Cystorelin Question

[inyati13]

I am aware that cystorelin treats follicular cysts and promotes fertility. What I have not been able to determine is the following: 1) does it reset the cows estrus cycle, in other words, if a cow was in a cycle in which they were due to come into estrus in 12 days, would that be reset so that they would be in day one of a 21 day cycle, 2) and if the cow had recently been bred and cystorelin were administered would it cancel out the pregnancy?

 

[dun]

I don;t think it would cause her to slip, it will retart the cycle clock though.

 

[sizmic]

I'm no vet but I am inclined to answer question 1 and 2 with, no. I'm also inclined to say that it will only restart the cycle clock if the gnrh were administered in the presence of a follicular cyst.

Sizmic

 

[dun]

GnRH causes the ripest follicle to be released and a new follicular wave to start. That's why some sync protocols call for a shot of GnRH at timed AI time.

 

[cow pollinater]

It will work on a follicle only.
Cows with a growing Corpus lutium will not restart their cycle.
Pregnant cows have a corpus lutium instead of a follicle so gnrh won't effect them.

 

[angus9259]

It will work on a follicle only.
Cows with a growing Corpus lutium will not restart their cycle.
Pregnant cows have a corpus lutium instead of a follicle so gnrh won't effect them.

why is it given before a CIRD?

 

[dun]

It will work on a follicle only.
Cows with a growing Corpus lutium will not restart their cycle.
Pregnant cows have a corpus lutium instead of a follicle so gnrh won't effect them.

why is it given before a CIRD?

To put the heat cycle back to zero

 

[Lucky_P]

If you knew the cow had been in heat 7 days or more earlier, there'd be no need for the GnRH. If she's got a CL, it does nothing.
However, if you're synching a bunch of cows(or even just one) and you don't know when she was last in heat, giving GnRH and inserting the CIDR essentially puts them all at the same 'starting point'.
Giving GnRH at timed-breeding in a synch protocol just ensures that the cow will ovulate within the next 10 hrs(if she's not already well on her way to doing so) - provided that she's cycling normally.

 

[inyati13]

I now see that Cystorelin was not appropriate for the cow in reference. It was suggested by the AI breeder. I have a cow that has been artificially inseminated on 8/15, 9/22, 10/15, 11/3, and 11/28. I know this cow well. She comes-in very regular. It is easy to see when this cow is in standing estrus. I was advised to give her 2 ml of cystorelin which I did on 12/2. She is now with a bull. So it is up to him. If you do not need GnRH when they have a regular cycle, it was counter-indicated. What is the CIDR?

 

[Lucky_P]

CIDR = Controlled Intravaginal Drug-Releasing Device; a progesterone-impregnated thingy that you insert into the cow's vagina, releases a constant level of progesterone, suppressing follicular development until it is removed. A prostaglandin injection(or two) are usually administered at the time of CIDR removal to lyse the CL, and start maturation of a fresh new follicle.

 

[blacksnake]

I would think 5 shots at AI would be very excessive. Some cows just don't breed very well AI. I would question her ability to be bred by the bull. I would definitely keep an eye on her. If she doesn't breed first time with the bull, I would send her to market as a slaughter animal.

 

[inyati13]

blacksnake, she has always gotten pregnant via bull. She has a very regular cycle. To up-date, the bull has been at her since about noon today. Lucky_P, thanks for the info. I suspected it was some sort of IUD.

 

[Merrick]

My cow had a heat and was AI Wednesday feb 24 the next Thursday she was standing again so I gave her 2cc cystorelin thinking she was cystic and now 43 days later I have seen no heat could she have been bred and had a false heat ?

 

[Fire Sweep Ranch]

WOW RON, this an OLD thread!!! You have come a long way...

Only a vet can determine if she is bred or not. You could pull blood to see if she is bred or have her preg checked.