If you check the "treat list" you'll see that all dry beans need to be cooked before giving them to your chickens, so that probably means the edamame as well. However, since these are immature, green soybeans I'm not sure if the toxic level would be as high? I think I would cook them just to be on the safe side.
Heat inactivates the antinutrients. Soy is not commercially heat-processed for any great length of time but I was just reading that the FAO was noting that whole dry legumes were boiled for 30 minutes in one of their studies on low-tech poultry feed. Probably edamame wouldn't require that much time.
If the chicks are young, you should probably use real caution about introducing any new food.
Did you have any luck feeding your chickens the fresh edamame? Our hens are plucking their feathers, I tossed in some fresh edamame into their pen today for the first time. I am hoping this will boost their protein intake and reduce the feather-plucking. I might also try mealworm although that makes me a little squeemish. Maybe a combination of both. Thanks in advance for the update.
The mealworms work great for mine, and yes, they took to the edamame with no ill effects at all. In fact, after the edamame they took to things they didn't like before! Fruit, boiled egg, whole wheat bread crust, they are no longer picky or choosy. If it looks like it MIGHT be offered, they lunge! No more picking at each other, now they seem to be sizing ME up : gulp : LOL!