Reproductive Management of the Broodmare

Question 1

How do we manipulate seasonality?

Answer 1

shift the breeding season back

shorten vernal transition

Question 2

How do we advance the breeding season?

Answer 2

Photostimulation

Question 3

How do we shorten vernal transition?

Answer 3

photostimulation and hormones
sulpride/domperidone
P4/progestagens
progestins/E2
GnRH/analogues (deslorelin)
eFSH

Question 4

What date are we trying to have foals for?

Answer 4

January 1

Question 5

What is the challenge in advancing the breeding season?

Answer 5

if you let go back into anestrus, a lot harder to bring back

Question 6

What is a risk of bringing a mare back from anestrus?

Answer 6

EED - becuase no CL to provide P4 for the first 70 days.

Question 7

What does combining light and hormones do in mares?

Answer 7

shortens time from initiation tx to ovulation

Question 8

HOw much light promotes transition and for how long

Answer 8

14-16 hrs total light with 200 W bulb for 60-90 days

Question 9

When is the best time to start light treatment?

Answer 9

5-7 weeks before dec 21

Question 10

what is the deal with flash lighting and all day lighting?

Answer 10

flash lighting is great (at 9.5 hr after sunset)

You CAN”T light all day though

Question 11

what are the new methods for photostimulations?

Answer 11

low intensity blue light

masks with a light in the right eye?

Question 12

How does domperidone and sulpiride work and what are their uses?

Answer 12

dopamine antagonist which increases prolactin –> increase FSH/LH –> follicle maturation, ovulation
also stimulates lactation

Question 13

When does domperidone/sulpiride work the best?

Answer 13

when mare in transition (22 days until ovulation)
with light
increasing temp

Question 14

Which (Sulpiride/domperidone) is used more and more efficacious?

Answer 14

sulp is better and used more

domp is easier to get

Question 15

How long does ovulation take using sulp in transition and anestrus?

Answer 15

22 days

50-60 days

Question 16

What is the mechanism of the progestins?

Answer 16

induce LH receptors on the follicle –> ovulation

Question 17

What is the downfall of the progestins?

Answer 17

need a large follicle

ovulation is unpredictable

Question 18

What are the progestin names?

Answer 18

altrenogest (Regumate), progesterone in oil (but has IS reactions)

Question 19

What is the mechanism of the progestins+estradiol? Downfall?

Answer 19

E2 causes LH surge but suppresses the FSH. then the PRogestin will increase LH sensitivity.
Here again, need a large follicle

Question 20

What was the deal with eFSH

Answer 20

stimulates the follicles. Give with HCG on the last of 15 days. Effective but no longer available

Question 21

What does GnRH do and how is it done?

Answer 21

induces ovulation, given via mini pump or SQ implant

Question 22

What are the downfalls of GnRH use?

Answer 22

costly, needs long, frequent tx, which dose, route, etc?

Question 23

What is Deslorelin and what are it’s claim?

Answer 23

GnRH analogue –> injectable and will pull a mare out from anestrus.
Cheap and effective.
Shortens vernal and advances breeding season

Question 24

How are the different ways that we manipulate the normal cyclicity?

Answer 24

shorten luteal phase
lengthen the luteal phase
shorten follicualr (induce ovulation)
synchronize estrus
Modify sexual behaviour

Question 25

How do PGF2a (Prostaglandins) shorten the luteal phase? How does it work?

Answer 25

induces luteolysis on a fully functional CL 5 days after ovulations. Then it will enter estrus in 1-9 days later

Question 26

What is the challenge with PGF2a's

Answer 26

need to know where they are in the cycle | even then, it is hard to know when they will come in again

Question 27

When is the mare not responsive to PGF2a tx?

Answer 27

the first 5 days of diestrus

Question 28

What are the ways that we can use PGF2a?

Answer 28

1. to induce estrus - give 5-6 days after ovulation OR 3-5 days after standing estrus 2. Give any time in 5 day increments until estrus 3. To catch a foal heat --> give 5 days after ovulation 4. with a persistent CL 5. Synchronize - 2 doses 14-18 days apart 6. give on the last day of P4 Tx to induce estrus

Question 29

Products of PGF2a for shortening luteal phase

Answer 29

Lutalyse - dinoprost tromethamine Estrumate - cloprostenol Lutalyse is the labelled product so we should be using that but estrumate works very well and almost better

Question 30

Side effects of lutalyse

Answer 30

sweating and colic

Question 31

What can be a problem with the PGF2as?

Answer 31

1. if you give when atresia, the E2 will decrease and then it will ovulate a lot later. 2. If there is a CL with a big follicle, may spontaneously induce estrus. Then the new CL won't be responsible again 3. Risk HAF

Question 32

Indications for lengthening the luteal phase

Answer 32

to delay the foal heat prevent estrus Synchronize for ET and AI

Question 33

What are some progestin products for lengthening the luteal phase?

Answer 33

Altrenogest - Regumate (labelled) Progesterone in oil CIDR Long acting Progesterone

Question 34

Indications for inducing ovulation

Answer 34

minimize breedings, inseminations per cycle to correlate with semen for AIing timed breeding protocols

Question 35

What drugs will induce ovulation?

Answer 35

hCG and deslorelin - implant or injectable

Question 36

What are some side effects of hCG and Deslorelin?

Answer 36

hCG - Ig formation when chronic | Des - will suppress ovulation for a little while after.

Question 37

How do some people use the ovulation induction products?

Answer 37

they will sometimes kep the implant in for 3 days and then take them out. not used really anymore.

Question 38

For estrus synchronization, what do we want for ET mares?

Answer 38

we want the recip to ovulate 0-2days after the donor mare

Question 39

So how do we go out about synchronizing mares?

Answer 39

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

Question 40

How do you superovulate mares?

Answer 40

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

Question 41

What is the best ET/superovulation protocol?

Answer 41

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

Question 42

What are the ways to suppress sexual behaviour?

Answer 42

``` 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 ovariectomy ```

Question 43

How to induce estrus in an ovariectomized mare

Answer 43

ECP (E 17 beta) - 30% effective - 1 per 3 mares will work

Question 44

How to induce lactation (and if fescue tox)?

Answer 44

DOmperidone

Question 45

How do you induce lactation?

Answer 45

Give Sulp and E2 and Regumate --> 7 days later will be milk. | Give sulp again 23 days later

Question 46

What do we have labelled for high risk pregnancies?

Answer 46

NO progestins labelled but still use altrenogest

Question 47

What are some of the high risk preg situations?

Answer 47

``` 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 ```

Question 48

what drug is used for management of high risk pregos

Answer 48

regumate (altrenogest) at double the dose