Lecture 7 Flashcards
Lactic acid absorption?
Cant be absorbed at high rates due to low pKa. Not until pH of rumen drops substantially can lactate be absorbed from rumen
- Grain overload, lactic acid produced rapidly h/e cant be absorbed quickly
What to do if ammonia toxicity occurs?
Give vinegar
- drops rumen pH forming NH4 (ammonium) which is absorbed more slowly. Thus decreasing amount of ammonia systemically present
How are VFAs delivered from rumen to liver?
Portal Vein
What is beta-hydroxybutyrate used for?
Used by most tissus for energy
- Provides initial carbon skeleton for fatty acids in milk
What happens to propionate and lactate at liver?
Propionate –> oxaloacetate —> glucose
Lactate —> pyruvate —> glucose
What happens to acetate at liver?
Forms acetyl-CoA
- Acetyl-CoA + Oxaloacetate = citric acid
- Used in fatty acid production
What produces majority of the ruminants maintenance energy?
VFAs
- Glucose production
- TCA cycle
How much of dietary protein is degraded by microbes?
50%
How do bacteria degrade protein?
Only 10 - 40% do
- Extracellular protease degrde protein into peptide fragments
- Absorbed into bacterial cell
- Degraded to amino acids
Where are bypass proteins broken down?
Abomasum/intestine
What are the sources of protein absorbed in ruminant intestine?
By-pass protein
Microbial protein
What is biuret?
Condensation compound of urea, equivalent to two molecules of urea less one of ammonia
What is wrong with NPN source of N
Ammonia - toxic
4-methylimidazole (neurotoxic)
Ammonium overwhelms liver
Excess ammonium affects the CNS
How to prevent bonkers cow?
Feed urea @ <3% of concentrate, ~ 1% of total diet
Slowly adapt to NPN feed
