Chitin Levels in Roaches

[blondebrowncoat]

I've read a lot about how mealworms are terrible for herps with one of the reasons being their high chitin levels. While cutting up some larger roaches today for my cham (still hand feeding due to previous neglect) I realized just how friggin hard their exoskeletons are.

Is this ok? Have you guys had problems with digestion etc? I know nutritionally they are way better than meal worms as far as vitamin levels/gutloading capacity etc. I am just speaking from a pure digestion point, wouldn't these be rough on the digestive tract?

Thanks for any facts/opinions/speculation.

 

[Syreptyon]

I think... And this is just conjecture, but I think that one of the major differences may be that roaches are super meaty on the inside, whereas mealworms have practically no internal substance. Therefore the ratio of chitin:"meat" is WAY higher in mealworms. So when you feed roaches, the chitin gets "diluted" by the useful protein, which is then easier on their digestive tract

 

[jamest0o0]

Wait lol, why are you cutting up roaches again??

And my main issue with mealworms is that they have pretty much no nutrition. I don't think a healthy cham will be impacted by them, but I also think a lot of them could make digestion a little difficult while providing nothing in return. It's just one of those 'why risk it/why bother' things.

 

[blondebrowncoat]

@jamest0o0 I'm having to hand feed a rescue (tongue isn't working well). He isn't crazy about roaches but I have to get some variety in his diet. So, I'm cutting off their heads and parts of their exoskeletons because he refuses to chomp them unless they are simi-soft (cricket texture or softer)... Rereading that, wow. Friggin brutal. lol. What has my life become...

It got me thinking about the whole chitin conversation.

@Syreptyon That's kind of what I was thinking may be the case. Good thinking!

 

[jamest0o0]

Sounds like a roach horror movie

 

[JacksJill]

When I look at fecals other than legs and mandibles I don't find many recognizable insect parts. I feed mostly dubia, superworms, crickets with some other soft bodied insects I don't think would make it thru.

 

[insectovore]

Unfortunately, there is a lot of misinformation on feeder insects. I suggest you read the research by a guy named Finke if you want to get really good information on the actual nutritional content of feeder insects. Many species are literally what they eat. So if you measure something raised in bran, it is going to look terrible. On the other hand, you take that some species in an appropriate gutload and it will have the right levels of the typical suspects ca, vitamin A, etc

 

[jamest0o0]

@insectovore

Edit: just skimmed through some things by finke, i see what you're talking about though. can you link the one you're talking about in particular?

 

[insectovore]

I've started putting together an article on feeder insect nutrition but it's just getting started. Here's what I've got so far in draft and lots of linked sources. Keep in mind that I have not proof read this yet so there could be mistakes, typos, etc.


Calcium, Availability, and Gutloading
Insects are invertebrates and most species do not contain very much calcium compared to vertebrates which have large amounts of mineralized bones (Finke & Oonicx, 2014). However, some species such as isopods and black soldier fly larvae do have mineralized exoskeletions (Finke & Oonicx, 2014). I have noted that some of the salamanders I fed black soldier fly larva to would sometimes pass the exoskeleton largely undigested. Finke and Oonicx (2014) note that mountain chicken frogs digested only 44% of black soldier fly larvae fed to them live, but that number went up to 77% when the larvae were mashed. The calcium levels of many feeder insects can be raised through gutloading. Research has shown that crickets fed calcium enriched diet contain significantly more calcium than crickets fed the same diet with less calcium (Finke, Dunham, & Kwabi, 2005). Diets with 65g Ca/kg and higher of calcium were found to produce insects with significantly higher calcium content. Finke also found that most commercially available gutloads that he tested did not actually contain the amount of calcim listed on the label. Particle size may also play a role as a finely ground diet with 65 Ca/kg versus a thicker particle size diet with 103g Ca/kg did not result in the proportionate increases in calcium content that one might expect. The higher 103g Ca/kg diet produced small cricket nymphs with only 8% higher calcium amounts and adult crickets with 30% higher calcium amounts (Finke et al., 2005). Based on the mixed results of actual contents of commercial gutloads and the impressive results from gutloading with a calcium enriched feed, I would recommend reptile keepers boost their cricket gutload to at least 65g Ca/kg 48 hours prior to being used as feeders. Such high calcium diets may affect the normal lifecycle of insects, thus the recommendation to feed them the special diet in a separate, small contain 48 hours prior to feeding them to reptiles. Costs to reptile keepers will be minimal as calcium is inexpensive.

Caroteniods, Vitamin A, and Insects
Caroteniods are found at higher levels in wild caught insects than captive reared (Finke & Oonicx, 2014). It is unclear which insectovores can convert these caroteniods into Vitamin A (Finke & Oonicx, 2014). In many insects these caroteniods are stored in the eyes of the insects and larval forms tend to have less eye material than adult forms. However, increasing caroteniod content in fruit fly medium did result in adult flies with increased caroteniod content (Finke & Oonicx, 2014). Dugas, Yeager, and Richards-Zawacki (2013) added 1.4g spirulina, .7g powdered marine algae, and .7g red phaffia yeast as a carotenoid source to 16.7g dehydrated potatoes, 3.7g Brewers yeast, 4.9g Confectioner's sugar, 2.7g Methlparaben, .3g bakers yeast, and 80g tap water. Pairs of dart frogs fed on the carotenoid supplemented diet produced fewer clutches but more tadpoles and metamorphs than pairs kept on an unsupplemented diet (Dugas, Yeager, and Richards-Zawacki, 2013).

