evening.
 If competition starts later in the day, the last grain meal should be
given early in the morning.
 Forage may be provided throughout the day in small amounts;
however, if a grain meal is missed during the day, do not attempt to
“make it up” during the next feeding by offering twice the amount.
Offer the normal amount at the scheduled time.

23.  Most of these recommendations are applicable for intense exercise of
longer duration, such as racing, polo, fox hunting and endurance
racing.
 Most of the drawbacks to a grain meal prior to exercise.
 Such as decreased fuel availability or increased heart rates, should
not adversely affect horses in low intensity or short duration exercise,
such as pleasure, equitation, or even short, timed events such as
barrel racing.

24. Fasting Before Competition?
 If feeding grain and hay before exercise (especially in large quantities)
can be detrimental to exercise performance, some might think it
logical to conclude that complete withdrawal of food (fasting) is the
best strategy.
 However, this is not the case--even short periods of fasting can result
in a marked decrease in liver glycogen stores.
 Prolonged fasting before exercise can limit water intake and
compromise hydration. In general, horses should not be fasted more
than six hours before hard exercise.

25. Feeding After Performance
 If the horse is exercising at high intensities, or for long durations, it is
imperative that it receives forage and grain (if needed) after a bout of
exercise, particularly if it is competing for multiple days.
 Concentrates should be fed two hours after intense exercise.
 Feeding forage and grain following an intense or long duration bout of
exercise is essential to restoring glycogen (stored carbohydrate) pools
in the liver and muscle.

26. Horses in race training
Training must have
 Water
 Adequate energy
 Protein
 Vitamins
 Minerals
 Overall feeding must be managed well.

27. Specially
 Energy
 Water
 Minerals

28. Horses in race training

29. Water
 The water requirement of working horses is mainly related to
losses in sweat and via the respiratory tract.
 At maintenance level horses need 4-5L water/100 kg BW/day.
 The amount required increases proportionally with activity
and sweat production.

31. Horses in race training

32. Energy
 Racehorses often require twice as much energy (measured in
calories) as do non-working horses.
 Must ensure that the racehorses’ diet provides enough energy to
complete the assigned work (Table).
 A significant challenge in feeding a racehorse is to achieve and
maintain ideal body condition for training and racing.

33. Body Condition Score
 Another feeding strategy for peak performance is the maintenance
(or achievement) of the optimal body condition score.
 To answer this, use the Henneke body condition scale, which runs
from 1 to 9, with a score of 1 assigned to a very thin horse and a score
of 9 assigned to a very obese horse.
 A score of 5 would represent a horse whose ribs are not seen, but
easily felt. A score of 5 is optimal for most disciplines.
 Ideally, adjust the horse’s ration so that it achieves and maintains a
body condition score of approximately 5.

34.  One way to reach a desired body condition score is to adjust the
concentrate amount by 20% for each score away from the target
score.
 For example, if a horse is a score of 6, and we would like it to be at a
5, we would lower its concentrate intake by 20%.
 On the other hand, if it was a 3, and we would like it to be at a 5, we
would increase his concentrate by 40%.
 This is assuming its exercise regime stays the same.

35. Henneke Body Condition Scoring Scale
Condition Neck Withers Shoulder Ribs Loin Tailhead
1
Poor
Bone structure
easily noticeable
Bone structure
easily noticeable
Bone structure
easily noticeable
Ribs protruding
prominently
Spinous
processes
projecting
prominently
Tailhead,
pinbones and
hook bones
projecting
prominently
2
Very Thin
Bone structure
faintly
discernable
Bone structure
faintly
discernable
Bone structure
faintly
discernable
Ribs prominent Slight fat
covering over
base of spinous
processes.
Transverse
processes of
lumbar
vertebrae feel
rounded.
Tailhead
prominent
3
Thin
Neck
accentuated
Withers
accentuated
Shoulder
accentuated
Slight fat over
ribs. Ribs easily
discernible.
Fat buildup
halfway on
spinous
processes, but
easily
discernible
Hook bones
appear rounded,
but are still
easily
discernible.

