Not laying blue eggs- is this more complicated than I thought?

[sophiejw]

One of my hens has just come into lay and I am sure she is laying tinted (almost pinky) eggs. Which is lovely but I thought she'd be a blue egg layer.

Her mum is an Old Cotswold Legbar. I let her run with 2 cockerels, so the hen's father was either an unknown breed but he hatched from a blue egg. Or a White Star which is a leghorn hybrid which lays pure white eggs. I think dad was probably the White Star as she is white and looks White Star like although with a small comb and some gold around her neck. I thought either of these crosses would produce blue egg layers as I thought blue (mum) x blue (dad)= blue egg laying stock; or blue (mum) x white (dad)= blue egg layer as blue egg laying dominant. Evidently not! I'm surprised though, where did the pinky egg trait come from, if it had been white I've had been less surprised.

I'm 100% sure of the fact that she came from a blue egg laid by her blue egg laying mother, as I hatched her and her mother in the incubator so know which eggs they came from.

What didn't I realise in doing this? Any thoughts would be really interesting to get. Thanks

 

[AccentOnHakes]

Quote:
The dad may have come from a blue egg, but maybe he had a gene for brown eggs from his father?

 

[Kev]

Your legbar hen is not pure for the O gene (the gene for blue eggshells). Chances for blue/green egger daughters would be higher with the unknown rooster if he inherited the O gene. only 50% from the White Star roo.

You were right in expecting colored egg layers though, but that would have depended on the Legbar hen being pure for the O gene. That pullet just proved she is not.

p.s. that's the "problem" with some dominants. There's no way to tell which is pure, which is not pure for said gene until breeding tests are done. Also a lot of basic genetics information depend on parents being pure for said gene, especially in examples of cross progeny. If the parent(s) happen not to be pure for these genes, the
results can seem very confusing because they are not following the neat textbook examples.

Also for same reason, do not expect a chick from a blue egg to be 'guaranteed' O gene carrier- such as your pullet.. but the same goes for the unknown rooster. You will not be sure if he has the gene until he is 'tested' via his daughters. One easy way is to breed him with brown or white egger hens and see what color eggs the pullets lay but you can make guesses based on him and the legbar hen, if well over 50% of their daughters lay colored eggs, he probably is a carrier.

 

[sophiejw]

Thanks for the info, that's really interesting. Thinking about it I seem to remember the ebay listing for the eggs I got the mum from said they laid a variety of pastel eggs- blue / green / pink. But they sent me all blue eggs and she lays blue eggs so I forgot. Oops.

The daughter is one of three from the same hatching- same mum running with the two cockerels at the same time. One of them looks very similar to the one who has just come into lay ie white but pure white bar a couple of small black dots on her back. The other is very similar to mum in looks (so completely different from her sisters), but much bigger. The unknown cockerel was massive so maybe she was fathered by him, here's hoping for a better chance she might be a blue egg layer then! Will be really interested to see what we get, as one has started laying hopefully I shouldn't have to wait too long.

Both cockerels have long gone I'm afraid, I couldn't keep them, especially the unknown one as he started being nasty to the other chickens.

 

[Kev]

Not knowing the color of the mystery rooster, your guess to that pullet being fathered by White Star is very good. Most if not all white leghorns have Dominant White which also works best on black(and poorly at repressing red/gold pigments) so a lot of leghorns are actually black chickens, with DW changing their black to white. They often also have extra genes thrown in them to help keep their white a pristine one.. such as barring, mottle, blue etc. That pullet sounds like a classic case of this kind of leghorn bred to a brown colored hen- red leaking on neck plus some black spots on body.

You'd be still able to produce more colored egg layers using the same legbar with any rooster, only expect 50% blue/green layers if the rooster is a brown or white egg breed, as it's now known she's not pure for the O gene.

Anyways hope the other girls lay blue eggs for you.

 

[sophiejw]

Thanks so much for all the info, that's really interesting and makes sense now. Mystery rooster was funny looking brown chicken so totally different to the White Star rooster in looks.

I shall update when the other two start laying. I'm not sure I'll breed the hen again, I'm getting into breeding pure White Stars and pure Chocolate Orpingtons next year so will have to watch my numbers. Though yesterday I hatched 2 more from her, father is an Australorp so if they are female and I keep them long enough will be interesting to see what they lay. I think I will have to keep them long enough to satisfy my curiosity! She's a great layer so as long as they take after her in that respect that's the most important thing I guess.

Thanks again

 

[nicalandia]

Quote:
and here is the issue with LegBars...

the O gene responsible for Blue eggs is tightly link to the Pea comb or the single comb that crossed over to(in the case of the well bar it crossed over to the single comb) so NOW that you have a hen that lays blue eggs with a single comb it is rather impossible to detect if the hen will lay blue eggs or not..! Why? again the O gene is tightly link to that single comb is very likely her mother was heterozygous for the O gene, and since the father is also single combed she hatch with a 50% chance of carrying that gene...

 

[sophiejw]

Well, I had a nice surprise yesterday when I collected the eggs- not one but two blue eggs

One from the mum and one from one of her daughters who I assumed must have started laying by now but hadn't. So I got a blue egg layer after all

Am very pleased!!

Edited to show pic (mum's blue egg is the lower one)

<a href="https://www.backyardchickens.com/gallery/image/view/id/4903855/album/6133406"><img src="https://www.backyardchickens.com/image/id/6131088/width/400/flags/LL"></a>