Charlotte Popescu explores the whole business of egg sizes, and explodes a few myths along the way…
It’s interesting how eggs from individual hens of the same breed can vary in size and eggs from the same hen can also vary depending on the beginning and end of her season. An established hen will invariably start her season with a small sized egg but the eggs get bigger as the summer progresses. Also older hens tend to lay larger eggs than young hens but gradually less of them.
On the whole POL hens will lay smallish eggs to start with and these will have undersized yolks. These hens may lay small eggs for their first few months. However, I find that if my hens come into lay a little later, for example at 25 weeks, the eggs tend to immediately be quite big, which is a bit of a bonus!
It is thought that chickens may find it painful and stressful to lay big eggs. However I think maybe we tend to look at the hen undergoing possible pain from a human angle (ie women giving birth to large babies!) Also a hen will not generally generate an egg that it cannot lay. Furthermore there is no strong published evidence of pain in hens laying eggs. I sometimes see bloodstains on freshly laid eggs but these are invariably on normal sized ones. I agree, though, that it might be stressful as it takes more out of a hen to lay a large egg. But amongst most of us who keep hens in the garden, a very large egg is not a daily occurrence. Farmers are paid more for larger eggs, so it is in their interest to provide them; by selective breeding and a high protein diet they can persuade their hens to lay these larger eggs. This may be counterproductive as the extra protein can make them fat… which would eventually make them lay fewer eggs! There is an argument for farmers to produce medium sized eggs as they taste better and there is less chance of breakages. Both a medium and a large egg have the same amount of egg shell enclosing them which means that on a large egg the shell is less concentrated and therefore thinner.
A while ago there was a story in the press about a hen laying a very small egg and its owner wanting to get this into the record books. But very small eggs are quite common and are due to a comparatively well known phenomenon. They are called wind, fairy or witch eggs; they tend to have no yolks and usually occur because the reproductive cycle has been disturbed. The hen doesn’t release a yolk before her body starts producing an egg to enclose it. She might also produce a small egg that contains a yolk, and again this could just be her system getting into rhythm or could happen with an older hen whose cycle has been disrupted by, for example, a sudden shock.
You would expect the large fowl breeds to lay big eggs and their bantam counterparts (who, after all, are meant to be a quarter of the size of the large fowl) to lay significantly smaller eggs, but this is not always the case. You would also assume that heavy breeds lay larger eggs than the slimmer-looking light breeds, but some, such as the Leghorns, often lay huge eggs; when I look at my svelte white Leghorn I wonder how she manages to lay such enormous eggs.
Rhode Island Reds are supposed to lay large eggs although mine lay eggs which are no bigger than my Isa Warrens or Black Rocks; my new Rhode Rock seems to lay very big well-rounded eggs that barely fit into an egg box. It is quite difficult to generalise since individual hens do differ in their abilities to lay large eggs and this must be down to the general make-up of each hen. The popular Pekin bantams lay a good-sized small egg! Dutch bantams are prolific layers of very small eggs although I have heard that they are only a touch bigger than quails’ eggs! Belgian Bantams and Sablepoots also lay very small eggs. Then there are the bantam versions of some of the large fowl breeds that lay a good sized egg. Wyandotte bantams lay good sized eggs which are only a touch smaller than the large Wyandotte hen’s eggs. Likewise large Orpingtons, Cochins and Brahmas lay rather small eggs for their size and I suspect their bantam counterparts lay eggs that are virtually the same size. The large fowl Appenzeller hen that is a relatively small light breed lays good sized eggs with a lovely large yolk.
I find that, on the whole, my friends like to be supplied with the biggest eggs that I can provide as these are so good to cook with and I guess they also consider that they are getting more for their money! My bigger eggs do not necessarily have bigger yolks though, just more egg white! But I do know one or two people who particularly like my bantam eggs. I also find bantam eggs very useful in cooking when one needs half an egg for a recipe. Bantam eggs also have surprisingly large yolks which can prove helpful in the kitchen and are perfect boiled for the younger members of the family.
A hen which lays a double yolked will obviously produce a very large one. These are caused by a mistake in the reproductive system. Ovulation can occur too rapidly and one yolk gets lost and is joined by the next one. These double yolked eggs seem to be most commonly laid by pullets whose productive cycles have not yet synchronised. I did once get a triple yolker from one of my hens but never managed to find out who laid it! Very occasionally a hen can produce a large egg which encases a smaller completely intact egg and this again happens due to a mistake in her cycle.