jarich
12-07-11, 10:45 AM
After doing some research, I thought I would try to post something here regarding feeder animals and the importance of what is fed to them. It is very common for keepers to buy prey animals from their local pet store and then feed them immediately upon coming home. This provides a poor nutrition source for reptiles and amphibians, and should be adapted to better supply them with the nutrients they need. More and more, keepers are breeding their own feeder items and therefore gaining more control over what the prey consumes, and by direct correlation, the prey items nutritional value for their reptiles. When it comes to prey animals, the old adage is true, "You are what you eat".
The first thing to discuss is the general care given to prey animals at the normal source, the local pet store. Luckily, for rodents and mammalian prey items there seems to be more care given, as these prey items die easier. I surveyed 10 local pet stores in the NYC area and found that all of them fed their rodents dry cat or dog food and provided clean water at all times in dripper bottles. While the nutritional value of cheap dry pet food is debatable (I didnt ask the type but Im guessing it was the cheap stuff), at least these animals are well watered and nourished in some sense.
However, invertebrate diets were not so good. Of the ten I surveyed, 6 fed their inverts a potato half, 1 a carrot and the others gave them no food or water item at all. Only one store put any kind of separate water source in with their invertebrates, and that one only with the crickets. Pet stores generally order once or twice a week, with the idea that all prey items are sold in that amount of time. Accordingly, they offer little to the insect.
What this means is that the cricket, mealworm or other invertebrate you are getting from your pet store is extremely dehydrated and probably ravenously hungry. This also means that they hold a very reduced nutritional value. Remember, the insect came from a breeding farm somewhere, so they also travelled for a couple days before getting to your local pet store. That means for many feeder invertebrates it may possibly have been a week or more since they last had food and water.
What this means for you as a keeper is that there are some things that need to be done before you feed pet store bugs to your reptile or amphibian. They arent fun if you dont like messing with invertebrates, but they are necessary to keep your reptile or amphibian healthy over time. First off, and perhaps most important, buy them a day in advance. This will give you time to nourish the insect so that they in turn can nourish your reptile.
At the very least, we need to get them some water and rehydrate them. While you can provide them with water crystals or a wet paper towel, the best way to do this is to give them a nice wet meal. For the sake of nutrients, there are some good combinations out there, green beans and kale being some great examples. They are normally pretty cheap, easily available, and you can eat the rest yourself if you have extra! Make sure to wash them thoroughly before feeding them to the invertebrates as many veggies have pesticides sprayed onto them at some point or another. Once they are washed, you can put it straight in with the bugs and reseal the container. In my area, crickets are normally sold in plastic bags. If this is the case for you as well, you will need to shake off any excess water from the vegetables, so that it does not run off into the bottom and drown the bugs. They will munch on the veggies and then get both water and precious vitamins and minerals for your reptile to later ingest.
It is good to do this 24 hours prior to feeding them to your reptile or amphibian so that the invertebrate is both well hydrated and also has time to digest the plant matter, thus incorporating the vitamins and minerals into its body. Most carnivorous reptiles can not digest plant matter, so if you feed the insects right away this undigested plant matter from the bugs will simply pass through your reptile. They wont be able to get the nutrients from that plant matter, so it would be a wasted effort without enough time for digestion in the invertebrate. Vitamin and mineral supplements can be added to the diet of the invertebrates to increase their calcium, phosphorous, and other vitamin/mineral levels. Keep in mind however that anything higher than about 12% calcium will be fatal to invertebrates.
If wet foods are simply not possible for you to feed the invertebrate prey then simple nutritious foods can be offered with vitamin/mineral supplements added. The easiest of these would be a mix of oats, whole grain flour, and ground corn. You can buy these foods in bulk for a cheap price and have available at all times to give your invertebrate prey as you buy them.
Also, keep in mind that with insectivorous reptiles and amphibians, the more varied diet the better. Try not to just feed it one type of insect only. Each of them have different nutritional values, so a varied diet will help your animal to be as healthy as it can be. Be creative; one of the healthiest invertebrates to feed is often not sold in pet stores - the earthworm. This is actually the only feeder invertebrate that requires no calcium/phosphorous supplementation. They naturally have both the right amount and the right ratio for reptiles and amphibians. However, only certain animals will eat these little gems unfortunately. The point, though, is to try to give your animal as much variety as it will allow.
