Swine > Feeding & Nutrition

For background, remember that starch is made up of two components, amylose and amylopectin. Amylose is a straight chain of glucose units connected by alpha 1-4 bonds. These bonds are broken by the enzymes maltase and amylase. Amylopectin contains the same chains, but also has "branch points" created by alpha 1-6 bonds. these bonds are broken by the enzyme isomaltase. Theoretically, amylose should be easier to digest because it does not require isomaltase, and does not have the steric hindrance caused by the branch points. However, amylose can form a very compact physical structure, which inhibits digestion. Therefore, amylopectin is actually digested better than amylose. In practical terms, waxy corn contains much more amylopectin (lower amylose:amylopectin ratio) than regular corn. My reading of the data on waxy corn is that it is slightly more digestible than regular corn, but the difference is so small it's hard to find in performance. I don't know of any effect of the ratio on feed intake.

Sincerely,

Gilbert Hollis Extension Swine Specialist Department of Animal Sciences University of Illinois