help to avoid "inbreeding"

[patandchickens]

Quote:
But parent-offspring matings also share a whole buncha the same genes (well, alleles). Like, half of my genes are the same as half of my father's genes (obviously since that's were I got them from). The other half of my genes (alleles) are the same as half of my mom's, because ditto.

My brother (ok so I don't have a brother, I have a sister, but let's pretend I have a brother you're considering mating me to... er, I mean, I don't even want to *think* about that, euuw, but, you know what I mean

) also would share about half the same particular genes (alleles) that I have.

So no matter whether you're contemplating mating me with my father or my brother (man, am I ever wishing I had not started this analogy!

), I'll share about 50% of my genes with EITHER ONE. The inbreeding coefficient over one generation of this is 25% in EITHER case.

I tell ya, a lot of this business of "parent-offspring matings good, brother-sister matings bad" is TRADITION (often for good and sufficient reasons, of course, but reasons that go beyond the mere relatedness issue). And there is SO much more to effective linebreeding programs than just parent-offspring OR brother-sister matings... I do not even remotely pretend to understand the subtleties of all that stuff.


Pat

 

[halo]

Quote:

Hey Gazinga - are you sorry you asked?

the rest of us are..

alright, alright, I can take a hint....

 

[LittleChickenRacingTeam]

Line Breeding
This system is called line breeding, which is scientific in-breeding, and may be more readily understood by reference to the chart below. The solid lines in the chart represent the course of the male blood and the dots the female blood lines. Suppose a pure-bred cockerel represented by group 1 to be mated to the pullets in group 2. The progeny of this mating would be represented by group 3.


Breeding chart.

The pullets in this group are mated back to the cock in group 1 and the progeny would appear in group 4 as three-quarters the blood of the sire.

The pullets from group 4, when mated to the cock in group 1, would give progeny in group 6, the chicks in which would be seven-eighths the blood of the sire, or practically pure bred so far as utility requirements go.

The chart is extended to show how other combinations occur. In group 9, produced by crossing a cockerel from group 6 with pullets in group 7, and also in group 13 produced by crossing a cockerel with pullets in group 10, the result is half breeds as in group 3. Group 5 results from crossing a cockerel in group 3 with the hen in group 2. The progeny in that case would be seven-eighths of the blood of the mother instead of the father as in group 6. In group 10, the chicks result from a cross of a cockerel from group 5 with pullets in group 7. The reverse of this is the case in group 8. Groups 11, 12, 14 and 15 explain themselves.





Should it be thought desirable to introduce a new line of blood, it is best to do this through a pullet or a hen mated to a cockerel as shown in group 8. The reason for selecting a female is that it is safer than to purchase a male whose influence might not be as desirable as hoped for. The progeny of one female could be more easily kept separate than the progeny of a male mated to several females. The proportions of blood would be somewhat similar to that in group 3; namely, there would be half the blood of the new female with 13-32 of the blood of the original cock in group 1, and 3-32 of the blood of the hen in group 2.


From the foregoing discussion it is evident that great care must be exercised to prevent breaking up the system of breeding; for by carelessness all the good results may be lost, since the progeny will be thrown back into one family and thus indiscriminate breeding result in ultimately spoiling the flock. It is highly desirable, therefore, that the plan be definitely laid out beforehand and followed without deviation in any respect.


If the best results are to be attained, the chart should be made and its tracings followed systematically from year to year. Without the aid of the chart careless breeding is sure to result and the whole system be spoiled by injudicious matings. If the lines of the chart are carefully studied and followed, a great improvement may be shown in the ordinary farm flock as instanced above. Thus flocks may be made more profitable at the cost of only a little thought and care.

There is only one more caution to be made. It is essential to select the best individuals in each generation so as to secure the largest proportion of improvement. By this system, it will be seen that while no brother and sister matings are made, the system is practically that of in-breeding. On this account any faults in the parents are likely to be exaggerated in the progeny, just as excellencies are. For this reason too much care cannot be taken to avoid mating individuals which exhibit the same kind of faults.

