A South African company is breeding maggots specifically for use in poultry feeds. Here are some news articles:

http://www.scienceinafrica.com/biotechnology/environmental/biorecycling-flies

http://www.howwemadeitinafrica.com/south-african-company-finds-economic-value-in-flies-and-maggots/21463/

http://www.farmersweekly.co.za/news.aspx?id=30113&h=Turningapestintoprotein

Insects can be vectors for many parasites, as well as many organisms that induce disease.  I would strongly caution against it, but that is simply my experience as a zoo vet

I think the subject needs more research, we are at the begining of the subject and days will tell more information, all therotical and partical points are wellcome  

Thanks for answering. I think the insect protein is very low digestible. The birds are very  sensitive about ingredients that fed. If this theoretical is true, we must doing more research about that. 

please read the recently All About Feed published white paper on Insect Meal (Why Insects are not allowed in feed?). in the article the advantages, disadvantages, where we are presently and what need to be done were highlighted.  i believed there yet more work to be done in the area of breeding & waste materials for the breeding of the insects, purification processes, and more importantly in the area of ehics and legislation.

I strongly agree about the last two comments 

If grown in controlled condition, can be used for feeding. The Spirurids (nematodes) are transmitted due to eating of IH (vector). It will be important source of protein in future due to population explosion. Need research.....?

Wesley, all commercial feeds are mixed using natural ingredients harvested from a variety of sources (with the exception of urea and the micronutrients). Oilcake, molasses, chicken litter, corn, lucerne (alfalfa), soybeans, fishmeal, eragrostis, bran, etc. Protein sourced from insects won't be any different. Dried and ground maggots would be sold in bulk with a known protein content and mixed into commercial feed rations by feed distributors or feedlots the same way every other ingredient is mixed.

Insects are used in making animals feed but  with caution on how they are obtained to prevent transfer of disease causing organisms to the animals. some insects also contain a lot of ash as a result of the exoskeleton which makes digestibility of the feed difficult.

Considering availability of animal protein sources, exploration of new protein source, including insects, is needed. Some researchers already attempted to study the use of insect as animal feed, using various species as well as different live stage of insect but of course need to be further investigated. Things to considers if you use insect are its digestibility, stage of live, its culture as mentioned previously by Wesley M. Burnside, possible disease and toxic and economical aspects.  FAO apparently also concern about insects and to have overview of insects you can check http://www.fao.org/forestry/edibleinsects/84629/en/  

This is also useful information