Dual part question here about Red Sex Links and their genetic background

[SleepyHollowFnF]

I have four hens that were sold to me as "Red Sex Links" Alongside these, I have about a dozen silkies of various colors.

Out of curiosity, I incubated several eggs from the sex links, none hatched but I opened them up and found a nearly fully formed bird that seemed to be silkie dominant. Blue skin and the funky silkie feet seemed pretty clearly visible.


Fast forward a month or so and the 20 or so eggs I have been incubating came due and only two were pipped.

The first wave that were due on the 18th I opened up to find half of the eggs had nearly fully formed birds, and three had birds still alive in them. Two of these have since died and the other is on its way out now.

One of the ones that was due today is out of the shell and slowly fluffing up, the other didn't make it out.

It seems they all have the silkie feet, but strangely enough, this batch doesn't have blue skin. It's much more orange colored, almost like a carrot. And what about this surprisingly high attrition rate? Why so many birds forming and quitting at the last minute?

This leads me to be very curious about genetics and what to expect from any future hybrids Is the silkie extra toe dominant? Is the blue skin or orange dominant? So far I've seen both.

Is it reasonable to expect an orange skinned silkie?
A large full sized silkie?
A silkie with sex link egg laying?
A silkie that is more easily sexed?
A sex link with blue skin?
A sex link with extra toes?
A red silkie?

On the genetic end, I have been trying to figure out what exactly "Red Sex Links" are...and it seems its more of a class than a breed...

"Red sex-links are a cross between a Rhode Island Red or New Hampshire rooster and a White Rock (This variety pair is known as a Golden Comet), Silver Laced Wyandotte, Rhode Island White or Delaware hen." - Wikipedia

The grammar here is throwing me.
Does this mean they can be

RIR x WR = CG
NH x WR = CG
RIR x SLW
NH x SLW
RIR x RIW
NH x RIW
RIR x D
NH x D

Am I interpreting this correctly?

It seems next to impossible to nail down exactly what my birds are genetically. So am I just going to have to see what comes out?

If theres some SLW in them can I expect to see some of those traits possibly make an appearance?

Thanks everyone, sorry for the lengthy series of questions, any and all help appreciated on any of these points.

 

[Ridgerunner]

I don’t know enough about Silkie genetics to try to answer those questions, but if you want to know about sex links I suggest you study the first post in this thread. Just the first post, forget the rest. And I do mean study, you may have to work on it. It usually takes a while for understanding to kick in, but eventually it becomes easy.

Tadkerson’s Sex Link Thread
https://www.backyardchickens.com/forum/viewtopic.php?id=261208

A Red Sex Link is not a breed, they are by definition some kind of cross. The mother carries the dominant Silver gene, the father has only the recessive Gold gene. This is a sex linked gene, which means the male has two copies of that gene but the mother only has one at that location on the DNA. The father gives a copy of that recessive gold gene to all his offspring but the hen only gives a copy of the dominant silver to her sons, she gives nothing to her daughters. So the dominant silver on the male produces a chick with yellow down while the gold only on the female produces a chick with red down.

The first chart in Tim’s post shows you which roosters and which hens can be used to make that cross. That’s not a complete list, there are several others that can work.

As for the chicks dying before they complete hatch, you might look through these. As you can see, there are many different things that can cause that. It’s not always easy to tell what is causing that but these might give you some clues. You should be getting much better hatch rates than that.

Mississippi State Incubation Troubleshooting
http://extension.msstate.edu/content/trouble-shooting-failures-egg-incubation

Illinois Incubation troubleshooting
http://urbanext.illinois.edu/eggs/res24-00.html

 

[NatJ]

This leads me to be very curious about genetics and what to expect from any future hybrids Is the silkie extra toe dominant? Is the blue skin or orange dominant? So far I've seen both.

Is it reasonable to expect an orange skinned silkie?
A large full sized silkie?
A silkie with sex link egg laying?
A silkie that is more easily sexed?
A sex link with blue skin?
A sex link with extra toes?
A red silkie?


Thanks everyone, sorry for the lengthy series of questions, any and all help appreciated on any of these points.

You should mostly get non-silkie (feather type) birds that are otherwise a lot like a silkie: 5th toe, crest, feathered feet, dark skin, and beard/muff if your silkies have it, are all dominant traits. (I learned this from various parts of the internet, having no personal experience with silkies.) The crossed chicks will have smaller crests and less feathered legs than pure silkies, because those genes are incompletely dominant.

