Biomaterial Database

Studies of the large intestine of sheep. 1. Fermentation and absorption in sections of the large intestine. 1982

R M Dixon, and J V Nolan

1. Fermentation and absorption of constituents of digesta in segments of the large intestine of sheep given different diets were studied by analysis of gut contents obtained at slaughter after a period during which the sheep had been administered a non-absorbable gut marker. 2. In sheep given chopped, dried lucerne (Medicago sativa) there was net absorption of water throughout the large intestine with concomitant increases in the proportion of dry matter (DM) and organic matter (OM). There was net disappearance of 62 g OM, 1.66 g non-urea non-ammonia-nitrogen (NU-NAN) and 0.6 g (urea + NH3(-N in the caecum and proximal colon. There was no significant change in OM and NU-NAN flow through the remainder of the large intestine but there was a net disappearance of 0.3 g NH3-N. There was also net appearance of volatile fatty acids (VFA) in the caecum, most of which was apparently absorbed before the rectum. 3. Metabolism in the caecum was also studied in sheep grazing fresh pasture or consuming one of three sugar cane-bagasse-based diets, or barley pellets. In the lucerne- and pasture-fed sheep there was a net disappearance of approximately 0.5 g NH3-N/d from the caecum, while in sheep fed on bagasse plus urea, 1.4 g NH3-N/d was apparently absorbed from this region. The addition of fish meal to this latter diet resulted in apparent disappearance of 5.3 g NH3-N/d from the caecum and proximal colon. 4. There was apparent loss of NU-NAN from the caecum of sheep on all diets except the barley diet. With the latter diet there was a net gain of 1 g NU-NAN/d which was associated with relatively high VFA concentration and production; taken together these results indicate that microbial fermentation in the caecum was more extensive in the sheep fed on the barley diet than in those fed on the other diets. 5. The proportions of individual VFA in digesta from the rumen and caecum of lucerne-fed and pasture-fed sheep and in digesta from the caecum of sheep given the bagasse-based or barley diets are also reported and discussed. 6. In general the results indicate that the caecum and to a lesser extent the proximal colon were the major regions of fermentation and absorption of the components of the digesta in the large intestine.

UI	MeSH Term	Description	Entries
D007408	Intestinal Absorption	Uptake of substances through the lining of the INTESTINES.	Absorption, Intestinal
D007420	Intestine, Large	A segment of the LOWER GASTROINTESTINAL TRACT that includes the CECUM; the COLON; and the RECTUM.	Large Intestine
D008297	Male		Males
D009584	Nitrogen	An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
D002432	Cecum	The blind sac or outpouching area of the LARGE INTESTINE that is below the entrance of the SMALL INTESTINE. It has a worm-like extension, the vermiform APPENDIX.	Cecums
D003106	Colon	The segment of LARGE INTESTINE between the CECUM and the RECTUM. It includes the ASCENDING COLON; the TRANSVERSE COLON; the DESCENDING COLON; and the SIGMOID COLON.	Appendix Epiploica,Taenia Coli,Omental Appendices,Omental Appendix,Appendices, Omental,Appendix, Omental
D004032	Diet	Regular course of eating and drinking adopted by a person or animal.	Diets
D005232	Fatty Acids, Volatile	Short-chain fatty acids of up to six carbon atoms in length. They are the major end products of microbial fermentation in the ruminant digestive tract and have also been implicated in the causation of neurological diseases in humans.	Fatty Acids, Short-Chain,Short-Chain Fatty Acid,Volatile Fatty Acid,Acid, Short-Chain Fatty,Acid, Volatile Fatty,Fatty Acid, Short-Chain,Fatty Acid, Volatile,Fatty Acids, Short Chain,Short Chain Fatty Acid,Short-Chain Fatty Acids,Volatile Fatty Acids
D005285	Fermentation	Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.	Fermentations
D000641	Ammonia	A colorless alkaline gas. It is formed in the body during decomposition of organic materials during a large number of metabolically important reactions. Note that the aqueous form of ammonia is referred to as AMMONIUM HYDROXIDE.