Variations in Phytoestrogen Content between Different Mill Dates of the Same Diet Produces Significant Differences in the Time of Vaginal Opening in CD-1 Mice and F344 Rats but Not in CD Sprague-Dawley Rats. - Thigpen, Julius E.; Setchell, Kenneth D. R.; Padilla-Banks, Elizabeth; Haseman, Joseph K.; Saunders, Hannah E.; Caviness, Gordon F.; Kissling, Grace E.; Grant, Mary G.; Forsythe, Diane B. (Environmental Health Perspectives, 2007)