Breeding brothers over sisters

greenaus · **Posted:** Fri May 15, 2009 6:39 pm

I know this topic has been covered a few times, but I keep having people say what I learned here is wrong.

My understanding is that we should avoid to the maximum extent possible ever putting brothers over sisters.

So...once and for all...

Under what circumstances should brothers be put over sisters? Why?

Anything else to add?

I'm asking because I have good looking cockerels, good looking pullets and crap looking hens (due to moulting and use and abuse by the cockerels -- their sons). I have refused to sell or even give the cockerels with the pullets as they are siblings (same father, 4/5 chance of a different mother). I fear people have hesitated due to the hens' appearance.

This is all academic now as I have a plan ready to put in place which will "park" my flock at two friends' properties so I don't have to lose them forever. If I don't sell the hens...GREAT. They will re-feather nicely and I already know they produce nice offspring.

But, the question remains for future reference and for others who are wondering why I'm taking the "no brothers over sisters" stance.

bunyanuternie · **Joined:** Wed Jul 11, 2007 10:31 pm **Posts:** 2903

The way you worded it is right , People still do brother over sister matings occasionly for several reasons , Cementing a Good trait , I have just Put a Really good Campine Brother and Sister together and bred succsessfully To cement the Perfect Barring and Neck hackles the male had , I did this on the advice of an old timer up here , and I'm very happy with the results , I will now use the Original Male back over the Daughters .

Theirs one of the Positives , Now for some negatives ....

pjh · **Posted:** Sat May 16, 2009 7:55 am

a brother sister mating is best avoided, it narrows the genetic material too much---it will fix a trait in the offspring, be it positive or negative.

A brother sister mating is often done in line breeding programs as a sort of "test mating" but it should be done with caution and then breed the offspring back out within the line.

But yours may not be brothers and sisters, only half brothers and sisters, and even if they were they would not be likely to throw deformities in the offspring.

cheers pam

b&p · **Posted:** Sat May 16, 2009 12:29 pm

But I have been told that doing brother/sister matings with F1's when developing some colours (especially if the gene doesn't exist in the breed) is how you help to retain the gene and than move it back into the breed of choice.

I hope that makes some sort of sense :-?

greenaus · **Posted:** Sat May 16, 2009 1:53 pm

Thanks for the discussion so far.

Pam: Are you saying that it is likely that an Australorp full brother-sister mating would be unlikely to throw deformities in the offspring? Is that because Australorps are resistant to inbreeding-caused deformities or single-coloured birds (eg. BLACK Australorps or WHITE Leghorns) are resistant or mine just look like such nice birds? :lol:

Sebastion: I think I know what you mean, but you may have to post an example, even a hypothetical one to be sure.

If I read right, this might be an example, albeit a greenaus one
eg. Breed Buff Sussex brother and sister together and then put the offspring over a Rhode Island Red to begin developing a Rhode Island Buff.

All: Someone who many consider an expert told me last year that to create a bantam you put brother over sister, then brother over sister, then brother over sister (3 x) and then outcross to avoid totally stuffing things up.

He said, "Size is the first thing to go".

FWIW, I'm not a fan of bantams....or a fan of purposely creating them.

b&p · **Posted:** Sat May 16, 2009 3:41 pm

Basicly yes Greenaus. Sussex and RIR are prob good birds to use as they reas similar

Orig mating: Buff Sussex to RIR

Resulting chicks = F1
These chicks bred back to each other using the better coloured chicks and those more similar to RIR = F2 creating the F3's

Now I think (bad brain day today :lol:

) Best F3's back to a RIR to further compliment and also retain the buff from the sussex.

These would than be the F4's.

I can't remember the rest of the plan but that may be because I am yet to be told it

pjh · **Posted:** Tue May 19, 2009 2:13 pm

most brother sister matings of most breeds will produce healthy chicks, the problems arise if you continue to do it , you continue to narrow the gene pool---so you should not mate a brother sister offspring to its brother or sister, you should mate them back to either their parent or grandparent,or some other not close relative in your program (aunt or similar), a brother sister mating narrows the variation in genes so much that there is very little progression to make, and basically we are mostly breeding to improve something or other, cheers pam

bunyanuternie · **Joined:** Wed Jul 11, 2007 10:31 pm **Posts:** 2903

Very well said Pam , Thanks .

b&p · **Posted:** Tue May 19, 2009 7:55 pm

I have to agree with Pam as well.

Only reasons a brother/sister should be done is

1. If you are trying to create something else (for which I have given up as to busy with other birds)

and

2. If you happen to lose a parent bird and don't have the opp sex available to mate back (mum/son or dad/daughter).

ROCKINGHAM · **Posted:** Sun May 31, 2009 5:15 pm

Perhaps with very rare breeds it would be nessasary to do this to keep the breed alive.

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