About your chicks with orange skin--this thread mentions some silkies hatching with light skin, so maybe that's what happened with yours: https://www.backyardchickens.com/t/112652/can-white-silkie-chicks-have-pink-skin-at-hatch
If a pure silkie can have light skin at hatch, I'm sure a cross could too!

The chicks' adult size, and the size of the eggs they lay, will probably be in between the parents' sizes.

I doubt anyone can predict the color without knowing what color your silkies are, although if the silkie rooster is "silver" (gene replaces all gold/brown/red/buff with white) you'll get only "silver" chicks and no "gold."

About the chicks dying at the last minute, I agree with Ridgerunner to look into the incubation details first--neither sexlinks nor silkies have a reputation for carrying lethal genes, and even if they did, I wouldn't expect a problem in a cross like this: lethals are more likely to show up when you breed closely related birds, which your sex-links and silkies are not!

Do you have previous experience hatching eggs? Did you hatch any other eggs in the same batch? (If pure silkie hatches fine and crosses did not, then it's more likely a genetic issue; if other eggs had the same problems, it's more likely an incubator issue.)

--NatJ

 

[SleepyHollowFnF]

Ridgerunner, Thank you so much!

I am very excited to take a look at this.

I have also been documenting the characteristics of the chicks as well as the stage of development at which they quit. I'm hoping things will look up for these chicks.

 

[SleepyHollowFnF]

You should mostly get non-silkie (feather type) birds that are otherwise a lot like a silkie: 5th toe, crest, feathered feet, dark skin, and beard/muff if your silkies have it, are all dominant traits. (I learned this from various parts of the internet, having no personal experience with silkies.) The crossed chicks will have smaller crests and less feathered legs than pure silkies, because those genes are incompletely dominant.

About your chicks with orange skin--this thread mentions some silkies hatching with light skin, so maybe that's what happened with yours: https://www.backyardchickens.com/t/112652/can-white-silkie-chicks-have-pink-skin-at-hatch
If a pure silkie can have light skin at hatch, I'm sure a cross could too!

The chicks' adult size, and the size of the eggs they lay, will probably be in between the parents' sizes.

I doubt anyone can predict the color without knowing what color your silkies are, although if the silkie rooster is "silver" (gene replaces all gold/brown/red/buff with white) you'll get only "silver" chicks and no "gold."

About the chicks dying at the last minute, I agree with Ridgerunner to look into the incubation details first--neither sexlinks nor silkies have a reputation for carrying lethal genes, and even if they did, I wouldn't expect a problem in a cross like this: lethals are more likely to show up when you breed closely related birds, which your sex-links and silkies are not!

Do you have previous experience hatching eggs? Did you hatch any other eggs in the same batch? (If pure silkie hatches fine and crosses did not, then it's more likely a genetic issue; if other eggs had the same problems, it's more likely an incubator issue.)

--NatJ

NatJ,

Thanks for the info! I am not sure what you mean when you say "silver" I have four Silkie Roosters. One is Buff, one is Salt and Pepper looking, and the other two are White.

I'm going to look more into incubation, We had success with pure silkies and silkie x showgirl mixes, but have still yet to have a single survivor with close to 40 of these sex link x silkie crosses. My girlfriend suggested it could be the shells being too thick for them to break out? But I am not sure of this because nearly all of the dead chicks still have the yolk still outside the body, often very much so. I'd have to guess this means they are dying long before they are ready to hatch. I am including a picture below to show the most common situation I am finding. Is this a day or two before expected hatch or earlier?



Two days after expected hatch I've found two birds alive in the eggs but the yolk was unabsorbed. I wasn't expecting to find anything alive and was giving them an extra two days to hatch if they were just feeling lazy and to not interrupt their natural processes. But what does that say that at day 23 they were still not fully formed but alive? Are there exceptions to the 21 day rule in certain crosses or breeds?


Thanks again!

 

[donrae]

Many of the Silkie traits are dominant--the fifth toe, the crest, the walnut comb,the feathered legs. This makes it easy to look at a bird and say it's a silkie mix, but not always what the bird is mixed with as the silkie traits are so strong.

the silkie feathers themselves, though, are recessive. Crossing a silkie with a non-silkie will give you regular feathers, with the recessive gene for silkie feathers.

