Exam 2 Flashcards
What is the major stimulating factor in secreting digestive enzymes:
Gastrin
What are the major functions of bile:
- Break up fat into small droplets
- Absorption of fats and fat-soluble vitamins in the small intestine.
“Prostaglandins” belong to
eicosanoids - subclass of lipids
“C3H6O2” is also known as:
- carboxylate ester
What is the function of abomasal lysozome?
efficiently breaks down bacterial cell walls
VLDL is a major transporter of:
endogenous lipids from the Liver to Fat and Muscle cells with help of LPL (Lipoprotein Lipase)
What is the major function of apolipoprotein CII and where does it come from:
Activator of extrahepatic lipoprotein lipase
Liver
What VFA is not utilized by the liver?
Acetate
What is Acetate utilized for?
de novo fatty acid synthesis
Oxidized via TCA
production of butyrate
Acetate utilization is dependent upon:
Energy balance
Arterial concentration
_____ is an important precursor for gluconeogenesis.
Propionate
_____ is metabolized by the rumen epithelium to ketone bodies.
Butyrate
Ionophore feed additives
_____ propionate
_____ acetate
increase
decrease
What are 2 things that affect the passage rate of feed?
how you feed
frequency of feeding
Rate of flow of solid is slow and dependent upon its _____ and _____.
size
density
What is the function of the omasum?
Poorly understood
Absorbs residual VFAs and bicarbonate
What is the function of the abomasum?
secretes lysozyme
allows material to enter the SI via pylorus
Give 4 examples of Gastric juices.
Pepsinogen
Rennin
Lipase
HCl
Give 4 examples of Pancreatic juices.
Chymotrypsin
Amylase
Lipase
Buffers
Give 4 examples of Intestinal enzymes.
Sucrase
Lactase
Maltase
Nucleases
_____ is the belching of gas
Eructation
Ruminants and Microbes have a _____ relationship.
Symbiotic
What is an apoprotein/apolipoprotein?
Protein component of lipoprotein
Stabilizes lipoprotein
allows lipoproteins to be recognized by receptors on cell surfaces
Stimulates LPL to remove lipids from the lipoprotein
Lipids are stored in _____.
Adipocytes
_____ promotes lipid storage by suppressing _____.
Insulin
hormone-sensitive LPL
Where does most absorption of amino acids occur?
duodenum
upper jejunum
What are the 3 types of Amino Acid Absorption?
Facilitated
Sodium dependent
Paracellular
What is paracellular absorption?
passage through tight junctions of enterocytes
Explain the events that take place in the body when a cow receives a dietary N source?
Broken down in rumen by Rumen microbes
Ammonia and CO2 production
Depending on energy levels
- leftover nitrogen will determine how much ammonia will be left over
Ammonia is converted to urea and brought to the liver
Some is brought back to the rumen through saliva
The remaining continues throughout the body and is excreted through urine
Rumen protected Nitrogen sources will be broken down in the abomasum and the SI
then absorbed through the SI
What are some examples that reduce feed intake?
Ration Characteristics - bulky (too much fiber)
Physiological state - comp for space (late pregnancy), sudden & significant increase in energy requirement (early lactation)
Environmental Factors - temperature, humidity, time
Forages - greater intake indicates _____
Faster digestion rate
Grain - greater intake may indicate _____
Less energy dense
The greater the intake, the _____ the nutrient supply above maintenance
greater
_____ : distention of the gut tells the animal to stop eating.
Physical fill
_____ : absorbed nutrient in blood is monitored by receptors in brain - tells animal to stop eating
Chemostatic
What are the 4 single Factor theories?
- Gastric distension
- Glucostatic Theory
- Thermostatic Theory
- Lipostatic Theory
Explain Gastric distension.
“Stomach growling”
hunger contractions of the stomach
increased rumen emptying = increase feed intake
Explain Glucostatic Theory.
Voluntary feed intake is controlled by glucose
hypothalamus –> blood glucose –> intake
Explain Thermostatic Theory
eat to keep warm constant body temp food intake --> heat production reduced intake --> body reserves over-eating --> activation of heat loss mechanisms
Explain Lipostatic Theory
maintaining body fat content
Explain the Multi-factor theory: Energostatic.
Energy supply to specific tissue
Chemo-receptors:
No evidence for glucose neg feedback
VFAs have different effects
Osmo-receptors:
increase rumen osmolarity, decrease voluntary feed intake (dry feed or silage)
Temperature receptors:
increase rumen temp, decrease intake and vise versa
Hormones:
- Insulin _____ intake
- Glucagon _____ intake
- Cholecystokinin (CKK) _____ intake
Decrease
Increase
Decrease
What are some dietary factors affecting feed intake?
Digestibility (# 1)
Energy content of ration
Ration Characteristics
- roughage content, grain, processing….
