Premium
Reproductive and hormonal changes during the estrous cycle and pregnancy in Asian elephants ( Elephas maximus )
Author(s) -
Mainka S. A.,
Lothrop C. D.
Publication year - 1990
Publication title -
zoo biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.5
H-Index - 54
eISSN - 1098-2361
pISSN - 0733-3188
DOI - 10.1002/zoo.1430090602
Subject(s) - estrous cycle , elephas , luteal phase , biology , endocrinology , estrogen , medicine , pregnancy , creatinine , urinary system , hormone , paleontology , genetics
Serum progesterone and urinary total estrogen concentrations were determined weekly to bi‐weekly in 2 female Asian elephants for 96 weeks. The mean estrous interval was approximately 16 weeks in the nonpregnant animal. A total of 5 cycles were observed in the 96 week study period. The serum progesterone concentration ranged from 150 pg/ml to greater than 350 pg/ml during the luteal phase of the estrous cycle. The serum progesterone was elevated for 8–12 week weeks of the 16 week estrous cycle. The urinary total estrogen concentration ranged from less than 10 to greater than 300 pg/μg creatinine. The second animal was pregnant at the beginning of the study period. The serum progesterone concentration was elevated (> 100 pg/ml) in the pregnant animal until parturition. The urinary total estrogens increased from approximately 50 pg/μg creatinine to greater than 400 pg/μg creatinine during the first year of pregnancy and remained elevated until parturition. Estrous cycling had not resumed by 3 months post partum.