Genetics Lesson please

[kizanne]

I have a mixed barnie with some obvious EE heritage as she lays green eggs.

My question is this: She lays almost every day 6 out of 7 days most weeks so far.
I thought that this would be good to continue on so I thought about breeding her.


If I bred her with a brown egg layer what would happen?

Is there a 25% chance her off spring would lay green eggs? or is it lower. They would have to get the blue gene from her and the brown gene from the dad right?
If I cross her with a EE rooster the odds go higher but the laying probably decreases right?

 

[Ridgerunner]

If I bred her with a brown egg layer what would happen?

I'm not 100% sure of her genetic makeup. The blue eggshell gene "O" is dominant over the white eggshell gene "o", so all she needs is one copy of the blue egg gene to lay green eggs. The green comes from the brown overcoating. If you mate her with a brown egg laying breed, one of two things will happen.

If she is pure for blue, which means she has two copies of the gene,"OO", her offspring will get one blue eggshell gene from her and one white from her father., so all offspring will have Oo and the females will lay green eggs.

If she is split (which I would expect) she is Oo and the brown egg rooster is oo. So half her female offspring would have Oo and lay green eggs and half would have oo and lay brown eggs. Of course, this half is just the odds. There is no guarantee that exactly half would lay green eggs. It depends on which gene O or o the offspring randomly gets.

If I cross her with a EE rooster the odds go higher but the laying probably decreases right?

Again, it depends on the EE rooster. Since he does not lay eggs, you don't know for sure if he has any blue egg genes or not. There are three possibilities. He could be oo, Oo, or OO. If he is oo, it is the same as the brown egg rooster above. If he is Oo, the odds go way up, either 75% or 100%, depending on the makeup of the hen. If he is OO, the odds are 100%, regardless of the makeup of the hen.

Now, the egg laying possibilities. There are a lot of myths on this forum about tendencies of EE's. EE's are mutts, not a breed. They do not have tendencies. They are simply chickens that have the blue egg gene, or at least should have it. They can be big, small, any color or pattern, have any leg color or even any comb type. They may lay real well or lay pretty poorly. The eggs may be large or small. It just depends on what chickens they have in their background. Many people think they have to look like Ameraucanas, but they don't. Ameraucanas were developed from EE's, not EE's developed from Ameraucanas. There is an interesting write-up on an Ameraucana Breeders Club website about that.

Whether or not the offspring of mating your hen to an EE results in better, the same, or worse laying depends on the laying tendencies of the parents of the EE rooster. Until a recent dog attack, my best layer was a solid red EE with yellow legs and a wonky sort of pea comb that laid large green eggs practically every day.

 

[kizanne]

Thanks for the input. This is similar to what I thought but....

I thought green was blue with brown bloom but that the bloom was from a brown egg gene so are you saying they can have two blue genes and still lay green eggs that the bloom is separate so to speak. My hen has the small lean body of a ameracauna but I'm sure she isn't pure. In fact, I started my flock (stupidly) with chicks from the flea market. The old farmer told me these were dominiques. Pretty sure they don't have any dom in them though one does have the mottled barring. But they mostly look like mixes of some standards like RIR, BR and EE's. I have loved that I tripped into a beautiful rainbow basket of eggs and really like that I have one blue egg layer and one green. I sell my left over eggs and this just makes the dozen prettier. The green egg layer lays consistently and even though she is a pullet her eggs are all over 50 grams the weight I like for selling. The blue egg layer is not very productive only laying 3 to 4 a week.
I am thinking in the spring of getting an australorpe straight run of 6 chicks and keeping one roo long enough to breed with the green egg layer. But I definately want to keep the green and the productivity. I figure grow out 24 eggs to point of lay and see who lays what. By the time I cull the roos, I should still have a few green layers and hopefully the australorpe will ensure continued productive egg laying.

 

[CMV]

Thanks so much, Ridgerunner. I always love your very clear and educational explanations. Sorry for the loss of your best layer.

 

[Ridgerunner]

Quote:
The basic egg shell is either blue or white. If you crack a green or brown egg and look inside under the membrane, you can see the true eggshell basic color. Genetically, there are only two choices, blue or white. You can also scrape the outside covering off, say with fine sandpaper, but looking underneath is easier and usually clearer. Even if the hen has two blue egg genes, she can still lay a green egg. The coating is separate. It's not really bloom since technically bloom is something else. But, yeah, the same general idea.

Where if gets a bit complicated is that there are several genes that control how much brown coating is added. It is not just one gene but several. Which ones that show up control what shade of brown or green you get. You can get anything from a pink or ivory color to a chocolate brown or a bright mint green to olive green, or anything in between.

You might think of it this way.

Basic blue + no brown coating = Blue egg
Basic blue + light brown coating = Light green egg
Basic blue + dark brown coating = Olive green egg

Basic white + no brown coating = White egg
Basic white + light brown coating = Light brown egg
Basic white + dark brown coating = Dark brown egg.

 

[kizanne]

Again thanks for the help. So if I understood you right then my plan would work.

I don't know whether I'll get a light or dark green but since Australorpe lay brown and she currently lays a nice green egg then I should have some kind of green egg out of 50% of my girls (assuming she is currently a Oo).