How to feed the rabbit (Oryctolagus cuniculus) gastrointestinal tract

Rabbits are found in virtually every country in the world, providing protein, fiber, animal research, and companionship (third to dogs and cats). Because of an ability to utilize low-grain and high- roughage diets, they have the potential to be a future protein source. Classified as an herbivorous nonrumi- nant, rabbits have a simple, noncompartmentalized stomach along with an enlarged cecum and colon inhab- ited by a microbial population (primarily Bacteroides). Rabbits practice coprophagy, which enhances strate- gies of high feed intake (65 to 80 g/kg BW) and fast feed transit time (19 h), allowing rabbits to meet nutritional requirements. Coprophagy also increases protein di- gestibility (50 vs 75-80% for alfalfa). Feces are excreted on a circadian rhythm, and data indicate that the inter- nal cycle differs when shifting from ad libitum to re- stricted feeding. Microbes digest cellulose (14% in rab- bits vs 44% in cattle) in the hindgut of the rabbit, but the contribution of amino acids from microbial protein is thought to be minimal. Lysine and methionine may be limited in traditional diets, and urea is not utilized. Acetate is the primary microbial VFA, with more buty- rate than propionate. Unlike ruminants, more VFA are