RESUMO
There has been no study aimed at directly determiningof the periods of Sertoli cell proliferation in birds evendomestic fowl. The aims of this study were to observe thecessation of post-hatching mitotic proliferation of Sertolicells in domestic fowl, and to determine the volumedensity of Sertoli and germ cells during this period. Atotal of 50 Leghorn chicks were used in this study. Thetestes sections of the animals were immunostained withBrdU to observe the proliferation of cells from one to 10weeks of age. The volume density of the Sertoli and germcells were determined using the standard point countingmethod. The volume density of the germ cell nuclei wasinitially less than that of the Sertoli cells but the volumedensity converged by week 6, and remained relativelyconstant until the commencement of meiosis. Clearlabeling of Sertoli and germ cells was observed from week1 to week 7. The only those cells still labeled after 8 weekswere germ cells, indicating that Sertoli cell proliferationhad ceased. Therefore, it is recommended that anyresearch into the testes of domestic fowl should considerthe cessation of Sertoli cell proliferation by approximately8 weeks.