Ruminant Digestion Flashcards
What are the four compartments of the ruminant stomach?
Rumen, reticulum, omasum, Abomasum
Where does digestion occur in the ruminant large intestine?
Colon
What is the percent of total tract capacity of ruminants that is Fermentative?
83%
What are the three herbivore classes?
Concentrate selectors, intermediate feeders, roughage grazers
What are some advantages to ruminants?
Eat cellulose, detox plan substances, relieves of needing an external source of vitamin b
What is saliva rich in?
Sodium, potassium, bicarbonate, and phosphate
What two components of saliva act as buffers in The rumen?
Phosphate and bicarbonate
What is the enzyme in saliva that begins starch breakdown but is not present in ruminants?
Salivary amylase
What enzyme is secreted by ruminant salivary glands?
Salivary lipase
What is the name of the post prandial regurgitaron reflex of partially digested feed?
Rumination
What can rumination do?
Allows physical breakdown, increases surface area, lowers ph
What is The intermediate of the rumination process?
Glucose
What is the removal of fermentation gases known as? Which gases?
Eractation removes CH4 and CO2
What does reticulo-rumen distention stimulate?
Eructation
What is the percentage of total tract capacity that is fermentative in ruminants?
83%
The rumen is a big fermentation vat and storage filled with papillae. What are some things that happen and in what environment?
Physical mixing, VFA absorption and in an obligate anaerobic environment
Metabolism of the rumen is through?
Microbial fermentation
What is the center intermediate for microbial fermentation?
Glucose
What enzyme digests starch?
Amylase
Do ruminants have salivary amylase?
No
What is the reticulum involved in?
Mixing and regurgitating, food bolus, collection of hardware
Are there enzymes present in the reticulum?
Not from the host, but there are from the microbes
The reticulum is characterized by what type of structure?
Honeycomb
The omasum is characterized by what type of structure?
Muscular folds
What happens in the omasum?
H20 and VFA absorption
Why should VFA absorption occur in the omasum?
So they don’t buffer the abomasum’s ph
Which of the 4 compartments of the ruminant stomach is the true stomach?
Abomasum
What does the abomasum secrete?
Proteolytic enzymes, HCl,
Pepsinogen, and rennin
What happens to pH in the abomasum?
Decreases because of protein denaturing
What happens to digestion if passing rate increases?
Digestion decreases
What factors affect digestibility?
Plant maturity, type of microbes, feed processing
The speed of undigested feed residue through the digestive tract is called?
Passage rate
What does the passage rate depend on?
Particle size and density
If feed intake increases, what happens to rate?
Increases as well
What processes are always competing?
Digestion and passage rate
What aspect of the rumen actually goes through with digestion of feedstuff?
Rumen microbes
What type of fermentation mostly occurs in the rumen?
Anaerobic
How many ATP molecules does glucose approximately have?
35-36
How much ATP does the host actually get from glucose?
Approx. 31
As the microbes use around 2-5 ATP molecules, what molecule they turn glucose into before they go into the VFAs?
Pyruvate
What does pyruvate get converted into?
VFAs: acetic, propionic, butyric acid
CO2, CH4, H2O and heat
What type of microbes can we find in the rumen?
Cellulolytic, hemicellulolytic, amylolytic, and proteolytic
What type of acid do cellulolytic bacteria produce?
Acetic acid
Propionic acid is the result of fermentation from what type of bacteria?
Amylolytic bacteria
What other organism apart from bacteria is a key component in the rumen since if animals are deprived of them they don’t do well?
Protozoa
What organisms digest fiber in the rumen?
Fungi
What’s the end product of microbial fermentation of protein?
NH3
What is the nitrogen source for cellulolytic bacteria used to growth and regeneration?
NH3
What do ruminant hosts provide the microbes?
Heat, nutrition, buffered environment, waste removal
What do microbes provide to the host?
Cellulose and hemicellulose digestion and VFA production
Cellulases come from what to provide High quality protein, detox, and a source of b and C vitamins?
Microbes
An increase in microbe efficiency can do what?
Increase amount of microbial protein available to host and reduce feed costs
Ideal rumen fermentation means that…
There is rapid fiber digestion, optimal VFA ratio, and efficient microbes that grow rapidly and don’t accumulate NH3 too much
