Dairy Cow Week 4 Study Questions Flashcards
What is the difference between stroma and parenchyma in the mammary gland?
stroma: supportive connective tissue
parenchyma: glandular secretory tissue
describe the aveoli and ducts including important cell types
aveoli = milk secreting epithelial cells
A spherical shape with epithelial cells around the inside. Myoepithelial cells cover the outside with the capillaries. This is connected to the duct.
–> myoepithelial cells and epithelial cells
myoepitheial cells
MYO=muscle (contract)
–> cells contract is response to oxytocin
epithelial cells
make milk and secrete into lumen
What is mammogenesis?
development of the mammary gland
describe the hormones and structures involved in mammogenesis
hormones: progesterone and estradiol
–>ducts
hormone: prolactin
–>aveoli
timing of duct and aveoli formation
1-2 months before calving
Where do the antibodies in the colostrum come from?
transferred from maternal serum to colostrum into mammary gland
When is colostrum formed and what two hormones are responsible?
4-6 weeks prepartum
–>estrogen and progesterone
Why do we vaccinate the mother to protect the calf?
because the antibodies will go to the calf
What hormones terminate colostrogenesis?
glucocorticoids and prolactin
What is lactogenesis?
initiation of lactation
describe the hormone cascade during late pregnancy that leads to lactogenesis
release of CRH –> release of ACTH –> release of glucocorticoids –> placenta converts progesterone to estradiol –> induces mother to make prolactin
prolactin and glucocorticoids initiate the production of milk
describe the hormone and receptor cascade that leads to calving
progesterone decreases in the myometrium and can express oxytocin receptors
describe the “neuroendocrine loop” that leads to milk let down
Nerve impulses from the teat: Washing the teat or nursing of the calf
Brain: oxytocin release in blood
–> milk let down
How long does it take to milk a cow?
10 minutes
What is a “parlor turn”?
time it takes to get a group of cows in and out of the parlor
describe or diagram a parallel parlor, herringbone parlor, and rotary parlor
-parallel = cows parallel to each other
-herringbone = diagonal stalls
-rotary = circular parlor
What is the difference between a monobox and rotary robotic parlor?
-monobox = one cow at a time
-rotary = multiple cows at once
What might be an advantage of a robot milker? What is a disadvantage of a robot milker?
less labor and cows enjoy being milked by robots.
–robot milkers are expensive–
What are the steps for prepping a cow to be milked?
pre-dip, strip, post-dip
Understand how a milking machine works
a vacuum suction that has milk and rest periods.
–> milk out=gland cistern emptied
–>rest=refill gland
What is an “automatic take off”?
A chain on the milking unit that removes it once the cow has finished milking
What the purpose of the “post-dip” (applied after milking)?
sanitize and seal the teat
Why would you milk 3x versus 2x daily?
increases milk yield by 10%
What is a milk cooperative?
make sure the farmer has a good price and a place to sell the milk
What is a continuous versus seasonal calving herd?
continuous: cows calve year round
seasonal: calve in springtime
What is the relationship between grass growth and milk production in a seasonal calving herd?
Cows lactate during the spring and summer when there is grass available for them to graze on
When do you breed cows in a seasonal calving herd?
May (about 2 months after calving in March)
When do you dry off cows?
60 days before calving