36. Henneke Body Condition Scoring Scale
Condition Neck Withers Shoulder Ribs Loin Tailhead
4
Moderately Thin
Neck not
obviously thin
Withers not
obviously thin
Shoulder not
obviously thin
Faint outline of
ribs discernible
Negative crease
(peaked
appearance)
along back
Prominence
depends on
conformation.
Fat can be felt.
Hook bones not
discernible.
5
Moderate
(Ideal)
Neck blends
smoothly into
body
Withers
rounded over
spinous
processes
Shoulder blends
smoothly into
body
Ribs cannot be
visually
distinguished,
but can be easily
felt.
Back is level Fat around
tailhead
beginning to
feel soft
6
Moderately
fleshy
Fat beginning to
be deposited
Fat beginning to
be deposited
Fat beginning to
be deposited
Fat over ribs
feels spongy
May have a
slight positive
crease (a groove
down back)
Fat around
tailhead soft

37. Henneke Body Condition Scoring Scale
Condition Neck Withers Shoulder Ribs Loin Tailhead
7
Fleshy
Fat deposited
along neck
Fat deposited
along withers
Fat deposited
behind shoulder
Individual ribs
can be felt with
pressure, but
noticeable fat
filling between
ribs.
May have a
positive crease
down the back
Fat around
tailhead soft
8
Fat
Noticeable
thickening of
neck
Area along
withers filled
with fat
Area behind
shoulder filled in
flush with body
Difficult to feel
ribs
Positive crease
down back
Fat around
tailhead soft
9
Extremely Fat
Bulging fat Bulging fat Bulging fat Patchy fat
appearing over
ribs
Obvious crease
down the back
Bulging fat
around tailhead

39. Energy
System of anaerobic energy metabolism
A racehorse must perform both aerobic and
anaerobic work
 Aerobic work
 Anaerobic work
In a race, a horse performs mostly anaerobic
work using carbohydrates, but a combination of
carbohydrates and fatty acids in the diet can help
a horse work harder and delay fatigue.

40. Energy
 Depending on the level of activity and the energy concentration of
the diet, a horse will take in forage and concentrate in amounts
ranging from 2.0 to 3.0% of its body weight daily.
 Race horses performing at intense level have high energy
requirements so they require grain-based concentrates and large
amount of highly digestible starch.

41. Energy
 We can incorporate fat or oil into a grain mix
and increase it to 10% of the concentrate
without negatively affecting dry matter or fiber
digestibility.
 To achieve maximum performance in
racehorses, feed them a fat-supplemented,
high carbohydrate diet…not a high-fat, high-
fiber diet
 Feeding some fat to racehorses helps protect
them from fatigue even when their body
condition is reduced.

42. Energy
When feeding a fat-supplemented diet, consider several factors:
 Horses need time to become adopted
 Decrease total feed intake
 If we plan to top-dress fat or vegetable oil on the feed, begin with a
small amount and increase it gradually

43. Energy

44. Energy

46. Horses in race training

47. Protein
 Overfeed protein because of misconception.
 They do require a small increase in protein in the diet
for optimum production and work performance.
 It is important to have a balance of amino acids in the
diet.
 We should consider protein intake in relation to energy
intake.

48. Protein
For mature racehorses it is enough to provide
 average-quality grass hay (7 to 8% CP)
 12% CP grain or concentrate mix
However, a higher percentage of crude protein may be
warranted in two situations:
1. When hay quality is suspect
2. When supplemental fat is being top-dressed onto the
concentrate.
It is useless to feed high-protein feeds to mature racehorses.

49. Horses in race training

50. Vitamins
 If a horse’s diet is well balanced and contains enough vitamins to
meet its needs, then supplementation is not required.
Vitamin A
 In an athlete, vitamin A helps maintain normal eating behavior
and respiratory health.
 Vitamin A is usually added at about 1,500 to 2,000 (IUs) /lb.
feed.

