Serum Progesterone and Conception Rates in Acyclic Embryo Recipient Mares Using a Bovine Progesterone-Releasing Intravaginal Device.

The objective of this study was to quantify serum progesterone levels, uterine features, and pregnancy rates in acyclic, embryo recipient mares using a bovine progesterone-releasing intravaginal device in a commercial embryo transfer (ET) program. The study included 73 recipient mares of unknown breed, aged 3-10 years, weighing 350-500 kg, and kept under an intensive management system on Tifton 85 (Cynodon spp.) pastures with water and mineral salt ad libitum. The horses were divided into two groups: a group with a progesterone-releasing intravaginal device (1 g progesterone, G-IVP4, n = 24) and a control group (G-iP4, n = 49) receiving an injection of 1,500 mg long-acting progesterone. Jugular blood was collected for the G-IVP4 group for subsequent progesterone measurement by radioimmunoassay on three occasions: Day 0 (D0), intravaginal device was placed; Day 5 (D5), day of the ET; and Day 9 (D9), day of pregnancy diagnosis. There was an increase (P < .0001) in serum progesterone levels on D5 and D9 compared with D0 (4.09 ± 0.81 and 6.45 ± 1.03 ng/mL vs. 0.71 ± 0.14 ng/mL). There were no differences among groups in the pregnancy rate (P > .05), with rates of 83.33% and 73.46% for G-IVP4 and G-iP4, respectively. In conclusion, the intravaginal route for absorption of 1 g of progesterone device increased the serum level of progesterone sufficiently to prepare the uterus of acyclic recipient mares for ET, and the conception rate was similar to the standard protocol using long-acting injectable progesterone. Copyright © 2020 Elsevier Inc. All rights reserved.

Citation

Wilson Luis Rigoleto Júnior, Waldomiro Dias de Camargo Neto, Guilherme de Paula Nogueira, Tiago Augusto Ferrari, Claudia Maria Bertan Membrive, Ines Cristina Giometti, Caliê Castilho. Serum Progesterone and Conception Rates in Acyclic Embryo Recipient Mares Using a Bovine Progesterone-Releasing Intravaginal Device. Journal of equine veterinary science. 2021 Feb;97:103325

Mesh Tags

Substances

PMID: 33478762

search → result