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#38905 - 09/04/08 02:24 AM Black chickens
Maria Ricardo Offline
Past Moderator
Coop Keeper

Registered: 03/26/05
Posts: 434
Loc: Hawaii
I started my flock with lt Brahmas, white Rock, buff Orp, and one dark Cornish. The roosters are lt Brahma and buff Orp. 4 years later the flock has 5 all black hens and one rooster similar to (except the comb), the one pictured in the recent post under Breed discussion "Whats this?". There is some slight feathering on their shanks which leads me to believe the Brahma is daddy. I'd like to use the black rooster on the black hens and the buff Orp hens. I'm supposing that all the black is coming from the one dark Cornish hen though none of the black hens has any brown feather markings. They do have a beautiful green sheen. Any ideas about what the chicks will look like? Is it too inbred for health? Are black and feathered legs dominate? My goal is to have more color and less feathered legs.

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#38906 - 09/04/08 02:59 AM Re: Black chickens
Henk69 Offline
Moderator
Classroom Professor

Registered: 02/13/06
Posts: 3208
Loc: Netherlands
I guess your white Rock hen was the most fertile.
Feathered legs are dominant but will reduce in abundance. Black is also dominant but tends to get rusty in males when crossed.
The white of your Rock is probably covering a genetically black chicken.

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#38907 - 09/04/08 06:57 AM Re: Black chickens
IPF Offline
Coop Keeper

Registered: 04/08/08
Posts: 466
Loc: Canada
Four years later - is that also four generations later? You started with how many roosters (2?)and how many hens? Your flock could be quite inbred.
Why not bring in some new blood? Inbreeding is useful for specific purposes, like "fixing" traits in purebred populations, but is generally not beneficial in the mixed backyard flock. It is convenient, but in my opinion it's worth bringing in new genes. Inbreeding reduces fertility, production, size and vigour; the more inbred, the greater the reduction.

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#38908 - 09/04/08 05:25 PM Re: Black chickens
Blackdotte Offline
Ruler of the Roost

Registered: 10/02/04
Posts: 913
Loc: Australia
Quote:
Inbreeding reduces fertility, production, size, and vigour; the more inbred, the greater the reduction.
This is not a given; depends on what you select for and how hard you cull. I have a line of bantams that all started from 2 birds some 30 years ago; no additional blood has been introduced. All the birds of this variety are related in the whole country. They lay well, grow well, are vigorous and healthy. My only problem is that they are tending to get larger than the Standard weight.

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#38909 - 09/04/08 05:47 PM Re: Black chickens
IPF Offline
Coop Keeper

Registered: 04/08/08
Posts: 466
Loc: Canada
It was a generalisation - and thus dangerous, I suppose; with most generalisations there are exceptions. I was thinking about the sort of inbreeding that goes on in some back-yard flocks more by default than by intent. With serious breeding and intensive culling I can see that you might avoid the problems, but most folks with backyard flocks don't practice intensive culling. ThHat's very interesting to hear about your 30-year-old population from two founding parents!

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#38910 - 09/05/08 01:19 AM Re: Black chickens
Maria Ricardo Offline
Past Moderator
Coop Keeper

Registered: 03/26/05
Posts: 434
Loc: Hawaii
"the white of your Rock is covering a geneticly black chicken". What does that mean? A geneticly black chicken has white feathers? Is the skin of the white Rock black? I haven't butchered one yet so don't know. Does that mean that the white Rock and Brahma are producing all black birds? I thought that my 2nd generation that was mostly white with only bits of black at the neck and tail were the white Rock x Brahma.
I started with 2 roosters and 18 hens. All 75 of my birds are from them. No intentional culling. The pure Brahmas seem to be getting smaller, the eggs too. The black hens are larger than the white Rocks.
So crossing the black rooster probably isn't as good an idea as getting an outside rooster. A RIR? I'd like to get partridge Brahmas in the flock.

