Breeding Genetics - Page 3

Light eyes, long toes and shoulders are almost impossible to fix.  Better to start with a dog that is exceptional in these area.  Feet are next to impossible to fix.  ( can you tell i can't stand bad feet!!!)

"It would be interesting to survey breeders who have maintained a line over a few generations and ask them about what they have noticed."

It's rare enough that a breeder is producing with dogs of their own kennelname, let alone a breeder that's done it for generations.  Not to single anyone out particularly, but look at some of what you consider big name kennels, and realize how little of their own producing they further upon.  For those that do, there's not a lot of reasonable incentive to share the intimate details of their work.

 That is the benefit of a good mentor, but books and web forums(like this) are the second best in my opinion.  

I atleast want to breed dogs for myself so I would be keeping those pups because their parents had the traits I like in a gsd, and I like to see pedigrees where the motherlne goes back 3 or 4 generations with the same kennel name and the dogs all look good and have the same type. It makes me think the pup from that breeding will carry those traits I was looking for, and predictably produce them. That's just from examining photos of these dogs though. 

I believe that is the goal of breeding... to predictably produce good dogs that show the traits you breed for. Not just physically, but temperament too.  

It would be cool to have known the grandparents of each litter you breed. 


Just as a note, I haven't bred a litter before, i bred rabbits before though. 

In my next planned litter, I have known/owned all four grandparents.  I feel a lot more omniscient of the offspring potential than any other non-repeat litter I've tested, as if imparting me with a deeper sense of empowerment.

 That is a really cool breeding there. I like Faro a whole lot, and I have been following your site since you got him. I'm excited to see what the pups look like. 

In the interest of keeping this thread rolling along, I'd like to discuss an observation that contradicts what some of us commonly believe about the influence of far back producers found in the pedigrees.

While a majority of genes are transfered to the offspring at roughly a 50/50 percent from each parent, and reduced to half by each producer in the second generation of 25/25/25/25 contribution from grandparents, we often conclude that the further back we go the less influence each dog receives from any particular ancestor.  By the 5th generation, this means 3.125%, and quite probably less evident regarding expressions that require polygenic interaction.

This is true of the genetics that are transfered by independant assortment, but then we find exceptions in the sire-line transfer of the Y-chromosome, as each generation of males receives the exact copy attained from the sire, the grandsire, great grandsire and so on.  Also, of the maternal (mitochondrial dna) from the dam, grand dam, great grand dam, etc.

This chart, illustrating the transferance of X-chromosomes, also shows the importance of particular producers by their various positions in the pedigree.  Remember, that females receive one X-chromosome from each parent, and that males receive no X-chromosome from their sires.  In summary, no male-to-male transfer.



From this illustration, you can see that the dog of this pedigree carries a 50% liklihood of carrying an x-chromosome attained from the producer at p20, and further back a 25% each from the sum of p41 and p42 in the 5th generation.  Out of 62 producers by the 5th generation, knowing a liklihood of 25% influence of X-linked traits vs. the 3.125% for the remainer are pretty high odds by my estimate.  The pedigree subject has additionally carried 100% of p15 and p31's Y-chromosome, and 100% of p30 and p62's maternal dna.

The important thing, as you've said, is identifying what genes are associated with X and Y chromosomes, and the mtDNA.  While all the data has been laid out by the efforts of the canine genome project, and some things have been verifiably linked already, there is mostly the matter of interpreting how these genetic instructions are affecting the dog's phenotype.  And also as you've expressed, what to avoid may be as much important as what to retain.  But also to consider, is WHERE to avoid and retain these genetics.

So now in regards to X-factored traits, you can see large influence from particular producers far back in the pedigree, with particularly higher probabilities through an alternating gender pattern (M, F, M, F...).

Anyone watch the recently released movie "Secretariat"?  The key trait of importance to performance racing horses is the size of their heart (literally), and this is an X-chromosome characteristic.  The average horse's heart weighs 8.5 lbs., and Secretariat's was estimated to weigh 22 pounds!  Probably like the difference between a Ferrari and a Geo.  This trait in Secretariat, and known to be produced in all great champions destined for spectacular racing performance careers, could only be passed to his daughters, who could in turn pass on to both their sons and daughters.  http://www.circledhorses.com/The%20X-Factor.htm 

By use of extended pedigree analysis, horse breeders are better able to stack the genetic deck in their odds of producing great champions, and consistently doing so through their homogenous X-factored mares.

Know how ya make a million in horses?  Start with two million.

Since broodmares aren't throwing litters of colts and phillies at a time, and horses take a lot longer to develop into their performance careers, horsebreeders don't have the luxury of haphazardly breeding in the way 95% of dog breeders do.  They must pay care to breed "selectively", have carefully planned breeding goals and adhere to them. 

In comparison, the average exploiters of this german shepherd breed just can't seem to wrap their heads around some very critical concepts for any measure of success beyond papered achievements, masterful handling, and slick marketing skills.  Yes, those things matter in the horse world too, but not at the expense of wrangling up some good genetics to work with from the get go.  Genetics FIRST.

Max, talkin about bloodlines that "nick together" particularly well, what are some of the combinations that come to your mind?

Darylehret,
                       The nick that seems to be going well for the last 5 years
is vom Haus Pixner to----------> Vom Waldwinkle stock. But I think alot
of kennels are starting to use vom  Haus Pixner dogs with more established bloodlines.
It is a very good mix and can correct some problem as well as maintain quality.
I have been watching this kennel for about 3 years. Here is an example.



http://www.pedigreedatabase.com/german_shepherd_dog/pedigree/498060.html

Side note..... Northern Dancer and Mr Prospector used to be a slam dunk for a good
race horse know it's their Progeny.