Rabbit Nutrition
I am no expert on rabbits by any means but following speaking at a nutrition debate at Cambridge University organised by the Association of Veterinary Students in November 2007, I learned the following from an excellent speech (top speaker of the day IMHO) by Cambridge University vet Tom Harcourt-Brown MRCVS. I include this page for informational purposes for rabbit owners and to demonstrate the lengths to which the pet food manufacturers will go to sell their products regardless of the impact on animal health.
Rabbits are designed to eat a relatively large quantity of poor quality fibrous food. It is for this reason that rabbits are coprophagic - ie they eat their green droppings produced when food passes through the digestive tract for the first time. They will then double-digest their food and produce the harder brown rabbit droppings we commonly see when walking our dogs in the countryside.
Rabbits are not designed to eat grain-based feeds as it is too rich from being nutrient-dense. Rabbit feeds produced as a mix (ie not pelleted) allow the rabbit to pick out the low grade fibrous elements, leaving the more nutrient-rich elements which contain those nutrients put back chemically to replace those destroyed by the original manufacturing process. This is researched fact that rabbits do this.
The alternative is to pellet all the ingredients together so that rabbits cannot pick and choose. The problem with this is that the resultant pellet is nutritionally too high quality and rabbits will tend to over-eat in order to get satisfaction from a stomach-fill volume perspective. This means they tend to get too fat. This is researched fact.
Both scenarios will inevitably result in dietary-related rabbit diseases which from what I could gather from Tom Harcourt-Brown MRCVS makes up the vast majority of rabbit cases he sees in veterinary practice. | 
