A medium eggshell, will yield roughly a teaspoon of eggshell powder, which contains roughly 750-800mg of elemental calcium and other elements such as magnesium, iron, manganese, etc. The composition of eggshells is very similar to that of our teeth and bones – hence rejection or allergies towards eggshells is slim to none, else your doggy will be having an allergic reaction inside-out, everywhere and anywhere, to his bones and teeth, so don’t needa worry pawrents!
Up to 90% gets absorbed, so just as a caution, I always add 40-50% more than what I should supplement. It’s always much better to have an excess of calcium than an excess of phosphorous!
Some websites advise that you leave the eggshells to dry over the counter for a night, or bake at a low temperature in the oven, immediately after you have used the egg.
Personally, I just store them in a large container, and after 3-4 weeks of collecting, pop them into the oven and bake at 100 degrees for 5-7mins, until they are warm to the touch, but not hot or charred.
Collecting a large amount works better if you are using a food processor like me, as if the amount is too little, the machine can’t really grind it that well. I think (though I wouldn’t know for sure) that using a blender, magic bullet or coffee grinder will work better if you’re very particular about the shells being completely ground into powder.
The food processor we have isn’t the top of the line, hence it normally takes 7-10 minutes of grinding for the eggshells to be grounded into powder like form. Even then, it still isn’t really powdery like flour or sugar, but more of a course sand consistency 🙂
After the entire grinding process, we store it in a disposable plastic container until it’s time to cook Cotton’s meals! For us, we make meatballs for Cotton for her meals and hence incorporate it into the meat before baking. If we have excess, we also add them into cookies if we are baking for her 😀
It’s super simple, literally costing nothing and helps the environment with no wastage 😉 I know some pawrents are worried about the ink stamp on the eggshells, but just remove that small part and you’re good to go! Organic/free range eggs also work best as if the chicken isn’t healthy, the eggs will be less nutritious too 🙂
Hope this helps!
Jamie and Cotton