So I've seen food coloring in the vent suggested many times to determine what hens are laying which eggs. But has anyone actually done this? How, exactly, does one introduce the food coloring into the vent? How long does it stick around coloring the eggs?Pictures of the eggs marked by food coloring would be great to see.
I've never seen any more detailed instructions than "put some food coloring up the vent to mark the eggs as they're laid" and never seen a picture of an egg marked in such a way. I'm starting to think y'all are pulling my leg on this one!
I've tried it.
Grab the hen, easiest to get her off the roost at night but any time can work.
Turn her upside down and drip a few drops of liquid food coloring on her vent. (Try not to get it anywhere else.)
Then let the hen go and watch for colored eggs.
I've had it work nicely.
I've had times when the eggs did not get marked (put food coloring in one hen's vent, another color in a different hen's vent, then get eggs that must be from one of the two: but no color on them.) I'm not sure why it failed to work.
I've had times when extra eggs get marked (two or more eggs with that color, even though only one hen has color in her vent. Or food color on an egg that she cannot lay: if she lays naturally blue eggs, but I find her color on a brown egg.) I assume the color smeared from her egg onto the other one, or that some got on her feathers and smeared onto the other egg.
I never did figure out what was causing all the variations.
I view it as something that can be useful, but not as reliable as some other methods.
If I really want to know what color eggs a hen lays, I can tell by watching her lay an egg, or by putting her in a cage by herself until she lays an egg. Or put her in a cage with another hen for company, then deal with two egg colors (two matching eggs means they both lay that color. Or if one hen's egg color is known, and the second egg does not match, then I know what color the other hen lays.)
If I want to be really sure what egg was laid by a given hen (example: to hatch), I either want that hen in a pen by herself, or in a pen with hens that lay other color eggs (such as one each of blue, brown, and white layers in one pen.)
For being medium-sure which egg goes with which hen, in a situation where I cannot put them in separate cages, then I do think food coloring is more useful than nothing at all. I just know it can be wrong, based on my personal experience.
Sorry I don't have any pictures of eggs marked with food coloring. If you have seen eggs with a streak of blood on them, it's similar to that, but with whatever color you used.
