Oyster Shells and heavy metals

Discussion in 'Feeding & Watering Your Flock' started by capitainamerika, Dec 20, 2015.

  1. capitainamerika

    capitainamerika New Egg

    Dec 20, 2015
    I'm new here, so please forgive me if this topic has already been covered. I looked first but didn't see anything.

    For many years, I have been reluctant to feed my chickens oyster shells because of where they come from. That is, oysters come from bays and estuaries, which is also where heavy metals end up being deposited. It's not that I've ever heard that oyster shells are laced with heavy metals, I just assume they are given the environment they live in.

    I give ground granite for grit, but haven't found another source of calcium. So I just feed a good laying mash and scratch grain.

    Am I all wrong about oysters and heavy metals? Does anyone know of another source for calcium?

    My birds always lay well and I've never had trouble with thin egg shells, so maybe it's a moot point.


  2. OrganicFarmWife

    OrganicFarmWife Overrun With Chickens

    Oct 21, 2015
    No where Nebraska
    Bone meal is another calcium option. I do not make it myself, it is hard work. But if you are worried, it is an option.
  3. oldhenlikesdogs

    oldhenlikesdogs I Wanna Be A Cowboy Premium Member

    Jul 16, 2015
    central Wisconsin
    You need to check the source of the calcium in your layer ration, it might actually be from oyster shells. When fed mostly layer ration, hens won't actually need or eat much oyster shells. You could also feed them back their eggshells for extra calcium.
    1 person likes this.
  4. Pork Pie Ken

    Pork Pie Ken Flockless Premium Member

    Jan 30, 2015
    Africa - near the equator
    My understanding is that shellfish are good bio-accumulators of heavy metals. Having said that I can only assume that oyster shells are a by-product of human consumption and they would not be harvested from sites high in pollution. Nothing to sweat imo.

  5. blucoondawg

    blucoondawg Chillin' With My Peeps

    Jan 27, 2013
    Northern Wisconsin
    Crushed limestone is another option and quite common it is actually used in alot of feed as the calcium supplement.
  6. aart

    aart Chicken Juggler! Premium Member

    Nov 27, 2012
    SW Michigan
    My Coop
    I've often wondered.....where does that crushed oyster shell come from??? <scratcheshead>

    Is it a byproduct of oysters harvested for humans?
    Where do those oysters come from....farmed or wild harvested?
    What is in either environment that might remain in the shells?

    Hard enough to pinpoint the sources of most human foods, let alone livestock/pet feeds.

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