Final: Mare cycle and breeding; Non-pregnant mare Flashcards
Descibe the cervix of a receptive mare.
Short and soft
Like a wilted rose
The dorsal commisure of the vulva should be at the level of the _________.
Ischial arch
A second degree _____________ is a common, frequently overlooked and serious lesion that is easily corrected.
Perineal laceration
What part of the anatomy helps create a seal between the vestibulum and the vagina?
Perineal body
On US evaluation of the repro tract, in which orientation are the uterine body and uterine horns viewed?
UB: Longitudinal
UHs: Cross-section
What is the ideal month for a foal destined to be racehorse to be born in?
January
Follicles formed during the transition period are
a. steroidogenically incompetenet
b. enlarged
c. steroidogenically competent and form estradiol
d. hyperfertile
a. steroidogenically incompetenet
How many waves do most horses have in their estrus cycle?
2
How much do follicles grow per day? What hormone reduces the growth rate of follicles?
3mm/day
Progesterone
At what size do follicles develop ovulatory capacity?
35mm
Ovulation occurs in response to rising ___ levels that peak ___ days after ovulation.
LH
Two
Which order is correct?
a. Follicle -> Ovulation -> Corpus luteum -> Corpus hemorrhagicum
b. Follicle -> Ovulation -> Corpus hemorrhagicum-> Corpus luteum
b. Follicle -> Ovulation -> Corpus hemorrhagicum-> Corpus luteum
The sperm revervoir in the uterine tube is adequate by ___ hours/days after breeding or insemination. These sperm remain viable for at least ___ hours/days.
4 hours
2 days
Occytes degenerate by ____ hours/days post-ovulation. This is why insemination should occur ____(prior to/ after) oculation.
12-16 hours
Prior to
When do fertilized embryos enter the uterus?
By 5.5 days after fertilization
What are the 2 requirements for inducing ovulation? What 2 agents can be used?
Must be in estrus and have a growing pre-ovulatory follicle at least 35mm large
hCG and GnRH
Why can administering hCG cause anaphylaxis?
Can cause production of autoantibodies
What is Deslorein accetate?
Long-acting injectable GnRH
What account for the difference in when the mare will ovulate when giving hCG (36hrs) and GnRH (42hrs)?
hCG = LH -> goes straight to ovary
GnRH -> Pituitary -> releases LH -> ovary
What are the side effects of Dinoprost (Lutalyse)?
Sweating
Colic
Depression
Prostaglandin labeled for horses (Cloprostenol/Estrumate is extra-label)
On what does the interval between PGF2a administration and estrus or ovulation depend?
Follicle size
- <25mm = 7-10d*
- >25mm = 3-5d*
- >35mm= 1-4d*
What is the most common exogenous P4 product for horses?
Regu-Mate(tm)
(Altrenogest)
How does a GnRH implant prevent estrus?
Superstimulation of GnRH receptors -> receptors internalize -> cannot be stimulated anymore
What is the best way to determine whether a mare is receptive?
Teasing with a stallion
How long does capacitation within the female repro tract take?
6 hours
This means it cannot immediately fertilize oocytes
If you are performing AI on a mare and inseminating her very close to or right at ovulation, what type of semen are you using?
Frozen
Immediately fertile but doesn’t last as long
Match the following types of semen with the expected rate of impregnation:
Fresh
Cooled
Frozen
50%
60%
70%
Fresh 70%
Cooled 60%
Frozen 50%