Milk 1

Question 1

When does the mammary gland develop?

Answer 1

During foetal growth, periods, pregnancy and lactation

Question 2

What is mammogenesis?

Answer 2

Initiation of milk synthesis and secretion during and after weaning

Question 3

Where is lactose synthesized?

Answer 3

Lactating mammary gland

Question 4

How is milk removed from the teat?

Answer 4

Alveoli are connected to duct system which flows milk to the teat canal where it is removed

Question 5

What are the 5 major precursors of milk production?

Answer 5

Glucose
Acetate
Beta-hydroxybutyrate
Triglyceride fatty acids
Amino acids

Question 6

Where are proteins, amino acids and fats synthesized and removed during lactogenesis?

Answer 6

Mammalian epithelia cells (MEC)

Question 7

What does cow feed contain?

Answer 7

Cellulose

Question 8

How do cows digest carbohydrates?

Answer 8

Reticulo-rumen produces enzymes which hydrolyse or ferment them into volatile fatty acids

Question 9

What is the primary energy source for the mammary gland?

Answer 9

Glucose

Question 10

What is the whole bodies energy source in ruminants?

Answer 10

Acetate

Question 11

What is the whole bodies energy source in monogastric?

Answer 11

Glucose

Question 12

What is the carbon source for lactose in ruminants and monogastric?

Answer 12

Glucose

Question 13

What is the blood glucose source for ruminants?

Answer 13

Propionate

Question 14

What is the main carbon source for fatty acids in ruminants?

Answer 14

Acetate and butyrate

Question 15

What is the main carbon source for fatty acids in monogastric?

Answer 15

Glucose

Question 16

What are the main sources of glucose for milk production?

Answer 16

Propionate, gluconeogenesis, lactate and glycerol

Question 17

1st step of glucose metabolism

Answer 17

Glucose becomes glucose 6-phosphate in blood

Question 18

2nd step of glucose metabolism

Answer 18

Glucose becomes trapped within blood cells

Question 19

3rd step to glucose metabolism

Answer 19

Excess glucose converted to glycogen

Question 20

4th step of glucose metabolism

Answer 20

Glycolysis converts pyruvate to acetyl-SCoA to enter citric acid cycle

Question 21

What are the fatty acids in milk fat?

Answer 21

Long chain fatty acids (LCFA) and linoleic acid

Question 22

What are the building blocks for milk fat?

Answer 22

Volatile fatty acids (VFA)

Question 23

What improves milk fat content?

Answer 23

Acetate

Question 24

What increases milk protein content?

Answer 24

Propionate

Question 25

What are the precursors of acetyl CoA?

Answer 25

VFAs

Question 26

1st step of carbohydrate metabolism

Answer 26

Acetate becomes acetyl CoA to enter TCA cycle

Question 27

2nd step of carbohydrate metabolism

Answer 27

Propionate becomes succinyl CoA which becomes glucose in gluconeogenesis

Question 28

3rd step of carbohydrate metabolism

Answer 28

Butyrate converted to B-hydroxybutyrate across rumen wall then into acetyl CoA

Question 29

What are the 5 precursors for milk fat?

Answer 29

Glucose Acetate B-hydroxybutyrate Triglycerides Lipoproteins

Question 30

How are milk lipids produced?

Answer 30

Absorbed from blood or synthesised from acetate

Question 31

Where are B-hydroxybutyrate and acetate absorbed?

Answer 31

Basolateral membrane

Question 32

Where are triglycerides synthesised?

Answer 32

Cytoplasm of mammary epithelial cells

Question 33

How are casein, alpha-lactalbumin and beta-lactoglobulin synthesised?

Answer 33

From amino acids in mammary epithelial cells