No sugar for tortoises?

[ryan57]

I wonder if anyone has conducted experiments with cultures of small and large intestine to determine and resolve the suggested intake of each (sugar and fiber) in grams? Is there any data or only conjecture?

Mine seems to enjoy berries and figs to a watermelon but on the two occasions of having watermelon, there was much more interest in the tug of war with thin rind of the smaller round melons.

 

[jaizei]

I would imagine it’s more the ratio of sugar to fiber. Watermelons are mostly water, and if we are talking about the actual fruit itself and not just the rind, it has extremely little fiber. Grass is 15 percent sugar, but from what I can find, it’s 35 to 50 percent fiber. This is why I say it’s not comparable. The grass takes much longer to digest than something like a watermelon that is basically just sugar water, so you don’t run as much of a risk of digesting too much sugar too quickly.

Along this line, the numbers for watermelon nutrition almost certainly includes the water in the 'serving size' whereas the grass numbers are possibly based on dry matter. apples to apples, (dry matter) the sugar content for the watermelon is probably much higher than the grass.

This lists 57g of dried watermelon as having 34g of sugar. 59.65% sugar

 

[jaizei]

But I generally agree that the way this forum talks about sugar as some boogeyman is misguided. Its the same idea as goitrogens, or oxalates, or protein where some sites goldilocks themselves into ultra limited diets. I don't think twice about including fruit in reasonable amounts.

 

[TammyJ]

 

[The_Four_Toed_Edward]

He may be referring to the plantain plant which is a weed rather than the plantain fruit like a banana.

Yep, I was referring to the plantain plant (weed)

 

[ryan57]

Yep, I was referring to the plantain plant (weed)

Large one eats these all the time. It's a staple in their enclosure.

 

[Pattjunior]

Maybe you should start a thread about this in the debateable section stating your views? I would like to chime in but don't want to go completely off topic here.
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I can definitely see how older, outdated information about tortoise keeping has circulated for years. In the interest of not parroting the same disinformation about sugar and sugary foods I would like to open a discussion beginning with the fact that grass is a sugary food. Where does the fuel for fermentation of alcohol come from in the brewing process? Right.

I have heard on this forum that tortoises can't process sugar. Well, due to the sugar content in the majority of their diet, they absolutely must be able to do something with the sugar because that's what they eat and live a century.

I try not to but if I had a scrap I wouldn’t have any heart burn throwing it in to my galaps or stars.

 

[Mad_Moose]

Really interesting topic to consider - Grasses in general have a high amount of variability in the amount of sugar, digestibility of said sugars and can often be too high in sugars for animals that are well designed to digest it (i.e bloat in ruminants and founder in horses)
In mammal nutrition we often use the term NSC for non structural carbohydrates to talk about sugars in both grains and hays. Sometimes grasses on pasture or hays can get as high as 25% NSC if not higher if you have a late freeze during the early growth periods, which causes problems even for animals well adapted to foraging (in horses founder, colic, in ruminants, bloat, acidosis)

In general, stemmy hays are lower sugar, while hays with lots of leaf matter tend to be higher in sugar content. After grasses have gone to seed, there's minimal sugar left in the actual stem and leaf of the plant (which is why grazing stubble fields is common) (I have a diagram from a textbook of the nutritional content vs stage of grass growth somewhere, I'll look for it)

Whenever forages are digested, the three steps to getting high efficiency nutrient absorption are a) mastication (physically breaking the forage down by chewing) b)fermentation c) chemical digestion, even if a grass is measured at having high sugar content, there's no guarantee that the animal is actually breaking it down enough to get use of all of those sugars

I have yet to find reliable sources for tortoise digestion so this is a lot of conjecture on my part!
I would assume that there isn't much mechanical digestion happening, tortoises seem to have the strategy of just cutting their forage when they initially bite, they aren't sitting there doing a lot of chewing on the items they eat, so there's not much physical breaking down of the cellulose, which is what actively impedes access and digestion of the cell solubles (where those carbs are located), so they'd primarily be working with how much their stomach acid does + whatever fermentation happens in the hind gut, if there's not much. Compared to a fruit, where the sugars are easy access, I'd have to assume that the cellulose in the forage keeps the amount of sugar actually accessed by the gut flora to a minimum, since they would be the ones breaking into the cells (instead of it being handed to them on a silver platter)

 

[The_Four_Toed_Edward]

Thank you for chiming in! I do wonder how much of the sugar in hay tortoises can actually digest?