L22- Milk Prod and Ketosis (#4) Flashcards

1
Q

3 general developmental processes culminate in milk secreiton- what are they?

A
  1. Mammogenesis
  2. Lactogenesis
  3. Galactopoiesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is mammogenesis?

A

Mammary gland development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is lactogenesis?

A

Induction of milk syntehsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does lactogenesis involve?

A

Regulation of gene expression and protein synthesis within the milk secreting epithelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

A few of genes turned during lactogenesis code for what 3 things?

A
  1. a-lactalbumin (required for lactose synthesis)
  2. Casein
  3. Several enzymes needed for Fatty acid synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is galactopoiesis?

A

The final stage of lactogenesis and refers to the mainteance of milk synthesis until it is no longer needed during an established lactation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Milking stimulates the release of _______(bST) which helps maintain milk produciton

A

Bovine somatotropin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Cows are in ________ during the first 12-14 wk of laction

A

Negative energy blaance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

During the first month, cows may obtain one third of their energy needs from body stores resulting in a ______

A

50-100 lb wt loss!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

AA from lost muscle of cows during demands of milk production are used for _____ and _______

A

protein synthesis and

Gluconeogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The ______ pathway for plasma components and leukocytes is open ONLY during pregnancy, involution, and inflammatory states like mastitis *

A

Paracellular*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Step 1 of pathway for milk secretion and synthesis by the mammary epithelial cell

A

I: Exocytosis of secretory vesicles containing milk protein, lactose, and other components of the aqueous phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Step 2 of pathway for milk secretion and synthesis by the mammary epithelial cell

A

II: Milk fat secretion via the Milk fat globule (MFG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Step 3 of pathway for milk secretion and synthesis by the mammary epithelial cell

A

III: Direct movement of the monovalent ions and water across the apical membrane of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Step 4 of pathway for milk secretion and synthesis by the mammary epithelial cell

A

IV: Transcytosis of components of the interstitial space (immunoglobulins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Step 5 of pathway for milk secretion and synthesis by the mammary epithelial cell

A

The paracellular pathway for plasma components and leukocytes. pathway V is only open during pregnancy, involution, and in inflammatory states such as mastitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is colostrum?

A

Special milk after parturition that is very high in proteins to act to improve the immune function of the calf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are milk proteins?

A

Synthesizes on the RER and move onto the Golgi stacks where they are decorated with oligosacchardies and phosphorylated, etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Class of milk proteins- describe the 1) solubility in acid, 2) protein(s), and 3) function(s) of WHEY** (vs caseins)!!

A

Whey (20% of total milk proteins):
-Soluble in acid
-Proteins: B-lactobulin (60% of total whey proteins)
a-Lactalbumin (25% of total whey proteins)
- Function:
B-lactobulin: no clear function possible a dietary protein
a-lactablumin: requred for lactose synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Class of milk proteins- describe the 1) solubility in acid, 2) protein(s), and 3) function(s) of CASEINS** (vs whey)!!

A
Caseins (80% of total milk proteins):
-Insoluble in acid
-Proteins:  Caseins (a,b,k)
- Function:
      Slows gastric emptying after precipitation, increases bioavailability of Calcium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Casein increase what in milk?

A

Bioavailability of calcium in milk (15% of calcium in milk is assoc with casein)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Whey proteins have a much higher _____ than casein

A

Biological value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Lactose synthesis requires what?

A

60-80% of the total daily glucose production

24
Q

Cow preserves glucose for what purpsoe?

A

Lactose production

25
Q

____________ is a dimer of galactosyltransferase plus a-lactalbumin!*

A

Lactose synthase

26
Q

Lactose synthesis controls what?* How? (2)

A

Controls volume of milk produced

  • Golgi vesicles are impermeable to lactose
  • Once made, lactose is trapped inside vesicles and osmotically draws water inside thus determining the volume of milk
27
Q

Energy in diet influences ___ production

A

Propionate

28
Q

Propinate controls the amont of ____ formed

A

Glucose

29
Q

Glucose controls the amount of _____ produced

A

Lactose

30
Q

Lactose determines the volume of ____ produceds

A

milk

31
Q

Lactose can be produced in 2 ways- from what two pathways?

A

AA–>a-lactalbumin–>lactose

Glucose- -> glucose –> lactose

32
Q

What does de novo FA synthesis start with ? (2)

A

Acetate and B-hydroxybutyrate

33
Q

FA are made where? what do they form?