One of our genetics guys, nicalandia, has posted in the past about crossing a silkie rooster (black skin) with a yellow or white skinned hen giving sex linked chicks. Females would have the black skin, males the yellow/light. I've not done this myself, am collecting eggs to set. But that would explain the difference in your chick's skin color, females vs males.

Feather color of your chicks is going to rely heavily on the color of the father. since the mother sex links are themselves a cross, chick color is going to be a wild card. I'd expect them all to have lightly feathered legs, five toes, partial crests if your silkies are crested, same for beards. They'll have funky mixed combs, as straight combs are recessive. Skin color may be sex linked. I'd expect them to be mid sized between the two breeds, and lay better than a Silkie but not as good as the sex linked mommas. They may also have a tendency to go broody like the silkies do. Sounds like a fun little cross.

 

[NatJ]

Quote:
Silver and gold are the genes used for sexing your red sexlinks--they are discussed in the thread ridgerunner linked to about sexlinks. With your silkie roosters: the buff is gold, and crossing with a red sexlink hen should give red or buff chicks, possibly with some patterns of white or black on them. Your Salt and Pepper rooster is most likely silver, and any chicks from him would be white-and-black themselves. The white I can't predict, because there are so many combinations of genes that could make a chicken white.


Quote:
Sounds like either the crosses take more days of incubation than other chickens, or else your incubator temperature was too low. I'm not sure how many days before hatch the chick in the photo is, but maybe someone else will know.

 

[Ridgerunner]

You say you’ve had success with other eggs but not with eggs from this cross. What is the sequence of those hatches? Have you had success with “other“ eggs in between your failures with these “cross” eggs? To me, it sounds like your incubator temperature may be too low. That photo would be consistent with that. Did somehow your thermostat get reset between those first successful and last unsuccessful hatches? Have you calibrated your thermometer to be sure it is now reading correctly?

That 21 day thing is just a guideline, a general target. There are many different reasons an egg may hatch early or late. A very common one is average incubating temperature. If the average incubating temperature is high, they can be quite early, low and they can be days late. There are many other reasons an egg can be early or late though: humidity, how and how long eggs are stored after they are laid, and just basic differences in eggs. Some of those basic differences might be porosity, how thick the whites are compared to how runny, and size. Small eggs are supposed to hatch a little earlier than larger eggs, but to be honest, I have not observed that to be true. I’ve specifically looked at that in a few hatches and did not see any difference.

Heredity is another reason for differences in hatch time. Whether in my incubator or under a broody hen, my eggs are usually a full day early, sometimes even more than that. I’ve had broody hens hatch a full two days early, I’ve had them hatch on time. I’ve seen the same variation in my incubator. It’s possible those cross eggs are late because of some genetics issue. That’s not because of breed, that’s because of the genetics of the individual. But it sounds extreme for heredity alone to account for that much difference.

I’ll mention one other thing that can make the eggs late, are you counting the days right? Since you have hatched before you probably are, but it’s a common problem on here. An egg does not have a full day’s development 2 seconds or 2 hours after it goes in the incubator. It takes 24 hours for an egg to have a day’s worth of development. So when you start counting days you say “one” 24 hours after the egg goes in the incubator. An easy way to check your counting is that the day of the week the egg goes in is the day of the week the 21 days are up. If you put them in on a Monday, the 21 days are up on a Monday.

Another possibility for the chicks dying at that stage, are they suffocating? The older they get the more they need fresh air to breathe through that porous shell. If your vent plugs are in they may not be getting enough fresh air. Again, you’ve had successful hatches before. Unless you’ve changed something this is highly unlikely to be the cause but I’m grasping at straws.

High humidity during incubation could possibly be a cause. If the egg doesn’t lose enough moisture during the incubation phase, it can’t pip and hatch. A chick does not necessarily absorb the yolk before internal pip. If it tries to internal pip and the air cell is too small it drowns before it gets to external pip.

I don’t know what is going on with those eggs. Heredity might be a factor but I really think it’s something else to do with your incubation, something that’s changed. If you can get some other fertile eggs and try to hatch those with your cross eggs maybe you can determine how much of it is those eggs.