AUSTRALIAN POULTRY FORUM™

All I have to say is BLOODY GENETICS. I tried getting into it once and I gave up I'll just stick to normal wild-type coloured stuff but that's besides the point. Most of the stuff these days are inbred one way or another anyway.

Anyway I'll hope to put this into practice when I get my Red Jungle Fowl.

Cheers Jax.

Line breeding really is not that complicated. Most inbreeders will breed three in and one out , sometimes four in and one out. Simply put, breed Rooster to a hen. Pick the best 1/2 & 1/2 and breed back to parents. This is your first in, Next is 3/4 & 1/4 both ways, this is your second in. Next pick the best stag and pullet and breed back to the originals, this is your third in, they are 7/8 & 1/8 of each side. Some breeders will go one step further. Either way at the point you choose you breed the lines back together and start over again. You can develope multiple lines this way. Always breed for health and vigor as you must cull any that are not perfect when using this methad ( good for a Sunday dinner ).

I have never tried this but would like to give it a go. A friend in Brisbane has good success line breeding with her blue laced silver & gold Wyandotte’s and leghorns so she and this info may just be the inspiration I needed.

Breeding of related individuals together is inbreeding. If inbreeding occurs as part of a plan to develop a strain with consistent desirable traits then its linebreeding.

Inbreeding is a powerful thing as it concentrates the genes in a chicken. Being powerful, it is also dangerous, because some of the genes being concentrated are desirable and some undesirable. Some linebred families fail because too many undesirable genes get concentrated and reach a dead due to faults like infertility or poor vigour. Other linebred families have excellent performance.

I recall hearing about inbreeding of laboratory rats in order to produce uniform animals. Out of 100 lines established by full sib mating (thats mating brother to sister in each generation) with the plan of doing that for 20 generations, only about a quarter of the lines made it to 20 generations becuase of various dead end faults. The other lines that remained had pretty good vigour and exceptional uniformity.

There are lots of examples of linebred animals with high performance. Thoroughbred horses are actually quite inbred as are Friesian cattle for example. Yet they are of very high performance for the traits for which they have been selected.

Line breeding is orsum I did it with budgies and now with my sebrights and highly recommend it. Great advice PA and a great basic - how to - for the newbies.
John

Interesting and stimulating post.
The interpretation and definitions of inbreeding and line breeding vary, according to who you talk to and if they practice either or none.
I have always understood line breeding to be the mating of relatives where the influence of any individual does not rise above 50%, ie 1/2 brother sister is linebreeding.The first example of 1 male and 2 females results in 1/2 bro x sis mating to continue with one female contributing a male and the other 2 female to produce the next generation, the result is always a 1/2 sib mating.
To begin with 1 male and 1 female and mate back father daughter, mother son is inbreeding as the input from the foundation birds is rising to 75 % in the second generation . A variant on this is to mate a ckl to a hen and keep the best pullets to thier father, next generation keep a ckl and mate to the 2nd yr hens ie always select progeny to mate to the youngest parent, so each generation you alternate with a ckl this year and pullets next year and so on.
From years of breeding and reading my understanding was that if a particular individual did not appear more than once in 4 generations it was not considered inbreeding.
The important thing is to have all the desirable characteristics somewhere in the breeding pen, breed as many chicks as you can afford and to cull hard to remove the undesirable genes as they appear.
Linebreeding is a very effective tool when used effectively and carefully as it can concentrate the good as well and as easily as it can the bad.
The mating of cousins is a strategy to mark time once you realise you need to go out for any reason, this allows you to breed until a suitable outcross can be found. It does not allow for continued improvement but you lose nothing either. For my own breeding programme I prefer to bring in new bloodlines via a female.By mating her to the best and most suitable male you get a small number of progeny to assess the effects of the outcross, far safer than a male over a pen of females and a large number of progeny that might all be a waste of time rearing. From the progeny of this outcross female I would then make 3 test matings, father to daughter, mother to son and siblings, this then gives me almost every possible combination of genes to assess if the new line will be benificial or has introduced unwanted or lethal genes or other possibilities that may completely derail all the advances I had made and ruin an otherwise successful breeding programme or strain.

From a brother and sister mating would you then use a non related bird or breed the brother and sister from that pairing together or is that going too far with the genes

No Farmways I would not then go to a complete outcross or unrelated fowl.
That would negate any improvements you might have made and defeat the purpose of the initial matings.
What you could do is mate the best male back to his dam, or the best female back to her sire, you could make both matings if enough good progeny resulted.
What I would certainly do is mate the best of this brother sister (sib) mating to a near relative that embodies the desirable qualities I was striving to breed.
This way you carefully bring in some new desirable genes and hybrid vigour without losing the gains of selective breeding you have made.
One careless outcross can destroy a lifetime of hard work and achievement, the trick is to scrutinise the new line to detect any weakness or faults before you introduce it into the mainstream of your breeding programme.

If you have a target in mind, then you might do such a mating as a 'once off'. However, brother-sister mating is rather extreme and you are likely to run into problems with vigour or fertility within a couple of generations if you persist with this.

I have used brother and sister in a 1 off mating then yes used a completely unrelated bird with qualities they lacked and it was an excellent decision. I would do it again if the need arrises