# Inbreeding and recessive mutations



## rudolph.est (May 14, 2009)

Hi all,

I was wondering today about the biological mechanism behind the fixing of recessive genetic traits in a population.

I came to the conclusion that some degree of inbreeding is the only way that rare spontaneous recessive mutations could possibly be fixed in a race or breed. All the recessive mutations we find in pigeons today have to be a result of inbreeding, whether by closely or distantly related individuals. Also, since many of the mutations originated very long ago, in ancient antiquity even, I assume that at least some of the inbreeding occurred 'naturally' without human intervention.

The question I set to you now is that I do not understand the reluctance of many people on this site to breed brother/sister pairs, or father/daughter or mother/son, while this is the easiest and most reliable way to fix a genetic recessive trait in a strain. Isn't that exactly what homer breeders want to achieve - homozygosity at the loci that make up a great racer?

Does anyone have any comments?

Kind regards,
Rudolph


----------



## "PA BLIND" (Nov 3, 2010)

child and grandmother


----------



## Timber (Jan 6, 2009)

I have personally tried to fully understand the genetics game, but for me theres way to many variables. There are documented cases from all sides of breeding from, total crosses, to line-bred and in-bred matings that have produced race winners or even show champions. Im the type that tries to "stack" the gene pool per say for racing, so should it be from father/daughter, mother/son, full siblings, half siblings, gparent/gchild and all the other combinations, if it produces success, I dont care who the parents are.


----------



## Pigeonmumbler (Jun 6, 2010)

I agree with you both Rudolph & Timber, I wrote an Article on the very same subject on my Website, maybe some of you may find it interesting…???

https://sites.google.com/site/dhfloft/the-chronicles/feb-pigeon-strains


----------



## sreeshs (Aug 16, 2009)

rudolph.est said:


> Hi all,
> 
> I was wondering today about the biological mechanism behind the fixing of recessive genetic traits in a population.
> 
> ...


Rudolph, is a gene/the genes associated with homing established ?

A good racer as per what I have read is a combination of many things, of course everything can be said to originate from genes but those alone does not seem to be the case here OR there is a variety of genes responsible which humans are not yet able to pin point.

Going with Pigeonmumbler's definition on in-breeding - the breeding of siblings, father-daughter or mother-son, this may enhance a desired recessive trait but will also play its role in enhancing undesired traits.

Excessive in-breeding is said to result in weaker pigeons and a fancier even if successful in obtaining/establishing in a pigeon the instinct for homing, would not proceed with that pigeon if its health is not up to his satisfaction.


----------



## rudolph.est (May 14, 2009)

Hi Shreesh,

I did mention loci (the multiple of locus) in my post. I am sure there is not juts one gene that improves stamina, nor just one that improves strength and speed, nor just one controlling homing ability.

The creation good racer is indeed a combination of many things, but mostly inbreeding (or linebreeding - which is still inbreeding since the birds are still related) and selective out-crossing. And most importantly, *selection*!

I do agree that inbreeding can also increase the incidence of the expression of genes with negative effects, but that is where selection comes in. If the inbred offspring are inferior, the offspring (and definitely their parents and probably the grandparents too) should be discarded and _never_ used in a breeding program. This is exactly the best way to remove deleterious genes from your gene-pool. If you keep out-crossing and never inbreed or line-breed, you will never know which individuals carry the bad recessive genes and you would never be able to get rid of them.

Such a system of selection should be less hit and miss than just pairing up random birds. Buy the best starting (2 or 4) birds you can, breed one set of babies and then set of line-breeding, creating two or more distinct lines and definitely discarding all inferior birds as soon as possible (to avoid temptation of breeding them). You will have created a strain (or two strains) of birds that are very similar and compatible genetically as well as relatively free of negative genetic influences. Crossing these lines (or strains) together for an out-cross will increase heterosity (or hybrid vigor) and these out-crosses can again be line bred for performance.

This is exactly how the tipplers/high-fliers that now fly 18 or more hours continuously were bred. So why can't the same logic apply to homers? (or maybe it has been - in the lofts of the creators of the famous strains)

Kind regards,
Rudolph Esterhuysen


----------



## sreeshs (Aug 16, 2009)

rudolph.est said:


> Hi Shreesh,
> 
> I did mention loci (the multiple of locus) in my post. I am sure there is not juts one gene that improves stamina, nor just one that improves strength and speed, nor just one controlling homing ability.
> 
> ...


Just check on the champions list of various races for past couple of years and how much in-breeding is involved in them, that might give some clues.

Racers who had success with in-breeds would have kept them, those who had success with a mating outside the family would have followed that. Anyway both does not guarantee that champions will be produced so it might be what the fancier thinks suits him.

Personally I would not do an in-breeding to establish a color/pattern related gene in my fancy pigeons. I would rather look for another bird with suitable characteristic among other fanciers. Mainly because of personal inconvenience involved in breaking and re-pairing the birds and the inside doubt of whether a weak offspring would be the result


----------



## sreeshs (Aug 16, 2009)

This has little reference to genetics but the articles on this site gives some examples in which famous strains were involved.

http://www.schaerlaeckens.com/


----------



## rudolph.est (May 14, 2009)

Thanks for the link Shreehs, I'm sure it will be fascinating reading. I'll also see what I can get off the pedigrees for these pigeons. Maybe there is some relation after all.

I think I will see if there aren't any clubs that keep pedigrees. Like the Kennel Clubs do, or maybe I will convince the local pigeon racing and fancy pigeon associations to send out a request for pedigrees and performance data to their members.

Would be an interesting project, I think.

Kind regards,
Rudolph


----------



## sreeshs (Aug 16, 2009)

rudolph.est said:


> Thanks for the link Shreehs, I'm sure it will be fascinating reading. I'll also wee what I can get off the pedigrees for these pigeons. Maybe there is some relation after all.
> 
> I think I will see if there aren't any clubs that keep pedigrees. Like the Kennel Clubs do, or maybe I will convince the local pigeon racing and fancy pigeon associations to send out a request for pedigrees and performance data to their members.
> 
> ...


I think there are many people here who can shed light on the same too  Just wait and Good Luck  Keep us posted


----------

