Repro Week 5

Question 1

What is the difference between lactogenesis and galactopoiesis?

Answer 1

Lactogenesis is the initiation of milk secretion at parturition- production of colostrum
Galactopoiesis is the continued milk secretion during lactation

Question 2

From what tissue does mammary glands originate

Answer 2

Epidermis, from lines called mammary ridges

Question 3

How does milk move from alveoli into the ducts?

Answer 3

Contraction of myoepithelial cells

Question 4

What is a monotreme?

Answer 4

Mammary tissue is a sweat gland, there are no teats, the milk just runs out along hair shafts

Question 5

How are abdominal mammary glands vascularised?

Answer 5

Branches of the cranial and caudal superficial epigastric

Question 6

What is the effect of ostreogen and progesterone on mammary gland growth?

Answer 6

Oestrogen- branching of ducts

Progestrone- formation of alveoli

Question 7

Where is the majority of milk synthesised?

Answer 7

epithelial cells

Question 8

What cells are found in milk?

Answer 8

Leukocytes and dislodged mammary epithelial cells

Question 9

Where is placental lactogen produced from and what is its action?

Answer 9

From binucleate cells in placenta, acts like prolactin and growth hormone to stimulate mammary growth

Question 10

Which hormones affect galactopoeisis?

Answer 10

Prolactin, oestrogen, progesterone, cortisol

Question 11

How is lactose synthase made?

Answer 11

galactosyltransferase binds to alpha lactalbumin

Question 12

Describe grade 3 mastitis?

Answer 12

Severe- changes to the cow such as pyrexia, tachycardia etc

Question 13

What is contagious mastitis?

Answer 13

Infection spread cow to cow almost exclusively during the milking process

Question 14

List some Contagious bacteria

Answer 14

Staph aureus, strep agalactiae, strep dysgalactiae

Question 15

List some environmental mastitis bacteria

Answer 15

E.coli, strep uberis, strep dysgalactiae

Question 16

What is the five point plan?

Answer 16

1. post milking teat disinfection
2. treat clinical cases
3. dry cow therapy for all
4. cull chronically ill
5. milking machine maintenance

Question 17

What are the steps of uterus involution?

Answer 17

Myometrial contractions- persistaltic waves towards cervix, discharge of fluid and tissue debris, compressing vasculature
All stimulated by oxytocin and PGF2alpha
Coordinated atrophy of myometrial cells

Question 18

What is lochia?

Answer 18

A second cleansing- bloond tinged, remnants of fetal placenta and endometrial tissue
Should be odourless

Question 19

How long is uterine involution in the ewe?

Answer 19

30 days

Question 20

Describe uterine involution in the bitch

Answer 20

Takes 90 days
1st lochia involves an immedite green part and days 1-3 a red and watery one
2nd lochia- 4-6 weeks later

Question 21

How does insulin effect reproduction?

Answer 21

Direct action on antral follicle growth and steroid production, regulatory of circulatory IGF (which enhances ovarian action of gonadotrophins and has direct effect on follicle growth and steroidogenesis)

Question 22

What is flushing

Answer 22

2 weeks prior to tupping increasing nutritional plane for ewes to increase fecundity. It increases leptin, insulin and decreases growth hormone, IGF unaffected
Transient increase in FSH, decreased oestradiol- increased folliculogenesis

Question 23

What relationship does selenium have with reproduction?

Answer 23

Deficiency leads to increased incidence of retained placenta, cystic ovaries, embryonic mortality, decreased conception rates, increased endoemtritis risk and birth of premature or dead calves

Question 24

What is the effect of tetrathyomolybdates on reproduction?

Answer 24

Increased leads to decreased progesterone, decreased maternal recognition, increased pregnancy failure

Question 25

What ist the result of zinx deficiency?

Answer 25

Reduced spermatogenesis, libido and testicular size

Reduced fecundity, increased pregnancy toxaemia