egg with no shell?

[chic_a_lay]

i found an egg yesterday that had no hard shell. only a soft leathery casing which burst. come to think of it this years' eggs are all abit thinner? softer? than last years.
the hens are all a year old and have plenty of oyster shell grit and natural food from the pastures.
i had recently started buying the cheaper tractor supply store brand of food instead of the layena they were used to. i wonder if the feed had something to do with it?
i also had noticed a bit of different poo? it seemed runnier, not, diarreah, just not firm. does the feed make that much difference?
anyway, i do live on a working farm and i'm wondering if the pesticides or herbicides my farmer uses would affect my hens?

 

[Judy]

A feed change could certainly cause a change in poo. For the pesticides, I'd be suspicious, too, but really you just have to research the specific pesticide, and hope someone has studied the effect on chickens, and published it.

Here's a good link for listing the possible causes of egg defects:

http://www.thepoultrysite.com/publications/1/egg-quality-handbook/11/egg-defects