 

[redhen]

Quote:
Heehe..sorry..thought i'd be able to slip that one in with out anyone noticing it...i'm just joking! really!...

..and my grandaddy who is also my uncle/father/brother combined..is from there..(.heehe..sorry again!!!

..).i'm just teasing!!.i dont have anything aganist Arkansas...deliverance was my favorite movie..

..

OT - You're forgiven, THIS TIME. If it happens again I'll break out my yankee jokes and show no mercy.

Blessings, Kat Who happens to be from NC. I've been transplanted to the beautiful state of Arkansas.

Thank you!...

...

p.s...i hope people know i am kidding about my grandpa/daddy/brother thing....

..

 

[us6reeds]

so say I have a few chickens all the same breed does it matter who mates with who?? I am confused or does it just matter with mixing breeds and how do you know whos brothers and sisters when you order chicks??

 

[Akane]

But parent-offspring matings also share a whole buncha the same genes (well, alleles). Like, half of my genes are the same as half of my father's genes (obviously since that's were I got them from). The other half of my genes (alleles) are the same as half of my mom's, because ditto.

The difference is that if the original pair is unrelated they should not have much of the same genes. So if we cross them the offspring should get different potential problem genes. Those offspring though now have a high chance of carrying the same problem genes as each other. Any offspring can have both the genes from the father and from the mother so if we cross them together any of those genes found in the original pair could cause problems. If we cross the offspring back to a parent though we only have any potential bad genes inherited from one parent and we're actually diluting the potential bad genes given by the other since as said before being an unrelated pair they should not carry the same genes. Crossing back to a parent concentrates genes from that parent while diluting ones from the other. Crossing siblings concentrates any genes they both inherited from either parent. Either way increases your odds slightly of having problems versus breeding out but one has greater odds than the other.​

 

[rdish50]

first i would say ,logically,that,provided a parent chicken had great stupendous ,wonderfull genes....then there would be great advantage to inbreeding....inbreeding would only concentrate and strengthen the wonderfull strong points.....of course,all pure bred chickens are come about by inbreeding..line breeding....else why would we call them purebreds.......consider the rhode island red bantam.....i have raised a lot of different breeds of chickens through the years....but these little rascals have a affinity for life...they are active, healthy(are strong as chicks), and very good foragers...they just exude life!.....i have gotten some columbian wyandottes from Murry Mcmurry hatcherie...25... that were very unhealthy,weak and slow developing....they were so sickly we just lopped the heads and threw away the bodies since there was no meat on then....next year they sent us a free batch of cornish cross to make up for our loss and of course they made fantastic meat birds...raised under the same conditions...but some couldnt walkj some of them..they grew so fast.....so my point is....some closely inbred birds could be very healthy if they have healthy genes to begin with.....and there you have this fantastic meat bird..the cornish cross with a problem walking normally because they grow so fast..please reply ..this is interesting

 

[Peregrine]

This all reminds me of that old song, "I'm my own Grandpa". Anyone else know that one?

I love smilies! They say so much more than I ever could! Here's how i feel about this whole thread:

 

[Oghdoff]

Quote:
ut hum

Heehe..sorry..thought i'd be able to slip that one in with out anyone noticing it...i'm just joking! really!...

..and my grandaddy who is also my uncle/father/brother combined..is from there..(.heehe..sorry again!!!

..).i'm just teasing!!.i dont have anything aganist Arkansas...deliverance was my favorite movie..

..

shame shame

 

[Pele]

I think all the confusion is resulting because the answer, as always with genetics, is 'it depends'.

The real point of contention is that you are only HALF related to your mother or father, while you are most closely genetically related to your brother/sister. There is a minor shuffling of genes, but they are as close to genetic matches as most people can get without having an identical twin.

Now, if you have a bad set of genes that you are wanting to eliminate, choosing the most closely genetically related animal isn't going to help you. BUT, if you have a perfect set of genes that you DONT want to lose, and start establishing a strong line, then yes, breed brother to sister to preserve it.

I hope that helps clear up some of the confusion. Well, as clear as 'depends' can get anyway