Progesterone during the breeding season and pregnancy in female muskoxen on different dietary regimens

• Published in: Rangifer
• Main Authors: Janice E. Rowell, Robert G. White, William E. Hauer
• Format: Article in Journal/Newspaper
• Language: English
• Published: Septentrio Academic Publishing 1997
• Subjects: estrous cycle; body condition; embryonic loss; abortion; progesterone; muskoxen; Animal culture; SF1-1100; Rangifer
• Online Access: https://doi.org/10.7557/2.17.3.1363; https://doaj.org/article/9d4f2a5b9780441bab4ce4c998084a59

Previously, we documented lowered calving success in captive muskoxen raised for 6 years on a low nutritional plane. In an effort to identify causes of lowered calf production, we looked at serum progesterone during the breeding season in muskoxen raised on either a high (HP) or low (LP) nutritional plane. Complete cessation of estrous cycli-city in 2 parous cows was the only irregularity identified. Abortion and/or embryonic loss occurred in both HP and LP cows. We also compared progesterone during pregnancy between the 2 nutritional planes and lactating and non-lacta-ting cows. The timing of the rise and fall of the mid-pregnant progesterone peak was consistent with stage of gestation and apparently independent of time of breeding, diet or lactational status.