Midterm 2 Flashcards
(112 cards)
How to obtain ruminal fluid
- orogastric tube
- ruminal puncture
Which examination can be delayed to 24h in refrigerator after rumen sample
Chloride and ammonia conc.
Why should the rumen samples be evaluated directly after collection?
minimize effect of cooling and air exposure on protozoal activity
what influences the ruminal fluid properties?
- composition of the diet
- circumstances of the feeding and sampling
- time interval from feeding and drinking
what can be seen in a rumen sample if taken immediately after feeding?
- VFA and gas concentration increase
- pH will be lower
What can be seen in a rumen sample taken after drinking?
- dilute sample
- decrease temperature
- decrease motility of microorganism
- decrease viscosity
give the normal and abnormal odor during physical rumen analysis
Normal:
Aromatic odor
Abnormal:
Ammonia smell (urea poisoning)
Moldy rotting (protein putrefaction)
Acidic or sour odor (excess lactic acid/grain overfeeding)
give the normal and abnormal color during physical rumen analysis
Normal:
Olive to brownish green (hay ration)
Deeper green color (green ration)
Yellowish brown color (grain or silage ration)
Abnormal:
Milky grey (grain overfeeding, lactic acidosis)
Darker greenish or brownish (ruminal stasis/decomposition)
Grey with clots of milk (calves with abomasal reflux)
give the normal and abnormal consistency during physical rumen analysis
Normal:
- slightly viscous
Abnormal:
- Increased viscosity (saliva contamination)
- Decreased viscosity, watery with few feed particles (inactive bacteria or protozoa)
- Excess frothy, stable bubbles (frothy bloat/ vagus indigestion)
In a rumen sample what can be seen in the sedimentation test for a very active fluid?
may exhibit sedimentation of fine particles with subsequent flotation
In a rumen sample what can be seen in the sedimentation test for an inactive fluid?
rapid sedimentation with little to no flotation, due to lack of fermentative gases
In a rumen sample during the sedimentation test, if a stable froth is present what can this indicate?
- frothy bloat
- vagal indigestions in Hoflund disease (stenosis)
- treatment with sympathomimethics against ruminal atonia
What is easily used for pH measurement
pH paper
What is a normal rumen pH, what can modify it?
- 6,3 - 7
- grain fed cows can have lower pH
- hay or green fed can have higher pH
Causes of an elevated rumen pH
-Simple indigestion or reduced feed intake for greater than 2 days
-Urea indigestion
-Putrefaction of ruminal content from prolonged rumen stasis
- Saliva contamination
causes of a lowered rumen pH
- Grain overfeeding
-Chronic ruminal acidosis
how can the rumen of an animal suffering from lactic acidosis have a normal pH
if anorexia has been prolonged due to continued saliva production
what is the acetic acid : propionic acid ratio
4:1
when pH decreases in rumen what happens to VFA
they decrease
how can VFA in rumen be measured
high performance gas chromatography
bacterias have an important role in which processes in rumen ?
redox
when is the redox potential increased in the rumen fluid?
in diet rich in starch and ruminal acidosis
when is the redox potential reduced?
ruminal flora is destroyed
Which test is for the reducing ability of anaerobic rumen flora?
méthylène blue reduction test