Q: What exactly constitutes a purebred chicken?

[Briza]

From my research, I've gotten different answers so I've come here for some input. Does it depend on the lineage of the chicken or whether or not it breeds true? The lineage bit seems a bit dangerous considering the strong potential to bottleneck the breed out of existence. Or, is there something else I haven't encountered yet?

 

[Torch404]

It means that you have a bird that matches the Standard of Perfection and if that bird is breed with another of the same breed will breed true. Meaning their off spring would have the same charicterisitcs as the parents/SOP.

The part that doesn't make common sence is that many pure breeds are breed with other breeds to gain particular charicterisitics. Then breed back to their breed till they breed true again.

Hope it helps

 

[Briza]

Thank you. That makes a lot more sense. So, it is acceptable to use a different breed bird to improve certain traits and introduce new blood but the future generations are not considered purebred until the breed characteristics breed true again? That clears up a lot of my confusion. I think the confusion comes from the definition of purebred in different animals.

 

[Matt1616]

Thank you. That makes a lot more sense. So, it is acceptable to use a different breed bird to improve certain traits and introduce new blood but the future generations are not considered purebred until the breed characteristics breed true again? That clears up a lot of my confusion. I think the confusion comes from the definition of purebred in different animals.

I would say that a "Purebred" means that it is one of the recognized breeds of poultry in the APA SOP. There are certainly other pure breeds of chickens in the world that are not represented in the American SOP but since we live in America that is the one that matters to me.

I would say that it is pretty rare that a good breeder of "purebred" poultry would outcross to another breed to achieve a desired trait. It is even not that common to cross different strains with in the same breed amongst well know breeders. We line breed to preserve the desired traits.

Matt

 

[Briza]

I would say that it is pretty rare that a good breeder of "purebred" poultry would outcross to another breed to achieve a desired trait. It is even not that common to cross different strains with in the same breed amongst well know breeders. We line breed to preserve the desired traits.

Matt

Then we're right back to bottlenecking the breed and the accumulation of undetectable undesired traits that lead to loss of vigor. I'm studying genetics and the last thing you want to do is bottleneck if you want something to survive longer than your own lifetime. Is it not possible to use a mixed approach for the overall health of the breed in the long run?

 

[Yellow House Farm]

Thank you. That makes a lot more sense. So, it is acceptable to use a different breed bird to improve certain traits and introduce new blood but the future generations are not considered purebred until the breed characteristics breed true again? That clears up a lot of my confusion. I think the confusion comes from the definition of purebred in different animals.

Then we're right back to bottlenecking the breed and the accumulation of undetectable undesired traits that lead to loss of vigor. I'm studying genetics and the last thing you want to do is bottleneck if you want something to survive longer than your own lifetime. Is it not possible to use a mixed approach for the overall health of the breed in the long run?

The difficulty with this sort of conversation is that it deals with matters in the abstract as great theories, but in reality, it is very hard (or darned easy) to breed a line into a bottleneck. As long as you begin with enough stock, which is much less than one might think, one can maintain closed pool for a very long time, respecting of course pedigrees, etc.

Now, as for crossbreeding, there are some breeds that are currently so decimated that without an outcross it will be very hard to redeem them; on the other hand, there are many, many breeds that need nothing of the sort.

Breed is defined by type, not by blood. The reason not to outcross, isn't because of polluting the breed, per se, but rather because it creates a whole list of traits, especially those recessives, that need to be bred out. Now if someone knows how to do it and will exercise the patience to do it, that's fine. Still, unless it were necessary, it's such a process and undermines so many other fixed traits, that one would be a fool to do it randomly.

Now, as for the inbreeding pool of negative traits, largely speaking these are traits that inbreeding causes to bring to the surface, but they're not caused by inbreeding; they're revealed by inbreeding. The trick is to breed beyond them.

 

[3riverschick]

