Comparative study between isolation techniques and PCR for mycoplasma and ureaplasma diversum detection in preputial mucus and semen from bulls used in natural breeding and AI centers - Cardoso, M; Teixeira, S; Miyashiro, S; Vasconcellos, Silvio Arruda; Scarcelli, E; Genovez, M (World Buiatrics Congress, 2004)