F1 ? F4 ?

[PhilNShirl]

Hi, I've seen on various websites the term F1 etc, what does this mean? We are due in March to welcome Spencer to our home, a 7th generation doodle

[Bid]

Hi there -welcome!

An F1 is a first cross, so lab x poodle
An F2 is an F1 crossed with any gen labradoodle
An F3 is an F2 crossed with an F2 or higher labradoodle
Once past F3 I think they are usually called multi generational, which is what yours will be

If a labradoodle is backcrossed to either a lab or a poodle then rather than increase the number, you append a b, so an F2 backcrossed to a lab becomes an F2b

A backcross that is backcrossed again becomes an F1.


There you go - clear as mud!

[jackieholmes19]

Bella's mum is an f1b and her Dad an F1. I've always thought she is an F2 - is that right

[Bid]

Bella's mum is an f1b and her Dad an F1. I've always thought she is an F2 - is that right

Yes - that's what I would have said.

[Lexi-dood]

This always gets me confused!

I understand F1 + F1 = F2 and so on.....

but what I don't really understand is the 'b' bit. What is an F1b + F1b? Is it only F2 and not F3 (even if both dogs are technically second generation already)? And what about the 'b' bit does that get carried over or not?

And who actually made up the 'rules' as the UK labradoodles have no official governing body and are not KC reg? I've seen some breeders advertise F1b + F1b as multi gens and other breeders adding the gens eg F2 + F1 = F3!!!

No wonder people get confused!!!

[Lexi-dood]

I forgot to ask ....

Why does two backcrosses make a dog go back to being F1? I think I read somewhere (years ago) that Australian labradoodles were allowed a maximum of 2 backcrosses in the first 5 or 6 generations. I don't know if this is or isn't the case for UK labradoodles?

Again, I wonder who makes up the rules because it is so confusing!

(I just looked on the ad for F7 labradoodles and the dad is F2 - so how did they come up with F7 puppies???)

[Bid]

They aren't labradoodle rules, it's just what they use in animal and plant genetics to describe hybrids.

If the Dad is F2 then the pups are going to be no higher than F3 depending on what the Mum is - must be either a typo, a mistake or a sneaky advertising ploy!

An F1b isn't technically a second generation labradoodle as it is a first generation backcross, which is why an F1b x F1b is an F2 = it's only the second generation of labradoodle.

(THe Australian doodles are different as I understand they all have to come from a few of the original doodles bred in Australia - and it's best not to look into that too closely imo! )

[Lexi-dood]

Thanks. I didn't realise the F1 bit referred to hybrids.

So can I confirm then an F3b mated to a poodle produces F1 pups and not F4b pups? (I thought the generations kept going up and couldn't go back down).

[Oscar2011]

They are all cute and furry, no matter what the F number they may have .

Oscar & hoomans.

[Bid]

So can I confirm then an F3b mated to a poodle produces F1 pups and not F4b pups? (I thought the generations kept going up and couldn't go back down).

THat is my understanding - it's why I call Beamish an F1. His Dad is an F3b and his Mum is a lab.

[Lexi-dood]

Oh, I would say Beamish is F4 or an F3bb!

Whatever they all are, I would agree with Oscar2011 - they are all cute (and totally bonkers!!!).