Rose Combed Breeds

[Hen-Gen]

I don’t know how many of you hatch eggs or read obscure publications on chicken genetics for that matter. But if you hatch chicks of Dominiques, Wyandottes, Hamburg’s or any other rose combed breeds then you need to know this. I did know what I’m about to say but verified it this year to satisfy myself the oft stated theory.
Pure bred cockerels which are true breeding for the rose comb gene have greatly impaired fertility. This is caused by both the short life and the impaired motility of their sperm. I set 35 eggs and got 7 hatchlings.
It is a good idea therefore to introduce a single combed breed from time to time to mitigate against this. In my case this means a Barred Rock to my Dominiques because the two breeds are very similar. Or if staying within the breed/variety keep a single combed cockerel which occur from time to time in all rose combed breeds. Pure breed hens which are true breeding for the rose comb gene are completely unaffected in this way and have normal fertility.
Interestingly if a whole bunch of hens and different comb type cockerels are housed together then the hens preferentially mate with the single combed cockerels. They seem aware that their reproductive success is maximised by this strategy.

 

[MrsBiscuit]

Well HG, I had no idea as I haven't never kept/bred a rose combed variety. but fascinating stuff. From my dim recollections, probably nothing to do with rose combs, isn't there a variety with some sort of mutant gene and high death rate/low fertility, possibly sebrights, I can't for the life of me remember any details. Anyway, I find the bit about hens preferring males with single combs (which I think must be the most common form?) very interesting.

 

[Hen-Gen]

You’re absolutely right MrsBiscuit, Sebrights are notoriously difficult to breed. Firstly they have been inbred for ever and this always results in the hatching of individuals lacking in vigour and fertility. But as if that isn’t enough the breed standard also requires the males to be hen feathered which means that they should be identical to the females in their plumage. Many breeders consider that the gene that causes this also reduces fertility.
It is somewhat an obsession of mine how breeders perpetuate the carrying of deleterious genetics in order to meet some human idea of beauty. French Bulldogs, Sphinx Cats, Norwich Canaries and many more varieties of domestic animals demonstrate this. None of my animals are pure bred apart from my sheepdog where selection is based on non deleterious factors. I’ve just hatched some Mottled Orpington’s from eBay but next year they’ll be going to an Exchequer Leghorn to give mottled but vigorous and unexagerated pullets. I think designer crossbred animals eg Labradoodles, Lurchers etc can be beautiful but also genetically sound.