Repro 8 Lecture 45 Parturition and Lactation Flashcards
What are the two stimulants of oxytocin release in the cow?
External Stimuli
Suckling
Time for endometrial repair in the dog?
130-140 days
Fetal stress leads to the release of __________ from the fetal ______________
CRH - corticotrophin releasing hormone
Hypothalamus
The release of CRH from the fetal hypothalamus leads to the release of ___________ from the fetal ___________
adrenocorticotrophic hormone (ACTH)
pituitary
The release of adrenocorticotropic hormone from the fetal pituitary leads to the release of _____________ from the fetal _____________
cortisol
adrenal gland
List the endocrine events following fetal stress that initiate parturition?
Fetal stress –> CRH released from fetal hypothalamus –> ACTH released from fetal pituitary –> cortisol released from fetal adrenal gland
3 enzymes involved in converting P4 to E2
Hydroxylase
Desmolase
Aromatase
What does fetal cortisol do in relation to hormones?
Promotes the conversion of progesterone to estradiol
Fetal corticoids promote conversion of __________ to __________ and cause the placenta to synthesize PGF2-alpha (prostaglandins)
Progesterone to estradiol
Fetal corticoids promote conversion of progesterone to estradiol and cause the placenta to synthesize________________
PGF2-alpha (prostaglandins)
What hormone serves to facilitate myometrial contractility?
Oxytocin
As fetal cortisol levels rise progesterone levels ________
fall
What hormone is stimulated by prostaglandins being produced by the placenta?
Relaxin
What are the 3 stages of parturition and what are they generally characterized by?
Stage I - fetal stress leads to a cascade of hormones which leads to fetal maturation and positioning and priming of the birth canal
Stage II - expulsion of the fetus
Stage III - expulsion of the fetal membranes
What does relaxin do?
Causes softening of the connective tissue in the cervix and increases the elasticity of the pelvic ligaments
In the cow: Cortisol mediated synthesis of __________from placenta leads to ______ and initiation of myometrial contractions
PGF2alpha
Luteolysis
Waterbag (other name/proper anatomical term)
Chorioallantois
What marks the end of stage 1 of parturition in cattle?
Dilation of cervix and entry of fetus into the birth canal + the rupture of the chorioallantois
What is the fetal orientation in birth canal? (cows)
Anterior presentation; dorsal presentation; head extended over fetlock joints
Ferguson reflex
Fetal distension on cervix stimulates a series of endocrine responses leading to oxytocin release and more myometrial contractions
In cattle what is stage III of parturition characterized by?
Detachment and expulsion of cotyledonary placenta
The dislodging of cotyledons is faciliated by strong _________ of chorionic villi.
vasoconstriction
The chorionic vili should be dislodged from the maternal side to avoid potential trauma which can lead to:
hemorrhage and metritis
Which species can withstand retained fetal membranes?
Cattle
Time taken for endometrial repair in cows
25-30 days
Time taken for resumption of ovarian function in cow
4 weeks
What purpose do myometrial contractions serve during the puerperium period? (3)
prevent hemorrhage
expulsion of lochia
involution
The mare may show estrus within how many days after foaling?
8-12 days
In the mare, how long for endometrial repair?
12-15 days
time for involution in mare:
12 hours (fast af boi)
Characteristic appearance of sow lochia
creamy coloured - will appear for a week
Involution time in the sow
21 days
Nursing sows are in what stage of the ovarian cycle?
Anestrus
How long before sows go into estrus after weaning?
5-7 days
How long are Does (sheep) expulsing lochia? what concern about their lochia should be noted?
4 weeks - potential for pathogens so this should be monitored but is not the same as postpartum metritis
How long and what is the appearance of lochia in dogs?
dark green mucoid lochia will be discharged for up to 12 hours and then it will be reddish brown for a week
time until next estrus for dogs after parturition?
7 months
The role of cortisol during parturition is to
A. Induce fetal maturation
B. Stimulate the conversion of progesterone to estradiol
C. Promote synthesis of PGF2a
D. All of the above
D - All of the above
What is the best indication of stage 1 of foaling in mares?
Sweating
About how long is stage II in the mare?
20 minutes
Among the following which statement is true with respect to
foaling
A. Expulsion of the fetal membrane does not occur until 3 h
after foaling
B. Foals are usually born in intact chorioallantois
C. Foals may born in intact amnion
D. Disconnecting the foal from the mare by severing the
umbilical cord is a common management procedure
C - Foals may born in intact amnion
How long are stages I, II, and II in ovine and caprine?
Stage I - 2-12 hours
Stage II - 1-3 hours
Stage III - 1 hour
How long can fetal membranes remain in ovine and caprine before concern of retained membranes?
12 hours
How are fetal membranes expelled in porcine?
Usually expelled after the last piglet
How long between piglet births before there is cause for concern?
more than 15 minutes between piglets is abnormal
what is the colour of the first discharge before the first pup is born?
Pink to dark red
During parturition dark green to black dischage is present due to breakdown of marginal hematoma
What actions happen during the puerperal period?
Myometrial contractions
endometrial repair
resumption of ovarian function
elimination of bacterial contamination
A healthy normal sow that farrows, nurses, and
subsequently weans a litter of pigs at 28 days postpartum is
most likely to exhibit a fertile estrus:
A. 2 to 3 days after weaning
B. Within 5 to 7 days after weaning
C. 60 days after farrowing
D. 21 days after weaning
B - Within 5 to 7 days after weaning
How long are stages I, II, and II in cattle
Stage I - 6 hours
Stage II - 30-60 minutes
Stage III - 8 hours
The role of cortisol during parturition is to
A.Induce fetal maturation
B.Stimulate the conversion of progesterone to estradiol
C.Promote synthesis of PGF2a
D.All of the above
D - all of the above
How long are stages I, II, and II in horses
Stage I - 1-4 hours
Stage II - 20 minutes
Stage III - 3 hours
How long can placenta remain in the horse before concern?
3 hours
Cervical star
contact area between the cervical folds and chorion - usually the site of rupture
Which fetal membrane layer is most closely associated with the fetus?
Amnion
During suckling, what cell type are stimulated in the mammary tissue that facilitates release of milk?
Myoepithelial cells
