My hens are going on one year. They are members of the family, and provide us, friends, and neighbors with such wonderful eggs and enjoyment. I am eager to do my best for them. I have been giving our fur babies a supplement of glucosamine, collagen, L-methamine, and MSM. It does enhance joint health. My family takes it too. I considered giving it to the hens and read up on the topic. It seems that others feel it helps their poultry, too. I am starting immediately. What I have been doing already is to recycle their egg shells. I will add this supplement to the mix. Here is what I do: After collecting a batch of shells, I put them in a bag and crush them to small bits with a rolling pin. Then I put them in a pot with a small amount of potassium or sodium hydroxide -- drain opener is a convenient source. I boil the mixture on low to medium heat. The proteinaceous material lining the inner shell is hydrolyzed by this treatment. It will foam up so a deep pot is advised. After a while, the foam breaks down to a minimal "scum" on the liquid surface. Then I deccant the liquid to sewer and rinse the shells several times to eliminate any residual alkali or organic residue. When the water is clear and non-bubbly, it is clean. (I could also test the rinse water for pH but haven't felt it was necessary.) I transfer the wet fragments to a pan to dry either naturally in open-air, in an oven, or on the stove top. When cool, I pour the fragments into a feeder with dry mealworms. The girls flock to the feeder, gobbling up the mealworms and taking up the calcium-rich shell fragments at the same time. They do discriminate between the worms and the shell, but appear to want the extra calcium as well. So far, so good. The eggs the girls produce appear to usually have normal thickness shells. There are no pathegens in the mix, and I haven't had to use the oyster shell supplement I bought when they were chicks.