Corn in rabbit food

Question
I have had lots of people ask me about feeding rabbits corn. I fed rabbits corn and alfalfa and other feed items for years without any problems.  If a rabbit was eating corn wouldn't it break up the outer hull (instead of ingesting it whole) and wouldn't it then get fermented by bacteria in the ceacum?  Furthermore research that compares the use of corn vs. wheat or barely in the diet of rabbits and found no statistical difference in digestibility, ceacal pH, muscle fatty acid composition and other factors.  What is wrong with feeding rabbits corn?

Answer
Dear David,

The hull of a corn kernel is composed of very tough polysaccharides (cellulose, hemicelluloses A, B, and C) and lignin that even a rabbit's intestinal flora may not be able to completely break down if the kernels are ingested in large pieces.  

Milled corn isn't a major problem.  It's already been broken up into very tiny bits that will pass through the rabbit's digestive tract without incident.  This is the form in which corn is added to commercial rabbit pellets.  The hulls are also less of a problem with dried corn, as a bunny will usually grind the kernels into very small bits before swallowing.

But fresh corn is another matter.  The endosperm is soft, and the hull is pliable.  So the whole thing can be swallowed with not much chewing.  If a lot of hulls are swallowed hole, they can cause an intestinal impaction.  I am not sure anyone knows exactly why, but my guess would be that the digestive enzymes and intestinal flora simply don't have enough surface area available on a large piece of hull to access and completely break it down.  

I've seen the results myself, firsthand.  But our Gryphon was lucky, and after a few days of unhappiness and constipation, he managed (with medical help) to pass a great wad of hulls, and we never fed him fresh corn again.

Corn isn't a natural part of a grazing herbivore's diet, so there's that to consider.  It's high in calories and sugar, neither of which is good for long-term maintenance of a healthy bunny.

So to be safe, we try to avoid foods with a lot of corn added, and we stay strictly away from anything with fresh corn.

Hope this helps.

Dana