Lecture 32: Ruminant Digestive Physio 2 (Exam 3) Flashcards
Describe the rumen @ birth
- Rumen is the same size as the abomasum
- No microbes
- Milk bypasses the rumen via the esophageal groove
- Has thin walls w/ short papillae & undev pillars
Describe the rumen @ 3 W old
- Calves start to ingest farage & concentrate
- Grain stimulates rumen papilla dev more than hay does
Where does the esophageal groove connect? What neural pathway is associated with this
- Connects @ cardia region to omasum
- Pharyngeal afferent neuronal pathways are involved in causing the fold of the reticulum to form this groove
What does the esophageal groove do
Bypasses the forestomachs b/c milk is poorly digested in the rumen
Slide 4
What gases are produced by rumen fermentation & are the most impt
- 65% CO2
- 25% CH4
How is eructation stimulated
- Gas pressure in the rumen
- Gas production peaks 30 mins to 2 H after feeding (just dep on the food they are eating)
- Secondary rumen contractions force gas into the reticulum towards the cardia
What are the 5 Fs of abdominal distension
- Fart (gas)
- Fluid
- Food
- Fetus
- Fat (visceral & subQ)
Why are the 5 F impt
To ascertain the cause of abdominal distention when examining a “bloated” animal
Describe Vagal indigestion syndrome
- Gradual development of abdominal distention secondary to rumoreticular distention
- Dx resulting in injury, inflammation, or pressure o the vagus nerv
- Has 4 types
Describe Type 4 vagal indigestion
- Indigestion associated w/ advanced preg
- Large fetus shifts the location of the abomasum
What does papple shape mean
- Lower left & upper left are bloated = apple
- Upper right is norm & bottom right is bloated = pear shaped
Slide 8
What is the primary gas produced by fermentation in the rumen
CO2
What is bloat (AKA ruminal tympany)
- Over distention of the rumenoreticulum w/ gases of fermentation
- Frothy bloat (primary)
- Free gas (secondary)
Who is bloat usually seen in
- Feedlot cattle (fed high amounts of grain)
- Cattle grazing on legumes
What is free gas bloat
Gas is separated from digesta
What is frothy bloat
- Foam mixed w/ ruminal contents
- Very stable foam w/ small gas bubbles (no eructation can occur)
- Froth get up against the cardia region & free gas under it can’t be eructed -> Gas accumulates in bubbles -> pressure increases & Pushes on the diaphragm (suffocation)
- Causes high surface tension
- Caused by high legume diets
- Seen in feed lot cattle b/c fine particle size allows gas bubbles to form
- Limit time on high risk pastures & give anti-foam agents
- Mineral oil can be used to tx
What can cause free gas bloat
Slide 9
What is the treatment of free gas bloat
- Pass a stomach tube to relieve gas pockets
- Trocar passed through the skin to the rumen
- Rumenotomy (incision in the rumen to relieve gas)
What do sweetlix have in them
Poloxalene to help reduced foaming
Describe Traumatic reticuloperitonitis (hardware dx)
- Cows are indiscriminate eaters so they freq consume FBs
- Heavy material/foreign objects fall into the reticulum during primary rumen contractions -> cause penetration of the wall & prevents movement of rumen contents through the reticulo-omasal orificix
What can result b/c of hardware dx
- Dep on the direction the FB is pointing
- Liver abscess
- Pleuritis
- Pericarditis
- ALWAYS w/ peritonitis
What are the clinical sx of hardware dx
- Decrease in rumen motility
- Decrease appetite
- Fever
- Ab pain
- Arched back
- Reluctant to move
- Grunt on expiration
Slide 12
What is the tx & prevention of hardware dx
- Medical - magnet or abx
- Surgical - rumenotomy
- Clean up the envi
- Magnets in feed equip
- Prophylactic magnets to all adult cattle
Describe left displaced abomasum
Will see less motility & gas production that causes displacement towards the left laterally to the rumen
Where is the abomasum
Suspended loosely by the greater & lesser omentum in the right front quadrant of the abdomen
Describe a RDA
- Same beginning as an LDA but abomasum rotates counter clockwise (looking @ px rear)
- Can lead to obstruction & ischemia (cutting off blood supply)
- Can cut off blood supply to the omasum & SI if severe
How does hypomotility contribute to displaced abomasum
- High grain diet leads to less motility -> gas flowing into the abomasum
How does periparturient changes in location of intra-abdominal organs contribute to displaced abomasum
- happen around 14 D of calving
- When preg organs have to move out of the way & after calving they have to move back to their origin positione