A

Made on SER surface to form TAGS

34
Q

What do TAGS do before forming the MFG?

A

coaslese into large droplets next to apical membrane and becomes enveloped into apical membrane that separates from cell as MFG

35
Q

Membrane as 2 functions (apical membrane)

A
  1. Solubilzes milk fat and prevents fat globules from coaslescing into larger fat droplets in milk ducts which could prove difficult to secrete
  2. Primary dietary source of phospholipid and cholesterol for calf
36
Q

High forage diet vs high grain diet- which increases butter fat?

A

High forage diet

37
Q

What is something that has been shown to inhibit de novo FA snthesis acting at the gene level?

A

Very low levels of 3 specific conjugated LA

38
Q

What are three dietary factors that increase the risk of MFD and prod of CLA? (whether working indiv or not)

A
  1. INCREASE IN DIETARY FAT- more substrate avail for biohydrogenation
  2. DECREASE IN RUMEN PH- will alter microbial populations such that bihydrogeation is favored
  3. MONENSIN decreases bacteria carrying out conventional biohydrogenation thus resulting in more of the CLA that inhibits fat synthesis
39
Q

______ biohydrogenate linoleic acid forming CLA

A

RMO

40
Q

What does a CLA look like?

A

Conjugated double bonds with no methylene group separating dbl bonds

41
Q

The EFA, linoleic acid, is converted to __ acid in the rumen via biohydrogenation involving several CLA intermediates

A

Stearic acid

42
Q

What is ketosis?

A

Common metab disease where energy needs are not being met and forced to use FA acids from her AT to make up the difference

43
Q

Diagnosis of ketosis?

A

Based on elevated ketones in milk and urinalysis

44
Q

Ketosis is triggered by a compination of factors which lower blood glucose and increase lipolysis- what are they? (2)

A
  1. Increased utilization of glucose
  2. Decreased glucose production
    - 1&2 lead to hypoglycemia
45
Q

What would hypoglycemia (tirggered by ketosis) trigger after leading to low insulin? (3)

A
  1. Increased lipolysis
  2. Increased B-oxid of FA
  3. Increased ketogenesis
    - Ketonemia (elevated plasma FA)
46
Q

FA in excess of those needed for B-oxid and ketogenesis are re-esterfied to form ___ and packaged in ____

A

TAG and packaged in VLDLs

47
Q

VLDLs are slowly reelased from liver and excessive accumulations will result in a ______

A

fatty liver

48
Q

One theory that explains ketosis is a shortage of hepatic ______

A

Oxaloacetate (OAA)

49
Q

Shortage of OAA would be due to a decrease in what and an increase in what?

A
  • NEB (neg E balance) would lead to less propionate and hence dec prod of OAA
  • Inc rate of gluconeogenesis results in increased utilization of OAA
50
Q

What does the shortage of OAA prevent?

A

Acetyl CoA from FA B-oxid from enterting TCA cycle and forces it into ketogenesis

51
Q

Why is FA B-oxid activity high in liver early on in lactation? (2)

A
  1. A lot of ATP requred for gluconeogenesis (6 ATP equiv/ glucose formed)
  2. NEB foces cow to use fat from AT because rumen isnt supplying enough acetate
52
Q

During fasting, low blood glucose activates lipolysis, which means and ___ in B-ox of FA, and OAA is __ because of (__ in gluconeogenesis, and __ in ruminant propionate prod), lower OAA will ___ entrance of ace coA into TCA cycle, and __ actyl coa is shunted into KETOGENESIS*

A

INCREASE, DECREASED, INCRASE, DECREASE, DECREASE, INCREASE

53
Q

Type 1 ketosis: what serum ketones, glucose, on-set, BCS?*

A
Type 1 ketosis:
Very high SERUM KETONES
Low GLUCOSE
ON SET IS 3-6 wks post calving
BCS: thin
54
Q

Type 2 ketosis: what serum ketones, glucose, on-set, BCS?

A
Type 2 ketosis:
Moderately elevated SERUM KETONES
normal GLUCOSE
ONSET is within first 2 weeks after calving
BCS: over conditioned
55
Q

Ketosis is not life threatening but ketotic cows are more apt to develop what 3 things?

A
  1. Displaced abomasum
  2. Decreased mlk prod
  3. Difficulting conceiving