Egg Fertility

[kkdossey]

I sold a group of 5 hens and 1 cock to a guy a few moths back.  All black LF.  I had them already in that group along with a couple more hens.  They are all last spring birds, so a little over a year old.  I hatched from this group for a couple months and everything was good.  I sold him the cock from the group and about half the hens that he chose.  Since then he's had problems with egg fertility.
At first I suggested it might be the movement to the new place, change in diet etc.
Then a few weeks later it's even less.  I suggested maybe egg storage but didn't really know what else to consider.  He's hatching well from other breeds at this time so I figure probably storage isn't a big issue.
It's not all hot here yet like it usually is, but I've stopped hatching so can't really comment on my fertility at present.  I offered to swap him the male but he wants to try some more. 
What might you consider telling someone having the same problem?

[Birdcrazy]

Kris, do you think a change of feed could be a factor in fertility? Another idea I had was location of his breeding pen. I had a rooster once that all he wanted to do was pace back and forth at his divider fence and try to get at the rooster on the other side. He didn't tend to business at hand and that pen had a low fertility rate. Oh rereading your post I see you had already ruled out diet. Keep us posted if you find the answer.

[kkdossey]

The distraction of other cocks is a good one to mention.  That could play a part.
The birds I would assume are on different feed than with me but I would think after 2 months they'd be used to it.
I have noticed that when hen escapes her cage with her male he will usually mate her right away when reunited.  I always thought I would try that if needed.  Recently noticed but haven't used yet.

[far149]

My first thought is diet also. What are the other breeds your customer owns? Once your birds arrived on his place did they accumulate a heavy parasite load?

[kkdossey]

He's got Marans for sure, maybe other stuff.
But the marans are hatching well for him.
It could be parasites too, maybe he's not feeding them well or they're just still thrown off by change in scene and feed.
After I hear from him next round I'll offer these suggestions.