EQUINE | Nutrition
correlate to how fast a foal grows, researchers began
looking at the effects of excess dietary energy (e.g.,
carbohydrates), said Pagan. Theorizing that high-carb
diets could lead to osteochondritis dissecans (OCD,
a form of DOD in which cartilage fails to properly
turn into bone), he and his team conducted a study
of Central Kentucky farms and found a relationship
between glycemic response (carbohydrates’ effect on
blood glucose) and OCD incidence.
“If farms had a high glycemic response, then the farms
had a high level of OCD,” Pagan explained. “Farms
with a low glycemic response had a low incidence of
OCD.”
Skeletal Health
Healthy bones are important not only for young,
growing Thoroughbreds headed to the sales, but
also for performance horses – both racing and sport.
Bones go through three stages, said Pagan: formation,
equilibrium, and demineralization. The latter stage can
occur when horses are confined for long periods.
When Pagan and his team came across a novel
ingredient purported to suppress bone destruction
called milk basic protein in the early 2000s, they
conducted a study to determine whether this protein
source could improve bone formation and density in
horses. They found that it did, in fact, help prevent
bone demineralization in horses during confinement.
They also studied the effect of buffered mineral
complex (a natural calcium source) on bone mineral in
racehorses in training and found that it increased bone
density fourfold.
Digestibility and Nutrient Requirements
absorbed by the horse). A vitamin’s source – synthetic
or natural – can also affect its digestibility. Thus, much
nutrition research over the years has focused on this
topic. Scientists have found, for instance, that a natural
source of vitamin E is about twice as bioavailable as
the chemically different synthetic source, said Pagan.
Most recently, he said, researchers have studied the
antioxidant nutrient coenzyme Q10 (CoQ10). Pagan
explained that in its raw form, CoQ10 is not very
digestible, but when it is processed to make it water-
dispersable it becomes three times as bioavailable.
“We’re just now scratching the surface, but I think it’ll
be one of the next big nutrients,” he said.
Gastrointestinal Health
It’s been well-established that horses are poor starch
digesters and don’t handle large grain meals well.
This can lead to hindgut acidosis—increased acidity
in the large intestine that alters its natural population
of microorganisms, possibly causing colonic ulcers or
diarrhea.
Pagan said many studies over the past few decades
have found that processing (e.g., flaking or extruding)
grains such as corn can make them more readily
digestible in the small intestine and help reduce hindgut
acidosis. His team also developed a protected sodium
bicarbonate (a type of baking soda) to buffer gastric
acid. In studies, they fed this product to horses on high-
grain diets and found that it reduced the amount of
lactic acid produced by microbes in the hindgut. They
also identified that it reduced lactic acid produced from
fructans (nonstructural carbohydrates often prevalent
in pasture that can cause hindgut acidosis) in pastured
horses.
Different vitamins and minerals have different levels
of digestibility and bioavailability (the rate at which it’s
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• Equine Health Update •