I only feed them occasionally maybe 1-2 a month. I like that they have a little vitamin A as well as calcium. I have found nutritional analysis of snails but it doesn't take the shell into account because people don't eat the shells. You might try to find and weigh an empty shell to guestimate the amount of calcium.
There was a study of digestion times of snails by Jackson's on Hawaii. It might have some info you could use. I'll see if I can find it.
There was a study of digestion times of snails by Jackson's on Hawaii. It might have some info you could use. I'll see if I can find it.