Hi Joseph at Yellow House farm,
So good to see you weighing in again! If I may, one reason it is more difficult to breed poultry into a bottleneck is because of the species wide genetic base and all the sex-linked genes. If one is studying mammalian genetics, one has to be careful about taking that knowledge into poultry breeding. Some of the general theories and laws translate, many do not because the mammal lack the plethora of sex-linked genes seen in poultry. I love books on breeding and genetics. If I may, there are some of my favs which I consider the basis of a well -stocked breeding library: The Card and Van Dort books are especially helpful and enlightening.
Yes, I have successfully strain built in collie dogs http://www.freewebs.com/bellwethercollies/ ( clicking on "Breeding Plans" will reveal the genetic history of the kennel, retired in 2009. Now am doing the same in poultry. http://www.waterfordsussexandmarans.webs.com/
Last season I did a strain-cross and had lovely results. Only one hen-hatched chick this year as we are taking a break but next year will begin our 3rd generation in Light Sussex. We don't have the Marans any more.
If I was wanting to line-breed, the first thing I would do is surround myself with quality knowledge
which would help me understand what I was seeing in the birds and how to manage cause
and effort for best improvement. These are the 9-10 books I would use as the core of my library
and why :
1. The 2010 APA Standard of Perfection . If you don't know the Standard, it's hard to breed to it.
The 1st 40 pages are extremely educational. http://www.amerpoultryassn.com/store.htm
2. Van Dort, Hancox, and Friends, :The Genetics Of Chicken Colours- The Basics".
An understandable text on "breeding to feather", latter half includes a superb pictorial encyclopedia
of poultry plumage, the pictures are captioned with the genetic formulas. http://www.chickencolours.com/pagina3.html
3. Van Dort, "The Genetics Of Chicken Extremities", A slightly more scientific but readable text
on "breeding to type" devoted to topics not covered in the 1st volume. http://www.chickencolours.com/pagina19.html
4. , Card, Wetherell Henry. , "Laws governing the breeding of standard fowls. ". By a respected
veteran poultry man describing the major and minor breeding laws. Plus the value of (and a
time tested technique) for linebreeding. Despite the book's age, the knowledge is timeless.
Wid Card was Danne Honour's uncle's uncle. http://babel.hathitrust.org/cgi/pt?id=chi.087299559;view=1up;seq=5
5. Davis, J. H. "The Art of Breeding". A classic, entertaining book describing the basic philosophies
behind "the art of breeding". http://babel.hathitrust.org/cgi/pt?id=coo.31924003135401;view=1up;seq=5
6. Brereton ,Grant , "21st Century Poultry Breeding", A great treatment of breeding techniques
focusing mostly on Wyandottes, yet with information for all to enjoy.
http://poultrykeeper.com/book-reviews/21st-century-poultry-breeding-book-review Available thru http://www.Amazon.com
7. Brian Reeder, "An Introduction to Color Forms of the Domestic Fowl"
http://brianreederbreeder.blogspot.com/
8. Brian Reeder, " An Introduction To Form And Feathering Of The Domestic Fowl"
http://brianreederbreeder.blogspot.com/ Brian writes a column for this ezine: http://www.exhibitionpoultry.net/
9. One or two classic books on one's chosen breed.
Many of these classic books are online. My fav book databases are :
Hathi Trust Digital Library
(some texts not available "full view" outside the USA)
http://babel.hathitrust.org/cgi/ls?a=page&page=advanced
Google Books
As these old public domain books get reprinted, they often succumb
to "snippet", "preview" or "limited search" options. If you see one you
like, download it.
http://books.google.com/advanced_book_search
The Internet Archive
https://archive.org/
I am having trouble with this site's security certificate , however, I
think it is the new security software I had installed, not the site.
Core Historical Literature of Agriculture (CHLA)
and of course the rest of the Cornell collections. The James Rice Poultry
Collection is esp. fascinating.
http://chla.library.cornell.edu/

This is the core of my breeding library. The only 2 books I have not read are 3 and 8. I look
forward to acquiring them this year, first 3 then 8. There are always more books to read,
however these 9 or 10 will form a a firm foundation on which to begin. If I could only afford 5,
it would be the 1st 5 in descending order. Books 4 and 5 are readable for free online.

 

[Yellow House Farm]

Oiweh, might I add that I am greatly, if pleasantly, disturbed by the nigh endless possibilities of the CHLA, of which I was regretfully ignorant until but a minute ago..

 

[3riverschick]

Oiweh, might I add that I am greatly, if pleasantly, disturbed by the nigh endless possibilities of the CHLA, of which I was regretfully ignorant until but a minute ago..

ha ha , I get lost in it's content and can spend hours mining it, hee, hee!

 

[Briza]

The difficulty with this sort of conversation is that it deals with matters in the abstract as great theories, but in reality, it is very hard (or darned easy) to breed a line into a bottleneck. As long as you begin with enough stock, which is much less than one might think, one can maintain closed pool for a very long time, respecting of course pedigrees, etc.

Now, as for crossbreeding, there are some breeds that are currently so decimated that without an outcross it will be very hard to redeem them; on the other hand, there are many, many breeds that need nothing of the sort.

Breed is defined by type, not by blood. The reason not to outcross, isn't because of polluting the breed, per se, but rather because it creates a whole list of traits, especially those recessives, that need to be bred out. Now if someone knows how to do it and will exercise the patience to do it, that's fine. Still, unless it were necessary, it's such a process and undermines so many other fixed traits, that one would be a fool to do it randomly.

Now, as for the inbreeding pool of negative traits, largely speaking these are traits that inbreeding causes to bring to the surface, but they're not caused by inbreeding; they're revealed by inbreeding. The trick is to breed beyond them.

Inbreeding can cause the accumulation of good traits as well as the accumulation of the bad. If the breed ends up with the first, that's excellent news but I was considering how you would deal with the latter if you ended up with the other and had to introduce something different in order not to lose it entirely. A lot of traits don't cause a problem on their own but in the right combinations can cause an animal to experience poor development and it can take a while for the individual genes in the stock to become common enough that they begin causing problems through combination in one individual. It's easy enough to breed out individual genes that cause problems but genes that are normally harmless, or even beneficial, that cause problems only in combination with other similarly harmless genes are something that might be difficult to control without introducing more variety into the genepool.

This is all hypothetical of course since the only experience with breeding I have is of the small mammalian sort. For mammals it can take a few thousand individuals in the original stock, depending on the species, to produce a population that will not suffer from the accidental accumulation of such traits. If chicken DNA is more diverse to begin with, I can definitely understand that it may take much less than that. I'm just wanting to understand more about it where it concerns chickens before diving in and potentially doing something irresponsible.