Experiences with hatching cross breeds

[NatJ]

My main question is this: I'm hoping to start hatching chicks later this year, raising them a lil while, and selling them as pullets. But let's say I was gonna cross two completely different-looking breeds, like a buff orpington rooster with a speckled sussex hen... would they actually be half-and-half color-wise, or inherit most of the genes from their mom and only some from their dad?

For any cross, people who know genetics can make reasonably accurate predictions about how the chicks will look. Occasionally a chicken will have a gene that is not expected (and may be "wrong" for their breed), and of course that can make the predictions wrong.

If the chicks inherit the same gene from each parent, that's what they show.
If the chicks inherit a dominant gene from one parent and a recessive gene from the other parent, they show the dominant gene.
Some genes interact in various ways, producing chicks that look much different than either parent.

To address your specific example:
From a Buff Orpington rooster and Speckled Sussex hens, you should get chicks that grow up with a lot of gold and/or brown feathers, probably with some black bits but possibly with white bits instead (depends on whether your Buff Orpington rooster has the gene called Dominant White, that turns black into white.)

They will not show the specific patterning of the Speckled Sussex, because the mottling gene is an important part of that pattern. The mottling gene is recessive, so all the chicks will inherit it from their mother but none of them will show any effects from it (maybe a tiny white tip here and there on their feathers, but often not even that.)

For any trait where the parents have the same genes, of course the chicks will match them both. In this case, it would include single combs and white feet/legs. The chicks should not have any of the fancy traits that some other breeds show (feathered feet, crest on the head, beard on the face, silkie or frizzle feathers, extra-long tail, 5th toe, other comb types, etc.)

 

[Sussex19]

Wow, and all those were hatched from that one hen's eggs?

Yes they did.
It was a hidden clutch, on the wrong side of the fence and only that hen found a way though.

 

[Sussex19]

Yes, she probably did lay all the eggs those chicks hatched from. That hen has a lot of recessive genes, which allows the father's contribution to be more obvious in this set of chicks.


That heritage gives him an impressive collection of gene variatns to pass on to his chicks!

A few of the ones I see most obviously:
He's got the genes for white barring, and for not-barred.
He's got the genes for black-all-over chickens, and for chickens that can show other colors.
He's got both the silver and the gold genes.

Just those genes are enough to cause:
--black chicks
--black chicks with white barring
--gold & black chicks (or red & black)
--gold & black chicks with white barring (or red & black with white barring)
--silver & black chicks
--silver & black chicks with white barring

I think there are a few other genes involved in a few of the colors too.

For each of those genes, the hen has the recessive trait, and the rooster shows the dominant trait but also carries the recessive one. So some chicks inherit the recessive from both parents and show it, while some chicks inherit the recessive from their mother and the dominant trait from their father which means they show the dominant one.

(I am leaving out quite a few details, trying to give the basic idea without getting too confusing.)

That is very interesting!
I always wondered just how the chicks came to be in such a lot of colours.

 

[Perris]

They will not show the specific patterning of the Speckled Sussex, because the mottling gene is an important part of that pattern. The mottling gene is recessive, so all the chicks will inherit it from their mother but none of them will show any effects from it (maybe a tiny white tip here and there on their feathers, but often not even that.)

That explains the plumage patterns I see with offspring from my SFH hen - whose genes I'm trying to piece together. So can I take it from this that it's the mottling gene that creates the spotty look on Swedish Flowers? photo of hen for clarification

 

[NatJ]

That explains the plumage patterns I see with offspring from my SFH hen - whose genes I'm trying to piece together. So can I take it from this that it's the mottling gene that creates the spotty look on Swedish Flowers? photo of hen for clarification View attachment 3392269

Yes, the spotty look on Swedish Flower hens is caused by the mottling gene.

 

[Chipmunk Chicks]

That heritage gives him an impressive collection of gene variants to pass on to his chicks!

I don't know that much about it all yet, but that was my first thought exactly!