chapter 4
Download
Skip this Video
Download Presentation
Chapter 4

Loading in 2 Seconds...

play fullscreen
1 / 73

Chapter 4 - PowerPoint PPT Presentation


  • 128 Views
  • Uploaded on

Chapter 4. Physiology of Milk Synthesis. FABP. MFGM. ACC. Milk Fat Synthesis. Circulation. Synthesis. Translocation. Secretion. UFA. TAG. LPL. NEFA. TAG. SFA. (C. -. C. ). 16. 18. +. synthesis. Glycerol. Glycerol. Glycerol. -. P. Glucose. Glucose. Acetate. de novo.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Chapter 4' - charles-vargas


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
chapter 4

Chapter 4

Physiology of Milk Synthesis

slide17

FABP

MFGM

ACC

Milk Fat Synthesis

Circulation

Synthesis

Translocation

Secretion

UFA

TAG

LPL

NEFA

TAG

SFA

(C

-

C

)

16

18

+

synthesis

Glycerol

Glycerol

Glycerol

-

P

Glucose

Glucose

Acetate

de novo

FA synthesis

(C

-

C

)

4

16

ßHBA

FAS

membrane

ER

membrane

Luminal

membrane

Basal

slide18

Epithelial Cell

Lumen of alveolus

Fat Droplet

Fat Droplet migrating

Golgi Body

Lysosome

Nucleus

Mitochondria

Mitochondria

E.R.

Blood Vessel

slide19

Epithelial Cell

Lumen of alveolus

Fat Droplet

Fat Droplet migrating

Golgi Body

Lysosome

Nucleus

Mitochondria

Mitochondria

E.R.

Blood Vessel

slide20

Epithelial Cell

Lumen of alveolus

Fat Droplet

Cell pinches off

Fat Droplet migrating

Golgi Body

Lysosome

Nucleus

Mitochondria

Mitochondria

E.R.

Blood Vessel

slide21

Epithelial Cell

Lumen of alveolus

Fat Droplet

Cell pinches off

Fat Droplet migrating

Golgi Body

Lysosome

Nucleus

Mitochondria

Mitochondria

E.R.

Blood Vessel

slide27

Changes in rumen conditions

that lead to milk fat depression

linoleic

linoleic

acid

acid

(

(

-

-

9,

9,

-

-

12 C

12 C

)

)

cis

cis

cis

cis

18:2

18:2

conjugated

conjugated

linoleic

linoleic

acid

acid

conjugated

linoleic

acid

-

-

10,

10,

-

-

12 C18:2

trans

trans

cis

cis

(

(

-

-

9,

9,

-

-

11 C18:2)

cis

cis

trans

trans

vaccenic acid

(trans-11 C18:1)

-

-

10 C

10 C

trans

trans

18:1

18:1

stearic acid (C18:0 )

milk fat concentration
Milk Fat Concentration
  • Most variable component of milk
  • Increased during periods of energy deficit
  • Decreased when fed diets containing unsaturated fatty acids (most grains) and low effective fiber (change rumen conditions)
    • Milk fat depression (<2.8% fat)
  • Fatty acid changes also occur
milk protein concentration
Milk Protein Concentration
  • Not too variable
  • Changes related to dietary energy intake, not dietary protein
    • little effect of dietary fat on milk protein concentration unless perturb normal rumen function
    • fermentable carbohydrate intake is the key!
      • Maximize VFA and microbial protein production
slide42

Udder Pressure & Secretion Rate

1.5

1.0

Secretion Rate (kg/hr) (____)

0.5

0

slide43

Secretion Rate

  • Influence of udder pressure
  • Milking intervals
    • 12 hour vs. other
    • 2X vs. 3X
    • young vs. old cows
slide45

Yield and Milking Frequency(Erdman & Varner, 1995 JDS)

Item Milk yield Fat% Protein %

# studies 40 18 4

2X 42.9 3.65 3.10

3X 50.6 3.51 3.05

# studies 4 3 3

2X 54.6 4.71 3.49

4X 64.5 4.53 3.44

slide46

Milk Let Down

  • Refractory period to oxytocin?
  • Adrenaline interferes
slide47

Milk Ejection

brain

nerves

P.P.

Stimulus

slide48

Milk Ejection

nerves

P.P.

slide50

Milk Ejection

Abdominal aorta

Oxytocin

Jugular vein

heart

slide56

Contraction of an Alveolus

arteriole

venuole

Lumen

Myoepithelial Cell

Oxytocin

Duct

slide57

Contraction of an Alveolus

Oxytocin

Myoepithelial Cell contracts

slide58

Contraction of an Alveolus

Releases milk into

duct system

slide59

Contraction of an Alveolus

Myoepithelial cell relaxes

biosynthesis of milk components
Biosynthesis of Milk components
  • Precursors from blood
  • One liter of milk requires 500 L of blood
  • Fat biosynthesis
  • Protein biosynthesis
  • Lactose biosynthesis
milk fat biosynthesis
Milk Fat biosynthesis
  • Requires fatty acids and glycerol
  • Two sources of fatty acids:

1- blood lipids (dietary lipids & adipose tissue)

2- De novo synthesis (within the MG)

ad