Consequences of inbreeding?

[Marigold4]

I am interested in a young (2), unbroken horse who has the same stallion on both sides of her breeding. On one side stallion is grandsire, on the other, stallion is grandsire. Hoping to view her after lockdown. Conformation photos look good. Would this worry you in a potential purchase?

 

[ester]

No it wouldn't worry me, but then I am used to welsh pedigrees.

 

[The Xmas Furry]

Line breeding, often occurs in registered native ponies.

 

[milliepops]

No it wouldn't worry me, but then I am used to welsh pedigrees.

yeah was just thinking, is it welsh?!

 

[ester]

one I shared the other day was a brother/sister mating which barely registered when I first looked at it. . .

 

[Meowy Catkin]

My gelding has El Shaklan fives times in his pedigree. His ancestor Om El Amira Estopa has El Shaklan as both grandsires (see link for pedigree).

https://www.allbreedpedigree.com/om+el+amira+estopa

I was always told that it is called 'line breeding' when it works and 'inbreeding' when it doesn't.

I would still view the horse. I wouldn't actively look for a horse that is so closely bred, but if I loved it and it was sound and healthy (and tested for any genetic issues known in the breed, if possible) then I would go ahead.

ETA - looking at that pedigree I linked to, you will also notice that El Shaklan also covered his own mother to produce Bint Estopa.

 

[Widgeon]

ETA - looking at that pedigree I linked to, you will also notice that El Shaklan also covered his own mother to produce Bint Estopa.

Now I don't know whether I'm just bringing some kind of human feeling into this but....seems wrong Surely not a good idea?!

 

[Marigold4]

My gelding has El Shaklan fives times in his pedigree. His ancestor Om El Amira Estopa has El Shaklan as both grandsires (see link for pedigree).

https://www.allbreedpedigree.com/om+el+amira+estopa

I was always told that it is called 'line breeding' when it works and 'inbreeding' when it doesn't.

I would still view the horse. I wouldn't actively look for a horse that is so closely bred, but if I loved it and it was sound and healthy (and tested for any genetic issues known in the breed, if possible) then I would go ahead.

ETA - looking at that pedigree I linked to, you will also notice that El Shaklan also covered his own mother to produce Bint Estopa.

 

[Marigold4]

Thanks for replying. So you would be put off to some degree? If its free of genetic disorders, what sort of negative consequences might come from inbreeding? Just to add, I am not intending to breed.

 

[Tiddlypom]

I was always told that it is called 'line breeding' when it works and 'inbreeding' when it doesn't.

That’s what I understand, too.

It‘s commonly practised, but it is something that I do not approve of and try to avoid.

 

[Marigold4]

My instinct is also against it but I'm just trying to put my finger on why. If I'm not going to breed and the horse has good confo, does it matter? What is going to crop up and "bite" me?

 

[Nicnac]

Find me a TB which doesn't have significant Northern Dancer. It's fine and more common than we think - not just in Wales. Lots of more unusual breeds have a significant percentage of inbreeding due to lack of approved stallions and mares. Wouldn't bother me if grandsires but look into dam sides to ensure no line breeding on those sides? As my maths is crap what percentage of inbreeding does that represent?

 

[Cortez]

Thanks for replying. So you would be put off to some degree? If its free of genetic disorders, what sort of negative consequences might come from inbreeding? Just to add, I am not intending to breed.

It wouldn't put me off in the slightest, it's how characteristics are "fixed" in a breed and has been done in every human-guided breeding program (including incidentally the breeding of humans, or royal ones at least) since, forever.

 

[cauda equina]

In humans consanguineous matings (ie where the parents are related) produce a higher incidence of genetic disorders due to the likelihood of a double dose of a recessive gene
Perhaps recessive genes are rarer in horses? I don't know

 

[ihatework]

It wouldn't put me off in the slightest, it's how characteristics are "fixed" in a breed and has been done in every human-guided breeding program (including incidentally the breeding of humans, or royal ones at least) since, forever.

Worked well for Prince Andrew ????

 

[Meowy Catkin]

Thanks for replying. So you would be put off to some degree? If its free of genetic disorders, what sort of negative consequences might come from inbreeding? Just to add, I am not intending to breed.

If it is free of genetic disorders, then unless you don't like the temperament (linebreeding will 'fix' mental characteristics as well as physical ones), there shouldn't really be a issue.

I do agree with Widgeon that close linebreeding feels very wrong and icky. I don't think my gelding lies awake at night worrying about it though.

 

[Marigold4]

Find me a TB which doesn't have significant Northern Dancer. It's fine and more common than we think - not just in Wales. Lots of more unusual breeds have a significant percentage of inbreeding due to lack of approved stallions and mares. Wouldn't bother me if grandsires but look into dam sides to ensure no line breeding on those sides? As my maths is crap what percentage of inbreeding does that represent?

My maths is not good either, but I guess grandsire (sire's side) = 25 % and great grandsire on dam's side is 12.5, so total inbreeding is 37.5?

