Serological evaluation of ovarian steroids of red-rumped agouti (Dasyprocta leporina) during the estrous cycle phases

- The mean length of the estrus cycle was 31 days with diestrus being approximately 19 days.
- Vaginal cytological methods corresponded to expected changes in serum P4 and E2.
- Within each estrous cycle, three E2 peaks were demonstrated; in estrus and also in proestrus and metestrus.
- Varying concentrations of serum P4 and E2 can be used to classify distinct phases of the estrous cycle in the Agouti.

The objective of this study was to evaluate serum progesterone (P4) and 17β estradiol (E2) concentrations throughout the estrous cycle in the red-rumped agouti (Dasyprocta leporina). A total of eight multiparous, captive-bred females were bled throughout their estrous cycle via saphenous venipuncture, with E2 and P4 concentrations being measured via ELISA of the serum collected. Serum E2 ranged from 1212 to 3500 pg/ml with a peak value coinciding with observed estrus. However, two additional peak values for E2 were also recorded, one each in metestrus and proestrus respectively. P4 concentrations reached a maximum of 4.23 ng/ml, and increases in P4 immediately followed the second E2 peak in metestrus. The highest concentrations of P4 were recorded in mid diestrus; between days 23-25 of the 31-day cycle. This phase was the longest in the agouti, consisting of approximately 19 days and accounted for 61% of the cycle. This study increased the basal scientific reproductive knowledge of this potentially valuable neo-tropical species.