| Abstract: | Urinary levels of estrone sulfate (ES), indexed by creatinine (CR), were evaluated by a direct radioimmunoassay of four Malayan (Tapirus indicus) and one Brazillian (Tapirus terrestris) tapir pregnancies. Levels rose above baseline ES values of 20 ± 1.2 ng/mg CR (n = 200) in the Brazilian animal and 25 ± 1.3 ng/mg CR (n = 105) in the Malayan animals at approximately 7 months prior to parturition and continued to rise in both species until just before parturition. Quantitatively, levels rose 10-fold higher in the Brazillian animal than in the Malayan animals through approximately 1 month prior to parturition in both species. These findings indicate that routine urinary monitoring provides an accurate means for detecting pregnancy in tapirs and suggests differences in estrogen excretion patterns between tapir species and with other perissodactyls. |
