Egg Fertilization question

[5 Points Wingfeather]

I have two hens I want to breed with a different rooster than the one they are with. I have a breeding pen set up. Two questions. Realistically, I know people say to wait a month before you know for sure that the new rooster will be the father but if I wait only 1 week, or 2, or 3 instead of 4, what is likelihood that new Roo will be the dad?

 

[sourland]

Hens retain high fertility for two weeks, moderate fertility for three weeks and some fertility for four weeks after being separated from a rooster. At one or two weeks there is high probability that the original rooster may be the father of any chicks hatched.

 

[U_Stormcrow]

^^^^ that. @sourland is absolutely correct. The biology is well understood. Reducing it down to a mathematical expression of probability, however, has not been the focus of study.

I counsel PATIENCE.

 

[Ridgerunner]

A poultry science professor that specialized in reproduction believed in the last in - first out theory. The last rooster to successfully breed with the hen is by far the most likely to fertilize the egg. The way he said that made me think maybe not all of his colleagues agreed with him.

I don't know why you want to use a specific rooster, if you could tell which rooster is the father by looking at the chicks, or any of that. I certainly cannot tell you what the actual odds are. It's just one of those things you'll have to make the call with some unknowns.

I'll go through this in case you haven't seen it. It might help your planning. It takes about 25 hours for an egg 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 takes place on a Monday, Monday's egg is not fertile from that mating. It just can't be. Tuesday's egg might or might not be, depends on the timing. Wednesday's egg would be.

 

[U_Stormcrow]

A poultry science professor that specialized in reproduction believed in the last in - first out theory. The last rooster to successfully breed with the hen is by far the most likely to fertilize the egg. The way he said that made me think maybe not all of his colleagues agreed with him.

Since sperm storage in birds is in a series of, essentially, tubules, this intuitively makes a sort of sense. But also includes the assumptions that the contribution of rooster "last in" successfully covered the openings of all the tubules, in effect capping them all with his offering. I'm not sure that's an assumption that can be reliably made.

I see both sides on this, from a theory perspective, and am almost completely unqualified to opine, otherwise. But its certainly consistent with what I've read.

 

[5 Points Wingfeather]

I really appreciate all the info. It’s not a matter of life and death—I just want one rooster over the other. And I’m just anxious to get the process rolling and didn’t want to wait a month, but it sounds like that is probably what I should do