Exam 4 - Lactation

Question 1

Lactation

Answer 1

A strategy to nourish offspring

Question 2

Lactation stages
1. __________ – development of the mammary gland
2. ___________ – initiation of milk synthesis and secretion
3. __________ – maintenance of milk secretion
4. ___________ – regression

Answer 2

1. Mammogenesis
2. Lactogenesis
3. Galactopoesis
4. Involution

Question 3

Mammogenesis

Answer 3

Development of the mammary gland, prenatal, peri-pubertal, post-conception

Question 4

Lactogenesis

Answer 4

Begins with colostrum and involves the initiation of milk synthesis and secretion
Secretory epithelial cells can transfer components directly to the lumen or further process/convert to milk-specific products

Question 5

In Lactogenesis epithelial cells of the alveoli have three main functions what are they?

Answer 5

1. Absorption of nutrients and milk precursors from the blood
2. Synthesis of milk specific nutrients
3. Transfer of milk components to the lumen of the alveoli

Question 6

Caseins

Answer 6

Unique to the mammary gland
Pulls calcium with it

Question 7

Lactose

Answer 7

Regulates water concentration
Along with galactose, unique to the mammary gland

Question 8

Triglycerides

Answer 8

Given that dietary fiber is the original source of VFAs and VFAs are used to form milk triglycerides that means that dietary fiber regulates milk fat

Question 9

Immunity

Answer 9

The ability of the body to defend against foreign invaders

Question 10

Three types of immunity

Answer 10

1. Innate
2. Adaptive
3. Passive

Question 11

Passive immunity

Answer 11

Ready-made antibodies received by the animal passively (i.e. animal’s own immune system did not have to do the work of making the antibodies)

Question 12

Passive immunity can be ________ or _______

Answer 12

Natural or artificial

Question 13

Passive immunity’s protective effect is _________, but antibodies are used up/broken down over time therefore protection is only __________

Answer 13

Immediate; transient

Question 14

Colostrum

Answer 14

‘first milk’, containing a high concentration of antibodies (i.e. immunoglobulins, IgG)

Question 15

Species vary in their reliance on _________ __________ ________ as a result of morphological differences of the placenta

Answer 15

Colostral antibody transfer

Question 16

Ability of the newborn to absorb intact colostrum _________ is a consequence of the maturity of the digestive system; ___________ with age

Answer 16

Proteins; decreases

Question 17

Antibodies are ______ molecules and absorption must occur ________ intestinal lining becomes impermeable to large proteins. Time of the intestinal closure is ________ _________ but in general the ________ the better.

Answer 17

Large; before; species dependent; earlier

Question 18

Galactopoesis

Answer 18

Maintenance of milk secretion

Question 19

Regulation of Milk Movement requires coordination between the ________ and _________ __________

Answer 19

Brain; mammary systems

Question 20

Milk composition

Answer 20

Contains all the major classes of nutrients and is variable by species and even within species

Question 21

Involution

Answer 21

Regression of mammary structures
Alveolar tissues collapse with loss of secretory function, but persist with much smaller lumens

Question 22

Retention of milk in the alveoli ________ as young require less milk and suckle less therefore this leftover milk in the lumen serves as a ________ __________ ________ to the process of milk production

Answer 22

Increases; negative feedback mechanism

Question 23

What is a dry period

Answer 23

Stage in the lactation cycle when cows are no longer being milked

Question 24

The absence of a dry period interferes with the increase in cell numbers that normally occurs during the early stages of ________ and would result in substantial ________ in _____ yield

Answer 24

Lactation; decrease in milk

Question 25

An animal that relies on colostrum

Answer 25

Horses, porcine, goats, bovine, swine

Question 26

An animal that doesn’t rely on colostrum and have placental antibody transfer

Answer 26

Humans, dogs, mice

Question 27

If an animal is highly stressed out, what hormone inhibits oxytocin/decreases milk let down?

Answer 27

Epinephrine

Question 28

_____ contains all the major class of nutrients

Answer 28

Milk

Question 29

Minerals - the ratio of dietary __ to _ is most important

Answer 29

Ca to P

Question 30

Major classes of nutrients in milk

Answer 30

Water, lipids, proteins, lactose, minerals, vitamins

Question 31

Lipids

Answer 31

Globules, mostly triglycerides, lighter than the rest of milk

Question 32

Milk price is affected by ____ ________

Answer 32

Fat content

Question 33

Proteins in milk

Answer 33

Casein, whey and immune globulins

Question 34

Casein

Answer 34

Coagulates at low pH, insoluble, majority of milk protein

Question 35

Whey

Answer 35

Serum proteins, minority of milk proteins, soluble

Question 36

Immune globulins

Answer 36

Very small amount in milk, no IgG absorption but IgA acts as a surface protectant for mucosal lining

Question 37

Lactose

Answer 37

Synthesized only by cells of lactating mammary glands, aqueous, sweet flavor

Question 38

Amount of lactose produced determines _____ _______

Answer 38

Milk volume

Question 39

Lactose is broken down by bacteria into _____ ____ and is important in _________ dairy product

Answer 39

Lactic acid; fermented

Question 40

Lactose intolerance

Answer 40

A sensitivity to lactose caused by greater lactose concentrations present than the body is able to digest, sensitive to the milk carbohydrate, occurs in GI system, regional occurance

Question 41

Milk allergy

Answer 41

An allergic reaction to milk proteins, triggered by the immune system, should avoid all milk and milk products

Question 42

The ratio of dietary Ca to P is most important - _:_ to _:_

Answer 42

1:1 to 1:2

Question 43

_______ and ___________ are important for growth/maintenance of skeleton

Answer 43

Calcium and phosphorus

Question 44

Vitamin A in milk

Answer 44

Varies by breed and by environment/feeding practices, green feed increases carotene and therefore vitamin A, less in jerseys and guernseys but more in Holstein, light can destroy vitamin A

Question 45

Vitamins are necessary for _______ _______

Answer 45

Tissue metabolism

Question 46

Vitamin D in milk

Answer 46

Not a great source naturally but milk is often fortified with vitamin D

Question 47

Why is milk fortified with vitamin D

Answer 47

Because vitamin D is needed for proper Ca and P metabolism/absorption of Ca

Question 48

Milk is a poor source of vitamin __ and __ and generally a good source of vitamin __

Answer 48

E; K; B

Question 49

Processing steps of milk

Answer 49

Milk is cooled to at least 39 degrees, transported to processing plant, heated to 161 degrees, quickly cooled back down.