How do I switch out bones for eggshells?

[clary7]

Sometimes my parents have leftover raw meat that they aren’t using and give it to me to use for my cats. The recipe I use uses bones though and usually the meat my parents give me doesn’t have bones or the bones are too big for me to grind. We do have tons of eggshells though since we have lots of chickens and quail. So I’m wondering how I can figure out the correct dose to substitute the bones with eggshells in this recipe:
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In short words, the recipe calls for 4.5lbs of chicken thighs and you remove 20-25% of the bones. So if there are 10 thighs, you take out 2 bones. How many eggshells do I need to substitute the bones properly?

 

[iPappy]

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This website seems legit. I use a premix most of the time, so I'm not up on supplements, calcium, (I didn't even know about feeding cats eggs!) etc., but hope this helps you out!
(From the first sub-link when you click on the above link: )

"If you are using boneless meat, you will need to add a calcium source, since meat contains very little. You will want to add about 1000 to 1200 mg of calcium per pound of meat. The three basic ways to add calcium are: bone meal powder, MCHA (microcrystalline hydroxyapatite) or eggshell powder. Because bone meal powder and MCHA also contain phosphorus and can throw off the calcium to phosphorus ratios, which are important, we recommend using eggshell powder.


Eggshells are about 90 to 97% calcium carbonate. Calcium carbonate is 35 to 40% elemental calcium, which is what we measure. When working with eggshell powder it is important to realize that different powders may have different densities; some may be more finely ground than others. For this reason, when you make your own, you will need to get an accurate measurement of what yours weighs per teaspoon to be able to add the right amount. You should aim to add approximately 3 grams per pound of meat.


For example: When we made homemade eggshell powder, which is finely ground, one teaspoon weighed 6.1 grams. This means that 6.1 grams/1 tsp of our eggshell powder has 1921mg of elemental calcium on the low end to 2366mg on the high end. Since we are aiming for 1000 to 1200mg per pound, we would add ½ teaspoon per pound of meat. Measuring by volume is more convenient, but the best way is still by weight. So, if you have a scale that can accurately weigh small amounts, use it to add 3 grams per pound. This will eliminate any variations on how finely ground a particular batch of eggshell powder is.



Eggshell calcium has the advantage that it is very low in phosphorus, so it can be added in amounts that will balance the phosphorus content of the meat. It also avoids the use of bovine bone and concerns about lead, mercury and prions."

 

[Tobermory]

I’ve found the Feline Nutrition site to be very helpful. You really do need to go by weight (3 grams per 1 lb. of raw boneless meats per that site) because eggshells can be ground to such different degrees of fineness. And, as they recommend, it’s good to bake the shells to make sure you’ve killed the bacteria lurking. Rinse the eggshells well and bake them approximately 10 minutes at 300° F. Then grind them to make the eggshell powder.

 

[iPappy]

I’ve found the Feline Nutrition site to be very helpful. You really do need to go by weight (3 grams per 1 lb. of raw boneless meats per that site) because eggshells can be ground to such different degrees of fineness. And, as they recommend, it’s good to bake the shells to make sure you’ve killed the bacteria lurking. Rinse the eggshells well and bake them approximately 10 minutes at 300° F. Then grind them to make the eggshell powder.

I used eggshells when I was making Tags food, and I ground them down with a coffee grinder until it was literal dust. Even moving the coffee grinder would create this cloud of eggshell dust, so watch out C clary7 in case you do this! I'd then slowly run them through a fine strainer to weed out all the pieces that were larger and re-grind. Some of the edges on the leftovers were actually kind of sharp.

 

[clary7]

Got it, thank you so much for the help everyone!