One of my 25 week old ISA Brown hens is laying extremely large eggs. They don't fit in the egg boxes and are quite often double yolkers. I've got an egg here on my desk now that she laid today. I used my caliper measure and it is 410mm diameter and 670mm length. It is really enormous, nothing like a hens egg. Its been suggested that perhaps its a double egg, like two seperate membranes and yolks inside. Can all this double yolking and large eggs be harming her in any way? There must be someone out there that can give me a little lesson on egg formation and the like, and offer a possible explanation for my freaks! Also, does anyone know how to "blow" eggs, as I'd rather like to keep this whopper on my mantlepiece as a trophy! Perhaps we could start a Coop "Mines bigger than yours" league!

No offence, but unless you have the only living elephant-chicken :), I think you have miss-measured your egg. Do you have any geese around? If you have an egg that seems too big for a chicken it might be from something else.
Also, just yesterday I was experimenting w/ blowing an egg & this seems to work: Take a sharp knife (I used an exacto blade) & carefuly poke a little hole in the narrow end of the egg. Now poke another hole, in the opposite end. Enlarge this hole till it's about 3 or 4 mm wide. Take a toothpick & poke around inside the egg till you break the yolk membrane. Then just blow into the small hole until the egg is empty. You might want to try this with another egg first if you're worried about damaging the egg. Hope this helps.

Oh dear!! Still, my measurements must have given you a laugh; my husband was in hysterics when he saw what I'd done! The correct measurement of my biggest egg is 54 mm diameter and 79 mm length. It really doesn't look like a hen egg. I've only got four hens and they are in a coop and large run, and nothing gets in and they sure don't get out (local fox problem), so its definately from one of them. I'll try your blowing technique, thanks for that.

I have a hen I named M.E.L. (mega egg-layer). She has laid some whoppers in her time, most double yolkers.
Another thing you may try instead of blowing the egg is to dehydrate it. Store it in a dry place, not too warm, not too cold and the egg will dehydrate and the innards will rattle around. We bought some painted eggs in Czechoslovakia that were done that way. Probably more stable, too, so they won't break as easily.

Rose, Am very interested in the eggs in Czech Republic. Will be in Prague in October. Were the eggs you obtained from a shop or from a home-craftsperson? I know about the designs and methods of lost-wax, and would love to obtain, maybe 3 or 4. They are sometimes sold in shops in the US, but it is nice to have something to look for that you really want, when traveling. CJR

We have some 'miniature' hen eggs that we have preserved quite by accident. We put them on the kitchen window-sill to admire and comment on and forgot to throw them out. About a month later, expecting them to be rotten, we found out that instead they were dry and light, with that little rattle Rose refers to. Interestingly, they were perfectly round, not oval like a hen's egg, and very small, like a bantam's. We also had the huge double-yolkers Tania refers to for a while (it hurt just to look at them, ouch!) when our Barred Rocks first started laying last year, but after a couple of months this stopped. Maybe whoever it was decided to become more conventional. We thought it was probably just a characteristic of 'beginner' eggs.

Those little eggs are called "teenies", and result when for some reason the egg-making process skips the yolk (usually--or an immature egg is released) and a trigger is started to finish, usually with very little white. If a hen does this just occasionally, no harm, but if you constantly find one in the nest, she may have ovary problem and will not produce good eggs any more. Most often, it is a rare or only occasional happening. I always have saved them, too, and place them in a mock bird nest, guilded, for decoration. CJR

Thanks for the info, Cjeanr! Now the kids and I have a name we can call those cute little round eggs...'teenies'...hmmmm. We, too, have them in a little nest...great minds think alike. They are, indeed, only an occasional occurrence, and we have actually never found them in the nesting boxes - usually on the floor of the coop or outside, of all places (almost like the hen didn't know she was going to drop an egg and it came upon her by surprise!). I suspected, but didn't know they were incomplete, i.e. with no yolk. Interesting process, this making of an egg. Do you know of any good books that describe it? I'd love to learn more about it with my kids!, and it might answer some questions we have, such as "how long after mating can a hen lay fertile eggs?"

Cedarfarm- - A nice little book with lots of information, diagrams, etc. is A GUIDE TO BETTER HATCHING by Janet Stromberg. It is available at most Poultry Supply catalogs--maybe from the bookstore or poultry supply on the Coop. CJR

I have a hen that lays extremely large eggs; they are never double-yolked, but contain a great deal of water. The egg seems fresh with no bad odors. My dog likes them. Any ideas about what could cause this?

You just have a hen that puts on a little "extra" when she forms her eggs--its an individual thing. Incidentally, I hope you are cooking the egg for your dog--raw eggs okay for cats, but not for dogs! Hardboil his/her eggs. CJR

Hi, I've got a hen that laid an egg that looked like an
hour glass it is got a very, very small middle and on
both ends is a little round egg, it is cool looking,
MV