51. Vitamins
Vitamin D:
 Normal exposure to sunlight
 Fed sun-dried hay
 Enough vitamin D for calcium homeostasis and mineral absorption
 Horse require no more than 10% of the concentration of vitamin
A, 150 to 200 (IUs) /lb. feed.

52. Vitamins
Vitamin E:
 Role in reducing tissue damage and as an antioxidant.
 Vitamin E is need at least 45 IU/lb. feed.
Vitamin K:
No dietary requirement for it
 Because adequate amounts are produced in the hindgut.
 Although vitamin K added to treat or prevent exercise-
induced pulmonary haemorrhage (bleeders)

53. Vitamins
B- Vitamins:
 Exercising horses may need supplemental vitamin B1 (thiamin)
beyond what they would normally synthesize in the intestine.
 Track sour: Loss of appetite is one symptom of a thiamin
deficiency.
 Biotin, is often added to enhance hoof growth & strength.
 Biotin supplementation reduces the incidence and severity of
hoof wall defects, increases hoof wall integrity.
 15 mg of biotin a day or about 1.5 ppm in the diet.

55. Horses in race training

56. Minerals
Race-horses require a balanced supply of minerals for;
 maintenance of skeletal tissue
 muscle contraction
 energy transfer
The total diet of horses being trained or raced should always
contain at least as much calcium as phosphorus.
 Diets (like cereal grains) with inverted ratios (more phosphorus
than calcium).

57. Minerals
 Ca and P needs of juvenile horses in training appear to be
increased by 30 to 35%, and Mg requirements increased by 80
to 100%.
2 year-old horse requires
 130 mg/kg/day of Ca
 70 mg/kg/day of P
 40 mg/kg/day of Mg
Juvenile horses in training (Dietary conc.)
 Ca of 0.60 %
 P about 0.35%
 Mg 0.2%.

58.  Lose significant amounts of electrolytes —sodium, chloride and
potassium — in the sweat.
 The majority of these increased requirements can be satisfied by
balanced diet.
 Horses that work hard and sweat profusely will still need about
3 ounces (90 grams) of supplemental salt per day in addition.
 A total of about 1 percent of the horse’s daily ration.
 The potassium requirement for heavily exercised horses is 1.2%
of the total diet.

62. Pre-Exercise Feeding Strategies
Racehorses
 Gut fill is a prime concern when feeding the racehorse.
 Reducing hay intake to 1% of body weight for a three-day period
before a race effectively will reduce body weight without causing
digestive disturbances.
 Timing of grain feeding is not as critical for racehorses as other
competitive horses, but pre-exercise grain meals should be small in
size (0.5-1 kg) and fed no later than four hours before a race

63. Three-day event horses
 As the speed and endurance test normally commences early in the
day, morning grain feeding is not recommended--high pre-exercise
insulin and glucose might limit fat oxidation and increase reliance on
carbohydrates for energy.
 On the other hand, feeding the horse a high glycemic meal (grain) or
administering glucose after completion of Phase D might help to
restore muscle glycogen more quickly.
 More rapid replenishment of muscle glycogen stores can be beneficial
to performance during stadium jumping the following day.

64. Endurance horses
 Forage intake should be high because of the associated increase in
size of the water and electrolyte reservoir in the hindgut.
 However, as with other disciplines, large hay meals should not be fed
within four hours of the start of a ride.
 Similarly, grain meals should be fed four to six hours before
competition. A high glycemic meal the night before a race is
warranted to "top up" liver glycogen stores.

65.  Unless the horse is used to receiving the "hyglycemic" grain, there
may be a danger of early exercise tie up, especially if training has
been reduced and the horse has not been warmed up adequately.
 The best rations are "complete" feeds based on beet pulp or other
readily fermentable roughage source.
 High-quality forage such as alfalfa should be offered at rest
stops/check points.
 Feeding small grain meals (~1 kg) immediately before exercise or at
rest stops might be beneficial--this practice will not disrupt fat
utilization and could supply carbohydrates during exercise.

