We have 13 hens at the moment, 7 that appear to be laying, 3 that are old enough to lay but don’t appear to be, and 3 that should begin laying by October. Our judgement of the number that appear to be laying is supported by the fact that the highest production for a day yielded seven eggs.
This brings about the question of how to determine which ones are laying.
The easiest, most accurate way to determine which ones are laying is to isolate each and see if or how often they lay. We built a smaller cage into our coop to be a brooder, and for the isolation of a bird if it is injured, sick, or requires other special care, but it seems impractical and time consuming to use this for determining which ones are producing. Luckily, there are some physical signs you can look for that will give you a pretty good idea which ones to watch. If it is really important to see if one is laying, these indicators can give you a good idea as to which ones should be checked for production by isolation.
The first, most obvious indicator is the color and fullness of the comb and wattles. When a hen begins laying, her comb and wattles should brighten in color, be full and soft to the touch. When not laying, a hen’s comb and wattles are paler, smaller, less soft, and can be slightly shriveled. This first indicator applies to our three that should be laying but don’t seem to be. Their combs have hardly developed from when they were adolescents.
Vent Size is another fairly easy to read indicator. When a hen is laying, her vent will be large and moist. A bird that isn’t laying will tend to have a smaller vent. As traumatic as it seems like it should be to a hen to be flipped upside down while you check her vent, they actually seem to complain less when they’re upside down than when they’re right side up and being held against their will.
While you’ve got the hen upside down, check the pelvic bones. These are just forward (towards the chest) of the vent. You should feel the points through the skin. If they are close together, almost touching, you can make a pretty sure bet she’s not laying right now. If they’re at least as far apart as the vent is wide, or wider, she’s probably either laying or soon to lay.
The last indicator tells you both whether or not she’s laying right now, but also how well she’s been laying over the last few weeks. When a hen is laying, the yellow pigment in her vent, the skin surrounding her eyes, her earlobes, her beak, and her feet and legs (in that order) will fade and disappear. As this pigment is used up in egg production, it is drawn from other parts of her body. When she stops laying, the pigment will return to those parts (in the same order it left). This history, combined with the other indicators, can tell you whether she’s laying steadily, or if she just started or stopped.
More information about the relationship between laying and pigmentation, and to some extent on the other methods presented here, check out http://www.extension.umn.edu/distribution/livestocksystems/di1182.html.