Abstract
To monitor reproductive status in female and male addax (Addax nasomaculatus) non-invasively, fecal reproductive steroid hormones were evaluated. Feces and blood were collected from three females and one male. Fecal contents and serum concentrations in progesterone (P_4) of the females and testosterone (T) of the male were determined by enzyme immunoassays. The changes in fecal P_4 contents during non-pregnancy and pregnancy showed the same tendency to changes in serum P_4 concentrations. There was a significant positive correlation between fecal and serum P_4 values (r=0.77, P<0.01). However, the profile of fecal T contents did not reflect the changes of the serum T concentrations in the male. A sequence of sexual behaviors as tenacious tracking, courtship and mounting by the male were observed around the time when P_4 values were basal in the female. Estrous cycle length was 28.4±0.4 days (n=5) based on the P_4 profiles. Fecal and serum P_4 values continued to rise gradually during the pregnancy. Fecal P_4 contents had reached a peak one week before parturition and then decreased rapidly. Fecal P_4 reached the basal level 3-5 days after parturition. Estrous cycles in one female recurred about 2 weeks after parturition, whereas in another female recurred about 3 months after parturition. Estrus recurrence in the latter female occurred immediately after cohabiting with a male. It was suggested that the fecal P_4 assay was quite a useful technique to determine the estrous cycle, evaluate the ovarian activity and diagnose or monitor the pregnancy.
