Sex-Links

[Auscal]

I keep reading that sex-lins tend to be "early-layers", and good layers, but, I'm having trouble understanding why. I do understand that if the cross is RIR x Leghorn, then the resulting sex-link chick will lay brown eggs, but, "earlier" than a RIR would. So, the benefit is a brown egg, but with the early laying & regular laying benefits that are white leghorn traits.

But, if the cross is RIR x Delaware (which I found out mine are), then why would I expect laying to start earlier, or be any more frequent than either a purebreed RIR or a purebred Delaware would be.

I do see where the benefit is in instant sexing of sex-link chicks (cheaper for the hatchery then vent sexing, and better for the backyard chicken owner who doesn't want to raise roosters), but, i just cannot understand the logic as to why what is in effect a crossbred chicken would lay earlier, and with more frequency than either of the purebred chickens that supplied their genetics.

Looking forward to any insight anyone can offer.

 

[Ridgerunner]

Where to even begin with this. I'll try to be nice. First, don't believe everythng you read on the internet, including stuff from me.

There is such a thing as hybrid vigor. You can look it up. Whe you cross two different varieties you can get a change for the good as compared to either of the parents. There could be some of that in play. But you can get hybrid vigor in chickens without crossing two different breeds. If chickens get inbred they can lose some genetic diversity. So if you cross two chickens of the same breed but from flocks that have been genetically isolated from each other for a while, you can get the benefit of some hybrid vigor. So if the chickens are crosses from two genetically different flocks, you can get some benefits.

The chickens used to make the hatchery sex links are from flocks that have been selected to be good egg layers. I'm not one of those that is going to bash the hatcheries over this. Different hatcheries have different management practices. I know all are not the same, but if you hatch out a lot of chicks and select your breeders from the chickens that you hatch, over time the good egg layers will provide more eggs to hatch, so you will tend to select the chicks from the good egg layers. It is not some subversive plot to take over the world. A hen that lays a lot of eggs is more likely to have her sons and daughters chosen for the breeding flock because there are more of them. Since a lot of hatchery flocks have been in existence for decades, they tend to lay a lot of eggs.

There is nothing magical about the sex links, other than you can sex them at hatch. They come from flocks that lay a lot of eggs, so they will probably lay a lot of eggs. They may get a boost from hybrid vigor. But them being sex links has nothing to do with it. One common sex link is the Cinnamon Queen, made with a Rhode Island Red Rooster over a Silver Laced Wyandotte hen. From hatchery flocks, they meet the requirements of being good egg layers. But if you reverse that and cross a Silver Laced Wyandotte rooster over a Rhode Island Red hen from those same flocks, you would not get a sex link, but you would get just as good a hen as far as laying. The genetics for egg laying are the same. Any boost from hybrid vigor is the same. But they are not sex links.

Will they lay earlier than either parent breed? I don't know. Chickens are so individual in their egg laying practices that you would have to have several large flocks of the sex links and the flocks used to make the parents to get a statistically significant number and keep them in the same conditions: hatched at the same time with the same food, lighting, climate and all that. I don't know what that statistically significant number would be. I suspect in the hundreds. My gut feel is that if you actually did the experiment, there would be no real difference, but I haven't done that so I don't know. But that would be for crosses from the two flocks, not just the sex link cross. And I strongly suspect the results would differ depending on how genetically diverse the parent flocks were.

Anyway that is my opinion on your topic. I would not be shocked if someone else disagreed. We do that a lot on this forum.

 

[CarolynF]

Very interesting explanation. I was sort of wondering the same thing and this, genetically speaking, seems to make sense. I'll be interested if anyone else posts an alternate explanation.

 

[SIMPleChick]

It seems to me that chickens just lay when they want to....I have asked before my hens started laying, "When will they lay" And you get a variety of answers. My White Leghorn is 21 weeks old and has not laid yet, my 21 week old EE has, just today actually. My BR laid at 19 1/2 weeks and my Red Sex-link started laying at 17 weeks old. She has laid 5 out of 6 days and her first egg and todays egg were both double yolkers! This is my first flock and first experience with all of these breeds, it will be interesting to see what others say! Good Question!

 

[Pele]

Quote:
While I disagree with the latter part of your post, I've never been so sorry to disagree! Your posting was very logical and done in a friendly and conversational tone. You sound like someone fun to have a coffee with and discuss the world

I personally have sex links, and all of my girls layed no later than 18 weeks, which is very early for any of the breeds used to make the hybrid cross. It is true that you can have varience by individual chicken, but this hybrid is widely known for early maturation.

You can take this with a grain of salt, because I am not a geneticist and can't name the early maturing gene, but I would speculate that it is very closely linked to the same gene that causes SLs to lay throughout the winter, unlike either of the purebred parents. Something about the crossing causes changes in the egg production genes. If I were to come up with a theory on genetics, I would say that the crosses involve high production egg-layers (which tend to be mediterranean in origin and thus winter sensitive), with heavy breeds, which tend to be early maturing.

