Bovine - Female Pharmacology Flashcards
Note… see flip side
Dr. Dohlman said that he would give us the protocols so this flashcard set is the basics of estrus sychronization
What are the advantages of estrus synchronization?
reduce time and labor, efficiency use of ART (AI + ET), group breeding/calving, and decrease bull utilization
What are the disadvantages of estrus synchronization?
cost of drugs, use of drugs, group calving, reduced conception rates, and planning
What is the goal of estrus sychronization?
to synchronize the group to the same phase of the estrous cycle (timing)
What does FTAI stand for?
fixed time artificial insemination
What does FTET stand for?
fixed time embryo transfer
What are the four important factors for controlling the estrous cycle?
synchronizing emergence of new follicular wave, terminate luteal phase, maintain the luteal phase, or synchronizing ovulation
What is defined by the degree of synchronization?
The speed at which progesterone falls and the maturity of the dominant follicle at the progesterone fall
What is the term induction referring to?
follicular wave emergence
What are the requirements for induction using exogenous drugs?
consistent termination of existing follicular wave, predictable induction of transient increase of FSH, and normal growth of dominant follicle after selection
When using exogenous drugs for induction, what type of feedback is removing the dominant follicle?
negative feedback
What will administration of GnRH induce?
LH (importantly) and FSH secretion - it mimics the surge center
What is an important factor for GnRH to work?
the estrous cycle must be at the dominant follicle stage otherwise nothing will happe
If in the dominant follicle stage, what does GnRH do?
it causes ovulation or luteinization which will cause a new follicular wave in 1.5-2 days
What specifically happens in luteinizaiton?
the cells, in the dominant follicle, are changing from granulosa and thecal cells to luteal cells which will then release progesterone
Why would you want to get rid of the dominant follicle?
Because it will restart the follicular wave and for this wave you can predict when ovulation or the second wave will be
Can you use estradiol for follicular wave emergence?
technically it would work, but it is illegal so stay away
What exogenous drug is used to terminate the luteal phase?
prostaglandin (PGF2alpha)
Natrually, how does prostaglandin terminate the luteal phase?
Naturally, estradiol release from the ovulatory follicle stimulates oxytocin production/secretion from hypothalamus/pituitary which stimulates uterine PGF2alpha by positive feedback
When does the corpus lutem have prostaglandin receptors and when do they become functional?
it has prostaglandin receptors after 2 days post-ovulation, however, they are not primed and functional until day 5-7 after ovulation
Traditionally, when has prostaglandin been given exogenously to lyse the corpus luteum?
if it is given between day 7-17, it would lyse the CL with one dose which wwould allow for standing estrus to be seen within 2-5 days (follicle dependent)
New data has shown that prostaglandin can ve given sooner in the estrous cycle, what is that protocol?
with a 2-dose prostaglandin protocal, luteolysis can occur earlier in the estrous cycle (5-day Co-Synch + CIDR)
What does CIDR stand for?
controlled internal drug release
What drug is a key player in ensuring the luteal phase?
progesterone
