Comparison of Digestive Function Among Rabbits, Guinea-Pigs, Rats and Hamsters. II. Digestive Enzymes and Hindgut Fermentation

The aim of this trial was to study the response of laboratory animals including omnivores (rats) and herbivores (rabbits, guinea pigs and hamsters) to the same level of dietary fiber on their digestive enzymes and hindgut fermentation. Ten weanling animals of each of four species, rabbits, guinea-pigs, rats and Syrian hamster, were fed a basal diet of 18% crude protein and 10% crude fiber for six weeks. The digesta and tissue of each intestinal segment were collected to measure the activity of digestive enzymes. Rabbits contained the highest secreted pepsin activity in the stomach, whereas rats contained the highest protease and ${\alpha}-amylase$ activity in the small intestine, and lower fibrous hydrolases in the hindgut than rabbits, guinea pigs and hamsters. The total VFA productions in the caecum and colon were highest in rats, followed by hamsters and rabbits, while the guinea pigs contained the lowest VFA and a different pattern of VFA molar ratio from the other laboratory animals. The degree of hindgut fermentation in these laboratory animals was in reverse to the trend for their fiber digestion.