Rumen physiology

Question 1

rumans microrganisms pruudce

Answer 1

cellulase to hydrolyze cellulose

Question 2

rumen microbes account for how much digestion

Answer 2

70%

Question 3

microbes cause

Answer 3

substantial fermentationof carbsad degredation of protein and synthessof microbial protein

Question 4

what is the rumen

Answer 4

large musclular compartment
have papillae
no enzymes
for storage,soaking, mixing and breakdown and fermentation
bacterial synthesisofwater soluble vitamins and vitamin k
bacterial synthesis of amino acids and protein
breakdown of fibrous feeds high in cellulose

Question 5

what is the reticulum

Answer 5

honeycomb
mucus membrane
no enzymes
move ingesta into rumen or into omasum

Question 6

omasum

Answer 6

sphericl
musculr laminae
reduces particle size of ingesta before it neters abomasum

Question 7

abomasum

Answer 7

glandular stomach

corresponds to simple stomach

Question 8

reticular groove

Answer 8

passageway from cardia to omasum

Question 9

rumination

Answer 9

ingest,thenregurgitate remasticateresalivate and reswallow

Question 10

eructation

Answer 10

microbial fermentationof hte rumen results in productionof large amounds of co2 n methane, if cannot escape bloat will occur

Question 11

pregastric fermenters can

Answer 11

use cellulose
convert npn to microbial protein
complete n recycling
microbial detox
reduces b vitamin requirement
effficient absorbtion of microbial end products like microbial protein and b vitamins in the small intestine

Question 12

downside of pregastric fermentation

Answer 12

lose energy by fermenting carohydrates
10-15% lost
high quality proteins decreased through fermentation
antibiotics need to be done iv

Question 13

Rumen environment

Answer 13

warmm anaerobic, chemmically reducing
rich in om
about 13% dry matter
takes up 80-85% of whole stomach
15% of body weight
end products and waste from microbial fermentationdo not accumulate in the rumen,theyare removed by diffusion across the rumen wall and passage from stomach

Question 14

ph of rumen

Answer 14

neutral
via saliva (phosphate bicarbonate buffer with some urea and mucous but no enzymes)
via diffusion across the rumen wall
rumen wall is permeable to many solutes
more volitale fatty acids diffuse across the wall into theblood than pass on to hte omasum

Question 15

temperature of the rumen

Answer 15

41 C

affects: ph, water, ions, viscosity, hydrratiion, toxicity, other unfavorable components

Question 16

gas mixturein the rumen

Answer 16

co2 from fermentation and bicarbonate,dietary carbonates and amino acids
ch4
h2 (used to reduce co2)
N

Question 17

oxygen

Answer 17

o2 diffusion across the rumen has caused adherent strains ofbacteria which are facultative anaerobes
on the lumenal surface of the rumen for oxygen scavaging to maintain anaerobic conditinsfor the obligate adherent anaerobes in the rumen

Question 18

urea in the rumen

Answer 18

enters as a feed supplement
source of nh3 for bacterial protein production
adherent bacteria have a much higher urease activity than bacteria in rumen fluid.
when epithelial cells fall off there is a high urease activity in the fluid.
bacteria adherent to the rumen wall can scavage o2 diffusing from the rumen wall and produces urease that digests urea diffusing across the rumen wall oor that enter the rumen via saliva.

Question 19

the rumen will…

Answer 19

hydrolyze ,biohydrogenate, and synthesize lipids