Back Breeding

[Maxwell Grantly]

Back Breeding KittyCats

I wanted to write a short extract about the strategy of back breeding for any new comers to KittyCats. Obviously, the more experienced KittyCats breeders will find no use for this information, but you may want to read through and cast your expert eye on my words. I would love to get your feedback.

I tried to avoid devolving too deep into scientific vocabulary and I also tried to keep all mathematics to a minimum. However, I wanted it make it engaging, so I included a load of photographs and tried to keep to real examples of KittyCats projects.

Do you think it is readable and easy to follow? Please do feel free to pass on some honest constructive feedback, either positive or negative. Thank you.

http://maxwellgrantly.wordpress.com/2013...kittycats/

[Tad Carlucci]

In terms of KittyCatS! the risks of back breeding is increased risk of Genetic Drift, whether that be losing a desirable trair, or the strengthening of a non-desirable.

Genetic Drift is the tendency of traits to either disappear, or become fully distributed, if they do not effect the survivability of the offspring.

It has two requirements:

1) Relatively small populations. KittyCatS! fully meets this criteria, especially on a breeder-by-breeder basis.

2) The trait must not effect survivability of the offspring. This is where YOU come in. You, and only you, determine which offspring survive and reproduce.

The relatively tiny number of values for each KittyCatS! trait mean the odds favor losing recessive traits and fully distributing only the most dominant.

Basically, then, this translates to 'If you're not watching the trait, you'll lose it'.

The easiest example of this are Small pupils since there are only two values: Big (dominant) and Small (recessive). Specifically, when, for example, you're breeding for Eye Color, and are not looking, at all, at Pupil Size, if any of the partners shows Big Pupil Size, it's extremely likely you'll completely lose the Small entirely. Later, when you do decide Small pupils are important, after all, they won't be there at all and you'll be forced to re-introduce them; running the risk of suppressing, or even losing, some of those other traits you worked so hard to bring out.

Similarly (it's all the same effect, just different ways to look at it) it's likely you'll strengthen a non-desirable trait. Again, using Eye Color as an example, if one of the partners is a Genesis fur, and you're not watching THAT, it's extremely likely, when you do produce the Eye Color you're working on, you'll find all the examples of it are on the Genesis fur.

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That said, back breeding is one of the very few ways to PROVE "pure".

You'll often see people falsely claim that, after several generations (sometimes only two) a trait is "pure". This may be true, but it's a false claim because they can not prove it. At best, it's simply a probabilistic statement. Unless you can prove no other trait value is possible, there always remains a chance, not matter how many generations are involved, that the visible trait value hides something more recessive.

Yes, there are other methods. And, yes, they have been used. But, they are complex and require a lot more information and effort, so they're rarely used. The only EASY method not involving back-breeding is the most-recessive trait. Small pupils are an easy example of that. Because there is nothing more recessive than Small, if you see Small, it must be pure. That works well for traits where values are rarely, if ever, added (such as Pupil Size); but can fail for traits (such as Fur and Eye Color) where there is always the risk of an undiscovered, more recessive, value lurking.

"Pure" traits are important to breeders because they speed the cross-breeding process; and back-breeding is (or should be) the "go-to" means of producing them.

[Maxwell Grantly]

Thank you for your feedback Tad.

I appreciate that back breeding tends to remove other desirable traits or strengthen any present non-desirable genesis traits too.

My initial main priority simply was to create a Russian Black with passion eyes and vampire ears, regardless of whatever other traits were present. In doing so, I have created a six-traited vampire cat. I guess, after successive breedings I can manage to achieve a seven (or perhaps even an eight) traited cat before I find myself at a dead end. However, I have set up four independent back breeding projects, all with the same end result as above. I wanted to maintain the integrity of each and so decided not to swap cats between these individual projects. When I reach a dead end with each of these, I will have a seven (or perhaps even an eight-traited) cat in each independent project. It was then my intention to use a cat from each independent breeding strand and then inter-breed these to try and remove the final one or two genesis traits.

I don’t know what the most effective way of achieving a nine-traited cat is, but I hoped that this method might be one means of achieving it.

Finally, I intend to use back breeding as a way of making the genetic background pure, simply for the fun of working on the project.

[Kayleigh McMillan]

Purifying isn't complex at all, Tad I do it all the time.
All it takes is a little patience and love shack test kitties.

Say I want a pure Russian Black I simply hide it's genes behind a more dominant fur, create two sibs and cross my fingers.
When the sibs are ready to breed I obtain two more recessive love shackers which will eventually tell me if the sibs hide that Russian Black or if my mission failed and the hidden of the Russian Black was given by one or both kitties.
If I succeeded and receive from both sibs the black as they are hiding it I trash the love shackers and their OS because these are obviously not pure anymore.
The Black Russian hiding sibs I pair together et voila one fine day they toss me both their hidden and I have my pure Russians.

