SIGNIFICANCE OF CHANGES IN HEXOSAMINE AND IN NITROGEN IN THE DIGESTA OF THE ALIMENTARY TRACT OF THE SHEEP.

Abstract

Previous work had shown that the method of killing an animal affected the integrity of the mucosa of its digestive tract and as a consequence the content of nitrogen in the digesta.In the contents of the abomasum and the small intestine (divided into 4 equal lengths) of a group of sheep shot and bled and in another group anæsthetized and bled it was found that total nitrogen and hexosamine concentrations in the dry matter of the digesta or in relation to the dietary lignin as a marker rose considerably from the abomasum to the first quarter of the small intestine. The increase in hexosamine was less than that of total nitrogen. After the first quarter of the small intestine a decrease in total nitrogen was observed distally, but the proportion of hexosamine increased. In a third group of sheep from which the contents were obtained under anæsthesia alone the increments, both of total nitrogen and hexosamine, were less. In conscious sheep on the same kind of diet and fitted with cannulas, similar but smaller changes were found.Mucoprotein is probably the main source of hexosamine in the proximal zone of the small intestine but distally microbial cell wall polysaccharides containing glucosamine become a considerable source.The condition of the animal at the time of sampling greatly affects the significance to be attached to the nitrogenous constituents of the digesta.