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Updated: Oct 13, 2025

Methods for Studying Uterine Contributions to Pregnancy Establishment in an Ovariectomized Mouse Model
Published on: April 7, 2023
Accessory corpus luteum regression during pregnancy II: reproductive outcomes
Pedro L J Monteiro1,2, Caio A Gamarra2, Rodrigo S Genari2
1Department of Animal Science, University of São Paulo, Piracicaba, São Paulo, Brazil.
Abstract:
The objective of this study was to evaluate the effect of accessory corpus luteum (CL) induction on fertility in dairy cows. On day 5 after artificial insemination (AI), lactating Holstein cows were assigned unequally to receive gonadotrophin-releasing hormone treatment (GnRH) (n = 641) or no treatment (control; n = 289). Cows had their blood sampled for progesterone (P4), and ovaries were scanned by ultrasound on days 5, 12, 19, 26, 33, 47, and 61 after AI. Pregnancy diagnosis was performed on days 26, 33, 47, and 61. On day 12, cows treated with GnRH were allocated to ipsilateral (n = 239) or contralateral (n = 241) groups based on the side of accessory CL formation relative to previous ovulation. Accessory CL cows had greater P4 than controls. In total, 52.7% (78/148) of pregnant cows in contralateral group had accessory CL regression earlier (
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