I’m studying pedigrees and pondering: Generally, how far back would one evaluate a bloodline in generations before it is too diluted to be significant?
I read that they consider that the powerhouse, the “engine room” of a pedigree is in the 4th to 6th generation.
As well, it now pretty accepted to my knowledge that no ancestors’ influences are ever lost.
With linebreeding, some far far back ancestors can actually have a percentage of blood accountability that is that of a much closer ancestor.
I will be interested to see what people say here. I used to think in terms of percentage, so if a stallion generations back is only 3% of the pedigree I figured he had very little influence on the end product (horse in question). Now I know better =)
I have a filly who (as best I can tell at this young age) looks to be strikingly similar in conformation to her great-grandfather, Inschallah. Time will tell but it certainly is interesting.
I also have a friend with 4 dogs from the same litter. They are mutts and were believed to be Lab/Golden Retriever/Heeler. All 4 look unrelated, none have Heeler traits. 1 looks like a flat coated retriever, one like a stocky Golden Ret, 1 like an oddly narrow Lab, and the last clearly has some Irish Wolfhound or other similar breed- as displayed in his gait, coat, and leggy appearance.
The point is, that when you breed dis-similar animals, you never quite know what will show up in which generation.
Wow. This is very interesting. I would love to hear about it and hope more people will chime in.
[QUOTE=GGStables;5970444]
I’m studying pedigrees and pondering: Generally, how far back would one evaluate a bloodline in generations before it is too diluted to be significant?[/QUOTE]
I think it depends on how far of an outcross we are talking about in recent pedigree. If we talking two different breeds or registrys recently or immediate in the pedigree, or same breed but completely different lines that are pretty distant from each other, or familiar lines on both sides.
If they are two different breeds or registrys recently I’d say there is a lesser chance of characters coming out in your horse from one specific horse several generations back (that anyone could pinpoint anyway). Id look very recent the more open the pedigree is because youve got sooooo many variations its too hard to narrow it down to any one ancestor.
If you are talking about the same breed, there is a higher chance that the attributes are double upped on each side and you can look further back IMO. Especially if you see some of the same lines on both sides obviously. Maybe you’ll get one characteristic you recognize even if its not from that one sire you think contributed it, simply because many closed breeding like that has multiples of the same characteristic genes.
I get most of this thought from the dog breeders I know. They are little more specific in breeding IMO then the horse ones I know about these types of questions 
Well, in short, an apparent TB lover and pedigree guru and made a face about Northern Dancer appearing in my mare’s bloodlines.
http://www.pedigreequery.com/cinamazing
Apart from the fact that I have no clue why it’s an issue of any sort, it had me wondering generally, when one can no longer assume specific hereditary significance. When we consider Dr Christmann’s article (fyi I have a copy here: http://ggstables.webs.com/articles.htm) then head, neck, saddle position and size/frame are the front runners in heritability, with trot and jump being the highest in movement.
Of course, even though there are no absolutes, do we assume this is true of all horse breeds, to touch on the previous poster’s point? In which case, what about speed in TB’s? If the above traits are the most heritable across the board, how much harder is it to breed for speed and/or soundness, good feet, or to avoid known issues, etc?
If Northern Dancer had lousy feet, let’s just say, why panic to see him 5+ generations back, if/when feet are not a high heritability factor…
not sure what a litter of puppies - all possibly from different fathers, has anything to do with the Ops question?
genotype and phenotype
Genotype is relatable to the pedigree of a horse…the general way we can look at ancestry and guess what it might carry forward to the horse we are looking at. We know some of these horses in a pedigree have produced eventers or jumpers…less about dressage talent. We know this because the Irish and British and French and now Australians have used these horses to successfully produce sport horses…primarily jumpers. They have a history of using TBs in sport horse breeding.
The horses they use have fallen off the ranks of top flat racers so they are affordable to the general public to use for breeding sport horses. Australians still use a lot of purebreds and so I think they are the place we will see if modern stallions show up in Australian eventers pedigrees…it used to be the British who took purebred TBs straight into sport but they are using warmbloods more too. The Irish have traditionally used the TB stallion on Irish Sport Horse dams. The French mix the TB in with the Anglo Arab and then that into the Selle Franc. The Germans and the Dutch use their approval process with some changes for TBs…but the pedigrees they like to see come from what they see from other countries experimentation.
The Germans Dutch and English seem very certain about the conformation of the TB stallions they will use…that’s the phenotype. The physical representation of the genetic information. This it the hard part about TBs in general. They are NOT selected for phenotype in racing. They are selected by race winnings and nicks. The races American horses run at have gotten shorter and shorter…there are just a small handful of races in America over 1 1/4 miles. In the 60’s there was just a handful of races still run over 1 1/2 miles, the betting public wants more races in a card. So to succeed at those differences over time the phenotype has changed and it always has.