Not to mention all traits a starter hides besides their genesis are always pure and if pure is what we want from them it is just a matter of being picky when it comes to selecting the right partner to hide those traits behind the partner's genes and make as such two sibs or backbreed one of them.
This works best with cats with as much as possible retired fairly dominant traits.

I have taught two new breeders and with new I mean, they did not breed more than a month, the way to go to make pure kitties and they make them now.
Nothing was Manderin Chineze about it for them.
They just like to make pure kitties and don't mind to spend the time and resources to make them.
Above all for themselves not even for the market just so they know they can rely on their kitties while breeding starters they created a dominant always running pure kitty line with retired or LE traits to breed their starters with.
Pure is basically that a kitty on certain trait slots hides the same as it shows.

When it comes to believing a pure claim this is I think up to the buyer.
From some I believe that blindly if they claim something to be pure even without proof and some not or not yet.
I think we should not say to easy a claim is false we should just be more wary about it.

[Devilness Chant]

I guess there are different levels of pure to be honest.

I agree with the things everyone here have said.

I knew the entire lines of my bali flames. (and yes mine are still pure in the purest sense of the word. my b flames are sacred to me lol) Yet one day, out of nowhere, porc shade popped out. (I am still thrilled don't get me wrong) But nowhere in the history of any of the lines I used was there a shade. It came from the begining when I started breeding with lazy dazies. That had been like over a year before my b flames. It proved to me that if there is a recessive trait anywhere in a line, it can come popping out.

But to me pure is when you have no chance what so ever of anything else ever popping out. The only way to truly achieve this is by backbreeding to a starter with another totally pure kitty. The way we do for the more recessive traits and use to do all the time with starters.

I think the only way to make a totally pure kitty, (just as an example) is to take say a sorrel, that has nothing but gens behind it and breed with a starter till it throws back the sorrel, then back breed the sorrel to the starter. Other than this, it's still pot luck. You just lessen the odds of the rec popping out by burying it behind the dom.

I too bury rec traits by constantly breeding the more dom traits till that's what they pass the majority of the time and so forth.

Since all the new traits now fall anywhere on the list, it changed the way we breed. There is very little "truly pure" left, unless it's the most recessive of traits.

[Kayleigh McMillan]

Technically we can purify all 9 traits my example was a fur.
That is pretty much possible.
It depends on the efforts one wants to make on a line how far they go in purifying.
I tend to do the things which I consider important.
Due to their recent retirement I wanted to make pure foldies for example as I like them not so much as the roundies but still.

[Tad Carlucci]

It's possible to produce provably pure using either line- or back-breeding. And, of course, it's always possible for luck to kick in and get a pure trait value from any cross-breeding which actually can be proven.

On average, though, when considered across all breeding programs, back-breeding will yield results about twice as fast.

I don't know where that comment about starters came from. Starters are not required. Perhaps it alludes to the fact that, for most traits, starters are guaranteed hybrids, so can be used in either the back- or line- programs without needing the extra parents a line-breeding program may require.

[Kayleigh McMillan]

(08-11-2013 03:05 PM)Tad Carlucci Wrote:  ... Perhaps it alludes to the fact that, for most traits, starters are guaranteed hybrids, so can be used in either the back- or line- programs without needing the extra parents a line-breeding program may require.

nods that is where it came from.

[Winter Phoenix]

I'd been working on a line of fire eyes.

Locking in the fur wasnt that important,
since its the eye color I want to lock down in this series,
and apply it to a variety of paintjobs.

In this instance I was aiming to 'genetic drift' the eyes into
a series of white russians.

So I started with what I thought was a pure white ruskie,

and what I thought was a pure bali lilac,

and I could track the lineage pretty far back,

and everybody had fire eyes.

and everybody for generations had flair shade locked down.

And I end up with a box that contains

a Snowshoe bluepoint with a TWINKLE shade!

It DID have fire eyes and a triple mysterious thing going on,

which fits my current criteria,

and it does look pretty damn sexeh,

but WTF!

Didnt see that coming.

Snowshoe bluepoint was surprising but

TWINKLE SHADE????

Sometimes this stuff comes out of the blue.

Its either elf magic or this stuff hides REALLY good.

Speaking of elf magic, I now release this hijacked thread.

Nice job on the blog Maxwell, that should be in the wiki.



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[Kayleigh McMillan]

I the blog as well every initiative which makes breeding and genes easier to understand is so valuable!
Winter is righ sorry for hijacking the thread