You would cross chickens to get any desired trait that you want that was not there before. If you can cross chickens that do not have crazy poofs on their heads, and eventually end up with crazy poofs, I don't feel that it's a far stretch to do the same for change in egg production (although I do admit that most genetic propensities take generations of careful breeding to develop).

Anywho, that's my 2 dollars and 2 cents

Facinating topic! Good question!

 

[Ridgerunner]

Quote:
Just to continue the conversation. Why would a Rhode Island Red rooster over a Silver Laced Wyandotte hen, A New Hampshire rooster over a Delaware hen, or a Speckled Sussex rooster over a Rhode Island White give you a better egg layer than the crosses from the same parent flocks but with the sex of the parents reversed? None of these are Meditteranean breeds. They all give you sex links if crossed correctly.

I've had non-sex links lay throughout the winter their first winter, not just my Australorp either. That's not unusual for a pullet's first winter, whether they are sex links or not. Many skip the fall/winter molt their first year and keep laying, especially if they start laying a bit later in the summer.

You mentioned you have sex links. Do you have any of the purebreeds from the parent flocks to compare them to? And by the way, what hybrid do you have?

 

[Pele]

Thanks for the response!

My particular sex-links are New Hampshire over White Rock. The reason I speculated about early maturing is because the New Hampshire was developed to do exactly that in order to make it a better meat bird. The White Rock is also not considered a purely laying bird, though they lay well, but rather more dual purpose. Neither parent is a superstar layer, but their offspring is threatening to bury me in eggs. There is something genetically happening there.

I thought I had read somewhere that the White Rock was developed partially from Dominiques, which were developed from Mediterranean birds, but I can't find the source again. I do know that the New Hampshire is developed from the Malay, which is an Asian bird that is much more suited to tropical to sub-tropical areas.

I do not have the original parent lines to compare to (that would be awesome!), but I was raised on a farm, and I do remember that we had New Hampshires and Cornish for meat. I also remember my mother cursing out our various laying hens for stopping in the winter

.

Of course that was years ago, and who knows what hatcheries have done with the lines since then. Genes are interesting stuff, I never get tired of thinking about them. Once I get a ranch or farm, I'm going to go gangbusters on trying different breeds and combinations!

 

[2overeasy000]

Very interesting topic. I am very new to chickens and don't have much to add, except that I have 7 different breeds including a RSL that I believe is a RIR-WR. Also have White Leghorn, BR, RIR, BO, and 2 EE. All 7 layed over the cold NE winter with no artificial lights in the coop. This was their first winter so I don't know if this will continue. The RSL was not the first to lay and the 2 EE and the Leghorn are by far the most consistent layers, as there is a white and 2 blue eggs in the coop everyday. Also, as a side note, my BR didn't start laying until 6 months old.

 

[SIMPleChick]

Quote:
Yeah, see, opposite of my girls here in Utah...I love genetics! My father was a research scientist and developed and patented the Imperial Star, thornless Artichoke and 2 other breeds. He did a lot of work on strawberries and I am sure that if he were still alive he would be in my back yard every day trying to figure out how to cross what to get what he wants! LOL! It's great stuff!!!! I wish I knew what my Red sex-link was cross with, got her at a feed store and she could have been from 2 different hatcheries. But with her early laying and double yolkers, I will get more RSL when it's time to refresh our flock!

 

[Fred's Hens]

Here's just another item to throw in the hopper of thought processing.

Some hatcheries, no doubt, sell sex links they breed themselves and are truthful and honest about the parent stock This or That over This or That. The hatchery gives them whatever cutsie name they wish, as there are no breed naming police running around to arrest them.

However, some hatcheries sell hundreds of thousands, no millions, yes, millions of chicks to the farms and commercial laying houses. These sex links are highly selected from genetics companies parent stock. The ISA/Hendrix/Bovan/DeKalb/Hisex/Shaver/Babcock Genetics Conglomerate comes to mind. This Conglomerate invests millions into research for a World Wide market, not just the US. The parent stock may be a "sort of" red bird over a "sort of" white bird. The parent stock used is highly selected for characteristic needed in the commercial industry. Quick maturity, tight feathering, heavy, heavy laying rates, ability to take confinement and great feed conversion rates. see this: http://www.isapoultry.com/en/Products.aspx

The backyard chicken owner, buying from either the hatchery directly or supplied through a local feed store is buying only a small fraction of these kinds of chicks. The vast majority are destined for the industry, where they are only known as Number 1347A bred to Number 436B, producing the Brown #2341 pullet.

In short, some sex links are indeed perhaps a RiR over a Delaware and called "Our Fancy Queen" our whatever, but a whole bunch of them are commercial layers sold to John Q Public.