Correct Order for Specific Genetics in Breeding

[davidmpenning]

I believe that is mostly false, but I can think of a few sort-of exceptions:

--sex linked traits are on the Z sex chromosome. A rooster passes that to both his sons and his daughters. A hen passes her Z chromosome to her sons, but W to her daughters. So for any trait on the Z chromosome, a hen can NOT pass it to her daughters. She gets it from her father, and gives it to her sons. A rooster may get it from his father or his mother, and pass it to his sons or his daughters. Several important genes are on the Z chromosome (silver/gold, barring, chocolate, light vs. dark skin, fast/slow feathering.)

--homozygous vs. heterozygous. If a given chicken is homozygous (pure) for a certain trait, they will pass it to all of their offspring. If they are heterozygous (split or impure), they will pass that trait to only about half of their offspring. If someone happens to have homozygous birds of one sex, and heterozygous ones of the other sex, I can see how a rumor like this might get started.

--dominant vs. recessive traits. If someone crosses a chicken with a dominant trait, and one with a recessive trait, of course they are going to see the dominant trait in the chicks. But they might think that is "the mother's trait" or "the father's trait," instead of understanding dominant & recessive.

--a rooster can generally sire many more chicks than the number of eggs a hen can lay. So if you need one chicken to pass a certain trait to a large number of offspring, you probably want that one chicken to be male.



If there is a particular trait that is very important, I might do it first. Examples might be a certain comb type to avoid frostbite in cold weather, or high egg production so there are more eggs to hatch.

After that, I would probably start with the things that are genetically simplest. It's fairly easy to breed out rose comb or a crest on the head (one gene each), but much harder to breed for the correct shape of rose comb or a correctly shaped crest.

Some things have to work in certain orders. For example, if you want a laced chicken, you might have to breed out the gene for solid black before you can see the lacing to work on the quality of it.

Seriously, so much good information here. Thank you! And it makes sense that some of the people I’ve read about are probably judging by their eyes and don’t actually know what’s hidden in the genes.

With being either heterozygous or homozygous, I’ve heard there’s only 2 real ways to figure this out - 1. Breed and see what the offspring are, or 2. Be able to prove/guarantee the pureness of that breed/line for that specific trait. Is there another way to do this?

 

[The Moonshiner]

If it's a recessive gene and showing its homozygous.
If it's a dominate gene ya you'll have to test breed.

 

[davidmpenning]

Okay.

I find it doesn't matter what order you cross, but only target the traits you desire to keep.

Is it possible to do multiple traits at the same time? Like if I have a male that has 3/5 traits I’m looking for, how hard is it to maintain all 3 in breeding? I’m guessing it probably depends on what those 3 in the female are, too? Or should I just pick one trait at a time, and then use that offspring with another chicken that has the next trait I’m looking for? And at this stage, does it really matter how closely related they are?

 

[NatJ]

Is it possible to do multiple traits at the same time? Like if I have a male that has 3/5 traits I’m looking for, how hard is it to maintain all 3 in breeding? I’m guessing it probably depends on what those 3 in the female are, too?

The female does make a difference, but it also matters how many chicks you want to hatch.

Many traits appear in 1/2 or 1/4 of the offspring (depends on whether it's dominant or recessive, and whether either parent is homozygous.)

But if you are looking for two traits, you might get the first trait in half the offspring, and the second trait in a quarter of those, so by now only 1/8 of the chicks have the right combination of traits. Add a third trait, and you are selecting a few chicks from the 1/8 that had the first two traits.

The numbers can get quite large, quite quickly.

Or should I just pick one trait at a time, and then use that offspring with another chicken that has the next trait I’m looking for?

If you only want to hatch a few chicks at a time, yes.

If you are willing to hatch hundreds of chicks at a time, and select only a few for breeding, you are likely to manage more traits at a time.

And at this stage, does it really matter how closely related they are?

You can breed brother/sister, or parent/offspring, and it's usually not a big deal. If you get chicks with major problems (that seem to be caused by genetics), you may want to cull the ones that are producing such chicks (even if it means re-doing a year's worth of breeding, to use a different bird of the same breed.) Most chickens will not have genes that cause trouble like that.

