L8: Lactation

Question 1

period following parturition where the reproductive tract returns to its non-pregnant state

Answer 1

puerperium

Question 2

what is the economic benefit to shortening the puerperium in livestock

Answer 2

• increases frequency of breeding
• increased pregnancy in dairy cows increases their lifetime milk yield

Question 3

what is lochia

Answer 3

blood, uterine lining and other discharge

Question 4

what are the main events of puerperium

Answer 4

• myometrial contraction shrink the uterus and expel the lochia
• endometrial repair
• ovarian cycling resumes
• elimination of opportunistic bacterial infections

Question 5

whaat is silent ovulation in bovines

Answer 5

after seasonal anestrus in the ewe or pregnancy in the cow, the ovary develops a follicle(s) that will ovulate without an accompanying behavior estrus

Question 6

occur as two lines of tissue that run ventrally from the axial regio to the inguinal region

Answer 6

mammary ridges

Question 7

name for the milk secreting cells of the mammary gland

Answer 7

parenchyma

Question 8

what is the purpose of cisterns in species such as cows and goats

Answer 8

they increase the storage volume of the udder

Question 9

most milk is stored within the _________ of the mammary tissue

Answer 9

alveoli system

Question 10

what is lactogenesis

Answer 10

mammary epithelial cells are converted from a non-secretory state to a secretory state

increase in lactose, total protein, immunoglobulins
decrease in sodium and chloride

Question 11

when does lactogenesis begin in cows

Answer 11

up to 4 days before parturition

Question 12

what are the two stages of lactogenesis

Answer 12

prenatal cytologic and enzymatic differentiation of alveolar epithelial cells, driven by estrogen and prolactin

postnatal secretion of milk components

Question 13

the sudden withdrawal of _______ at birth causes blood flow to mammary glands to increase

Answer 13

progesterone

Question 14

T/F: milk production begins independent of newborn suckling

Answer 14

T

Question 15

what is galactopoiesis

Answer 15

the maintenance of lactation once lactation has been established

Question 16

what is involution

Answer 16

return to a non-secretory state

Question 17

what are the two main components that contribute to the maintenance of lactation

Answer 17

galactopoietic hormones and the removal of accumulated milk (suckling)

Question 18

what is the ‘first’ milk

Answer 18

colostrum

Question 19

colostrum provides _______ immunity to newborn

Answer 19

passive

Question 20

immunoglobulin absorption from the colostrum to newborn is limited to the first _______ hours of life

Answer 20

24-36 hrs

Question 21

what molecule is important for the postresection adaptation response

Answer 21

IGF-1

Question 22

glycoprotein w/ strong anit-microbial activity

Answer 22

lactoferrin

Question 23

why does cheese color differ

Answer 23

due to nutrition and species differentiation of B-cartoene in their milk
white = grain fed
yellow = grass fed

Question 24

what is the main E component of milk

Answer 24

fat

Question 25

what is needed to break down lactose and what does it become

Answer 25

lactase lactose---> glucose+galactose

Question 26

composition of milk fat

Answer 26

mono, di and trigylcerides, FFA, phospholipids, steroids

Question 27

composition of milk protein

Answer 27

casein, albumins, globulins

Question 28

disaccharide composed of galactose and glucose

Answer 28

lactose

Question 29

what hormones immediately decline with the birth of placenta

Answer 29

estrogen and progesterone

Question 30

immediately after birth of placenta, ________'s role in milk synthesis is activated

Answer 30

prolactin's

Question 31

how is prolactin secretion inhibited when there is a lack of suckling

Answer 31

neurons in secretory parvocellular cells reelase dopamine **dopamine acts in anteriror pituitary to inhibit prolactin secretion**

Question 32

how does suckling lead to prolactin release

Answer 32

suckling stimulates nipple mechanoreceptors that synapse w/ neurosecretory cells in the hypothalamus * inhibits dopamine * stimulates vasoactive intestinal peptide * release prolactin

Question 33

how does oxytocin lead to milk let down

Answer 33

oxytocin causes contraction of myoepithelial cells which moves the milk into ducts and cistern

Question 34

what are the steps in milk let down

Answer 34

1. suckling/milking stimulates mechanoreceptors 2. paraventricular nucleus cells release oxytocin via the posterior pituitary into blood stream 3. oxytocin causes myoepithelial cells to contract, causes milk to move into ducts 4. milk let down

Question 35

milk fever occurs with the sudden demand in ________ that occurs w/ _______ production

Answer 35

Ca+ colostrum

Question 36

explain how milk fever occurs

Answer 36

*Hypocalcemia* - PTH secreted by parathyroid gland in response to low blood serum Ca

Question 37

insufficient removal of milk can cause pressure ________

Answer 37

atrophy

Question 38

mechanical pressure on alveolar epithelial milk secreting cells inhibits ______, resulting in ________

Answer 38

galactopoesis involution

Question 39

what is active involution

Answer 39

1-2 days of increased pressure inhibits milk secretion Prolactin release is still responsive to feedback

Question 40

what is steady state involution

Answer 40

sustained period of inhibited milk synthesis that lasts until the enxt birth prolactin release is blocked

Question 41

inflammation of udder and mammary gland in response to infection w/ bacteria, fungi, mycoplasma, algae

Answer 41

mastitis

Question 42

what does mastitis cause

Answer 42

formation of non-funcitonal CT in order to wall off infection

Question 43

What animal has 4 inguinal teats, with 1 cistern/canal per teat?

Answer 43

cow

Question 44

What animal has 12-18 teats with 2 ducts per teat?

Answer 44

sow

Question 45

What animal has 2 inguinal teats with 2 ducts per teat?

Answer 45

mare

Question 46

What animals have 6-8 teats with 5-6 ducts per teat?

Answer 46

bitch and queen

Question 47

What kind of cheese is typically made from sheep and goat milk or grain-fed cattle?

Answer 47

white

Question 48

What kind of cheese is made from grass-fed cows or dyes such as annatto?

Answer 48

yellow

Question 49

Where are proteins in milk (casein, albumins, globulins) synthesized?

Answer 49

ER

Question 50

Without stimulation, neurons in the secretory parvocellular cells release _________ to inhibit prolactin secretion.

Answer 50

dopamine

Question 51

Milk fever is characterized by depression, reduced activity, and paralysis. This issues are due to a decrease in ____________ and an increase in _____ that takes too long to correct the problem in the blood.

Answer 51

Calcium PTH

Question 52

Insufficient milk removal can lead to this

Answer 52

pressure atrophy