Now we are selecting for the right phenotype among a breed of horse where that phenotype is more rare. The sport horse phenotype is pretty well proven. There are rare horses that are not sport horse type who succeed but they are usually at the lower levels. People like Viney are always watching the pedigrees of successful sport horse looking for patterns. Is it really true that Northern Dancer is bad, that Mr Prospectors are not sport type, do all Raise a Natives go lame and do any of these matter when they are the great and great great grandsires.
Some things do matter…the conformation matters, soundness matters, trainability matters, jumping ability matters, honesty matters…more and more gaits matter. The ability to jump is heritable but does that mean you can’t find jump randomly or does it just tell you where to look. Do Storm Cats fail at jumping or sport horse challenges or do we not select them to try because everyone knows Storm Cats don’t jump? Bias has a big impact on breeding and selecting and purchasing. It isn’t a fair testing ground for sport…for Pete’s sake some analytical Germans don’t allow chestnuts in the Holsteiner breed…how silly is that!
I look at pedigrees to see what is there…I like to see French TBs, I love to see Abernant, Tourbillon, Umidwar, the tribe of Teddy, Rock Sand. If there is only some French I want it on the bottom. I could careless about the top line unless it is a known sport horse producer. I believe in looking off the page or back in the pedigree because I believe some genetics are more dominant than others. I try to keep track of who the British are using because they have so many TB sires being used and they have a lot of eventers running…I have seen double Raise a Native in upper level eventers…so they CAN hold up.
Genes come in pairs and one gene might be dominant over another and that gene can come from Precipitation or an Umidwar daughter or all the way back to the Byerly Turk or Buzzard. They come THROUGH a modern relative but they were inherited from ancesters, Maybe you are looking for two recessive genes and to do that you cross horses who don’t even SHOW the trait you want but their offspring can jump so you believe it is there. That’s the fun of it. PatO
genotype and phenotype
Genotype is relatable to the pedigree of a horse…the general way we can look at ancestry and guess what it might carry forward to the horse we are looking at. We know some of these horses in a pedigree have produced eventers or jumpers…less about dressage talent. We know this because the Irish and British and French and now Australians have used these horses to successfully produce sport horses…primarily jumpers. They have a history of using TBs in sport horse breeding.
The horses they use have fallen off the ranks of top flat racers so they are affordable to the general public to use for breeding sport horses. Australians still use a lot of purebreds and so I think they are the place we will see if modern stallions show up in Australian eventers pedigrees…it used to be the British who took purebred TBs straight into sport but they are using warmbloods more too. The Irish have traditionally used the TB stallion on Irish Sport Horse dams. The French mix the TB in with the Anglo Arab and then that into the Selle Franc. The Germans and the Dutch use their approval process with some changes for TBs…but the pedigrees they like to see come from what they see from other countries experimentation.
The Germans Dutch and English seem very certain about the conformation of the TB stallions they will use…that’s the phenotype. The physical representation of the genetic information. This it the hard part about TBs in general. They are NOT selected for phenotype in racing. They are selected by race winnings and nicks. The races American horses run at have gotten shorter and shorter…there are just a small handful of races in America over 1 1/4 miles. In the 60’s there was just a handful of races still run over 1 1/2 miles, the betting public wants more races in a card. So to succeed at those differences over time the phenotype has changed and it always has.
Now we are selecting for the right phenotype among a breed of horse where that phenotype is more rare. The sport horse phenotype is pretty well proven. There are rare horses that are not sport horse type who succeed but they are usually at the lower levels. People like Viney are always watching the pedigrees of successful sport horse looking for patterns. Is it really true that Northern Dancer is bad, that Mr Prospectors are not sport type, do all Raise a Natives go lame and do any of these matter when they are the great and great great grandsires.
Some things do matter…the conformation matters, soundness matters, trainability matters, jumping ability matters, honesty matters…more and more gaits matter. The ability to jump is heritable but does that mean you can’t find jump randomly or does it just tell you where to look. Do Storm Cats fail at jumping or sport horse challenges or do we not select them to try because everyone knows Storm Cats don’t jump? Bias has a big impact on breeding and selecting and purchasing. It isn’t a fair testing ground for sport…for Pete’s sake some analytical Germans don’t allow chestnuts in the Holsteiner breed…how silly is that!