Other Vitamins and support for a varied diet
Finke & Oonicx note that Vitamin E levels appear to be low in captive reared insects and the diet may be a factor as different studies have shown different amounts even for the same species (2014). However, butterworm larvae, silkworm larvae, fruit flies, and house flies all tend to contain higher levels of vitamin E (Finke & Oonicx, 2014). With Vitamin B1, both wild and commercially reared insects varied greatly in thiamine content. House crickets, butterworms, red runner roaches, and superworms had low levels of thiamine, while mealworm larvae (but not adults), waxworms, silkworms, adult house flies, and black soldier fly larvae contained higher levels.


Chitin
Look on any lizard or amphibian forum and you'll soon see discussions about chitin content in various insects. Unfortunately, much of the information on the subject found on the Internet appears to be incomplete. Finke (2007) found the chitin content actually appeared to be higher as measured in mg/kg in crickets than in giant mealworm larvae or waxworms. Furthermore, Finke (2007) found that the hardness of insects exoskeletons appeared to be related to factors other than chitin content, such as a higher concentration of ammino acids. In my own personal experience, I have found that if a particular insect exoskeleton can truly not be digested, you will see that in the feces. It seems that the digestability of insect exoskeletons is more complicated than whether or not they contain a certain amount of chitin.

Dugas, M. B., Yeager, J., & Richards-Zawacki, C. L. (2013). Carotenoid Supplementation Enhances Reproductive Success in Captive Strawberry Poison Frogs (Oophaga Pumilio). Zoo Biology, 3, 655–658.
Finke, M. (2007) Estimate of Chitin in Raw Whole Insects. Zoo Biology, 26, 105–115.

Finke, M. D., Dunham, S.U., & Kwabi, C.A. (2005). Evaluation of Four Dry Commercial Gut Loading Products for Improving the Calcium Content of Crickets, Acheta domesticus. Journal of Herpetological Medicine and Surgery, 15(1),7-12. https://doi.org/10.5818/1529-9651.15.1.7

Finke, M., & Oonicx, D. (2014). Insects as Food for Insectivores. In J.A. Morales-Ramos (Ed.), Mass Production of Beneficial Organisms (pp.586-616). Cambridge, MA: Academic Press.

 

[jamest0o0]

Running around atm, but I appreciate that response @insectovore going to read through it asap!

 

[nightanole]

https://dubiaroachdepot.com/guidance/dubia-roaches-vs-other-feeder-insects

Still want to know where the "mealworms are EEEEEEEvil" comes from.

No nutritional value, very large amounts of chitin.

Really? They are higher in fat and lower in protein vs dubia, but too high of protein is not good for chams either. On top of that the whole theory that they have mad amounts of chitin and should be fed in moderation to prevent impaction, well they still have half the amount vs crickets...

If you go by the chart, supers have 3x less chitin vs silkies.

 

[jamest0o0]

^You're going by percentages though. Mealworms are much smaller. Chams are going to need to eat many mealworms to = that of a cricket or roach.

that said, I don't buy into the chitin causes impaction thing. I just don't feed mealworms because they don't gutload well and are too small and insignificant to be bothered with. If chameleons can eat dirt, leaves, etc(which I've witnessed mine do) and pass it fine, there's no reason they shouldn't be able to pass mealworms. Just like humans should be able to eat fiber without problems. I think a lot of these impaction fears come from a time when chameleons and reptiles were getting sick/dehydrated due to poor husbandry and then had trouble digesting random things. Leading people to blame mealworms, substrate, etc for their animal's death.

 

[nightanole]

^You're going by percentages though. Mealworms are much smaller. Chams are going to need to eat many mealworms to = that of a cricket or roach.

that said, I don't buy into the chitin causes impaction thing. I just don't feed mealworms because they don't gutload well and are too small and insignificant to be bothered with. If chameleons can eat dirt, leaves, etc(which I've witnessed mine do) and pass it fine, there's no reason they shouldn't be able to pass mealworms. Just like humans should be able to eat fiber without problems. I think a lot of these impaction fears come from a time when chameleons and reptiles were getting sick/dehydrated due to poor husbandry and then had trouble digesting random things. Leading people to blame mealworms, substrate, etc for their animal's death.

Yup, you have to wonder about the scientist who do these things. They weighted a starved meal worm, and a completely gut loaded meal worm. What they found was that up to 10% of a meal worms body weight could be gut load. By comparison i think crickets where 25% and dubia 33%. I still cant find the study, i lost alot of papers from 5-6 years ago.