# oxalates



## Kapidolo Farms (Jun 14, 2019)

I'll try and pull together other threads, by link, that have already beat this topic up.

What I have found, most plants that tortoises like have oxalates in them. It's a 'secondary'compound with some direct uses by the plant, but for the most part seems to be a leaf eating insect deterrent.

When looking at what it does in the tortoise gut we need to sort out a better C: P ration where the C is reduced by the amount of oxalates, so that a more true C: P can be determined. Not that oxalates are the only compound that precludes bio-availability of calcium, but it seems to be one of special concern as so many info sources so heavily indicate how horrible oxalates can be. My growing contention is that oxalates don't really matter in tortoises.

This post https://www.tortoiseforum.org/threa...of-opuntia-with-citation.129949/#post-1217586 put me on this path of inquiry. Though opuntia is high in oxalates, it is a favored food as both a native diet item for some species, and an introduced diet item for many many more. It turns out even with oxalate burden in opunti, the C: P ration is still positive.

a few more
https://www.tortoiseforum.org/threads/oxalic-acid-not-as-bad-as-we-think.62761/#post-594792
https://www.tortoiseforum.org/threads/oxalates-what-are-they.37761/

$1 for any links to or PDF loaded here that have oxalate content values for any plants that we feed, any quote from the tortoise table and you'll be fined $100.


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## dmmj (Jun 14, 2019)

What I have tried to figure out is does it bind 1:1 or some different ratio. 1:1 it may not be the best food but can always supplement more calcium rich food. Interesting about it being an insect deterrent, plants do not want their foilage eaten.


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## Kapidolo Farms (Jun 14, 2019)

In table 1, they use molar ratio. That's simple put as counting the molecules, not weight but count.


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## Kapidolo Farms (Jun 14, 2019)

@Toddrickfl1 if you know of the others, doubters on FB, please @ them in.


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## Kapidolo Farms (Jun 17, 2019)

A easier to read paper on oxalates and their effect of people, not tortoises. But even the dreaded spinach comes out net positive for calcium.


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## ZEROPILOT (Jun 18, 2019)

I've read that too much oxalate intake into a human body can contribute to kidney stones.
Is that not an issue for tortoises?
(Oxalates in foods like Spinach and Purslane)


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## Tim Carlisle (Jun 18, 2019)

ZEROPILOT said:


> I've read that too much oxalate intake into a human body can contribute to kidney stones.
> Is that not an issue for tortoises?
> (Oxalates in foods like Spinach and Purslane)


In addition to renal problems, excessive oxalates have been known to cause problems with bone structure as well.


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## Kapidolo Farms (Jun 19, 2019)

Based on NO result ever being found by vets, it does not seem to be a problem for tortoises. The U of Minnesota has a funded urolith research center, it's free to submit samples, and over 30 years of receiving samples (n=66 for tortoises ) no tortoise is reported to have any oxalate based 'lith. Another independent report looked precisely at tortoise liths, non were formed based on oxalates. Both studies are talked about here https://kapidolofarms.com/wp-content/uploads/2018/11/KapidoloFarmsTTPG.pdf

I have read popular articles in magazine like "Reptiles" and heard vets in lectures issue warning based on human results, but none of those vets, when asked, did an actual analysis of whatever stone they are talking about and seem to have assumed what it is. Of stones analyzed, the vast majority are protein waste product concretions, which indicates to me the tortoise was water stressed.

I'm not advocating feeding a spinach only diet, that violates the number one rule of tortoise diet (Variety), but there is no value in picking the spinach out of spring mixes either.

As discussed by others, who's posts I linked in the OP, oxalates in any form, are a secondary compound in many plants. Opuntia being a common food, I focused on that. Their role is to inhibit animals from eating the plant, mostly leaf eating insects.

It would seem that most plants have more calcium than calcium used up (bound) by oxalates, after all the plant needs 'free' calcium as well. So the issue, the real issue is, of the free calcium, is it a positive ratio to phosphorus. At least in the case of opuntia, it still has a C: P ratio of not less than about 10:1. Other plants, the oxalate bound calcium may turn this ratio opposite to what we desire for tortoise food. When calcium is measured in foods, there is not often any distinction made between bio-available calcium, and total calcium. So we get a positive C: P ratio of total calcium, not the more appropriate for our purposes, a C: P ratio of bio-available calcium.

I imagine some folks are rolling their eyes if they read this far. Up your game, or be chicken little. The sky is not falling.


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## ZEROPILOT (Jun 19, 2019)

I appreciate all of the information.
I've worried about the amount of Purslane my Redfoot eat out in the yard.
Sometimes it's a lot.


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## Tom (Jun 19, 2019)

How does this all translate Will? Do you think its okay to feed oxalis and other high oxalate foods to the tortoises? Who will be the guinea pig? I throw buckets of tender juicy oxalis in the garbage every year. I'd much rather feed it to the tortoises if its not going to do harm to them.


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## Yvonne G (Jun 19, 2019)

Tom said:


> How does this all translate Will? Do you think its okay to feed oxalis and other high oxalate foods to the tortoises? Who will be the guinea pig? I throw buckets of tender juicy oxalis in the garbage every year. I'd much rather feed it to the tortoises if its not going to do harm to them.


Personally, I would not give 'buckets' of purslane or oxalis to a tortoise, however, if it's growing in their yard and they have free choice to eat it or not, I wouldn't worry about them eating it. Dudley's pasture has quite a bit of oxalis in one section. I don't see him graze that section very often.


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## ZEROPILOT (Jun 19, 2019)

Yvonne G said:


> Personally, I would not give 'buckets' of purslane to a tortoise, however, if it's growing in their yard and they have free choice to eat it or not, I wouldn't worry about them eating it. Dudley's pasture has quite a bit of oxalis in one section. I don't see him graze that section very often.


They eat it and little else when they are allowed to roam the yard.
It would be nearly impossible to remove it all.
But not letting them roam the yard is an option.


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