The cloacal gland--an external indicator of testicular development in coturnix [Quail]

The quantitative relationship between cloacal gland size and testes weight during the stages of initial growth, involution and recrudescence is described. Cloacal gland foam was found to be a reliable indicator of testes size and function. The mean testes weight associated with the first presence of cloacal gland foam was 377 mg. and this occurred at a mean age of 29 days. The physical measurement of the cloacal gland provides a valuable noninvasive method of predicting testicular activity especially suited for long term experiments involving multiple measurements where a few coturnix may be used repeatedly (as their own control) rather than periodic killing of a large group of animals.