repro endocrinology Flashcards
in mid / late anestrus what are oestradiol / progesterone / lh / fsh levels?
all low
except FSH which increases during anoestrus
what happens with the hormones one week before anoestrus?
increased pulses of LH
slight increase of FSH
what happens to the hormones in proestrus?
oestradiol and progesterone increase
LH and FSH decrease
what happens in late proestrus?
LH peak and FSH peak
In the bitch what is different about the LH and FSH peaks?
the FSH peak is about 1 day after the LH peak
what does ovulation occur in the bitch?
about 2 days after the LH surge
What is unusual about the bitch ovulation?
the egg hasnt yet undergone its first round of meiosis
normally the LH surge triggers it and meiosis is complete before ovulation
What affects progesterone in the luteal phase in the bitch?
from CL
affected by LH and PRL
Why is PRL so important in the bitch?
maintains the CL after day 25
why is relaxin so important in a bitch?
from the placenta and increases and progesterone and PRL
used to detect pregnancy as not detectable in the non-pregnant animals
How can oestrus be controlled int he bitch?
- OVH
- synthetic progestagens ( anti - gonadotrophic , weakly prostagenic, antioestrogenic)
- testosterone (can affect future fertility and external genitalia appearance)
What is pseudopregnancy in the bitch?
- see weight gain, mammary development and lactation and behaviour changes from about 45d after oestrus
- normal luteal length and progesterone conc
- due to high PRL or a sudden drop in progesterone
how do you treat a pseudopregnancy in the bitch?
- spontaneous remission
- synthetic progestagens
- oestrogens and androgens together
- dopamine agonist
What is going on with the hormones in the interoestrus period in the queen?
21d follicular waves of LH
what happens post mating in the queen to LH?
rapid release
need multiple matings for ovulation
what happens post mating in the queen to progesterone?
increases and peaks after 30 d
then decreases if not pregnant or stays high throughout preg
cant return to oestrus until progesterone back to baseline
what happens post mating in the queen to PRL?
elevated for the last 20 day of preg and during lactation
What is pseuodpregnancy in the queen?
non pregnant luteal phase
after mating if not conceived or spontaneous ovulation
How can you control oestrus in the queen?
OVH
hCG - induce pseudopregnancy to stop callings
androgens - postpone calling
progesterone - suppress calling , prevent conception, prevent oestrus
How would you treat anovulatory acyclicity in the cow?
- PRID or CIDR for 12 days
- eCG on day of removal
What is a PRID or CIDR? and how do they work?
PRID = progesterone releasing internal device CIDR = controlled internal drug release
progesteron is negative to GnRH so when its removed get a GnRH surge
5 ways to induce oestrus in seasonallly anoestrus ewes
1) hourly GnRH for 30-40 hrs
2) 16h dark : 8h light
3) regulin implants (release melatonin)
4) P4 sponge(12d) and eCG on removal
5) ram/boar effect
normally combine sponge and ram/boar effect
how to induce puberty in gilts?
at 6-7 mo / 100 kg bw
PMSG and hCG
How to prevent anoestrus in first litter sows?
PMSG and hCG on day of weaning
