Luteal Function and Pregnancy Rate in Bos taurus Heifers Treated With GnRH Prior to Timed Artificial Insemination.

IF 1.6 3区农林科学 Q2 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Reproduction in Domestic Animals Pub Date : 2025-03-01 DOI:10.1111/rda.70025

Julia Nobre Blank Camozzato, Bruna Favretto de Souza, João Marcello Rodrigues, Alinne Machado Petrarca Léo, Luiz Francisco Machado Pfeifer, Marcelo Bertolini, Monique Tomazele Rovani, Rafael Gianella Mondadori, Bernardo Garziera Gasperin, Fernando Caetano de Oliveira

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引用次数: 0

Abstract

The study aimed to evaluate the effects of GnRH given 34 h after progesterone (P4) intravaginal device (IVD) removal in a timed artificial insemination (TAI) protocol. In Experiment 1, 17 Hereford and Braford heifers (control, n = 7; GnRH34; n = 10) received 2 mg estradiol benzoate (EB) and a 1 g P4 IVD on Day 0 (D0). On D8, IVDs were removed and 150 μg d-cloprostenol (PGF) and 1 mg estradiol cypionate (EC) were administered. In the GnRH34 group, animals received 25 μg lecirelin 34 h after the IVD removal (D9). TAI was performed in both groups on D10 (48 h after IVD removal). Follicular dynamics were evaluated from D8 until ovulation; blood samples were collected 7 and 12 days after TAI. In Experiment 2, to evaluate the effect of GnRH34 on pregnancy rates (control, n = 187; GnRH34; n = 203), heifers were subjected to the TAI protocols described in Experiment 1. No significant differences were observed in preovulatory follicle (POF) diameter on D10, follicular growth and ovulation rates until 72 h and P4 concentrations on days 7 and 12 after TAI (p > 0.05). Pregnancy rates (PR) were similar between groups (Control = 50.2%; GnRH34 = 50.2%; p = 0.65). A significant effect of body weight (BW) and body condition score (BCS) on PR was observed for control (p< 0.05), but not for GnRH34. In conclusion, GnRH 34 h after the IVD removal in beef heifers previously treated with EC had no effect on luteal function and fertility.

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来源期刊

Reproduction in Domestic Animals 农林科学-奶制品与动物科学

CiteScore

3.00

自引率

5.90%

发文量

238

审稿时长

4-8 weeks

期刊介绍： The journal offers comprehensive information concerning physiology, pathology, and biotechnology of reproduction. Topical results are currently published in original papers, reviews, and short communications with particular attention to investigations on practicable techniques. Carefully selected reports, e. g. on embryo transfer and associated biotechnologies, gene transfer, and spermatology provide a link between basic research and clinical application. The journal applies to breeders, veterinarians, and biologists, and is also of interest in human medicine. Interdisciplinary cooperation is documented in the proceedings of the joint annual meetings. Fields of interest: Animal reproduction and biotechnology with special regard to investigations on applied and clinical research.