Digestion Flashcards
what are the 4 types of digestive systems?
avian, monogastrics, ruminants, hindgut fermenters
which type of digestive system does a pig have?
monogastric
which type of digestive system does cattle, goats, sheep, and deer have?
ruminant
which type of digestive system does horses, rabbits, and ostrich have?
hindgut fermenters
what role does saliva play in the digestive system?
buffers pH from the rumen and moistens the food
what is the order of how the food bolus travels in a ruminant?
- rumen
- reticulum
- omasum
- abomasum
- small and large intestines
rumen
aka “paunch”
largest stomach compartment
microbes, protozoa, and fungi use fermentation to digest food
produces proteins, volatile fatty acids, hydrogen, and CO2
contracts to mix food
what role do the volatile fatty acids produced during fermentation in the rumen play in nutrition for ruminants?
VFAs make carbohydrates
what type of relationship do the microbes and the ruminant have?
symbiotic
microbe needs warm moist environment
ruminant needs VFAs
what are the 4 layers that the rumen contains?
gas at the top, solid in the middle, slurry forms in the middle just below solid, and liquid at the bottom
reticulum
looks like honeycomb
controls rumen contractions
honeycomb pattern allows for more surface area to be used for nutrient absorption
omasum
aka butcher’s bible (folds look like a book)
has folds that increase surface area for water and nutrient retention
absorbs water and salts
food bolus is squeezed
abomasum
aka true stomach
secretes acids and enzymes
how do ruminants get rid of the hydrogen and CO2 gases created from fermentation?
by belching otherwise animal will bloat
this is how methane is released into the atmosphere because hydrogen and CO2 gases produce methane
eructate
belch
what happens in the rumination process?
aka chewing the cud
forage from the rumen is regurgitated for further chewing and mixing with saliva
what is the order of the rumination process?
- regurgitation
- re-chewing into smaller pieces
- re-salivation
- re-swallowing to go to the reticulum
what is the average pH of ruminant saliva and why is it so important?
pH ~8.2
keeps rumen at a stable pH level otherwise VFAs would lower pH and could kill bacteria involved in the fermenting process, most food eaten by ruminants is acidic too
saliva also has a foam suppressing effect in the rumen which helps reduce bloat risk
rumen canula
a surgical fistula created that allows direct access into the rumen
used for education, health monitoring, and treatment
transfaunation
transferring rumen contents through a rumen canula to feed to other cows, sheep, or goats with impaired rumen digestion
esophageal groove
muscular folds from the reticuloreumen
suckling reflex triggers esophageal groove to close so milk bypasses rumen and flows directly into abromasum
prevents milk from fermenting in rumen
how does the rumen develop in young ruminants?
once they start eating solid food some will stay in the rumen and lead to microbial population developing and then gradually the rumen walls develop
grazers
eat grass, ground vegetation
browser
eats leaves, shoots, twigs
more selective diet
forage
high-quality pasture crops supply nutrients needed through grass, oats, rye, barley and legumes like red clover, alfalfa
what can goats not digest?
plant cellulose
give them lush pasture and supplemental hay or grains in winter
most common high energy feeds
high-starch grains like corn, sorghum, barley, wheat
creep feeding
supplemental feeding to nursing calves
goat flushing
supplemental feed prior to breeding to induce ovulation of multiple eggs
what does grain overload cause?
production of lactic acid which leads to bacteria production causing acidosis and bloat
