Equine reproductive immunology Ph.D speaks out in 2010 against using PZP on wild horses

PM President Obama Listen to the Science

November 27, 2010

Jared Bybee, Wild Horse and Burro Specialist

Department of the Interior

Bureau of Land Management

Billings Field Office

5001 Southgate Drive

Billings, Montana 59101-4669

VIA FAX: 406-896-5281

RE: Pryor Mountain Wild Horse Range Fertility Control Preliminary Environmental
Assessment Tiered to the Pryor Mountain Wild Horse Range Environmental Assessment and Herd Management Area Plan May 2009 EA DOI-BLM-MT-0010-2011-0004-EA

Dear Jared Bybee:

Background

I appreciate the opportunity to submit comments on the Pryor Mountain Wild Horse Range
Fertility Control Preliminary Environmental Assessment Tiered to the Pryor Mountain Wild
Horse Range Environmental Assessment and Herd Management Area Plan May 2009 EA DOI-BLM-MT-0010-2011-0004-EA. My background is in equine reproductive immunology and wildlife conservation. I applaud the Billings Field Office of the Bureau of Land Management (BLM) for a thoughtful approach to this issue. Cover letter 4700 (010.JB) dated November 2010 and signed by James M. Sparks, Field Manager states that the BLM would consider comments and revision to the EA or unsigned FONSI as appropriate. I urge a “no action alternative” as outlined on page 7 and 8 of the EA. This request is based on two pieces of new scientific evidence about effects of current immuno-contraception use.

Porcine Zona Pellucida (PZP) Contraception

The proposed action as stated on page 7 of this EA would exempt “mares ages 5-10 unless they have produced foals, or are part of a large bloodline.” This is reminiscent of the approach taken with the Assateague Island wild horse population. It is a compromise approach to this issue, in comparison to placing all mares on PZP. However a recent study shows that mitochondrial DNA diversity is low in the Assateague Island horse herd (Eggert et al. 2010). Since mitochondrial DNA is inherited from the mother (mare), this is evidence that female inherited genetics on Assateague Island wild horses is under represented. It is imperative that this be assessed before rolling out a similar management plan for the Pryor Mountain wild horses.

There is a recent Princeton University study on PZP effects. Consecutive PZP applications, analogous to the proposed action plan in this EA, showed that mares gave birth later in the season, and were cycling into the fall months (Nunez et al. 2010). In a state like Montana where freezing temperatures are found in the fall, this can have serious and long term effects on foal survivorship.

I must include a statement on long term consecutive use of PZP. Any form of PZP contraception is not completely reversible in mares depending on the length of use of PZP. Contraception can only be reversed when the antibody titer decreases to 50-60% of the positive reference sera (Liu et al. 2005). Mares treated for 7 consecutive years do not return to viable fertility (Kirkpatrick and Turner 2002; Kirkpatrick et al. 2009). The issue of reversible contraception is very important to be able to maintain wild equines in the United States. Long term treatment with PZP has inherent negative potential for this herd.

I am requesting a new look at the proposed fertility control action for the Pryor Mountain wild horses.

Sincerely,

Christine DeCarlo, Ph.D.

Lori S. Eggert, David M. Powell, et al. (2010). “Pedigrees and the Study of the Wild Horse
Population of Assateague Island National Seashore.” Journal of Wildlife Management
74(5): 963-973.

J. F. Kirkpatrick, A. Rowan, et al. (2009). “The practical side of immunocontraception: zona
proteins and wildlife.” J Reprod Immunol 83(1-2): 151-7.

J. F. Kirkpatrick and A. Turner (2002). “Reversibility of action and safety during pregnancy of immunization against porcine zona pellucida in wild mares (Equus caballus).” Reprod
Suppl 60: 197-202.

I. K. Liu, J. W. Turner, Jr., et al. (2005). “Persistence of anti-zonae pellucidae antibodies
following a single inoculation of porcine zonae pellucidae in the domestic equine.”
Reproduction 129(2): 181-90.

Cassandra M. V. Nunez, James S. Adelman, et al. (2010). “Immunoctraception in Wild Horses (Equus caballus) Extends Reproductive Cycling Beyond the Normal Breeding Season.” PLos ONE 5(10): 1-10.

