Fecal progestagen evaluations to monitor the estrous cycle and pregnancy in the okapi (Okapia johnstoni)

Abstract

AbstractThe present study was conducted to establish a noninvasive method of reproductive monitoring in the okapi (Okapia johnstoni). Fecal samples were collected three times a week from nonpregnant okapis (n = 3) for periods of 2, 9, and 23 months, respectively, and for 2 months each from pregnant okapis (n = 4) at different stages of gestation. Samples were analyzed with an enzyme‐immunoas‐say (EIA), using an antibody against pregnanediol, and the results are considered as measurements of unconjugated total immunoreactive progestagens (Pd‐Pgs). Mean values of Pd‐Pgs during the follicular (FP) and the luteal phases (LP) of the estrous cycles were 0.6 ± 0.1 μg/g and 6.1 −0.3 μg/g feces, respectively. Matings occurred at the terminations of the LP. By dividing the number of entire LPs into the time over which samples were available, average estrous cycle lengths in two okapis were estimated to be 15.5 (n = 11 LP) and 15.8 (n = 36 LP) days, respectively. In three animals, gestation lengths of 423, 424, and 431 days were calculated by observed matings. During days ‐280 to ‐220 before parturition, the fecal Pd‐Pgs constantly increased from about 20‐‐60 μg/g fecès. Values were 100‐‐350 μg/g during the last third of gestation. Values decreased in the week before parturition, and a continuous decline to FP values was observed within 3‐‐4 days postpartum. During the 2 months postpartum investigated in one animal, the Pd‐Pgs were in the FP range except one LP 3 weeks postpartum. It was concluded that fecal Pd‐Pgs in female okapis are present in a ratio of ∼1: 10:>100 during FP, LP, and late pregnancy, respectively. Their measurement by EIA enables noninvasive monitoring of the estrous cycle and pregnancy diagnosis. © 1993 Wiley‐Liss, Inc.