Dwarfs and genetics???

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zoey829

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I know this is a touchy subject but this is something I need to know.

I know of a mare that was bred and had a dwarf so they sold her. The sellers were not honest to the new buyer. So the new buyers bred her and got a dwarf. Even so they bred her again and got a normal size foal. Would you rebreed her? I would not with that history but I want professional opinions.
 

zoey829

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That is what I thought. It makes me sick. I hope they dont breed her again. I am so sad. I could never knowingly breed if thier is a defect.
 

RobinRTrueJoy

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I am so NOT an expert on this, and so far have never had a dwarf. One can never say they never will. You never know when the gene will show up, in the best of bloodlines and best of horses.

But...This is my humble opinion.

I think these things need to be disclosed to buyers. I tell everything that I know. I never want people coming back to me saying that I didn't tell everything. If I know it, so will they.

The mare in your post was bred to one stallion and had a dwarf, and was sold. She was bred again to a different stallion had another dwarf and another regular foal. I myself would not breed that mare again. I would sell her to a pet home, disclosing her history and explaining the importance of NOT breeding her or keep her myself as a pet.

Several months back, I started looking for Mr. Right, a blue eyed homozygous black pinto stallion, and finally found him. But in my search nearly bought two stallions from two different farms.... and it wasn't until each deal was almost done, that I finally asked if the stallion had produced any dwarf foals. I was lucky and the sellers told me the truth... yes, in both cases.

BUT... if I hadn't asked, they would not have offered the information.

I was surfing web site the other day and saw that those stallions( from 2 seperate farms) were sold to other breeders and I wonder if the buyers are aware that these stallions have produced dwarves. These stallions would make spectacular geldings!

Robin
 

Carolyn R

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I know what you mean Robin.

I know of a stallion that produced dwarfs (yes plural) in one year, and was sold as a stallion, I doubt the new owners were ever told. The same goes for a mare, if she has produced a dwarf, well all I can say is
, and especially if she has produced dwarfs from more than one stallion,
.

Carolyn

I guess I need to ad, this is MHO, and I feel that there are too many nice horses out there without any baggage, I personally would cut my losses and not breed them again.
 
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Riverdance

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I am not an expert by any means and I am not experienced with dwarfs. But, I think in the human world it only takes one carrying the gene to produce a dwarf, so I would think that in the horse world it would only take one too.

Just because a stallion may have produced a dwarf with one mare and never with any other mares, could that not be the mares fault? Especially if she has produced dwarfs before out of different stallions.

Same for a stallion. If he has produced dwarfs only with mares that have produced dwarfs before, perhaps it is not the stallions fault.

I have known stallions who have had many foals on the ground and all of the sudden produce a dwarf out of a mare who has produced dwarfs before. Is it fair to blame the stallion?

I know this gets very comlpicated and I know that they have been unable to trace the dwarf gene as of yet, and I am pretty sure that the dwarf gene is in most of the minis. But, perhaps with Mini's, like humans, it does not take two to tango.

In the case of the mare who has now produced two dwarfs by two different stallions, I would suggest to not ever breed her again.
 
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jrae

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I guess my question is...how do you determine if its the mare who carries the dwarf gene (I don't know if its a gene really...) or the stallion?? Do you cull the mare and/or the stallion when the first dwarf is born? Could it be that the particular cross caused it?

This is a subject I want to learn more about....
 
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backwoodsnanny

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Finally a topic I can reasonably respond to. We bought a mare in foal to a nice little stallion. When she delivered she had a dwarf who Im sorry to say died after 4 months of a compromised pulmonary system so we were not going to breed this mare again but on the advice of our vet we did breed her once more to our stallion and she did not produce a dwarf but she did produce our much beloved Helen who was born with a developmental defect without eyes. I will never breed her mom again and will be sure when she moves on that she and Helen will have a forever home where neither will be bred. To answer your question after the fact I did some research and the mare had had another dwarf at the original farm that they did not tell us about. Its just passing on the heartache. No I would not breed a mare who has had even one dwarf again. Very expensive lesson for us anyway.
 

tagalong

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Both mare and stallion have to carry the gene, is my understanding.
So far it appears that it takes two to tango - and two to produce a dwarf.

Check out the specifics in the Dwarf forum... but with two known carriers (not dwarves themselves) you have a 25% chance of getting a dwarf. 25% chance of not passing the gene along. And a 50% chance of the resulting foal being a carrier....

.
 

zoey829

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Thanks for the advice. Born without eyes. OMG!!! I knew my gut was right. This mare is an absolute beauty and she be shown and hugged everyday but NOT bred!!
 

RobinRTrueJoy

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Hey Tagalong, that is one heck of a scarey lottery! Very scarey odds. Wow!