I look at pedigrees to see what is there…I like to see French TBs, I love to see Abernant, Tourbillon, Umidwar, the tribe of Teddy, Rock Sand. If there is only some French I want it on the bottom. I could careless about the top line unless it is a known sport horse producer. I believe in looking off the page or back in the pedigree because I believe some genetics are more dominant than others. I try to keep track of who the British are using because they have so many TB sires being used and they have a lot of eventers running…I have seen double Raise a Native in upper level eventers…so they CAN hold up.
Genes come in pairs and one gene might be dominant over another and that gene can come from Precipitation or an Umidwar daughter or all the way back to the Byerly Turk or Buzzard. They come THROUGH a modern relative but they were inherited from ancesters, Maybe you are looking for two recessive genes and to do that you cross horses who don’t even SHOW the trait you want but their offspring can jump so you believe it is there. That’s the fun of it. PatO
[QUOTE=mbm;5971713]
not sure what a litter of puppies - all possibly from different fathers, has anything to do with the Ops question?[/QUOTE]
nevermind I thought this was directed to my post and it was not so … DELETED
[QUOTE=NOMIOMI1;5971946]
I don’t know a single dog breeder that breeds their bitches like that… I wasnt speaking about dogs loose on the street (obviously eye roll)
Dog breeding on the higher end is indeed a science.
The fact that I have to explain that genetics is genetics is really something.[/QUOTE]
Seriously? She was not saying dogs are intentionally bred this way. Different male dogs can breed one female thus you could have 4 different fathers in a litter of 4.
This is in a stray type of situation scenario.
Back to the topic at hand.
Colombus, nice post.
Terri
xx
I apologize MBM I thought you were saying to my post above about dog breeders. I did not see the post about the puppies lol
I read an article (about dog breeding, actually LOL!) by Keith Weber, which explained Fido’s genetics in a fun way:
The genes contributed to Fido’s parents by his grandparents are not marked and bundled as a package.
Rather, they simply become part of their genetic makeup. Then, during cell division 50% of Fido’s parent’s genes are copied and stored within the sperm/ egg. Since this process follows random assortment there is no guarantee that the genes added represent Fido’s grandparents equally.
Select 10 black marbles and 10 white ones. These 20 marbles will represent Fido’s father’s genetic makeup. The black marbles were contributed by Fido’s grandfather while the white marbles were contributed by Fido’s grandma.
Next, place all 20 marbles in a paper bag and shake them up. Without looking, draw 10 marbles (50%). These marbles represent the genes that will be contributed to Fido from his sire. Under nearly all individual instances, you will not select 5x black marbles and 5x white marbles. However, if you repeat the experiment numerous times, you will average five each.
To reconcile a Great-grandfather or distant ancestor (Spot or Northern Dancer etc) to Fido, one would need thousands of bags of marbles and impeccable record keeping. That’s not to say that there won’t be one unlabelled but pertinent trait/marble representing them in the newest grouping that becomes Fido.
[QUOTE=NOMIOMI1;5971954]
xx
I apologize MBM I thought you were saying to my post above about dog breeders. I did not see the post about the puppies lol[/QUOTE]
no worries… looks like the post i responded to was deleted…
[QUOTE=GGStables;5970444]
I’m studying pedigrees and pondering: Generally, how far back would one evaluate a bloodline in generations before it is too diluted to be significant?[/QUOTE]
Unfortunately, the idea that bloodlines get “diluted” is a total misunderstanding. It’s not like a glass of salt water that by adding more water, you’re diluting the salt. It’s more like ticking boxes A or B. Think color for example. If you look at a pedigree where a stallion 5 generations back was a gray and you keep going forward, you stand a 50% chance (unless you breed to another gray) of the resulting offspring being gray. If the resulting offspring is gray, the next generation you still have that same opportunity. Some traits are multi-gene determined, such as height. And of course, with recessive traits - think a chestnut here - you can breed bay horse after bay horse after bay horse after bay horse, and suddenly end up with a chestnut horse! How’d that happen??? ;). How many times have you looked at a horse and thought WOW…he looks like his grandsire? Or great grandsire?
The goal is to produce horses that have desirable traits that are dominant genetically. But those darn recessive genes can creep up when you least expect them :P. It’s why line breeding and in breeding are so popular with some breeders! You can make the pool of genes MUCH smaller and thereby increase your chances of matching up the desirable genes/traits. Unfortunately, you also increase your chances of matching up undesirable traits, as well!
So in answer to your question, I think it really depends on what you are looking for or breeding away from. Genetics are a weird and wonderful thing :D!
Great post, btw, Columbus
If you’re talking about me, I’ve recently learned that Relaunch is about average for TBs in racing where soundness is concerned. He did have a tendency to throw back at the knee, though.
