Ch.43.DzesofReproductiveSystem Flashcards
(251 cards)
During the breeding season, mares ovulate every how many days?
every 21 days
How long is estrus in the mare?
5 to 7 days
What is estrus characterized by in the mare?
-presence of ovarian follicle
-serum progesterone less than 1 ng/ml
-sexual receptivity
-cervix palpably relaxed
-uterus is edematous
When does ovulation occur?
24 to 48 hours before the end of estrus
- may be accompanied by ovarian sensitivity
The first postpartum estrus (“foal heat”) occurs in what time period after foaling?
1 week after foaling
–ovulation between 7 to 15 days
When does diestrus occur?
**luteal phase
regression of CL, caued by released of endometrial prostaglandin F2alpha (PGF2alpha) occurs 14 to 15 days after ovulation
What is the estrous cycle of cows?
ave 21 days (17 to 25 days)
What is the duration of estrus in cows?
12 to 16 hours ( range 6 to 24 hours)
In the absence of a bull, estrus can be detected in cows by:
Signs of homosexual (bisexual) activity
-restlessness
-increased activity
-vulvar hyperemia
-edema
-clear mucous discharge
When is the optimum time for insemination of cows?
between 16 to 24 hours after onset of estrus
Well managed dairy cows with uncomplicated periparturient experiences may ovulate how many days after calving?
how about in beef cows?
approx. 20 to 25 days after calving
–beef cows with nursing calves– 40 or more days after calving
Coarse wooled breeds of ewes are seasonally polyestrous in what seasons? in temperate climates
autumn and winter (short photoperiod)
Ewes of fine wooled breeds are are polyestrous in what seasons?
year round
**if adequately nourished
When does lambing typically occur in ewes, in relation to their reproductive cycle?
during anestrous season
**do not return to estrus until the next breeding season
In what seasons are goats in estrous?
polyestrous from late summer until early spring (short photoperiod)
How long is the estrous cycle in goats?
ave 21 days
**lasts 18 to 26 hours
When does ovulation occur in goats?
in 24 hours after onset of estrous
Do South American camelids bred in North America have a breeding season? and when?
Nonseasonal
– bred in a seasonal manner to avoid newborn crias born in the hottest and coldest months of year
Why do South American camelids have nonseasonal breeding season?
because they are induced ovulators
Define ovarian cysts
follicle-like ovarian structures that arise because of failure of ovulation of a dominant follicle
–persist in absence of a CL for 10 days or more
What is the mechanism of ovarian cyst development?
unknown
What is the percentage of cows that are affected by cystic follicular development?
70 to 80% of cows affected by CFD are anestrus, whereas 20 to 30% display frequent or intense estrus (nymphomania)
**affects 10 to 30% of dairy cows
Why is cystic follicular degeneration not seen in beef cattle?
b/c commercial beef cows are culled for reproductive failure
Diagnosis of cystic follicular degeneration is based on:
-accurate history
-constant or frequent estrus
-short interestrous intervals
-anestrus may suggest CFD
-clinical exam
-evaluation of ovary via rectal palpation– presence of enlarged fluid-filled structures