Keeping purebreds pure.

[Chesneys]

I have a pair of young blue Ameracanas in with my Salmon Favorelles. A new coop and yard is almost ready, but Early, the young roo, has started hopping some of the SF girls. My question is how long will it be before the FS girls are laying purebred FS eggs again? Actually, I intend to do some crossing later on, so this would be good to know for the future breedings as well.

 

[ChickenCanoe]

After a mating, a hen can retain viable sperm up to 3 weeks or more.

http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1628&context=usdaarsfacpub

 

[dheltzel]

True, but within a few days, the probability of the new roo being the sire of any egg is much higher than for the old roo. The 3 week period was derived from letting a hen be without a cock and checking the eggs for fertility, in some cases they can store sperm for 3 weeks. However, the sperm is used for fertilization on a last-in, first-out basis, so as long as the new roo keeps doing his job, he is the likely father after as soon as 1 day. The trick is, you can't be certain, and when doing important matings with similar roos where you can't tell the chicks male parentage by physical characterics, the 3 week rule is crucial.

My source for this is a video of a presentation by a poultry science prof from the Univ of Arkansas. I found the link on this site, but don't have it right now. Worth looking for and watching.

 

[ChickenCanoe]

That's not necessarily true. With multiple semen storage sites where it can remain viable for up to a month, as you said, one can't be certain.
You clearly haven't read the University of Nebraska report I posted the link to.
It's definitely not a last in first out thing.
Semen is initially stored in the sperm storage glands in the vagina. From there, some is expelled each time an egg is laid and can then travel up to the infundibulum where they can fertilize the ovum. At any of the storage sites, there's no telling which male's semen is present.
Further, studies show that a hen can choose to expel sperm from an undesirable male immediately after mating.
Anecdotally, lots of people report offspring from a previous mating weeks after a hen has been housed with a different male.

 

[Ridgerunner]

ChickenCanoe that is a hard read, quite a bit of technical language. I did not see anything in there where it talked about last in – first out or anything like that. Perhaps you could reference a specific section to help me out. I did see this statement from the bottom of page 6.

“Little is known of the mechanisms of sperm transport to and storage in the infundibulum.”

I understand the infundibulum is secondary storage and not the primary container where the last in – first out would take place. I also don’t know how long the sperm remains viable in the infundibulum.

That paper you referenced is a 1998 paper. I can’t remember exactly when Dr. Bramwell gave that talk but it was probably around 2010 or 2011. Maybe there has been some progress in knowledge in the intervening years? I did get the feeling from Dr. Bramwell’s body language that maybe not everyone in the industry agrees with him on that.

Here is a link to that talk. It’s pretty long and from the quality was obviously made by an amateur at the meeting. I think it is worth watching.

I agree there are things that can cause a mating to be unsuccessful. So you have to consider the last in – first out to be after a successful mating if you accept it at all.

Chesneys, something else that might help. It takes an egg about 25 hours to go through a hen’s internal egg making factory. That egg can only be fertilized in the first few minutes of that journey. That means if a mating (a successful mating) takes place on a Monday, Monday’s egg is not fertile. Tuesday’s egg might or might not be, depending on when the mating took place and when the egg started its journey. Wednesday’s egg will be fertile.

 

[Chesneys]

Thank you all for your input. It would appear that not hatching eggs for at least a month from separation would be a relatively safe bet.. interesting article, if a little dense for the first cup of coffee in the morning. The pics of the actual fertilization were fascinating, and I now know a lot more about the inner plumbing of a hen than I did before. I will watch the video a little later, and thanks for the link.

 

[Chesneys]

dhetzel, I hope you don't mind another question. Since you have many breeds of chickens, I thought you might know which breed is most likely to lay pink eggs? I have read Light Sussex? I posted this in another section, but since you are handy......) .

 

[centrarchid]

Genetic markers? Cull all hatch not conforming to SF.