The present invention consists in the design of an ELISA test, specific to determine through fecal feces, urine or plasma of birds, reptiles and mammals, the levels of concentration of the hormone testosterone as an indicator of masculine sex in these species for a better handling of the reproduction and the production of birds, reptiles and mammals. The procedure can be applied for practical purposes in any commercial operation that involves these species. With this method a greater efficiency and economic return is obtained, which reports improvement and greater benefits to the producers.
