Physio 2 - Hind-Gut fermentor GI

drraythe's version from 2015-06-09 01:48

Hind Gut Fermenters⁰

Question Answer
How much energy coverage through hind fermentation in rabbits? Horses? Pigs? Dog/Man?r=30-40%, h=50-70%, p=15-30%, d/m=6-9%
What are the cecum fermenters?Rabbit, Chinchilla, G-pig, Koala
What are the colon fermenters?Horse, Elephant, Rhino, Pig, some primates
Size/sections/fxn of cecum?Ca 1.5m, base/corpus/apex, gets slurry from SI so it can do mixing b/t haustra & occasional mass movements (apex → corpus → base) ingesta moves through cecocolic orifice into ventral R colon
Is the cecum haustrated? Is the ventral colon?Yes & yes
Where is the longest retention time in the gut? How can it stay there so long?Ventral colon...stay bc of peristaltic+antiperistaltic movements.
What are the portions of the ventral colon?Ventral R colon, sternal flexure, L ventral colon, pelvic flexure
What does the pelvic flexure mark?Marked reduction of diameter, similar to pyloris, helps retain lg particles & pass liquid/sm particles
What are the portions of the dorsal colon?L dorsal, diaphragmatic flexure, R dorsal, jxn to sm colon
Fxn of dorsal colon?Similar movements to ventral colon w/ retention of ingesta at jxn
Total retention time of large colon is?24-96hrs!
Total volume of large colon?Up to 130L
If you compared hind gut fermenting & ruminal fermenting, youd say they were?VERY similar
What type of substances does the hind gut receive?Pre-digested mixture of feeds, endogenous fluids & cells
How would you describe digestion in the small intestine for a hind-gut fermenter?NOT efficient, FAST passage rate, pancreatic enzymes not very important
Large water movements occur in & out of hindgut during fermentation how?Osmosis & Cl secretion from crypts
What is the daily volume of fluid entering & leaving hindgut?Total ECF vol (20-25% of its body weight) (double its blood volume)
How does the horse buffer against the VFAs produced during its fermentation?Mucosal secretion of HCO3- (ileum & hindgut secretion)
What is the 1 thing she remarked that the horse was better at doing than the cow?Produce ACETATE instead of METHANE so there is LESS ENERGY LOSS
Does the horse nitrogen recycle? If so, how?Yes. Urea can be secreted into cecum & colon
Why do horses/rabbits eat their feces?Many of the microbial proteins & vitamins (K & B complex) are unavailable to be absorbed in the lg intestine, so the animal eats the feces rich in these so that it can absorb them in their upper GI (small intestine digestion/absorption)