Post Ruminal Fat Digestion Flashcards
Is lipid absorbed in the omasum?
no significant absorption of lipid in omasum
Why is lipid reaching the small intestine often higher than what is fed?
microbial phospholipid contributes lipid
What is de novo lipogenesis?
Synthesis of fatty acid
What VFA is the major precursor for fatty acid synthesis?
Acetate
What are the 5-6 general steps in intestinal lipid digestion?
- Desorption from feed particles
- Breakdown of microbial phospholipids
- Micelle is formed and absorbed
- Resynthesis into TAG, DAG, MAG in enterocyte
- Packaged into chylomicron and VLDL in enterocyte
- Entry into bloodstream
What molecules are used to form micelles in ruminants? Why are those molecules able to form micelles?
BS, FA’s, Lyso-L
They are ampipathic
Where does most fatty acid absorption occur?
Jejunum (20% upper, 60% remainder)
How are fatty acids >14 carbons absorbed and processed? Fatty acids <14 carbons?
> C14: lymph
<C14: enter blood and to liver
What happens to free fatty acids (>14C) when they enter the intestinal cells?
re-esterified to MAG, DAG, and TAG
How are chylomicrons and VLDL formed?
MAG, DAG, TAG are packaged with phospholipid, cholesterol, & apoproteins
Are VLDL processed in the ruminant liver? Why or why not?
No because Apoprotein-C inhibits liver removal
What is the primary site of lipogenesis in ruminants? In non-ruminants?
Ruminants: tissue
Nonruminants: liver
Where does glycerol come from for production of triglyceride?
adipose tissue
What form are fatty acids stored in in fat tissue? What form are they in blood?
Tissue: Free FA
Blood: NEFA, VLDL, triglyerides, Acetate
Describe the progression of an animal from a normal state to a ketotic state?
- demand for NEFA
- NEFA released from tissue
- NEFA in circulation increases and liver is flooded
- NEFA is oxidized to ketone bodies