I hope this will open up some further discussion on the topic, and here are a few easy to read and well written articles that discuss feeder invertebrates and nutritional contents. If you would like further reading, each of those articles have quoted sources that are easily found online.
http://www.nagonline.net/Technical%20Papers/NAGFS00397Insects-JONIFEB24,2002MODIFIED.pdf
http://globalgeckos.com/articles/file_An%20Assessment%20of%20the%20Nutritional%20Co ntent%20of%20Feeder%20Insects_20101109081530.pdf
Complete nutrient composition of commercially raised invertebrates used as food for insectivores | Mendeley (http://www.mendeley.com/research/complete-nutrient-composition-of-commercially-raised-invertebrates-used-as-food-for-insectivores/)
http://www.academicjournals.org/AJB/PDF/pdf2006/2Feb/Banjo%20et%20al.pdf
The first thing to discuss is the general care given to prey animals at the normal source, the local pet store. Luckily, for rodents and mammalian prey items there seems to be more care given, as these prey items die easier. I surveyed 10 local pet stores in the NYC area and found that all of them fed their rodents dry cat or dog food and provided clean water at all times in dripper bottles. While the nutritional value of cheap dry pet food is debatable (I didnt ask the type but Im guessing it was the cheap stuff), at least these animals are well watered and nourished in some sense.
However, invertebrate diets were not so good. Of the ten I surveyed, 6 fed their inverts a potato half, 1 a carrot and the others gave them no food or water item at all. Only one store put any kind of separate water source in with their invertebrates, and that one only with the crickets. Pet stores generally order once or twice a week, with the idea that all prey items are sold in that amount of time. Accordingly, they offer little to the insect.
What this means is that the cricket, mealworm or other invertebrate you are getting from your pet store is extremely dehydrated and probably ravenously hungry. This also means that they hold a very reduced nutritional value. Remember, the insect came from a breeding farm somewhere, so they also travelled for a couple days before getting to your local pet store. That means for many feeder invertebrates it may possibly have been a week or more since they last had food and water.
What this means for you as a keeper is that there are some things that need to be done before you feed pet store bugs to your reptile or amphibian. They arent fun if you dont like messing with invertebrates, but they are necessary to keep your reptile or amphibian healthy over time. First off, and perhaps most important, buy them a day in advance. This will give you time to nourish the insect so that they in turn can nourish your reptile.
At the very least, we need to get them some water and rehydrate them. While you can provide them with water crystals or a wet paper towel, the best way to do this is to give them a nice wet meal. For the sake of nutrients, there are some good combinations out there, green beans and kale being some great examples. They are normally pretty cheap, easily available, and you can eat the rest yourself if you have extra! Make sure to wash them thoroughly before feeding them to the invertebrates as many veggies have pesticides sprayed onto them at some point or another. Once they are washed, you can put it straight in with the bugs and reseal the container. In my area, crickets are normally sold in plastic bags. If this is the case for you as well, you will need to shake off any excess water from the vegetables, so that it does not run off into the bottom and drown the bugs. They will munch on the veggies and then get both water and precious vitamins and minerals for your reptile to later ingest.
It is good to do this 24 hours prior to feeding them to your reptile or amphibian so that the invertebrate is both well hydrated and also has time to digest the plant matter, thus incorporating the vitamins and minerals into its body. Most carnivorous reptiles can not digest plant matter, so if you feed the insects right away this undigested plant matter from the bugs will simply pass through your reptile. They wont be able to get the nutrients from that plant matter, so it would be a wasted effort without enough time for digestion in the invertebrate. Vitamin and mineral supplements can be added to the diet of the invertebrates to increase their calcium, phosphorous, and other vitamin/mineral levels. Keep in mind however that anything higher than about 12% calcium will be fatal to invertebrates.
If wet foods are simply not possible for you to feed the invertebrate prey then simple nutritious foods can be offered with vitamin/mineral supplements added. The easiest of these would be a mix of oats, whole grain flour, and ground corn. You can buy these foods in bulk for a cheap price and have available at all times to give your invertebrate prey as you buy them.
Also, keep in mind that with insectivorous reptiles and amphibians, the more varied diet the better. Try not to just feed it one type of insect only. Each of them have different nutritional values, so a varied diet will help your animal to be as healthy as it can be. Be creative; one of the healthiest invertebrates to feed is often not sold in pet stores - the earthworm. This is actually the only feeder invertebrate that requires no calcium/phosphorous supplementation. They naturally have both the right amount and the right ratio for reptiles and amphibians. However, only certain animals will eat these little gems unfortunately. The point, though, is to try to give your animal as much variety as it will allow.
I hope this will open up some further discussion on the topic, and here are a few easy to read and well written articles that discuss feeder invertebrates and nutritional contents. If you would like further reading, each of those articles have quoted sources that are easily found online.
http://www.nagonline.net/Technical%20Papers/NAGFS00397Insects-JONIFEB24,2002MODIFIED.pdf
http://globalgeckos.com/articles/file_An%20Assessment%20of%20the%20Nutritional%20Co ntent%20of%20Feeder%20Insects_20101109081530.pdf
Complete nutrient composition of commercially raised invertebrates used as food for insectivores | Mendeley (http://www.mendeley.com/research/complete-nutrient-composition-of-commercially-raised-invertebrates-used-as-food-for-insectivores/)
http://www.academicjournals.org/AJB/PDF/pdf2006/2Feb/Banjo%20et%20al.pdf