Vet World   Vol.17   June-2024  Article - 22 

The effectiveness of different hormone protocols for improving ovarian function before ovum pick-up in crossbred Japanese black cattle

Background and Aim: Producing and transferring embryos in vitro are profitable for enhancing premium beef genetics. Reducing costs and enhancing the effectiveness of hormone protocols before ovum pick-up (OPU) yield advantages. This study aimed to confirm that estradiol benzoate (EB) treatment resulted in more medium- and large-sized follicles before OPU and of higher oocyte quality after OPU than non-hormonal treatments, comparable to those undergoing gonadotropin-releasing hormone (GnRH) with follicle-stimulating hormone (FSH) plus prostaglandin F2α (PGF2α) and progesterone-releasing controlled internal drug release (CIDR) or EB with progesterone-releasing CIDR hormonal treatments. 

Materials and Methods: 30 crossbred Japanese black cows were divided into five equal groups, which were either untreated or treated with different hormone protocols before OPU. Group 1 (cows in estrus) and group 2 (cows in diestrus) were the untreated controls. Cows in group 3 were treated with GnRH + FSH + CIDR + PGF2α. Cows in group 4 received EB, and those in group 5 received EB + CIDR + PGF2α. After administering the protocols, all cow follicles were examined through ultrasonography and categorized by size. Subsequently, all cows underwent OPU, and the oocytes were collected and graded from A to D according to standard criteria. 

Results: Group 3 presented the highest large follicle numbers, and groups 3–5 had more medium follicle numbers, not different among groups but they had this parameter more than those of control groups 1 and 2. Moreover, groups 3–5 did not differ in combined grades A + B oocytes (good-quality oocytes). Groups 3 and 4 had more A + B oocytes than control groups 1 and 2, whereas group 5 was not different in this parameter from group 1. 

Conclusion: Among the three hormone protocols, EB treatment proved the most cost-effective and efficient, yielding more high-quality oocytes compared to the non-treatment protocols. To reduce the limitations of EB use in the future, this study suggests researching natural EB phytoestrogens as alternative treatments for improving ovarian function before OPU in other cattle breeds. 

Keywords: estradiol benzoate, follicle-stimulating hormone, gonadotropin hormone-releasing hormone, Japanese black cow, ovum pick-up.

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How to cite this article: Kajaysri J and Intrarapuk A (2024) The effectiveness of different hormone protocols for improving ovarian function before ovum pick-up in crossbred Japanese black cattle, Veterinary World, 17(6): 1362–1369.

Received: 2024-01-31    Accepted: 2024-05-31    Published online: 2024-06-21

Corresponding author: Jatuporn Kajaysri    E-mail: jatuporn.kaj@cra.ac.th

DOI: 10.14202/vetworld.2024.1362-1369

Copyright: Kajaysri, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/ by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.