Energy Forages are the most important source of energy, and many horse
owners do not work on improving pastures, said Breuer. Attention to soil
fertility, weed control, and grazing management is of utmost importance. Due
to an increase risk of laminitis and colic caused by increased hydrolyzable
and rapidly fermenting carbohydrate content of early spring and fall
pastures, he recommended doing forage analyses year-round. Researchers in
Virginia found peak levels of these carbohydrates in forage samples taken in
October and March. He suggested that owners restrict access to pasture for
at-risk horses, and that pasture management can help control lush pastures.
Forage analysis will also allow owners to supplement for any
deficiencies.
Glycemic response is the relative response in blood glucose
and insulin after eating a starchy food. Research at Kentucky Equine Research
determined that the highest glycemic response is from sweet feed, then oats,
corn, and a high-fiber feed. Adding fat can reduce the glycemic response.
Feeds with a low glycemic response might be beneficial to horses, according
to Breuer.
The theory is that feeding a high-glycemic feed to any horse
that has problems utilizing glucose or has insulin resistance, or is
laminitic, might be detrimental. Studies are also underway to determine if
feeds with a high glycemic index are detrimental to young horses.
The
effect of feed processing on glycemic response was also
measured. Steam-flaked corn was found to have the highest glycemic response,
ground corn was next, and cracked corn has the lowest glycemic
response.
In another study, giving glucose and fructose to horses did not
affect the glycemic response. This is because fructose is well-absorbed in
horses and is rapidly converted to glucose. Glucose and fructose sources such
as molasses are well used by the horse.
Further research into the
feeding of fat discovered that there was almost 100% absorption of various
fat sources--corn oil, peanut oil, soy oil, soy lecithin, tallow, and fat
blends. These fat sources did not depress digestion of fiber or nutrients.
Breuer recommended choosing a fat source based on availability and cost,
although many researchers recommend vegetable sources of fat over animal
sources due to increased palatability.
In another study, it was confirmed
that corn oil had little or no effect on feed intake or digestibility of
other nutrients; however, a study in The Netherlands showed that diets very
high in fat might cause enough fat to enter the large intestine to depress
fiber fermentation by bacteria, according to Breuer.
In Finland,
researchers fed fat to fat-adapted horses and non-fat adapted horses. They
found depressed glycogen repletion (rebuilding of the glycogen stores) after
an exercise test in non-fat adapted horses. But they also found glycogen
repletion was not depressed after horses were fed fat for three
weeks.
The benefits of omega-3 fatty acids have been touted in human and
canine nutrition. Omega-3 and omega-6 are recognized contributors to normal
cell function and help prevent immune disorders, skin conditions,
inflammatory conditions, and certain disease conditions. There is
considerable interest in the dietary ratio of omega-6:omega-3 fatty acids; in
particular, diets that promote an increase in omega-3 relative to omega-6
fatty acids are advocated because of purported health benefits. One equine
study showed that feeding fish oil (a good source of omega-3 fatty acids)
increased omega-3 fatty acids in the horses' blood serum profiles. As a
result, the omega-6 fatty acid concentration was lower, as was the
omega-6:omega-3 fatty acid ratio. "Changes in blood levels of insulin, free
fatty acids, and glucose during an exercise test may indicate that insulin
sensitivity and glucose metabolism was affected by the fish oil (for the
better)," according to the authors of the study.
--- Outgoing mail is certified Virus Free. Checked by AVG
anti-virus system (http://www.grisoft.com). Version: 6.0.510 /
Virus Database: 307 - Release Date: 8/14/2003
