FOR GENERAL INFORMATION ABOUT SCOTS DUMPY'S - CLICK HERE
The Genetics of Scots Dumpy's
This is some of the information I have gleaned so far - I will add more as I have time and find it out - if you know anything that might be of interest to be included here please let me knowTHE CREEPER GENE
The Creeper gene is not sex linked and is denoted by Cp for the dominant allele and cp for the recessive. The Phenotypes (physical features) seem to be as follows- cpcp = Long Legs
- cpCp or Cpcp = short legs
- CpCp has no phenotype as this is the lethal combination - the chick dies in the shell
I have not found out yet where the intermediate legged or the super legged fits in - there must be other gene interactions that cause this.
|
Parents |
Short legs X short legs |
Short legs X long legs |
|
. |
|
|
|
Progeny |
CpCp = Dead in shell (25%) |
cpCp = Short legs (50%) |
There is anecdotal evidence that the long legged birds are more robust and lay more eggs.
If you breed long legged (cpcp) to long legged (cpcp) all the offspring will be long legged.
This would have some strong significance for the productivity of the birds.
It might be a good idea in a breeding program to breed long legged hens with good laying records with long legged cockerels to produce good long legged cockerels for breeding a more vigorous true short legged dumpy.
The egginess of a hen comes from her grandmother through her father not her mother. So to get round the dead in shell problem most breeders breed long legged parent to short legged parent.
Therefore if breeders have been using short legged cockerels to long legged hens it is possible this is why many are not very good layers these days.
Colour genetics and sexing
The cuckoo and the black colouring genetics is sex linked - that is to say that the genes are on the chromosomes that determine the sex of the bird. In humans XX is female and XY is male - in chickens it is the other way round and is denoted as follows: ZW is female and ZZ is male. This means that the parent male has most effect on the female chicks for sex linked features. The black and cuckoo are also variants of the same colour - the differences being caused by a single gene for barring.
The alleles for cuckoo and black are :
| Male Parent | Female Parent | Male Offspring | Female Offspring | |
| Black (bb) | Cuckoo (B | 1 | Dark Cuckoo (Bb) | Black (b) |
| Black (bb) | Black (b) | 2 | Black (bb) | Black (b) |
| Dark Cuckoo (Bb) | Cuckoo (b) | 3 | Dark Cuckoo (Bb) Light Cuckoo (bb) |
Black (B) Cuckoo(b) |
| Dark Cuckoo (Bb) | Black (b) | 4 | Black (bb) Dark Cuckoo (Bb) |
Black (B) Dark Cuckoo (b) |
| Light Cuckoo (bb) | Cuckoo (b) | 5 | Light Cuckoo (bb) | Dark Cuckoo (b) |
| Light cuckoo (bb) | Black (B) | 6 | Dark Cuckoo (Bb) | Cuckoo (b) |
Sexing the different colours
All chicks have greyish - black down with white patches.
Using the right combination of hens and cockerels it is possible to SEX THE CHICKS AT HATCHING if you know which cuckoo coloured male you have. That is colour cross (1) is the best - (2) (4)and (6) cannot be sexed on colour (3) allows you to sex half the hens and with practise (5) allows you to sex from the head patches and general colouring.
In adults the black is obvious - Dark cuckoo males are very similar to cuckoo hens being dark grey and black banding. The Light cuckoo males are mostly much paler, more like a grey and white, sometimes having white feathers in the tail - and are not so prized. To be sure though you really need a trial mating as there can be closer similarities in the light and the dark in some lines. If your cuckoo male is mated to a black hen - you have a dark cuckoo male if you get black males out - no black means it is a light (as long as you have crossed long and short legs to prevent the off chance of the dead in shell being black males)
