I have six black Australorps hatched Feb. 28, 2011. I got my first pullet egg on July 24th, which weighed in at 1.55 ounces. Slowly, the others have started laying, with the first pullet eggs weighing in as low as 1.31 ounces, as would be expected. The first egg layers' eggs have been progressing in size until they have been nearing 'large size" and the other two that started laying were increasing in size daily. I got one double yolk egg that weighed in at 2.5 ounces, but other than that the eggs were ranging between 1.6 ounces and 1.92 ounces. It was not until yesterday that I noticed that egg size could no longer be counted on to judge weight. I always weigh biggest to smallest, so when the size didn't jive with weight, I was puzzled. Yesterday was the day I got the egg that weighed 1.92 ounces, which is almost large sized. I have gotten three eggs a day for nearly a week, so I was thrilled when I saw four eggs in the nest box this morning. Especially since one looked like the biggest yet, so I was hoping to have my first "large" egg. Two looked to be almost mediums, and there was another little pullet egg, indicating a new layer. I've weighed them three times now, just in case there is a problem with my scale, but today's weights are way off according to visual appearance of size. I still have the egg that weighed 1.92 ounces, so I was really surprised when the egg I got today that looks larger only weighed 1.76 ounces. The two that looked to be close to "mediums" and almost identical in visual size, weighed 1.69 and 1.41 ounces, respectively. The biggest surprise, though, was when the little pullet egg weighed 1.45 ounces--more than the egg that was the same size as the one that weighed 1.69 ounces. That difference has me totally stumped. I am not getting enough eggs yet to break them all open at the same time to see what the insides are like. So far, all the eggs that I have broken had yolks in proper proportion to the whites. I don't even know for sure that yolks weigh more than whites by volume. I am gathering eggs at the same time each day, and weighing them right away, so heat, humidity, length of time in the nest, etc., shouldn't be a factor. It's been hot and humid every day since they started laying. Any thoughts from seasoned laying hen keepers?
Well....I don't weigh my eggs, except sometimes the really tiny pullet eggs to laugh at how small they are, or the occasional whopper to gasp at how big it is, so I haven't conducted any scientific experiments on size vs. weight but at first blush, my thought would be that some have evaporated more than others. The shells are porous and evaporation occurs over time so I would guess that how much would vary according to the temp/humidity on the day, how long it sits in the nest box before being collected etc.