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#38911 - 09/05/08 05:40 AM Re: Black chickens
Jocelyn Offline
Lord of the Fowl

Registered: 08/26/02
Posts: 1467
Loc: Canada
Your white rocks are probably dominant white, as the first chicks were white with some black feathers here and there. The occasional black feather means they were also black, but the white covered that, like a sweatshirt with holes in it, covering a black T-shirt. Dominant white "leaks" colour, and the colour of the scattered feathers tells you what colour is under the white. I started a flock of rapanuis from 3 birds in the fall of 1980, or perhaps the spring of 1981. They are still going strong. No offspring will be more inbred than the most inbred parent, so cross Momma to son, then granddaughter to the other grandfather, that sort of thing. Then, you can let them choose their own pairings, and free range them, allowing Nature to cull the unwise, the unhealthy....and have still healthy birds 27 or 28 years later.

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#38912 - 09/05/08 07:18 AM Re: Black chickens
IPF Offline
Coop Keeper

Registered: 04/08/08
Posts: 466
Loc: Canada
Quote:
No offspring will be more inbred than the most inbred parent.
This is not true. Inbreeding is quantified by calculating the inbreeding coefficient, F. If you cross a non-inbred (F=0) female to her (non-inbred, also F=0) son, the offspring will have an F of 0.25. The inbreeding coefficient will steadily increase in a small closed population.
The good news is that outcrossing re-sets F to 0; if you cross a highly inbred individual with an unrelated individual (inbred or not), the offspring will have an F of 0.

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#38913 - 09/05/08 09:51 AM Re: Black chickens
Jocelyn Offline
Lord of the Fowl

Registered: 08/26/02
Posts: 1467
Loc: Canada
Generally what you said is true, but you are assuming a quick turn over in the generations. If a twenty year old male is used on his great, great, great granddaughters, it is almost like having a new individual to breed from, if he has not been used in that line for many years. If he, himself, is not inbred, his genes shake things up almost as much as a whole new line being added. What you are calculating is how many genes will an individual likely share from the same line of descent. In the case of the old male not used in that line for a great many years, most of his genes got diluted and lost in the offspring 6 or 7 generations, or more, down the road. Bringing in his genetic contribution again brings in mostly new genes.

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#38914 - 09/05/08 11:21 AM Re: Black chickens
Jocelyn Offline
Lord of the Fowl

Registered: 08/26/02
Posts: 1467
Loc: Canada
How about an example with very little math? Would that help? The inbreeding coefficient is the probability that any two alleles on a chromosome pair came from the same line of descent. OK so far?

Lets make up breedings One Eye was a golden duckwing who was e+/e+ at the E locus and S/s at the S locus. Since we are interested in line of descent, let's take the E locus and tag it e+(OE). We'll mate him to Coal, who was E/E at the E locus, and since we are doing the line of descent thingy, let's tag her contribution E(C). All chicks get E(C)/e+(OE). Take a son back to a sister, and the grandchicks get E(C)/E(C) or e+(OE)/E(C) or E(C)/e+(OE) or e+(OE)/e+(OE). So the odds of any chick getting both E locus genes from the same side of the house is 50 percent, or F = .5. George is a BBR rooster, and he is not related to the other two. He is e+/e+ at the E locus, but he is not related. If I mate George to one of the grand chicks, say I take that pretty black pullet, she can pass E(C) to her chicks or e+(OE), unless she is the E(C)/E(C) bird. (1/3 chance, since she is not e+(OE)/e+(OE)). If any of her chicks are BBR or duckwings, she is E(C)/e+(OE). Since George is BBR, I'll choose a BBR chick to illustrate the point. Any BBR chick in this mating of George to One Eye BBR grandkids will be e+(G)/e+(OE) at the E locus. Let's name one of these Joe. Take Joe (BBR) back to Coal, and half the chicks get E(C)/e+(G)and the rest get E(C)/e+(OE). It is only if I immediately go back to One Eye with a chick of Joe and Coal, that any chick gets e+(OE)/e+(OE). If I did this, then the chicks would have been either e+(OE)/e+(OE) for any BBR or duckwngs, and or e+(G)/e+(OE) for those same BBR or duckwings. Any blacks would be E(C)/e+(OE), had I chosen a black to mate to One Eye. Does this help any?

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