Turkistans lower moisture content, coupled with a nearly double the protein and ash content are possible contributing factors to that issue. In my opinion this reinforces the need to provide variety in an intelligent manner.
In combination with even just one other feeder type the values of the entire diet change quite alot. In the macronitrient realm protein content is almost always going to be reduced, and the types of amino acids that total combined protein value will average out. Same goes for fats, carbohydrates, and ash content.
Each insect even when fed an identical diet, converts their diet into a completely differing set of proteins, fats, etc.
While I have had good success using a single staple feeder, I have always had better results when feeding two or more feeder types, I do not shun the higher fat content feeders, rather I use their typically lower protein content as an averaging tool.
In general my opinion is that 20 - 22% protein is enough in the insectivorous reptiles diet, not that this is a hard and fast figure but rather the good average that covers most of my reptiles needs very well.
Crickets work well as feeders because they contain close to the right levels of protein. Their ash (mineral content) is half as much as most roaches, the result is complicated supplementation requirements.
Many who use a variety of feeders and fawn over their insects food and care use far less supplementation because the diet provides most everything that is required.
While I will fully agree with you that there is evidence that suggests that a very high protein site leads to issues in reptiles including those issues you have had direct experience with I maintain that a varied diet along with proper husbandry alloys the use of turkistan roaches as feeders.
Maurice Pudlo