 

[Marigold4]

Find me a TB which doesn't have significant Northern Dancer. It's fine and more common than we think - not just in Wales. Lots of more unusual breeds have a significant percentage of inbreeding due to lack of approved stallions and mares. Wouldn't bother me if grandsires but look into dam sides to ensure no line breeding on those sides? As my maths is crap what percentage of inbreeding does that represent?

In humans consanguineous matings (ie where the parents are related) produce a higher incidence of genetic disorders due to the likelihood of a double dose of a recessive gene
Perhaps recessive genes are rarer in horses? I don't know

But if this one has tested neg for all likely genetic disorders for the breed? And I'm not going to breed?? Would it still be an issue to purchase as a potential riding horse?

 

[ester]

No 25% would be the offspring of a sire daughter mating.

 

[cauda equina]

But if this one has tested neg for all likely genetic disorders for the breed? And I'm not going to breed?? Would it still be an issue to purchase as a potential riding horse?

That still potentially leaves unlikely disorders, and risks accentuating less than desirable 'normal' traits
It's a good idea not to marry your cousin, but perhaps it's not such a problem in horses - welsh cobs would probably be extinct by now if it was

 

[Marigold4]

No 25% would be the offspring of a sire daughter mating.

Ha ha. Knew I was useless at maths!

 

[PinkvSantaboots]

My gelding has El Shaklan fives times in his pedigree. His ancestor Om El Amira Estopa has El Shaklan as both grandsires (see link for pedigree).

https://www.allbreedpedigree.com/om+el+amira+estopa

I was always told that it is called 'line breeding' when it works and 'inbreeding' when it doesn't.

I would still view the horse. I wouldn't actively look for a horse that is so closely bred, but if I loved it and it was sound and healthy (and tested for any genetic issues known in the breed, if possible) then I would go ahead.

ETA - looking at that pedigree I linked to, you will also notice that El Shaklan also covered his own mother to produce Bint Estopa.

You beat me to it was going to say line breeding is used a lot in Arab breeding

 

[Marigold4]

Haha - it is indeed an arab!

 

[spacefaer]

Line breeding is very commonly used in both horse and dog breeding - it's used to "fix" desirable traits. (Hopefully!)

I believe inbreeding is direct in brother /sister, father/daughter - where line breeding is combining bloodlines from either side of the pedigree.

Looking at bloodlines, the tail female line is the most important - it's the one that qùte often produces the temperament

 

[Marigold4]

Line breeding is very commonly used in both horse and dog breeding - it's used to "fix" desirable traits. (Hopefully!)

I believe inbreeding is direct in brother /sister, father/daughter - where line breeding is combining bloodlines from either side of the pedigree.

Looking at bloodlines, the tail female line is the most important - it's the one that qùte often produces the temperament

What does "tail" breeding line mean please?

 

[Meowy Catkin]

Haha - it is indeed an arab!

http://www.waho.org/genetic-disorders-in-arabian-horses-current-research-projects/

The AHS and WAHO are very open about genetic disorders, how to prevent breeding an affected foal and being transparent about stallions that are carriers.

 

[spacefaer]

What does "tail" breeding line mean please?

The tail female line is the bottom one in a pedigree - the dam, her dam, her grand dam etc.

 

[PurBee]

My gelding has El Shaklan fives times in his pedigree. His ancestor Om El Amira Estopa has El Shaklan as both grandsires (see link for pedigree).

https://www.allbreedpedigree.com/om+el+amira+estopa

I was always told that it is called 'line breeding' when it works and 'inbreeding' when it doesn't.

I would still view the horse. I wouldn't actively look for a horse that is so closely bred, but if I loved it and it was sound and healthy (and tested for any genetic issues known in the breed, if possible) then I would go ahead.

ETA - looking at that pedigree I linked to, you will also notice that El Shaklan also covered his own mother to produce Bint Estopa.

crikey - el shaklan got around a fair bit then! He’s grand-sire to my gelding..now it makes sense why my gelding tried to cover his dam...? its in the genes!

I’m also not a fan of inbreeding. Ultimately if continued on surely the end result would be all the worse dna polymorphisms in one horse. Of course if completely loaded with these dna markers it would be obvious, but other erroneous dna markers wouldnt necessarily be noticed in a youngster and would slowly develop issues as they age - like human genetic traits rarely affect us when kids and teens and start showing moreso in late 20’s/30’s.

BTW - have your dna sampled and you’ll be amazed how many gene mutations you have! I did it and others and all results were loaded with gene mutations. Hundreds and hundreds of them! The dna forum regarding this common fact was eye-opening - the world is full of mutant humans...all of us mutants! ?
Although seriously - inbreeding has been out of fashion for humans for quite a while now...so it just goes to show that its not just inbreeding that causes many dna mutations, otherwise we humans would have near-perfect dna we’ve mixed so much.

 

[tristar]

when breeding i look for outcrosses, use the best bloodlines, cross breed. would never inbreed or breed from inbreds, for example the immune system can be weakened