If you inbreed closely for too many generations, you can reach a point where nothing is obviously wrong, but the eggs do not hatch well, and the birds are a bit sickly or stay smaller than they used to. That would be a good time to cross in something else.

 

[SegiDream]

If it's a recessive gene and showing its homozygous.
If it's a dominate gene ya you'll have to test breed.

Exactly. IMO this is the easiest to understand but possibly the hardest to overcome if you want, but don't have homozygous dominant.

Like my single comb brahma mixed rooster (pprr) for example. I thought my hen was pure but couldn't be sure. So I test bred them knowing the results would tell me the truth about her. The result I got was half the babies have a single comb. So she is Pprr - heterozygous uh oh. I kept 3 from that 1st gen that have the pea comb. I know the babies have to be Pprr which means about 1/4 of their offspring will be single comb, 1/4 will be pure pea comb PPrr, and 1/2 half will be carrying the recessive p. So visibly it will look like 3/4 of the 2nd gen have pea combs but most will have the potential to produce single combs in their future offspring. If I want to weed out the single combs from all future offspring, I will have to test breed the pea combs from the 2nd gen offspring (with a pp) and I will know that if they produce ANY single combs then I can stop breeding the 2nd gen. I won't be able to use any of that 3rd generation for breeding purposes - maybe freezer camp for them or keep as layers only.

If I don't test breed the 2nd gen then there is the potential for any offspring to produce single combs randomly. Of course they will also produce PP offspring but I can't know without test breeding and unless they are separated from Pp it's just going to be a continuation of single comb randomness.

This is just an example of me thinking out the "what ifs" for ONE gene. Not including the lacing, color, body issues which can be so much more complicated. I'm not sure if I want to continue but it might make an interesting side project. If I would start such a project I would focus on body type as priority. If you have the opportunity to fix other issues along the way then go for it...

 

[NatJ]

If I want to weed out the single combs from all future offspring, I will have to test breed the pea combs from the 2nd gen offspring (with a pp) and I will know that if they produce ANY single combs then I can stop breeding the 2nd gen.

You're right in general, but for pea comb there may be a shortcut. PP birds usually have much smaller comb and wattles than Pp birds, at least at maturity. Of course you can choose to test mate just to be sure, even if you think you can tell visually, but you might not need to when you have both PP and Pp there to compare with each other.

 

[The Moonshiner]

You're right in general, but for pea comb there may be a shortcut. PP birds usually have much smaller comb and wattles than Pp birds, at least at maturity. Of course you can choose to test mate just to be sure, even if you think you can tell visually, but you might not need to when you have both PP and Pp there to compare with each other.

That's good on paper but it's also how a lot of genes get continued on in a line.
Depends on what the project means to you and your goals but knowing for sure is where I'd want to be at.
I know people that love working with dominate genes because they show up faster and it looks like progress but for myself I'll take recessives all day long.

 

[SegiDream]

You're right in general, but for pea comb there may be a shortcut. PP birds usually have much smaller comb and wattles than Pp birds, at least at maturity. Of course you can choose to test mate just to be sure, even if you think you can tell visually, but you might not need to when you have both PP and Pp there to compare with each other.

I would love that. But the original hen in question is my profile pic. You can see how large hers are and they haven't changed and isn't noticeably larger than other brahmas I have that are known PP's. So I dunno how much I would trust it.

 

[NatJ]

That's good on paper but...

I would love that. But the original hen in question is my profile pic. You can see how large hers are and they haven't changed and isn't noticeably larger than other brahmas I have that are known PP's. So I dunno how much I would trust it.

That's why I said there "may" be a shortcut. It works some of the time, but you seem to have an exceptional hen (the inconvenient kind of exceptional.)

I know people that love working with dominate genes because they show up faster and it looks like progress but for myself I'll take recessives all day long.

I think incomplete dominants are nicest, but there aren't very many of them.

I agree that if you want true-breeding chickens, recessive genes are much easier than dominant ones!

 

[sdm111]

Using the male or female of a breed matters in weather you're trying to enhance physical or mental attributes. The time of year you breed can alter body type and can be corrected with just one breeding if done correctly