Horsefield length weight monitering

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Merlin M

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So, since getting my new Horsefied a few days ago have been hunting around for ways of monitoring its growth, weight etc. and stumbled across a thread in another forum http://www.tortoise-protection-group...30.asp?tID=667
which gave a formula from someone in the stated is basically
Length(cm)xWidth(cm)xHeight(cm)x0.75=Weight(g)

So got the other half to make me an Excel spreadsheet to calculate this for me (with a square dividing the outcome of above formula with the measured weight, making a value of 1 being the best out come)

I only have 1 weeks data for this but came out at 1.037 so it could be fairly accurate.

am happy to share my excel sheet and get any advice on this measuring system.
 

ascott

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WOW! Fancy stuff. I bet there are people here that would appreciate you duzint that excel....I wish I could begin to brag about how awesome I am in regards to keeping those type of records....BUUUUT yeah I can't. I am more of a pen and dog eared pad of paper with the torts name in the top....:D
 

PS95

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That is a very clever formula. The left side of the formula calculates the approximate volume of the tortoise in cubic centimeters. It is necessary to multiply by 0.75 since a tort's body is not a perfect rectangular solid. The right side of the equation says that each cubic centimeter of a tort's body should weigh about 1 gram. This makes sense since the body of most animals is made up mostly of water, and 1 cubic cm of water weighs exactly 1 gram. Amazing! The question is, how do we know what the volume and weight for a horesfield should be, given its age? How do we know what the healthy weight for a horsefield is?
 

lynnedit

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My understanding is that horsfields are often rounder than other torts, so they can come out heavier in some of the tort length/weight calculations.

The Donaghue Ratio works for any tortoise species.
SCL*cm^3 x 0.191 = WTgr

(*Straight-line Carapace Length in centimeters, or SCLcm). To get this, push the tort up against a wall on a piece of paper. Mark the end of the shell and then remove tortoise and measure.

Scroll down on this thread for more info:
http://www.tortoiseforum.org/Thread-What-should-a-4-5-inch-2-3-yr-old-russian-weigh#axzz1nMYVfMpI
 

GeoTerraTestudo

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lynnedit said:
My understanding is that horsfields are often rounder than other torts, so they can come out heavier in some of the tort length/weight calculations.

The Donaghue Ratio works for any tortoise species.
SCL*cm^3 x 0.191 = WTgr

(*Straight-line Carapace Length in centimeters, or SCLcm). To get this, push the tort up against a wall on a piece of paper. Mark the end of the shell and then remove tortoise and measure.

Scroll down on this thread for more info:
http://www.tortoiseforum.org/Thread-What-should-a-4-5-inch-2-3-yr-old-russian-weigh#axzz1nMYVfMpI

^^Good post. :)
 

Merlin M

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ascott said:
WOW! Fancy stuff. I bet there are people here that would appreciate you duzint that excel....I wish I could begin to brag about how awesome I am in regards to keeping those type of records....BUUUUT yeah I can't. I am more of a pen and dog eared pad of paper with the torts name in the top....:D


To be fair I wan't before, but after the death of last tortoise slightly paranoid about getting everything right!!!

PS95 said:
That is a very clever formula. The left side of the formula calculates the approximate volume of the tortoise in cubic centimeters. It is necessary to multiply by 0.75 since a tort's body is not a perfect rectangular solid. The right side of the equation says that each cubic centimeter of a tort's body should weigh about 1 gram. This makes sense since the body of most animals is made up mostly of water, and 1 cubic cm of water weighs exactly 1 gram. Amazing! The question is, how do we know what the volume and weight for a horesfield should be, given its age? How do we know what the healthy weight for a horsefield is?

Yeah that is something I just haven't been able to find out!!!
 

wosman

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not to piggyback on this thread.

But when I got my tortoise last year he was 400 grams. Now he's 500.

I did the equation with SLC^3 x 0.191. and he should apparently be 200 grams ish..

Did I use this equation wrong because my god if my tortoise is meant to be 200 grams then I am REALLY over feeding him
 

lynnedit

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I can't imagine your tort is that far off. I am sure you are doing a fine job with him.
Are you measuring his length correctly?
 

wosman

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lynnedit said:
I can't imagine your tort is that far off. I am sure you are doing a fine job with him.
Are you measuring his length correctly?

I am measuring his carapace length using a ruler, but I am not bending the ruler to match the curve of his shell. comes out to be 4.5 inches (11.43 cm)
sorry so he should be 300 grams ish.
 

lynnedit

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Just to be sure: it is better to measure the bottom of the tort. Put him with his (retracted) head right against a wall or fixed edge on a large enough piece of paper. You want to measure the bottom shell only (head not included). Mark the opposite end on the paper and then measure the length. Might be close to what you are getting, but more accurate.
 

wosman

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^ it turned out to be the same :(

Man, now i have to get this fatty running and exercising. The weather isn't good enough to put him outside and thats really the only time he will run around and play.
 

GeoTerraTestudo

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GeoTerraTestudo said:
lynnedit said:
My understanding is that horsfields are often rounder than other torts, so they can come out heavier in some of the tort length/weight calculations.

The Donaghue Ratio works for any tortoise species.
SCL*cm^3 x 0.191 = WTgr

(*Straight-line Carapace Length in centimeters, or SCLcm). To get this, push the tort up against a wall on a piece of paper. Mark the end of the shell and then remove tortoise and measure.

Scroll down on this thread for more info:
http://www.tortoiseforum.org/Thread-What-should-a-4-5-inch-2-3-yr-old-russian-weigh#axzz1nMYVfMpI

^^Good post. :)

Once again, I have to say, "Good post." My male Russian lost quite a bit of weight in hibernation this past winter, and I think it's because he wasn't heavy enough going in to begin with. According to the Donohue formula, he was supposed to be 145% above the minimum weight, so I thought he was in fine condition. However, he didn't brumate deeply, lost weight, and became depleted of vitamin A and developed dry-eye. He's fine now after some TLC, but I am letting him pig out as much as he wants to, so he can gain more weight. The female weighed 156% of the minimum according to the Donohue formula, which apparently was enough of a difference to keep her well.

As Lynn wisely mentioned above, I think that the Donohue formula was devised for tortoises with more average body shapes, which are not particularly long (redfoot), flat (pancake), or short (Russian). I think that with the Donohue equation, Russians seem to be higher above the minimum weight than they really are, simply because of their rounder body shape. Next year, I won't let my guys hibernate unless they weigh more like 200% of the Donohue minimum, to compensate for this effect.
 

lynnedit

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wosman said:
^ it turned out to be the same :(

Man, now i have to get this fatty running and exercising. The weather isn't good enough to put him outside and thats really the only time he will run around and play.

GeoTerra Testudo makes some good points, interesting observations about your hibernation experience! (that will certainly help me next year).
So if Mango looks good, and isn't bulging out of his shell, then I wouldn't change a whole lot about what you are doing. The Donaghue Ratio is good, but I still think Russian torts come out on the 'heavy' end, when they really are not.
I think torts know what they need. See how he does over the summer when he is outside and running around. Might be that it averages out. If you want to be sure, post a pic or two of him to be sure.
 
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