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

被引：0

作者：

Camozzato, Julia Nobre Blank ^{[1
,2
]}

de Souza, Bruna Favretto ^{[1
]}

Rodrigues, Joao Marcello ^{[1
]}

Leo, Alinne Machado Petrarca ^{[2
]}

Pfeifer, Luiz Francisco Machado ^{[3
]}

Bertolini, Marcelo ^{[1
]}

Rovani, Monique Tomazele ^{[1
]}

Mondadori, Rafael Gianella ^{[2
]}

Gasperin, Bernardo Garziera ^{[2
]}

de Oliveira, Fernando Caetano ^{[1
,2
]}

机构：

[1] Univ Fed Rio Grande do Sul, Fac Vet, Porto Alegre, RS, Brazil

[2] Univ Fed Pelotas, Fac Vet, FiBRA, Capao Leao, RS, Brazil

[3] Empresa Brasileira Pesquisa Agr Embrapa, Porto Velho, RO, Brazil

来源：

REPRODUCTION IN DOMESTIC ANIMALS | 2025年 / 60卷 / 03期

关键词：

beef cattle; fertility; ovulation; pregnancy; timed artificial insemination; ESTRADIOL CYPIONATE; BEEF HEIFERS; OVULATION; ESTRUS; PROGESTERONE; AI; SYNCHRONIZATION; EXPRESSION; INDUCTION; PROTOCOLS;

D O I：

10.1111/rda.70025

中图分类号：

S8 [畜牧、动物医学、狩猎、蚕、蜂];

学科分类号：

0905 ;

摘要：

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 mu g d-cloprostenol (PGF) and 1 mg estradiol cypionate (EC) were administered. In the GnRH34 group, animals received 25 mu g 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.

引用

页数：5

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