feeding a diet high in oxalates affecting egg fertility/viability?

baldegale

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does anyone know of any papers written about this topic or research done? bonus points if geared towards galapagos tortoises.
 

Markw84

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I don't know of any papers specifically on that subject.

However, high oxalates would normally affect the amount of free calcium available in the diet. If the foods with high oxalates are not compensated for with other foods with ample calcium, there could be an issue with the tortoise becoming hypocalcemic. As long as the total calcium available in the total diet is high enough to overcome this, it should be of no concern.

Egg laying does demand good calcium availability. This would come from the diet, or can come from the bones as the body in hypocalcemic animals will release calcium to compensate. This could lead to thin eggshells, and/or metabolic bone issues. So those would be the issues I would be concerned about and look for.

I see no way oxalates would directly affect fertililty. However, calcium is required for most all body functions. So if the signs of hypocalcemia are there, I would be concerned.

I do believe young tortoises, and galapagos in particular have quite a high need for calicum as their young bodies spend a great deal of metabolic energy ossifying the new bones. So I would ensure to watch the oxalate level and more importantly the ratio of oxalates to free calcium in the diet.
 

baldegale

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Feb 14, 2017
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I don't know of any papers specifically on that subject.

However, high oxalates would normally affect the amount of free calcium available in the diet. If the foods with high oxalates are not compensated for with other foods with ample calcium, there could be an issue with the tortoise becoming hypocalcemic. As long as the total calcium available in the total diet is high enough to overcome this, it should be of no concern.

Egg laying does demand good calcium availability. This would come from the diet, or can come from the bones as the body in hypocalcemic animals will release calcium to compensate. This could lead to thin eggshells, and/or metabolic bone issues. So those would be the issues I would be concerned about and look for.

I see no way oxalates would directly affect fertililty. However, calcium is required for most all body functions. So if the signs of hypocalcemia are there, I would be concerned.

I do believe young tortoises, and galapagos in particular have quite a high need for calicum as their young bodies spend a great deal of metabolic energy ossifying the new bones. So I would ensure to watch the oxalate level and more importantly the ratio of oxalates to free calcium in the diet.
were trying to figure out a hatch rate problem more than anything, me and someone else believe its a diet problem, trying to find actual documented papers to prove it to someone else cause that's the only thing that theyll listen to lol
 

Markw84

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were trying to figure out a hatch rate problem more than anything, me and someone else believe its a diet problem, trying to find actual documented papers to prove it to someone else cause that's the only thing that theyll listen to lol
I know! Especially when it comes to Galapagos, most people involved end up being institutions and long-time keepers who are very reluctant, or simply untrusting, to most anything but the old, and out of date info on tortoise husbandry. They want all the proof for newer ideas, despite ample examples of it working, yet have no positive proof that what they are currently doing is correct. In fact, most situations we see - the experience should tell them something's wrong!

I'm sure you've gone through everything, but how old is the male? Is he nicely concave? Do you know the genetics? So many Galaps outside of the Galapagos are hybrids now and that in itself can lead to fertility issues. Males seem to mature much later than most tortoises. As with Aldabras, it seems the concavity must develop substantially to successfully mate. Some males can produce very fertile results while others have quite low fertility. Anecdotally, it seems a group will produce much better results than a pair or trio.
 

baldegale

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I know! Especially when it comes to Galapagos, most people involved end up being institutions and long-time keepers who are very reluctant, or simply untrusting, to most anything but the old, and out of date info on tortoise husbandry. They want all the proof for newer ideas, despite ample examples of it working, yet have no positive proof that what they are currently doing is correct. In fact, most situations we see - the experience should tell them something's wrong!

I'm sure you've gone through everything, but how old is the male? Is he nicely concave? Do you know the genetics? So many Galaps outside of the Galapagos are hybrids now and that in itself can lead to fertility issues. Males seem to mature much later than most tortoises. As with Aldabras, it seems the concavity must develop substantially to successfully mate. Some males can produce very fertile results while others have quite low fertility. Anecdotally, it seems a group will produce much better results than a pair or trio.
we have 7, one male and 6 females, all have been raised with the owner since they were babies. (were raising up more aswell) the breeders are all roughly 35 years old and have only produced i believe the last 5-6 years. i dont personally know the genetics but i know he does, also dont personally know the concavity. we had about a 30% hatch rate this year and i think up to 50% other years
 
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