oyster shell... or tums... or...?

Discussion in 'Chicken Behaviors and Egglaying' started by gretchen, Mar 6, 2008.

  1. gretchen

    gretchen In the Brooder

    Jul 18, 2007
    So I recently just ran into a fellow backyard chicken lady and her boss who is a Vet.... as in Animal Doctor, not Veteran. We got on the subject of calcium supplementation and they very strongly advised me not to give oyster shell because it was ground from some washed up shells and full of mercury and other toxins, she uses mashed up Tums to supplement the calcium. I have switched over to the Tums, all I can find is peppermint flavor, although they don't seem to mind and it hasn't affected the taste of the eggs but it seems odd to give them flavored stuff and is pretty pricey. I am an artist and have ceramic supplies on hand and I have a bag full of straight up Calcium Carbonate, which is the main ingredient in Tums. Does anyone know if that is OK? It would be easier to just sprinkle some Calcium Carbonate in their feed then to buy Tums at the market and crush them up. I just want to know if anyone has a clue... Thanks.
  2. patandchickens

    patandchickens Flock Mistress

    Apr 20, 2007
    Ontario, Canada
    We got on the subject of calcium supplementation and they very strongly advised me not to give oyster shell because it was ground from some washed up shells and full of mercury and other toxins

    Not really "full of".

    My take on this is that it's far more likely to be a legitimate health issue for a person consuming calcium supplements daily for forty years than for a chicken that lives for, well, however long your personal chickens live [​IMG]

    And it is not like chickens aren't exposed to other sources of heavy metals too, well beyond what's considered acceptible for humans... heck, we use galvanized waterers [​IMG]

    she uses mashed up Tums to supplement the calcium.

    Sure, if she can afford it and is okay with the *other* ingredients in Tums (Sucrose, Calcium Carbonate, Corn Starch, Talc, Mineral Oil, Natural & Artificial Flavors, Adipic Acid, Sodium Polyphosphate, Red 40 Lake, Yellow 6 Lake, FD&C Yellow 5 Lake (Tartrazine), Blue 1 Lake), then why not.

    OTOH to *me* anyhow there is not a persuasive case not to use oystershell for chickens. Dry and crush their eggshells and feed 'em back to the chickens if you are concerned... that way you will use only a minimum of oystershell and will therefore have minimal inputs of whatever contaminants you are concerned about.

    Me, I'd feed oystershell and eggshells, and if I felt guilty about it I'd take the money I saved by not feeding Tums and give it to the charity of my choice [​IMG]

    I am an artist and have ceramic supplies on hand and I have a bag full of straight up Calcium Carbonate

    Actually I'd be more worried about using that than using the oystershells, since at least we have some idea what the general level of contamination is in oystershell [​IMG] No source of calcium carbonate (well, no cheap source) is going to be COMPLETELY pure, and many sources have a considerable amount of lead and other heavy metals, moreso than oystershell has. Personally I wouldn't do it.

    Basically there's no such thing as a free lunch -- pretty much everything has *some* contaminants or production aspects to object to [​IMG] Not all levels of Stuff are necessarily a realistic health threat.


  3. DrakeMaiden

    DrakeMaiden Overrun with Drakes

    Jun 8, 2007
    Kitsap County, WA
    I agree with Pat for the most part.

    Your calcium carbonate is probably not as pure as it needs to be for consumption. It is an industrial grade product, not a food grade one.

    Feeding them back their eggshells works great.

    I also worry about oyster shells and marine contamination. Use them sparingly, if at all.
  4. foux003

    foux003 In the Brooder

    Aug 20, 2010
    R I, Apple Valley Area
    Quote:Calcium Carbonate is Calcium Carbonate. CaCO3 It realty doesn't matter where you get it from. We used to add GROUND LIMESTONE in all feed that we mixed, over 200 tons a week in an old batch mixer.. I am sure that the pottery CaCO3 would work just fine, the chickens don't care if it's FOOD GRADE. As far as Oyster Shells I found only one reference to Mercury in the Oyster Shells and that was shells that were dead and washed up on the shore. The packaged Crushed Oyster Shells are made from shells that were alive when harvested, shucked and then ground. The Oyster like all Bivalves build their shell from their own secretions, for the shell to have mercury then the Bivalve would have to be already contaminated with mercury and NOT FIT FOR HUMAN CONSUMPTION.

    I would use shells from the Common Soft Shell clam, if I had a way to crush the them.

    Many times the only difference between " fit for human consumption" and "animal food grade" is whether the plant is FDA inspected and the cleanliness of the plant. Ground limestone is meant to be used on your lawn or garden but you could eat some and it wouldn't hurt you.

  5. gaillardia

    gaillardia Songster

    Apr 20, 2010
    Larkspur, CO
    Mercury collects in the fat of animals, so the shells really should not be a problem. I just feed the eggshells back to my girls. They love them.
  6. elmo

    elmo Songster

    May 23, 2009
    Quote:Why on earth would they put talc in Tums?!
  7. bakerjw

    bakerjw Songster

    Apr 14, 2010
    Johnson City, Tn
    Chickens eat rocks. I've seen it and I don't believe that they're too particular about what kind they are. That said. I occasionally feed mine ground up egg shells other than that they get what they need from their feed. And I don't know where the calcium in their feed comes from but I wouldn't be surprised if it comes from oyster shells.

    I wouldn't worry about too many contaminants.
  8. rcr191

    rcr191 Hatching

    Aug 14, 2010
    Okay I'm confused, "do or don't feed oyster shell"? And if you feed them their own shells, doesn't that make them eat their own eggs?
  9. mulewagon

    mulewagon Songster

    Nov 13, 2010
    rcr191, I just crush the shells out of shape and throw them into the pen. The chickens seems to recognize eggs by shape, that's why golf balls work as nest eggs.

    I'm giving away a lot of eggs, though, so lots of the calcium is leaving the cycle. So I also leave oyster shell out in a jug for them to eat as needed. They don't eat much of it.
  10. Pixarbuff

    Pixarbuff Hatching

    Aug 18, 2014
    This article indicates that "Ninety-seven percent of the egg shell consists of calcium carbonate. The shell weighs approximately 6.0 g, so almost 6.0 g of calcium carbonate must be synthesized and deposited on the shell each time the hen produces an egg. . . . The most common source of calcium for layer feeds is limestone. Consisting primarily of calcium carbonate, this mineral supplement is well digested by the chicken." So, while I don't know enough to provide a specific recommendation about Tums, in particular, it seems clear from the article that straight CaCO3 from ground limestone is commonly used as a feed supplement and provides benefits for eggshell quality.

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