Test 2 Part 2 Flashcards
What is the source of CHOs in monogastric animals?
Plant starch and and glycogen which break down into glucose
Where does digestion and absorption of monogastric animals occur?
Small intestine
How does glucose get to the liver in monogastric animals?
Hepatic portal vein
What is the source of CHO is ruminant animals?
Starch and cellulose
Is fermentation of CHO in the rumen aerobic or anaerobic?
Anaerobic
What do starch and cellulose break down to? What does that product give off?
Glucose
VFA
In a high cellulose diet for ruminant animals, what happens?
Increase rumen acetate to make milk fat
In a high starch diet for ruminant animals, what happens?
Increase rumen propionate. The process is gluconeogenic
What is the goal of the anaerobic rumen? How does it do this?
To regenerate NAD
Transfer electrons from NADH from glycolysis (Page 42)
What do the NADs transfer to in the rumen? What do they form?
Pyruvate
Lactate
How many ATP is produced in rumen glycolysis?
2
What serves as the terminal electron acceptor in the rumen?
CO2
What does glucose become in the rumen? (3)
Lactate –> propionate
Butyrate
Acetate
What is lactate build up in the rumen known as?
Lactic acidosis or acidosis
What can lactate build up lead to?
Grain overload
Laminitis (founder)
What is the cause of lactate build up?
Abrupt increase in starch intake which increases lactate production and decreases rumen pH
When does lactate build up occur?
When taken from pasture and immediately placed on high CHO diet
Why would you look at the ration between propionate and acetic acid?
Acetic acid is lost as CH4 and is wasteful, but propionate is less CH4 and more digestible energy trapped as metabolizable energy
What does propionate make?
Glucose
What factors alter rumen fermentation?
Type of CHO
Feed additives
Total VFA produced
What are feed additives?
A type of antibiotic that selectively inhibits acetate producing microbes
What are 3 types of feed additives?
Ionophores
Monensin (rumensin)
Lasalocid (bovatec)
What does ionophore specifically do?
Alter propionate, acetate ratio to have better utilization of feed
What factors of VFAs alter rumen fermentation?
Physical form (surface area) Type of CHO
What does acetate break down into?
Acetyl CoA
Does acetate go through gluconeogenesis?
No
What does butyrate break down into?
2 Acetyl CoA
Does butyrate go through gluconeogenesis?
No
What does propionate break down into?
Succinyl CoA
Does propionate go through gluconeogenesis?
Yes
What VFA’s are used for energy?
Acetate
Propionate
Butyrate
What VFA’s are used for fatty acid synthesis (ketogenic)?
Acetate
Butyrate
What VFA’s are used for glucose synthesis (Gluconeogenic)?
Propionate
What is the blood glucose concentration of monogastric animals?
~90-100 mg/dL
What is the blood glucose concentration of ruminant animals?
~40-60 mg/dL
What is gluconeogenesis?
Glucose synthesis from non-CHO sources
What are the non-CHO sources involved in gluconeogenesis?
Propionate
Lactate
Glycerol
Some amino acids
What are the 3 irreversible reactions of glycolysis? Make sure they are in the correct order
1) Phosphoenolpyruvate to pyruvate. Pyruvate to oxaloacetate to phosphoenolpyruvate
2) Fructose-6-phosphate to Fructose-1,6-bisphophate
3) Glucose to Glucose-6-phosphate
