Dairy Cattle Lactation (Part 3)

Question 1

Milk Fat

Answer 1

3.6%

Question 2

Milk Fat chemically

Answer 2

98% are triglycerides

Question 3

De novo synthesis of FAs

Answer 3

50%
C4 - C16 and some C20
from acetate (mainly) and ß—hydroxybutyrate

Question 4

Pre-formed long chain FAs

Answer 4

50%
C16 —C20
form the ration and lipolysis

Question 5

Milk glycerol comes from …

Answer 5

blood glucose (glycolysis)

Question 6

FA type in milk

Answer 6

62% of milk FAs are saturated

Question 7

Milk cholesterol

Answer 7

< 0.5% (500 mg/ LOO g) of total lipids in cow and buffalo milk

Question 8

Site of milk synthesis & secretion pathway

Answer 8

Smooth ER secreted though the milk fat route

Question 9

Milk Physical from

Answer 9

Oil in water emulsion (globules of 1—10 mm)

Question 10

Milk fat route - Fat globule

Answer 10

Small lipid droplets fuse together as
they move toward the apical membrane

At the apical membrane the large-lipid droplet forces out the apical membrane of the cell, which surrounds the-lipid droplet

This budding process results expulsion
of fat droplets into the alveolar lumen

The droplet often contains portions of cell cytoplasm.

Question 11

Milk fat droplet often contains portions of ..

Answer 11

cell cytoplasm

Question 12

Saturated fat limit

Answer 12

16 g per day

Question 13

Dietary cholesterol limit

Answer 13

No more than 300 mg per day

200 mg if you had a high risk of heart disease

Question 14

200 ml milk provide

Answer 14

3.72 gram SFA
30 mg cholesterol

Question 15

Milk Vitamins and Minerals

Answer 15

All are supplied from the blood

All essential vitamins and minerals are in appropriate quantities for specific neonatal growth

At least 10 times more Ca and P than blood

Question 16

Has the highest concentration among minerals in milk

Answer 16

K

Question 17

Some elements can be increased in milk by increasing the amount in the diet

Answer 17

I, Br, boron, Mn, Co, Mo, Se, and Zn

Question 18

Milk levels of B vitamins

Answer 18

Synthesized by rumen MOs
Constant in milk

Question 19

Levels of fat-soluble vitamins (esp. A and D)

Answer 19

Depend on their quantities in the ration and body reserves

Question 20

Milk Water %

Answer 20

87.4%

Question 21

Milk Water drawn into the secretory vesicles (SV) due to the osmotic effect of …

Answer 21

lactose, not blood pressure

Question 22

Because of the tight junctions (TJ) between epi. cells

Answer 22

There is little or no flow of materials between the adjacent cells

Anytime a substance passes between the cells the pathways is called the paracellular route

Question 23

TJ may become Ieaky (permeable) as during

Answer 23

1. Mastitis
2. OX supraphysiologic doses

Question 24

lgs moving into colostrurm time

Answer 24

Before parturition , lgs move into colostrurm via the paracellular route prior to the formation of TJ

Question 25

Paracellular during mastitis

Answer 25

Leakage of Na and Cl to decreased lactose content through (to maintain osmotic balance)

1. Moving of lactose from the-lumen into the interstitial space
2. Down regulation of the a-lactalbumin gene (a component of lactose synthase)

Question 26

The majority of SC in milk

Answer 26

Leukocytes

Question 27

Secretion of milk is a … process but not at a …

Answer 27

continuous

constant rate

Question 28

Approximately … hour after the last milking, milk secretion stops

Answer 28

35 h

Question 29

Secretion is fastest immediately after milking and slows dramatically …

Answer 29

by 8-10 h

Question 30

Water secretion is also dependent on the secretion of

Answer 30

ions (Na , K , Cl)

Question 31

diagnostic of udder health

Answer 31

Leukocytes