Reptile & Amphibian Forums

The reason wild foods are so much better for tortoises than store vegies is because of the calcium/phosphorus ratio. This ratio must be a certain way for the calcium to be absorbed. Weeds and grasses have the ratio just about perfect in most cases. Greens in markets have been tinkered with genetically in many cases over the years to make them more palatable and also to give them a longer shelf-life.

Also, and this is extremely important, they are grown on farmland where the mineral content of the soil is next to nil. Very little calcium is in store-bought produce, but it is very high in phosphorus because of the inorganic fertilizers used by commercial farmers. This is the reason you must supplement calcium in feeding tortoises and other vegetarian herps. Don't give them anything that has phosphorus in it.

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"That's gonna be REAL tough if you feed any plant."

That is not only an imcomplete sentence, but a non-sequitor in the context it was given.

Learn rudimentary English and then get back to me.

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np

There may be some truth to what you are saying but then again maybe it is not quite so proven. I have kept tortoises for 30 years and fed them all kinds of things that are now considered to be "BAD" for them. Yet all they have ever done was thrive and reproduce and develope very solid shells. The only time I have ever got mild pyramiding is when the young ones were growing abnormally fast due to constant feedings and did not have access to natural sunlight. Even then, what little unevenness they had when small, smoothed out as they grew after being kept outside.
As for the soils "in the wild" being more mineral rich than in farms....well that is just a ridiculous statement. When you do any research at all regarding the habitat of redfoot tortoises in South American one of the first things you learn is how POOR THE SOIL IS in most of their range! Also, here Florida many of the vegetables are farmed in the mucklands that are VERY rich soils.
True, some types of lettuce have been found to be unbalanced in the 'proper' ratios but I don't think you can treat these food items like they are plagued either. A varied diet is the key no matter what. And once again, I myself and many of my old friends who are tortoise keepers from way back have had very good success feeding ALL THE WRONG THINGS.
I would agree though that given the choice, weeds and various other natural fodder is better, but only a few of us can actually provide this.

"Poor soil" is a relative term. Farmers usually consider a poor soil to be low in nutrients useful to a plant such as nitrogen, phosphorus, potassium, etc. Most “poor soils” are also typically low in organic matter. However, these soils usually have extremely high amounts of calcium. Anyway, it’s relative.

Jeff

I really don't know what you mean when you say you feed your tortoises all the "wrong" things, so I really can't comment on that. At the very least, if you don't give them enough calcium, they can't be healthy.

I was mainly talking about arid habitat tortoises. Yes, many tropical habitats are lacking in minerals, especially calcium, because of high rainfuall. But the fact is, MOST torts are from arid areas and that is what I was concentrating on. That is why Redfoots supplement their diet with other food items besides vegetation. Carrion, insects, bone fragments and even feces from other animals are eaten when they are found.

If you were to look at a map of arid sandy areas on the earth with high concentrations of calcium carbonate in the soil and intense sunlight, and then looked at a map of where tortoises are found, you would find that they are virtually one and the same. The exception would be Australia, which has no tortoises at all. Low rainfall equals calcium in the soil in almost every instance because it is rain that washes the calcium away. Not enough calcium....dead tortoise.

Now, let's look at what you said about me being wrong about the farmland. One of my dreams was to be an organic farmer, so I studied farming practices and soil composition for years. Here are the FACTS. The soils in America and almost all other countries that have been farmed for more than a few years are almost totally devoid of minerals. That is well over 90 percent of all farmland in the US. The reason? Because plants pick up minerals when they grow. How do you think you get the minerals when you eat the plant? If you keep planting and planting and planting and harvesting what you plant, eventually the plants will have picked up all the minerals in the soil. Of course, the farmers will say they replenish the soil, but that is pure nonsense. They only apply chemical fertilizers which have virtually ZERO mineral content. NONE. Even organic farmers usually don't replenish minerals, although some of them are starting to now.

In "wild" areas that have not been farmed, the minerals remain because the plants die and return the minerals to the soil and the animals excrete any excess back to the soil as well. If the rain is low, the minerals stay there forever.

