Alimentary - Ruminant Flashcards
How many stomachs are there in the rumen?
1 stomach - 4 chambers
What is the vasculature of the rumen stomach?
Coeliac artery
What can you feel on the left hand side of a rumen?
Rumen, reticulum and ventrally is the abomasum
What can you feel on the right hand side of the rumen?
Intestines, omasum and ventrally is the abomasum
What is the anatomy of the rumen?
Covered in papillae.
4 layers - stratified squamous epithelium, lamina propria and submucosa, muscularis interna.
Grooves run externally with pillars to make papillae muscular.
What is the chemistry of the rumen?
Near neutral pH (6.8) supporting a microbiome of bacteria.
VFA are produced and and needs saliva to buffer it
How much saliva is produced by a cow?
200L
What are the VFAs produced?
Propionate
Butyrate
Acetate
What does the animal eructate?
Methane
CO2
Ingesta
What type of cells line the rumen ?
Stratified squamous epithelium to protect against abrasive diet
Absorbs the VFAs but not water
How long do animals ruminate for?
20 hours in a day
How do cows regurgitate?
Contraction of reticulum floods cardia with food
This is drawn into the oesophagus and up to the mouth via anti-perisaltic contraction.
How are ruminations regulated?
CNX to dorsal vagal nucleus of the brain stem
What monitors the afferents?
Afferents on the ruminoreticulum monitor distension, ingesta consistency, pH and VFAs conc
What kind of movements of the rumen are there?
Primary and secondary
What are the primary movements of the rumen?
Ruminoreticular mixing cycle starting in reticulum. Follows a figure of 8 formation and happens every 60s
This is to allow microbes to circulate around the food
What are the secondary movements of the rumen?
A caudal to cranial wave to lead to eructation and rumination
Occurs every 20s and can be heard at paralumbar fossa
What is the anatomy of the reticulum?
Honeycomb structure with layers of stratified squamous epithelium, lamina propria and lamina muscularis mucosae
What happens in the reticulum?
Fermentation and if there are heavier materials they will sit here for a while like hardware disease
What is the anatomy of the omasum?
Between ribs 8-11 on right hand side
Comrprised of keratinised stratified squamous epithelium, with muscles, looks like leaves
What does the omasum do?
Contracts to absorb fluid and then moves solids onto the abomasum
What is the abomasum?
Most like a simple stomach
What is the oesophageal groove?
Abdomen of the calf isn’t using rumen so when it head is tilted the milk misses the rumen and reticulum it goes straight through.
What happens in milk gets into the calfs rumen?
It will undergo bacterial breakdown and produce lactic acid leading to acidosis and clotting
