RE: [RC] Molasses/sugar over concern - Kristen A Fisher
From Glycemic Index of Practical Horse
Feeds Anne Rodiek, Department of Animal Sciences and Agricultural
Education California State University,
Fresno
Enzymatic digestion of starch
yields glucose, which is absorbed into the bloodstream, increasing the
glucose concentration in the blood and producing an elevated glucose response
curve. Grains (oats, corn, barley and wheat) are comprised primarily of starch,
a soluble carbohydrate digested largely by the enzymes in the small
intestine. On the other hand, forages are generally quite low in starch and
high in structural carbohydrate, which is resistant to enzymatic digestion in
the small intestine. Structural carbohydrates pass to the large intestine
where they are digested by the microbes of the large intestine, yielding not
glucose, but volatile fatty acids. While volatile fatty acids contribute
energy to the horse, they do not alter blood glucose levels. By-product
feeds are similar to forages with respect to blood glucose response, as they
are low in starch and sugar also. Beet pulp is the residue from a process
that extracts sugar from beets; rice bran and wheat bran are the outer
covering of the rice and wheat grain, where most of the starch is located.
Carrots are somewhat higher in sugar concentration than the other by-product
feeds, but the water content of fresh carrots is very high and the total
sugar contribution of carrots is low. Corn produced the largest glucose
response of the trials, with its area under the glucose curve 117 percent
of the area under the oats curve. Therefore, its glycemic index was 117. Beet
pulp produced the lowest glucose with an area under the curve of only one
percent of the size of the glucose curve. In general, concentrate
feeds, primarily grains, produced the highest glucose responses, no doubt
due in part to their relatively high starch content. Forages (hays) and
byproduct feeds (primarily by-products of human food production) produced
relatively lower glucose responses. The glycemic indices of the 16 feeds
assessed in this study, in descending order, were as follows: • Corn:
117 • Oats and molasses: 105 • Barley: 101 • Oats: 100 • Oats and
oil: 86 • Alfalfa and molasses: 85 • Wheat: 71 • Vetch blend hay:
53 • Carrots: 51 • Wheat bran: 37 • Timothy hay: 32 • Alfalfa cubes:
30 • Alfalfa hay: 26 • Bermudagrass hay: 23 • Rice bran: 22 • Beet
pulp: 1