And Vice Regent is becoming a good lines for event horses, if results are any indication. A couple of generations back is a very good place for him. This is also from new results research.
It’s really quite a nice TB pedigree for sport.
Edited to add: Years ago I saw a chart detailing the color possibilities for a colored corn hybrid, and the FI was fairly simple. But by the time you got to F3 the diversity was amazing. This was from breeding Hybrids to hybrids.
[QUOTE=GGStables;5971649]
Well, in short, an apparent TB lover and pedigree guru and made a face about Northern Dancer appearing in my mare’s bloodlines.
http://www.pedigreequery.com/cinamazing
Apart from the fact that I have no clue why it’s an issue of any sort, it had me wondering generally, when one can no longer assume specific hereditary significance. When we consider Dr Christmann’s article (fyi I have a copy here: http://ggstables.webs.com/articles.htm) then head, neck, saddle position and size/frame are the front runners in heritability, with trot and jump being the highest in movement.
Of course, even though there are no absolutes, do we assume this is true of all horse breeds, to touch on the previous poster’s point? In which case, what about speed in TB’s? If the above traits are the most heritable across the board, how much harder is it to breed for speed and/or soundness, good feet, or to avoid known issues, etc?
If Northern Dancer had lousy feet, let’s just say, why panic to see him 5+ generations back, if/when feet are not a high heritability factor…[/QUOTE]
I’ve asked a similar question to the OPs before, and was not real satisfied with the the detail of the responses, so thanks to everyone who has contributed to this post so far. An understanding of the question really is critical to being able to use pedigree in any sort of predictive way.
I have started on a project that is looking at TB blood % of certain ancestors in top eventing horses since 2005. My analysis uses the 9-generation linebreeding reports of the Allbreed and TB pedigree query sites (and I know they are not always reliable, but it is what we’ve got).
Below is a copy of a post I submitted yesterday on the TB pedgree query message board, hoping to get a thread started on this same issue; so far no responses. By way of background, “AGR” is a metric used on those sites that (as I understand it) takes into account earlier generations and position in the pedigree to come up with a number that is similar to blood percentage, but ostensibly more accurate and predictive. Here’s the post:
[INDENT]
[I]I’m trying to get some information (hopefully from the geneticists on board) to assist with a research project regarding thoroughbred influence in top eventing horses.
Back in October, vineyridge asked about AGR, and was provided links that explain the theory behind it. She was actually asking on my behalf, to some extent.
Getting past what it is, is it viewed as being a more valid indicator of influence than blood %? i.e., is the science behind it accepted as valid? Is AGR controverisal? Can the geneticists out there comment?
On a related question that has probably been dealt with here before (I have seen differing views on this), is an analysis of blood % or AGR in a group of horses helpful, and if so, where does an analysis of data like blood % or AGR become unhelpful?
For example, let’s say a horse has the following data line for Hyperion:
Name Linebreeding Lines Blood % Influence AGR
HYPERION 7s x 6S 2 2 (1) (1) 2.34% 6x7 3.32%
(The horse is Courageous Comet, by the way – a top eventer).
So we’ve got 2 lines, and Hyperion shows up in the 6th and 7th. The blood % is below 3%, and the AGR is only a little better. Is this a non-event, genetically? Is there a blood % or AGR cut-off after which one can confidently say that there is little-to-no genetic impact for an ancestor?
On its face, 3% of a pedigree seems like no big deal. I have seen commentary that it is all a crapshoot, or that really only the first 2 generations matter, or that one should look at generations 4-6 (the “engine room” of a pedigree) as the primary source of information. The theory behind AGR suggests that older ancestors can push through to greater levels of influence than their generational position in the pedigree or blood % might suggest.
Is there a consensus on this? Even if there is no consensus, what are the leading theories? If I’ve got a modern horse with 20 crosses to St. Simon, a blood % of 4%, and an AGR of 2%, does that say anything about the horse?
Thanks for any insights.
PF[/I][/INDENT]
Anyone here have a perspective on these questions? Are they even the right questions?
Thanks in advance.
PF, can you provide me with the links explaining the AGR please?
Just so you’ll know what AGR stands for, it is Average or Ancestor’s Genetic Relevance. It’s calculated from the whole pedigree, and it will often be very different from the Ancestor’s Blood percentage.
[QUOTE=mbm;5971713]
not sure what a litter of puppies - all possibly from different fathers, has anything to do with the Ops question?[/QUOTE]
Just so everyone is clear, there was one father. The idiot owner did not realize that keeping his 6 month old female in the same kennel as his intact male could result in puppies. I was making the point that when you have unrelated animals breeding (or vastly different phenotypes), the results can be varied and unpredictable. Sorry this was so “off track” 
