Genetics with Painteds

[iaos]

Brett, I still think you are better off breeding 80 odd spilt yellows in a season and being able to sell them as such rather than breeding generations of normals, selling them as normals, then having a yellow pop up when the lines cross.

With single mutations, I believe that test breeding is essential in trying to get a normal line.

Cheers Ian

[E Orix]

Ian
I must have missed something in the translation. Why would I breed more splits and why use any yellow birds when I want
to get rid of them.
I guess the only direction I can take is try and use chicks from clutches that are all red and hope I am lucky.
The clutches this season have been good sized with most fledging 5 a couple of 6 and 3 or 4 under 5.
If my clutches are not all red then there could be one yellow,if both birds need to be split then why isn't the ratio more even.
It would be lucky to be 20% from memory and maybe those yellows are possibly cock birds also from memory.
please note this is a genetics question only.

[arthur]

red/ yellow X red/ yellow gives 25% pure red 50% red/ yellow 25% yellow

So your 20% figure is pretty close to expectation

Sex ratio should be close to even

Hope that is the question you have asked

[Alf63]

As both birds are split (autosomal recessive) you can expect 25% Normal, 50% Split & 25% Yellow. As only test mating can verify which are normal or split you effectively breed 75% possible split and 25% coloured.

If you only want normals you need to start from scratch.

[iaos]

Ian
I must have missed something in the translation. Why would I breed more splits and why use any yellow birds when I want
to get rid of them.
I guess the only direction I can take is try and use chicks from clutches that are all red and hope I am lucky.
The clutches this season have been good sized with most fledging 5 a couple of 6 and 3 or 4 under 5.
If my clutches are not all red then there could be one yellow,if both birds need to be split then why isn't the ratio more even.
It would be lucky to be 20% from memory and maybe those yellows are possibly cock birds also from memory.
please note this is a genetics question only.

David, by test mating a red bird with a yellow bird if you breed no yellow offspring you are effecttivky proving that the red parent has no hidden spilt mutation. The yellow parent and all offspring from the test mating get culled from your collection. You then pair up the red partners from the pairings that haven't produced yellow offspring. These new pairs are now your mutation free red painted as you have proved that they aren't split for yellow.

Hope that's a bit clearer.

Cheers Ian

[finchbreeder]

These new pairs are now your mutation free red painted as you have proved that they aren't split for yellow.
Not from one season you haven't. Apart from a genetic blood test (which may or may not be available in Australia, and would be very expensive anywhere in the world) There is no 100% proof of purity. I just produced a black headed hen gouldian in a line of red/yellow that had not produced black in over 6 years. I am one who likes red painteds and is left completely indifferent by the yellows. So if I produced a yellow in my line I would sell it. The only way to "cleanse" the yellow out of red is to sell/remove all yellows and the parents (splits) from your line. Keep the red young who have a 1/3 chance of being pure. (25% pure red, 50% splits, 25% yellows) Breed with these and apply the same rule of removing any that produce yellow and keeping the red chicks or parents who do not produce red. On your deathbed you MAY then have a line of pure reds. Sorry genetics is really very straightforward. And not subject to the wishes of simple human beings like me and you.
LML

[E Orix]

Now I know why I have dodged the genetic field for so long.
I have enough trouble breeding some of the species in my collection now with out other concerns.

[iaos]

FB, if you breed a yellow to a red and breed 12 offspring in a season and produce no yellow, there is a 1 in 2048 chance of that red parent being spilt yellow on probability. That's good enough odds for me (if my maths is any good).

Cheers Ian

[SamDavis]

These new pairs are now your mutation free red painted as you have proved that they aren't split for yellow.
Not from one season you haven't. Apart from a genetic blood test (which may or may not be available in Australia, and would be very expensive anywhere in the world) There is no 100% proof of purity.

True that "mutation free red painted" is not proven with 100% certainty but a single season of Ian's strategy can get very very close. If the mating of red phenotype to yellow phenotype produces say 10 chicks in a season. If any chicks are yellow then (as Ian says) the red parent bird is definitely a split (Ry) and can be discarded. What if all chicks are red then what can we say?

Let's hypothesis that the red parent bird is actually a split (i.e. red parent bird is Ry not RR). The probability of producing 10 red chicks (0 yellow chicks) from Ry to yy is (1/2)^10 = 1/1024 which is approximately 0.1%. If the experiment is repeated over and over many thousands of times then we expect this result to occur just once in roughly every thousand trials - all other trials will produce one or more yellow birds. However if our hypothesis is incorrect then the red parent bird is actually RR and all trials will produce all red birds. Therefore if 10 red (0 yellow) birds are produced from a red and a yellow bird then approx. 99.9% of the time the red parent bird will be RR. Clearly it's reasonable to assume the red parent is RR.

The other strategy - culling yellow birds as they emerge - will reduce the fraction of yellow genes present in your flock but will be a slow process and confidence that birds you sell are free of the yellow gene is much more difficult to assess.

[Tiaris]

Breeding with only normal-looking birds is not the most efficient way to breed out recessive genes with certainty but its the only way to breed them out if you only like to keep & breed predominantly normal-looking birds. If I had to spend a whole season (or more) of intentionally test mating all my Painteds & Gouldians with yellows & white-breasteds to identify split genes for elimination I would most likely discard those two species from my collection altogether as I by far prefer to breed red Painteds & purple-chested normal Gouldians. I gather that E. Orix has similar personal preference with red Painteds in his aviaries so I was suggesting the means by which I have largely culled the recessive genes from most of my Painted & Gouldian flocks. Along the way I have been able to enjoy the sight of my preferred phenotypes of these species breeding in my aviaries & the incidence of recessive mutants being produced has reduced from very common to virtually non-existent over the past 6-8 years. I know I can never guarantee that my birds are not carrying split recessive genes but that doesn't bother me at all. If I had to deliberately breed from mutations and splits which I do not personally like, I would most likely choose to allocate that breeding aviary space to other species. I do like and intentionally breed some finch mutations, but there are some which I do not like or choose to breed in my aviaries. Yellow Painteds did/do exist in wild populations as I have been told by more than one old-timer about scanning wild shipments for yellow specimens as they arrived in dealers' premises. Whether they are a "natural" mutation or not is not an issue for me as I simply find them to be an inferior visual spectacle to a decent red bird, hence my personal choice to not breed them intentionally.