| Author |
Message |
    
Joanne Carlton (210.54.69.163)
| | Posted on Wednesday, April 17, 2002 - 03:04 am: | 
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Where is Oestrogen, Progesterone, FSH, GNRH, and LH Produced? What role do they play in equine Reproduction (What is their purpose?), And what effect do they have on the horse?
Please answer my Questions. Thankyou
Email Hunfied@hotmail.com |
Anonymous (63.24.56.165)
| | Posted on Wednesday, April 17, 2002 - 11:04 am: |
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Perhaps you should take the time to read the article at this location on this site. |
Anonymous (12.149.180.143)
| | Posted on Wednesday, February 05, 2003 - 03:59 pm: |
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What hormone is found in 8-10 month preg. mares? And is there anyway to detect this hormone? |
Barbara Lewis
Neonate
Username: Baraka
Post Number: 1
Registered: 06-2008
| | Posted on Sunday, June 22, 2008 - 02:38 am: |
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We are not always able to have ultrasounds done in a timely manner. I have a mare who has been holding on to CL's, has to be given Lutylse to throw it out and come in heat, then stays in heat for up to 10 days.
I am considering bringing her in (she currently is holding another CL), breeding her, and giving her HCG. My question (aside from whether or not you agree that this is "a plan"), is whether or not any harm is done if HCG is given at the wrong time? By that I mean, if the follicle is not develped as much as we think, etc. I am aware that it simply won't work.... just want to be sure there are no ill effects. |
Jos
Board Administrator
Username: Admin
Post Number: 2050
Registered: 10-1999
| | Posted on Sunday, June 22, 2008 - 12:14 pm: |
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Unlikely to cause any harm as long as the mare is not already pregnant. You may want to consider using Deslorelin though, as it will work on smaller follicles than hCG, so the window of success may be greater. |
Sally Chamberlain
Neonate
Username: Sally
Post Number: 4
Registered: 07-2008
| | Posted on Wednesday, August 06, 2008 - 04:11 am: |
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Jos - have just read your extremely interesting article re The Mare's Estrous Cycle. very well explained and clear.thank you.
Question: IF you mare is "in season" and has been scanned showing a 30mm follicle would you still give her a PG injection or wait for "nature to take its course"? |
Jamie Anderson
Neonate
Username: Jamieander
Post Number: 5
Registered: 04-2008
| | Posted on Wednesday, August 06, 2008 - 05:19 am: |
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Sorry to jump in here, Jos, but I know you're busy, so I thought I'd try to answer Sally's question.
Sally - PG is used to lyse (break down) the corpus luteum (CL), a structure formed after ovulation, which keeps the mare out of estrous. So, PG is used to destroy the CL, and bring the mare into season. If the mare is showing in season and has a 30mm follicle, then the CL has already been destroyed/lysed by PG which the mare produced herself (endogenous release). So, giving PG at this stage will have no effect on encouraging ovulation. It might make her sweat though!
So, in this case - let nature take its course 
Hope that helps |
Sally Chamberlain
Neonate
Username: Sally
Post Number: 5
Registered: 07-2008
| | Posted on Wednesday, August 06, 2008 - 09:18 am: |
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thank you very much it does help and is the answer I was looking for.
I did query this with the vet involved (my mare was off premises with an AI centre) as I did not think it necessary but he said it was used to "encourage precise dates for ovulation".
new one on me!!! but then I am not a vet.
mare home with me - not in foal - but with laminitis (which she has never had - she is 14 yrs old) and we are now trying to prove the case that this laminitis was induced by the unnecessary over use of PG. The last PG injection was given with this 30mm follicle AND the mare had been in 8 days being treated for laminitis!!!
beyond my comprehension |
Jos
Board Administrator
Username: Admin
Post Number: 2125
Registered: 10-1999
| | Posted on Wednesday, August 06, 2008 - 09:28 am: |
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Actually Jamie... although there is no need to use Prostaglandin F2α to destroy the CL and induce estrus (she already being in estrus), I am going to take you to task for your observation "giving PG at this stage will have no effect on encouraging ovulation"
Prostaglandin F2α given in the face of a large (>2 cm) follicle can actually have a stimulating effect on follicular growth, encouraging ovulation. This effect is even more pronounced if given when there is a follicle =>3 cm present. It is generally not used as an ovulatory stimulant, for a variety of reasons, not the least of which is an indication that there may be lowered pregnancy rates. If one were wanting to enhance onset of ovulation, then hCG, Deslorelin or recombinant LH are the more usual enhancing agents. |
Jamie Anderson
Neonate
Username: Jamieander
Post Number: 6
Registered: 04-2008
| | Posted on Wednesday, August 06, 2008 - 10:19 am: |
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Thank you Jos |
