|MadSci Network: Zoology|
Dear Phyllis, The testicles of a rooster are located slightly above and forward of the kidneys which is well inside the abdominal region. The only efficient technique to castrate is to enter under the rib cage with a hooked probe and extract the testicles with the hook. The birds should be given a mild anesthesia to relieve any discomfort. This is done with great precision because the correct area of entry is very precisely "land-marked". This procedure is no longer performed on a large scale basis mainly because of changing production demands. It has also led to a misconception that a roosters testicles, or sex organs, are located under the wing. This is not altogether inaccurate, however they are also located inside the body cavity, which has led to this "wives-tale".
Try the links in the MadSci Library for more information on Zoology.