Rocks, Minerals & Micronutrients

This forum covers all aspects of tortoise diet and nutrition, including mineral and vitamin supplementation and foods appropriate for different species.
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Aimee
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Joined: 22 Jul 2017, 17:42

Rocks, Minerals & Micronutrients

Post by Aimee » 22 Jul 2017, 18:02

A bit of a lead in to my question. A few weeks ago, in an effort to stop my year old Hermann (Elliott!) from dragging dirt clods into his lime powder, I tried sinking the lime dish in a little garden of gravel. He was thrilled with this and immediately started eating gravel bits, and managed to swallow three or four before I noticed and took them away (he's fine, no damage done). I looked up this behaviour and found lots of information on turtles and tortoises eating rocks and soil looking for trace minerals and micronutrients, and plenty more on the risks of impaction if a little guy eats too many stones. Seems like a bad idea. But not too much later while looking for limestone powder I found a product that is just powderized rock. Here's a link to what I bought.

http://www.gaiagreen.com/images/downloa ... 202015.pdf

Thinking that if limestone was okay to snack on, this shouldn't be too different, I picked it up and gave him some. He is crazy about it. It's pretty clear that there are some minerals in there he was starving for. The thing is, I can't find any information on tortoise keepers feeding anything like this to their tortoises, for or against. There is plenty of evidence that this is probably a natural behaviour:

https://blogs.scientificamerican.com/te ... that-mine/

but I can also see in the product breakdown trace amounts of things like lead and arsenic. In those cases it looks like 10-20 parts per million, probably not different from any of the elements in a back yard, but the aluminum ratio is much higher. And I am the opposite of an expert in any of this. Is anyone aware of any research on this?

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Nina
Posts: 277
Joined: 16 Mar 2017, 11:22

Re: Rocks, Minerals & Micronutrients

Post by Nina » 22 Jul 2017, 22:37

Hi Aimee and thanks for a really interesting post (and sorry it has taken us so long to get back to you)!

First of all re Elliott eating stones and a bit of soil. Obviously if he eats too many stones there is the risk of impaction, but it is quite normal for tortoises to eat some stones (as is mentioned in your second link). Sometimes they are looking for extra calcium (and in my experience it does tend to be 'white' stones that they eat), but sometimes they are just testing the environment and sampling things. Most stones will go straight through the system and out the other end, but some might stay in the gut (and a few stones shouldn't cause any problems). I find that after a period of 'sampling' the little stones in their enclosure they usually stop eating them, but that is only my experience, and there certainly are cases of tortoises becoming impacted by eating stones, etc.

Secondly your product. The calcium content is good, but I think it has an alarmingly high aluminium content (sorry, but in the UK we spell aluminium with an extra 'i' in it, but I'll switch to the American spelling for the rest of this post), and I would be worried about that. Here is an article about aluminum in the diet (it is aimed at humans, of course, but the same principles apply), and it is interesting that there is already a bit of a risk of too much aluminum in our diet due to the way water is treated for human consumption (and in fact I have read articles that theorize a link between aluminum deposits in the brain and dementia).
http://emedicine.medscape.com/article/165315-overview

You already provide your tortoise with limestone powder (we call it limestone flour here), and that is just powdered rock too. It's ground down limestone, so it will have some impurities in it, but I think it has fewer impurities in it than the Gaia Green Rock Dust. You can also buy pure calcium carbonate on the internet, and that will have even fewer impurities.

I do know that tortoises -- and especially female tortoises -- need a huge amount of calcium in their diet. When you think about it they are mostly shell and bone with a bit of muscle thrown in, so calcium is really essential for good health (and females need extra calcium when they are producing eggs). What I am less sure of is how much they need other trace minerals in addition to those that would be found naturally in their diets, or the diet that we provide for them. It is true that calcium can inhibit the absorption of trace elements, and we do recommend the use of products like Nutrobal and Reptavite, etc. that provide calcium and other vitamins like D3, which is essential. Here is a link the page on our website that describes some of them: http://www.thetortoisetable.org.uk/tort ... XPFG-mQyM8

So in summary I think that although I don't know if the aluminum content in that Gaia product is too high for your tortoise, I think the limestone powder that you are feeding him (and cuttlefish bone is another product that you can just leave in his enclosure for him to nibble at will), should be more than adequate and I would be a bit wary about supplying him with a constant supply of the Gaia dust.

Nina

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Jon
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Joined: 16 Mar 2017, 13:34

Re: Rocks, Minerals & Micronutrients

Post by Jon » 23 Jul 2017, 21:47

Hi Aimee,

The team have been discussing this product a bit more today. A couple of things cropped up that we are concerned about and wanted to bring to your attention. Ultimately it entails that we would advise against this product unfortunately being used as a supplement for your tortoise.

One of our concerns is that the product is not food-grade or designed for ingestion. Products often go through various stages of processing before reaching the market. This can be for many reasons; some might be to ensure that the product has the advertised levels of ingredients or perhaps to remove the risk of certain bacteria contamination. When a product is not food-grade, we can't be sure what chemicals have been used as part of the refinement or processing stage. Different chemicals are used during these stages depending on it's intended purpose as they carry their own risk of contamination. It’s for this reason we can't be sure any contaminates or harmful compounds are not present.

Our main concern is when reading the materials safety sheet (see here: https://www.groworganic.com/media/pdfs/f045-m.pdf ) we can see that it's WHMIS Class is D2A. This code entails that the product is classed as a Poisonous and Infectious Material, Very Toxic. It shows this is due to the risk of crystalline silica inhalation which is carcinogenic and can cause a number of health problems. As I'm sure you know tortoise have sensitive respiratory systems so this is certainly something I would be cautious about having them exposed to.

Just to add, I think it's a very interesting angle and is certainly worth looking into for food-grade products of a similar nature. It's always good to think outside the box after all,

Kind Regards,
Jon
Jon - The Tortoise Table

Aimee
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Joined: 22 Jul 2017, 17:42

Re: Rocks, Minerals & Micronutrients

Post by Aimee » 25 Jul 2017, 04:59

I removed the rock dust. Thanks so much for your diligence looking into this for me!

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