66.  Many top competitors feed a beet pulp or bran-based slurry at rest
stops.
 Many horses will not consume 1 kg of regular grain at such stops but
will eat the slurries (carrots and apple included) to increase water
intake in addition to boosting energy.

67. Strategic Nutrition
 The simplest part of the ration is the hay. One must don’t count on
much nutritional input from forage.
 Prefer nice soft (2nd or 3rd cutting) grass hay, free choice.
 You can go crazy trying to match the nutrient values of rich green hay,
like alfalfa, with the grain ration.
 Each shipment of hay is going to be different and you can spend lots
of money getting hay analyzed, particularly if it contains clover or
other components. Best to stick with plain grass hay, and center your
nutritional strategy around the concentrate.

68.  Hay intake should be about 50% of the total feed intake. This keeps
the gut and gut flora happy.
 The reason you want to avoid first cut hay is that the stems are too
sharp and tough—they can poke holes in the gut lining.
 You have to watch out for spring pasture, too—very rich and
sometimes dangerously rich. You’re not looking for richness in forage
because there is really not way to control the precise qualities of the
hay from day to day and month to month—certainly not like you can
with the concentrate.

69. What do you want to get into the athletic
horse? Something like this:
 Crude Protein Min. 14%
 Lysine Min 0.71%
 Crude Fat Max 4%
 Calcium Min 0,8% Max 1.30%
 Phosphorus Min .78%
 Salt (NaCl) Min .30% Max 0.80%
 Sodium Min 0.20% Max 0.40%

70.  Copper Min 58 ppm
 Manganese Min 38 ppm
 Selenium Min 0.3 ppm
 Zinc Min 85 ppm
 Vitamin A Min 2,460 IU/lb
 Vitamin D3 Min 970 IU/lb
 Vitamin E Min 145 IU/lb
 Biotin Min 2.6 mcg/lb

71. In a feed with this nutritional configuration, typical
ingredients used in building the product would
include:
 Cracked corn, cane molasses, oats, soybean meal, wheat middling's,
salt, yeast culture, di calcium phosphate, choline chloride, Vitamin E
supplement, Calcium carbonate, Ferrous sulphide, Copper sulphide,
zinc oxide, manganous oxide, corn oil, niacin supplement, sodium
selinate, d-calcium pantothenate, vitamin D3 supplement, Vitamin A
supplement, thiamine mononitrate, d-biotin, riboflavin supplement„
folic acid, vitamin B12 supplement, ethylendiamine dihydroicoxide,
cobalt carbonate and lignin sulforate.

72. •Some
formulations

77. Summary
 Nutrition can play a key role in achieving peak performance. Fat
supplementation may increase the time to fatigue, reduce the
amount of carbohydrates needed and help horses get a beautiful,
shiny coat that sparkles under arena lights!
 Timing of feeding is also crucial to performance since grain meals fed
too close to performance can lower necessary fuels and possibly
increase heart rates. We must always strive to keep our horses in
prime condition.
 Perfecting our feeding strategies will help us maximize our training
and conditioning programs and keep our horses in peak physical
condition.

78. Summary
Adjustments
 Ration formulation
 Feeding management
 Training regimens for racehorses offer the best opportunity to
 improve athletic performance
 delay fatigue
 reduce injuries to the high performance horse

80. The End

81. Reference
 The Equine manual 2nd Edition
 Feeding Race Prospects & Racehorses in Training by P. G. Gibbs, G. D.
Potter and B. D. Scott
 http://www.merckvetmanual.com/mvm/management_and_nutrition
/nutrition_horses/nutritional_requirements_of_horses.html
 http://www.thehorse.com/articles/10168/pre-exercise-feeding
 http://extension.uga.edu/publications/detail.cfm?number=B1365#Pri
or