Robin
 

MeadowRidge Farm

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From my understanding...It takes both the mare and the stallion to carry the "gene" to produce a dwarf. I also know of a few farms here in Wisconsin, who's mares and stallion have produced dwarfs, but when the horses were sold never was anyone told. I think buyers NEED to know this information. I had a email from forum member out of California, who had emailed me about breeding this one particular stallion..I asked her NOT TO since I know it had produced alot of dwarves in the past.(not mentioning any names since the exowner is a forum member) When, I asked the ex-owner about the history of the stallion,( just so I would be sure I was right) I was told..this stallion should of been gelded a long time ago. HELLLOOOOO...why the heck did they sell it as a breeding stallion??? (to someone who also went on to sell it as a breeding stallion after it started producing dwarfs for them,) and then when I asked the ex-owner about the stallion..she seemed to get a very "sour taste" in her moth about this stallion, because I was asking for the NEW owner in California. This particular stallion has traved and been resold quit a few times..going on to produce dwafs along the way. That is sad, that the original owner couldnt of been honest enough to say he has produced drarfs or that someone didnt think enough of the horse to spend the time or money to geld him. So sad!
 

Greystone

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That's why I don't understand why the registries don't step up and let owners (I can't say mandate) have the foals registered with this information. Information is a powerful thing. My mare (Patton's Ebony) just had a dwarf with my stallion (Tenkans Iceman). I wish I could have researched to their lineage and maybe know they had the potential to produce a dwarf. I have sold the stallion to a family that gelded him in the fall (I sold him last summer). If I do sell her I will certainly let the new owners (pet only owners) know.

Iceman had a foal three years ago that is normal (colt). Now my question is do I automatically geld Iceman's son?
 

zoey829

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If both parents have to carry the gene why did this mare throw 2 dwarfs? THe odds are in the favor NOT to produce a dwarf when you look at the breeding ratio. I mean out of all the foals born what percent are dwarfs? Let alone 2 coming from one mare. Could it be she might carry the gene more heavily? I know that is not scientifically possable but what are the ods?
 

Bunnylady

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Genetics 101, if I may!

Every living thing has genetic material in its cells. You string it all together and it's like one incredibly long sentence that reads basically: "This is how you make a _______ (example, horse.)

Every animal has two complete copies of that sentence, one that came from the mother, one from the father.

Genes are specific instructions in that sentence.

A trait (very simply) can be defined as something you can see about an animal (eye color, hair length, etc.)

Each trait has one gene that controls it.

Some genes come in more than one form. An animal that has only one form (both the one that came from the mother, and the one that came from the father, are the same) are said to be homozygous. Animals that have inherited two different forms of the same gene are said to be heterozygous.

A recessive gene is one that "takes a back seat" to the dominant form. The only way you see the results of a recessive, is if it is the only form present (homozygous for that gene).

A dominant gene is one that, if it is there, you will see the results. It only takes one copy of the dominant form, the other could be another dominant, or a recessive.

Dwarfism is thought to be the result of recessive genes. If that is the case, then the only way an animal can be a dwarf, is if it inherited a "dwarf gene" from both parents. If the parents are not dwarfs themselves, then they are heterozygous, having one dwarf gene and one normal gene. The normal gene is dominant, so the parents grew normally. Such animals are said to be carriers, having inherited the recessive, but not showing (expressing) it.

If a normal appearing animal has produced a dwarf, then you know it carries the recessive gene. It doesn't express it, because it also has the normal gene, which is dominant. Assuming this follows the normal pattern of inheritence, it makes no difference whether the animal is male or female, both parents must be carriers to produce the dwarf.

As I said, this assumes the normal pattern of inheritence. There are some weird ones! But if this understanding is correct, then any animal that produces a dwarf carries the dwarf gene. Every one of its offspring has a 50/50 chance of inheriting that gene.

If you breed two carriers together, your odds are 25% for a homozygous normal foal, 50% for a normal-appearing heterozygous foal, and 25% for a dwarf. That DOES NOT mean that you will get 3 normal foals for every dwarf this pair produces. It means that, if you could do this cross 100 times, about 25 of the foals would be dwarfs, and of the remaining 75, roughly two-thirds would be carriers. If you only did this cross say, 10 times, you could get 10 dwarfs, or no dwarfs, all homozygous, all heterozygous carriers, or any possible combination of the three.

Okay, retiring from the podium now. Did that make it any clearer? Or just more confusing?
 
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maestoso

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"If She's produced a dwarf once, she'll do it again"

I think this needs to be more accurately stated.

If she has produced a dwarf once, she COULD do it again, and is more likely to produce another than perhaps a mare who has never produced a dwarf.

I wouldn't rebreed the mare either, however there is no statistic or proof that states if a mare has produced a dwarf she will definitely produce another.
 

zoey829

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That was excellent Bunny lady!!!

That is in the horse world. But a bit off topic. When I was in high school they said the dwarf gene in humans is dominate!!! That 2 reg size people can not produce a dwarf. But 2 dwarfs can produce a reg size person if they carry the recessive gene.
 

RockRiverTiff

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An important thing to remember when choosing to breed dwarf producers again is that even if they don't produce another dwarf in their life, there is a high likelihood that they will produce carriers, which only perpetuates the gene and results in more dwarves somewhere down the line. For that reason, I do wish horses that had produced dwarves in the past received a special designation. While it is their owner's choice to continue breeding them, it is a shame that people breeding that horse's get and grandget are often not made aware of their possible carrier status until they produce a dwarf too.
 
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