The following link is to:
Are Depleted Soils Causing a Reduction in the Mineral Content Of Food Crops?
James W. Lyne and Phillip Barak
Dept of Soil Science, University of Wisconsin - Madison
depleted soils

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You didn't say all farms had mineral poor soil did you.
I read your post before my first cup of coffee and thought that was your implication.
No offense meant.

I believe the vast majority of farmland is devoid of minerals and I will stick by that. Do some research on it and you will find out I am right. It is only common sense if you think about it.

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if you are correct about the farmland being so poor, then where on Earth do the vegetables that are high in calcium come from?
Surely you are aware of the fact that many vegetables are very high in calcium right? The calcium must be somewhere...if not in the soil then where?

I have to say though that despite all the disputes back and forth about tortoise nutrition, I still believe that our biggest problem is that we are trying to raise them too fast. We are feeding amounts to juveniles that they probably never get in the wild and this causes the unbalanced growth. It is exactly the same with blue tongue skinks. Keepers are feeding them so much that they appear to be adults after only a year. Yet many if not most of these 'pushed' animals show signs of MBD. Even with all kinds of supplements and a rich diet it still occurs too often. I can't help but think it is because they are simply growing too fast to assimilate all of the nutrients and minerals in their skeletal structure.

Posted by: mayday at Mon Nov 10 11:53:58 2003 [ Report Abuse ] [ Email Message ]

if you are correct about the farmland being so poor, then where on Earth do the vegetables that are high in calcium come from?
Surely you are aware of the fact that many vegetables are very high in calcium right? The calcium must be somewhere...if not in the soil then where?

I have to say though that despite all the disputes back and forth about tortoise nutrition, I still believe that our biggest problem is that we are trying to raise them too fast. We are feeding amounts to juveniles that they probably never get in the wild and this causes the unbalanced growth. It is exactly the same with blue tongue skinks. Keepers are feeding them so much that they appear to be adults after only a year. Yet many if not most of these 'pushed' animals show signs of MBD. Even with all kinds of supplements and a rich diet it still occurs too often. I can't help but think it is because they are simply growing too fast to assimilate all of the nutrients and minerals in their skeletal structure.

I think what it really happening to some degree is that it is only the BELIEF that certain vegetables are high in calcium. That is probably based on research done years ago when there actually was a much higher mineral content than today. It is a slowly degrading situation in farm practices, and gets worse each year. Also, there are some crops that have a natural propensity to extract as many minerals from the soil as possible, and it is usually plants that reach deep into the soil with a long taproot. Root crops like turnips would fit in that category. They can still reach what little calcium is left deep below. But even then, the calcium content in turnip greens today is much lower than it was a hundred, or even fifty years ago. I am talking in general terms here. There may be a little mineral content left, but it is soo much less that in the past.

Type in "soil" "farmland" and "mineral content" in a search engine and you will see what I am talking about. You will also see that farmers do not add minerals to the soil at all. Too expensive, and they really don't care about the nutritional content of their crops. Just the price they get for them.

As far as your other comments, I couldn't agree with you more. I believe overfeeding is causing all kinds of problems. Reptiles are simply not programmed to eat a lot and grow really fast.

Not absolutely true.
Turnip greens have gram per gram more bioavailable calcium than milk.

The key to proper nutrition is variety.

It doesn't matter what the books say about what a plant supposedly does or does not contain. A plant cannot contain any mineral that is not found in the soil it grew in. Plants can produce vitamins on their own, but NOT minerals.

Thats from the USDA nutrient database, not a book.

100g rams of turnip greens have 190 mg of calcium.

Milk has 111 mg.

I'm curious, where does the calcium come from to give you that content if it is not available to the plant?
Ed

When was the information in this database compiled?

At any rate, I think what I said to Mayday covers the reason for certain crops possibly still showing some mineral content.

USDA National Nutrient Database for Standard Reference, Release 16 (July 2003)