Article about oxalic acid

[pagan queen]

I took this from a bird diet article but thought it was interesting for tort owners too.
The whole article is in the link below and worth a look, it goes into quite a bit of detail about nutrition and can be applied to torts in a lot of the article.

http://www.holisticbirds.com/pages/foodpp1002.htm

Oxalic Acid Several foods, though excellent sources of nutrition, are also high in oxalic acid. If fed frequently, oxalic acid can cause health problems.
When you feed a food high in oxalic acid and balance it with foods low in oxalic acid, it becomes less of a concern. Regardless, foods high in oxalic acid should not be fed on a daily basis.
Oxalic acid
(g/100 g) asparagus .13 beans, green .36 beet leaves .61 broccoli .19 brussels sprouts .36 cabbage .10 cauliflower .15 celery .19 chicory .21 chives 1.48 collards .45 corn, sweet .01 cucumbers .02 eggplant .19 endive .11 kale .02 lettuce .33 okra .05 onion .05 parsley 1.70 peas .05 peppers .04 purslane 1.31 spinach .97 squash .02 tomato .05 turnip greens .05 watercress .31 Although oxalic acid binds to calcium (producing calcium oxalate crystals), and making calcium unavailable for absorption, many vegetables that contain oxalic acid also contain calcium. The amount of oxalic acid is what determines how much calcium is bound. So if there is more calcium than oxalic acid present, the calcium that has not been bound will be available for use by the body.
To the right is a table with the oxalic acid content of some vegetables.
Above Ground Vegetables In addition to green leafy vegetables, other vegetables are a part of the pyramid base and can provide 10 - 15% of the diet.
Stem vegetables include asparagus, celery, and fern head. In this category we also list the buds and branches of edible trees and bushes such as apple, willow, poplar, aspen, and American lilac. Birds relish these particularly in spring when the sap begins to flow and the leaf buds fill.
Flower Vegetables are vegetable flower heads that are consumed before they open into their flower form. Among these are broccoli, artichoke, cauliflower, and Brussels sprouts.
Edible Flower Blossoms include squash, pumpkin, nasturtium, chamomile, dandelion, hibiscus, lilac, thistle, apple, and many more. For more information regarding edible flower blossoms, you are invited to read Carolyn Swicegood's article about Edible Flowers from our first issue.

Do not limit the diet to one type of food. Rotate many foods to provide a variety of nutrients and to avoid food sensitivities.

Vegetable Fruits form after a plant's flowers have fallen. They contain seeds within the pulp much as typical fruit does. These vegetables come in all colors and varieties along with a wide array of nutrients. Among them are pumpkin, squash, peppers, tomatoes, and okra. Birds often enjoy eating the seeds as well as the pulp of these vegetables.
In general, vegetables with the most color contain more nutrients. Different colors indicate different plant chemicals, so it is helpful to strive for a mixture of colors in the diet.
The nutrient value of foods (except for the phyto-nutrients) can be obtained from the United States Department of Agriculture Food Composition Database. http://www.nal.usda.gov/fnic/foodcomp/
In general, vegetables have fair amounts of potassium, magnesium, phosphorus, calcium, folic acid, and vitamins C and A. They also have smaller amounts of other vitamins and minerals not listed in the table.
Veggies protein % carbs %

phyto and micro-nutrients

asparagus 2 4.5 saponins, C, A, folate, potassium, magnesium, calcium, celery 0.7 3.6 pthalide, sedanolide, sodium, potassium edible fern head 4.5 5.5 C, A, niacin, calcium, magnesium, potassium, artichoke 3.2 10.5 silymarin, polyphenols, A, Calcium, potassium, phosphorous, folate broccoli 2.9 5.2 sulforaphane, indole-3, quercetin, lutein, C, A, Calcium, potassium, folate,
brussel sprouts 3.3 8.9 protease inhibitors, sulforaphane, indole-3C, A, Potassium, folate cauliflower 1.9 5.2 indoles, isothyocynates, C, potassium cucumbers 0.5 2.5 potassium pepper, hot 2 9.4 capsaicin, lutein, C, A, sodium pepper, sweet
9 6.4 C, A, potassium pumpkin 1 6.5 A, potassium squash, winter 1.4 8.8 C, A, calcium, potassium squash, summer
1.1 4.3 potassium tomato 0.8 4.6 lycopene, quercetin, kaempferol, C, A, potassium, folate
It really is not necessary to know the exact nutrient content of different foods unless we feed the same food every day. Feeding a limited diet of the same food can lead to diseases of malnutrition.

[Suze65]

Thanks Wendy, I for one found that very useful and interesting,as I don't know much about the subject.

[FLINTUS]

Agree with Suze, thanks for that. Very much appreciated.

[pagan queen]

Glad it was useful. I think it's better to read it via the link, the tables are easier to read. I think bird and reptile nutrition is very similar so the link can be useful in the whole.

[Ozric Jonathan]

Worth mentioning that food plants should not contain too much phospherous and preferably should have several times as much calcium as phospherous, the Ca:P ratio.

Some plants have quite a lot of calcium in them but also lots of phospherous and those are not so good for tortoises.

Some plants have lots of calcium in them but also oxalic acid and this incldues dandellions. The amount of calcium and oxalic acid varies between the many species of dandellions and so does the amount in individual plants and leaves. I think the flowers and stems of dendellions are the 'worst' parts of the plant for oxalic acid.

Rather than not feeding dandellions what I do is to not feed the stems and flowers.

From what i can remember I think Plantain has a more or less ideal combination of calcium and phosperous.