I need your help!!!! Genetics question.

[Settler'sDreamFarm]

I was wondering, if you cross a bird (for example bantam buff cochin) and breed it too another bird of a different breed (for example a buff silkie )And you get chicks from them which are like a mix of the two, but are kinda like a breed of their own. What if you take these crossed chicks and cross them would their off spring be the original breed or would they breed true and be the same as their parents who are crossed. It is confusing, let me know if you dont understand, I am just wondering if I can make my own breed, that will breed true. Thanks!!!!!!!!!
Maybe you can understand this????
Chicken 1 (Male) x Chicken 2 (Female)
| |
Chicken 3 (Mixed Breed of Chicken 1 and 2)

A year later when chicken 3 are grown up:

Chicken 3(Mixed Breed of Chicken 1 and 2)xChicken 3(Mixed Breed of Chicken 1 and 2)
| |
What would Chicken 4 Be????????

 

[Settler'sDreamFarm]

This is so hard to explain but I really want to know the answer!!!

Maybe you can understand this.........

 

[Sonoran Silkies]

The 2nd generation is when you will really start seeing the gene segregation.

Let's assume you have two chickens that are completely opposite for every gene (unlikely, but it will help illustrate my point). Let's also assume that each chicken is homozygous (identical alleles for each gene) for all genes (equally unlikely). (We're also ignoring all lethal genes.)


Let's assume that there is a gene named A.

Chicken1's genotype is A/A; Chicken2's is a/a.

Their offspring will be A/a.

If you breed two of these offspring together,
25% will be A/A,
50% will be A/a and
25% will be a/a

Realize that there are hundreds of genes in each chicken, and that for the most part the genes are not linked and thus inherited together. Thus, the 25% who are A/A will not be A'/A' (a second gene), but will also include ones who are A'/a' and a'/a'. Likewise with the A/a and a/a.

The odds of accidentally getting a bird who exactly, or even nearly matches one of the original birds is pretty astronomical. Now, if you narrow the scope, say you have two birds of the same breed (so there are many matching genes) but different varieties, you will still segregate the genes when you breed F1s together, but there will be far fewer genotypes that could result.

Using just the first 4 genes listed on the Chicken Calculator (and leaving the rest at default, there are 8 different phenotypes, and if you look at genotypes, you need to hatch 512 chicks to statistically get one of a specified geneset. And that is only 4 genes.

 

[Junkmanme]

SonoranSilkies,

THAT is an excellent explanation! (Even I understood it!)

Like I've said before, You're a GOOD teacher!

-Junkmanme-

 

[Settler'sDreamFarm]

Thank you very much!!!!!
So it pretty much impossible to make your own breed to breed true even after 5 generations or more?

 

[Chris09]

Settler'sDreamFarm:
I might be wrong but it looks like your talking line breeding.
If so this might help.. It was in a rabbit book I have but should work with chickens..
Chris

 

[Sonoran Silkies]

Settler'sDreamFarm :

Thank you very much!!!!!
So it pretty much impossible to make your own breed to breed true even after 5 generations or more?

I guess, my question would be, what are you trying to achieve?

If you are bringing a trait (be it colour, pattern, comb type, egg colour, whatever) into a breed, once you bring in the trait, you breed back to the breed, selecting until you have the breed (to match the standard), and also the new trait.

If you are creating a new breed, then you need to determine which breeds bring you closest to the desired traits. It is probably easiest to bring in a trait or two at a time rather than trying to bring them all in at once. The later introduces too many variables to reasonably select for/against. You have to hatch too many chicks that don't fit your needs.

You can bring in multiple traits by having multiple breeding pairs--work on comb with one pair, pattern with another, breed back to the opposite parents then breed the offspring that best match the breed and the new trait together. This saves chronological time, but you need more space to devote to your project.​

 

[Henk69]

So you created a nice F1 bird?

Breeding F1's together would give a lot of segregation. True.

But if the traits you like are fully dominant, I mean like a switch on switch off situation, there is a chance that you can purebreed these traits.

By testmating you could figure out which traits are purebreed already in your new generation.

It is a lot of work but it can be done.
In fact this is how new breeds are made given that the endproduct looks like intended when the project was started...

 

[Sonoran Silkies]

I guess I was looking at not creating something new, but trying to get back to the original by breeding F1s together. Something like: if I have a brahma and a polish, and breed them together, can I get a pure brahma by breeding the brahmaXpolish together?

I don't quite understand the reason behind the question, but figured that at least part was trying to understand how things work.

And Henk, I agree with your answer.