(Posted for educational purposes)

 

10 thoughts on “Equine reproductive immunology Ph.D speaks out in 2010 against using PZP on wild horses

  1. I am amazed that Anne Novak has been thrown out for speaking the truth on PZP. what is the matter with speaking a truth that is known by many to be true. I am so disappointed in this action. Does freedom of speech mean anything? Is this not America? Why are we afraid of the truth? We are fighting to save the Horses. This will take us all back a step in doing so.. We must come together on this. So sad. To bad whoever did this could not have said Anne I disagree and it could have been talked out. Disappointed.

  2. This is how interests of corrupt ranchers and mining companies are putting the screws on wild horses.

  3. Thank you, Dr. DeCarlo. I had thought this was probably the case — the PZP was not a good option for our wild free-roaming horses or burros.

    We have just 1% left in the wild of what we used to have, so until those numbers increase, we need a moratorium on birth control and round ups.

  4. With respect to the BLM’s plan to begin a regime of PZP treatments of the best known herd of wild equines in America, if not the world, the phrase that comes to mind is: “Fools rush in where angels fear to tread,”. Dr. Christine DeCarlo’s cautionary comments should be enough to cool the heels of any wild equine manager for whom the health of the herd is paramount:

    “There is a recent Princeton University study on PZP effects. Consecutive PZP applications, analogous to the proposed action plan in this EA, showed that mares gave birth later in the season, and were cycling into the fall months (Nunez et al. 2010). In a state like Montana where freezing temperatures are found in the fall, this can have serious and long term effects on foal survivorship….
    Any form of PZP contraception is not completely reversible in mares depending on the length of use of PZP……Long term treatment with PZP has inherent negative potential for this herd.

    The questions that Jared Bybee and BLM’s Wild Horse & Burro Program team should be asking:

    1. Is the goal of their PZP treatment program for the Pryor herd maintaining a genetically viable herd for many decades to come or is it to permanently and steadily reduce the herd size, at any cost, long term viability be damned ?

    If it is the latter, do they really want to start their campaign of ‘death by attrition’ with America’s and perhaps the world’s best know wild horse herd and attract international attention to this cynical program ?

    But, if BLM actually hopes that PZP will spearhead a viable, long term management strategy that relies less on intensely disruptive helicopter roundups and more on birth control and other forms of science-based management, shouldn’t the y start by paying more attention to the science and pay attention to the inherent flaws in a PZP-based birth control system ?

    Even if the science matters little to them, are they really so reckless and headstrong that they want to begin their risky experiment with the best known horse herd in the world ? After all, isn’t promoting positive PR, at any cost, the cornerstone of their “new approach” to managing our dwindling wild horse and burro herds ?

  5. if it wasnt for horse we would all be still in the stone age .we should be a shamed of what worlds be come

  6. Wild horses have been around for a very long time and if they and mother nature didn’t do their job to thin the herds there would be more wild horses than people. I don’t believe in PZP. It wasn’t around then and what they and the elements did to keep herds down worked. Many horses died in winter very young and very old where most likely not to make it but they weren’t the only deaths. The difference is they were in the wild as they were meant to be and died in the wild as was intended not shipped to slaughter or roundups or died in holding pens.

  7. PZP is not legal for domestic horses. Who wants to harm their brood mares or performance horses with a drug that does not perform within humane parameters and is at best, chancy? Sanctuaries with wild horses are seeing problems ranging from death to reactions that are hard to treat in wild mares. We can develop healthy, harmless, holistic management with the introduction of the portion of the WH&B Act that says independent study is needed to prevent conflict of interest. I now see individuals who have made 180 degree turn on wild and free and no PZP to hard core pushers of this unstable drug. We can do better than this. If so many PZPers want to buy time why not have a 10 year moratorium and do the independent studies BLM has never wanted done because it would prevent them from doing as they have wanted; zero out herds and use the land for corporate profit, send to slaughter and not do any real in depth studies that would make them stop their abusive management causing the loss of thousands of wild horses and burros. Those of you mimicking BLM ( and our position against it also) are expecting all of us to change our minds after 5 to 7 years in this movement as if you are right. You are jumping the gun for particular individuals who have been making their living off the wild ones with no idea of what science can accomplish. The public needs a say. You are behaving just like BLM. Stop the dangerous use of PZP on our wild horses on their lands.

    reply

  8. Joan Meeker, the truth is in the science. The horses and the land hold the answers. Not BLM or PZPers.

  9. Pingback: The War on Women and Horses | Pass the SAFE Act!

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