Reproductive Management of the Broodmare Flashcards
How do we manipulate seasonality?
shift the breeding season back
shorten vernal transition
How do we advance the breeding season?
Photostimulation
How do we shorten vernal transition?
photostimulation and hormones sulpride/domperidone P4/progestagens progestins/E2 GnRH/analogues (deslorelin) eFSH
What date are we trying to have foals for?
January 1
What is the challenge in advancing the breeding season?
if you let go back into anestrus, a lot harder to bring back
What is a risk of bringing a mare back from anestrus?
EED - becuase no CL to provide P4 for the first 70 days.
What does combining light and hormones do in mares?
shortens time from initiation tx to ovulation
HOw much light promotes transition and for how long
14-16 hrs total light with 200 W bulb for 60-90 days
When is the best time to start light treatment?
5-7 weeks before dec 21
what is the deal with flash lighting and all day lighting?
flash lighting is great (at 9.5 hr after sunset)
You CAN”T light all day though
what are the new methods for photostimulations?
low intensity blue light
masks with a light in the right eye?
How does domperidone and sulpiride work and what are their uses?
dopamine antagonist which increases prolactin –> increase FSH/LH –> follicle maturation, ovulation
also stimulates lactation
When does domperidone/sulpiride work the best?
when mare in transition (22 days until ovulation)
with light
increasing temp
Which (Sulpiride/domperidone) is used more and more efficacious?
sulp is better and used more
domp is easier to get
How long does ovulation take using sulp in transition and anestrus?
22 days
50-60 days
What is the mechanism of the progestins?
induce LH receptors on the follicle –> ovulation
What is the downfall of the progestins?
need a large follicle
ovulation is unpredictable
What are the progestin names?
altrenogest (Regumate), progesterone in oil (but has IS reactions)
What is the mechanism of the progestins+estradiol? Downfall?
E2 causes LH surge but suppresses the FSH. then the PRogestin will increase LH sensitivity.
Here again, need a large follicle
What was the deal with eFSH
stimulates the follicles. Give with HCG on the last of 15 days. Effective but no longer available
What does GnRH do and how is it done?
induces ovulation, given via mini pump or SQ implant
What are the downfalls of GnRH use?
costly, needs long, frequent tx, which dose, route, etc?
What is Deslorelin and what are it’s claim?
GnRH analogue –> injectable and will pull a mare out from anestrus.
Cheap and effective.
Shortens vernal and advances breeding season
How are the different ways that we manipulate the normal cyclicity?
shorten luteal phase lengthen the luteal phase shorten follicualr (induce ovulation) synchronize estrus Modify sexual behaviour
How do PGF2a (Prostaglandins) shorten the luteal phase? How does it work?
induces luteolysis on a fully functional CL 5 days after ovulations. Then it will enter estrus in 1-9 days later
What is the challenge with PGF2a’s
need to know where they are in the cycle
even then, it is hard to know when they will come in again
When is the mare not responsive to PGF2a tx?
the first 5 days of diestrus
What are the ways that we can use PGF2a?
- to induce estrus - give 5-6 days after ovulation
OR 3-5 days after standing estrus - Give any time in 5 day increments until estrus
- To catch a foal heat –> give 5 days after ovulation
- with a persistent CL
- Synchronize - 2 doses 14-18 days apart
- give on the last day of P4 Tx to induce estrus
Products of PGF2a for shortening luteal phase
Lutalyse - dinoprost tromethamine
Estrumate - cloprostenol
Lutalyse is the labelled product so we should be using that but estrumate works very well and almost better
Side effects of lutalyse
sweating and colic
What can be a problem with the PGF2as?
- if you give when atresia, the E2 will decrease and then it will ovulate a lot later.
- If there is a CL with a big follicle, may spontaneously induce estrus. Then the new CL won’t be responsible again
- Risk HAF
Indications for lengthening the luteal phase
to delay the foal heat
prevent estrus
Synchronize for ET and AI
What are some progestin products for lengthening the luteal phase?
Altrenogest - Regumate (labelled)
Progesterone in oil
CIDR
Long acting Progesterone
Indications for inducing ovulation
minimize breedings, inseminations per cycle
to correlate with semen for AIing
timed breeding protocols
What drugs will induce ovulation?
hCG and deslorelin - implant or injectable
What are some side effects of hCG and Deslorelin?
hCG - Ig formation when chronic
Des - will suppress ovulation for a little while after.
How do some people use the ovulation induction products?
they will sometimes kep the implant in for 3 days and then take them out. not used really anymore.
For estrus synchronization, what do we want for ET mares?
we want the recip to ovulate 0-2days after the donor mare
So how do we go out about synchronizing mares?
3 recips for each donor. Those with a big follicle should just induce ovulation with hCG or des
Then we give REgumate for 10-14 days
give PG on the last day as well.
OR
give the Progestins+E2 will be better yet then PG on last day
How do you superovulate mares?
eFSH - will recruit more than one follicle. but can’t get n Canada
5 days after ovulation, give eFSH until 35 mm follicle and PG on day 7. breed 36-48 hours later
What is the best ET/superovulation protocol?
prog/est until 20 mm, then start eFSH until a dominant follicle develops and should get better quality embryos. Match to the recips. Can use ovariectomized mares
What are the ways to suppress sexual behaviour?
altrenogest
P4
LA Regumate - comp
- these don't stop ovarian activity
Progestin + E2 - will stop ovarian activity
Oxytocin - high dose twice a day tho
induce diestrus ovulation
IU marbles - endometritis
Anti-GnRH vaccine - effective
ovariectomyHow to induce estrus in an ovariectomized mare
ECP (E 17 beta) - 30% effective - 1 per 3 mares will work
How to induce lactation (and if fescue tox)?
DOmperidone
How do you induce lactation?
Give Sulp and E2 and Regumate –> 7 days later will be milk.
Give sulp again 23 days later
What do we have labelled for high risk pregnancies?
NO progestins labelled but still use altrenogest
What are some of the high risk preg situations?
true CL deficiency when they just can't carry to term when the vesicles are smaller and can't inhibit PGF2a and luteolysis may need supplementation until eCG long term placentitis
what drug is used for management of high risk pregos
regumate (altrenogest) at double the dose
