ruminant forestomach Flashcards
what are three unique things about ruminants
- cloven footed
- chews cud
- digest plant cellulosic material
what are pesudoruminants
- 3 chambered stomach
- camels and hippos
what stomachs do marsupials have
- anterior sacciform and posterior tubiform stomach
- don’t produce methane
what is the rumen linked to
- improved feed efficiency
- multidrug resistance
- cellulosic ethanol
- greenhouse gases
- improved forage varieties
is the rumen functional at birth
no - neonates are like monogastrics
up until 3 mo. of age
how much does the reticulorumen occupy of mature volume
80%
folds
areas of tissues dividing the reticulorumen into different compartments
pillars
muscular areas that forms grooves on the outside of the rumen
how many chambers is the rumen divided into and what are they
5
* crainal chamber
* dorsal chamber
* ventral chamber
* dorsal blind sac
* ventral blind sac
reticulum
- honey comb appearance
- feed forms a bolus
- regurgitation initiated
- collects hardware
rumen
- papillary lining
- harbors microbes
- absorption of VFA
- primary digestion
omasum
- muscular folds/laminae
- particle size reduction
- more absorption
- connects to abomasum
what is the capacity of the reticulo-rumen in cattle
125L
what is the capacity of the reticulo-rumen in sheep
17L
why is the capacity of the reticulo-rumen so large
large capacity needed for feed to be fermented
what are the factors that govern the process within the rumen
physical, chemical and microbial
what are the driving forces of the rumen
dietary, host, environmental, and health factors
pH of rumen
6-7
rumen contractions help with
- digesting feed material
- allows for determining how much time the feed spends in the rumen
layers of rumen (stratified)
- gas
- course hay (rumen mat)
- liquid in center
- fine particles in ventral sac of rumen
why is the rumen mat important
microbial colonization and feed fermentation
what are the 4 Rs in rumination
- regurgiation
- remastication
- reinsalivation
- redeglutition
regugitation
reverse peristalsis carries food to mouth
remastication
- liquid squeezed from bolus and swallowed
- bolus chewed
reinsalivation
adding more saliva
redeglutition
swallowing bolus and liquids
what are the two types of contractions
- primary
- secondary
what is primary contraction
initiated in the reticulum
* helps movement of digesta and facilitates rumination
* mixing contraction
* evacuation contraction
what is secondary contraction
starts in rumen and helps with erucation
where do heavier particles (digested particles go)
pushes to cranial sac-reticulum-RO orifice
where do lighter particles (undigested) go
join the mat in the dorsal sac-ventral sac pushed to cranial sac to esophagus through cardia
where do high densisty foreign bodies go
pushed towards both RO orifice and cardia and settle in the floor of the reticulum
what are the 4 functions of contractions
- mixing incoming feed with existing to avoid stratification
- fermentation productions towards wall for absorption
- sort particles for rumination or passage through omasum
- facilitate rumination and eructation
primary and secondary contractions are under control of which nerve
vagus nerve
eructation
expulsion of gases through mouth
microbial fermentation of feeds produce large quantities of gases which accumulate where
CO2, CH4, H2
in the rumen
how many liters of gas per cow per day is produced
650L (methane)
what nerve controls eructation
vagus nerve
what is the normal pH for the rumen
- 6.2 to neutral (or 5.5-7)
- fibrous diet > 6; concentrate rich diet 5-6
- intra-day changes (5.5-7)
how does diet control pH
saliva production
long forage particles produce more
saliva - desirable
what is the normal ruminal pressure
980 to 1020 mbar
what is the normal ruminal temperature
38.5 - 39.5 degrees C
the rumen is a capacious anerobic fermentation chamber that is colonized by
complex microbial ecosystem
what kind of association exists between host and rumen microbes
symbiotic
how much energy does microbial fermentation provide and how much protein needs of the host
> 70%; 50%
what are the benefits to the microbes
- anerobic conditions and moisture
- energy: ATP released during fermentation
- nitrogen from ammonia and peptides for growth
- minerals and vitamins
what are the benefits to the ruminants
- energy in the form of VFA
- amino acids in the form of microbial protein
- detoxification of antinutritional factors
what are the side effects of symbiosis
- methane
- biohydrogenation
where are ruminal microbes found
- free in the liquid phase
- attached to feed particles
- attached to epithelial lining of rumen
- attached to protozoa
- methanogens
pH > 6
microbes
fiber digesters
pH < 6
microbes
amylolytic digesters
pH - 5.5
lactic acid producers - dysbiosis in the rumen microbiota
frothy rumen contents is due to what
accumulation of polysaccharide slime that traps gas and inhibits erucation mechanism
what type of feed predisposes ruminants to frothy bloat
forages (alfalfa, winter wheat) high in soluble sugars and proteins
