New approaches to investigate feeding and digestive system in hervbivorous mammals

摘要

To elucidate the mechanism of assimilating the cellulose-rich food by Small mammals, morphofunctional investigations were supplemented by biochemical evaluation of digestive functions of symbiocenoses in forestomach and caecum aswell as by experimental determination of food passage rate and degree of cellulose fibers reduction in the digestive tract. Two model species of rodents having hemiglandular stomachs, great gerbil Rhombomys opimus and bank vole Clethrionomys glareolus were investigated. The success in cellulose assimilation in these rodents is related to careful grinding of fibers by teeth, that is accompanied in gerbits by fiber separation in the digestive tract: coarse and thick fibers are quickly evacuated, whereas small and thin ones are fermented in the caecum. In voles thick fibers are also destroyed as the cellulase enzymatic complex starts functioning already in the forestomach. The obtained results permit to calculate that in C. glareolus 24-30% of the cellulose assimilated are fermented in the forestomach.