linebreeding questions

[blaundee]

I want to know HOW inbred you want to go? What is a dangerous amount of in/line breeding?

Here are my 2 examples-

1- I have 1 cockerel and 3 pullets- the pullets are full blood sisters, cockerel has same sire as pullets but different dam. I am going to breed them together. Would it be wise to breed the cockerel to the resulting daughters, or to breed the resulting brothers and sisters together before introducing new, unrelated blood into the line?

2- I have 5 full sister pullets to breed to one completely unrelated cockerel (different breed). How many generations can I breed him down to his daughters? (breed him to his daughters, granddaughters, great-grands, etc- How far down the line can I use HIM?)

 

[blaundee]

I want to add that I understand that linebreeding produces the best of the best and the worst of the worst, even in just a short line of generations. In goats we would breed a buck to his daughters, but would run into problems when breeding him to his granddaughters (out of his daughters). So we made it a rule to breed a buck to his daughters, but never his granddaughters (out of HIS daughters).

 

[cgmccary]

Never breed brothers to sisters. For me, this means never breed half-brothers to half- sisters as well.

Instead,
breed Fathers/uncles to daughters/nieces, Grandfathers/Great uncles to Granddaughters/grand nieces, great Grandfathers/uncles to Great grand daughters/nieces etc.

AND

breed Mothers/aunts to sons/nephews, Grandmothers to grandsons, great Grandmothers to Great grandsons, etc.

 

[blaundee]

Why not breed brothers to sisters?

 

[cgmccary]

Breeding brothers to sisters significantly magnifies any bad traits (I can't explain the genetics behind it but there are those on here who can.) There are a number of scientific studies on breeding brother to sister and they all showed decreased fertility, decreased egg production & decreased vigor. That is also how you end up with some of the strange genetic quirks happening.

 

[Chris09]

THREE WAYS OF IN-BREEDING.
The A.B.C. of Breeding Poultry for Exhibition, Egg-Production and Table Purposes

1919
" In-breeding," says Mr. Harry R. Lewis" commonly means
the mating of individuals related for one generation. In-and-in
breeding indicates those showing a longer period and closer degree
of relationship. Three ways of in-breeding are:--

In-breeding chart showing distribution of inherited 'characters. The black
denotes the blood lines of the male and the white those of the female. The
solid black lines show that a male has been chosen from the group from
which they start and the dotted lines a female
X-Male. O-Female.

• 1. Breeding sire and daughter which produces ¼
blood like the mother.
• 2. Breeding son and mother which produces progeny
with ¾ blood of the mother.
• 3. Breeding brother and sister which gives progeny with
blood lines from both sire and dam in equal proportions.
The latter (No. 3) is the mating referred to above as
undesirable. It is often adopted by breeders of both
Fancy stock and heavy egg-producers, but it must
not be over done. He must be sure of the vigour of
the parent stock, else this fault will be intensified in
the progeny.

Here is another Line-Breeding Chart

Chirs

 

[blaundee]

Quote:
THANKYOU!!!!! That explains it VERY VERY well!!!!!