Silva Filipe Prudente da, Neves Kedson Alessandri Lobo, Correa Francisco R A, Silva Lílian K X, Batista Helder R, Silva Welligton C da, Mercado Caruso Nohora, Minervino Antonio Humberto Hamad
Centro Universitário da Amazônia, Santarém 68010-200, PA, Brazil.
Laboratory of Animal Health (LARSANA), Federal University of Western Pará (UFOPA), Rua Vera Paz, s/n, Salé, Santarém 68040-255, PA, Brazil.
Vet Sci. 2022 Jul 22;9(8):377. doi: 10.3390/vetsci9080377.
This study aimed to evaluate follicular dynamics and pregnancy rates in Nellore heifers submitted to fixed-time artificial insemination (FTAI) protocols associated with equine chorionic gonadotrophin (eCG) or follicle stimulating hormone (FSH). Nellore heifers (n = 259) were used, divided into two studies. Experiment I evaluated the ovarian follicular dynamics in 64 Nellore heifers submitted to different FTAI protocols (n = 32/group) using either FSH or eCG. In Experiment II, the pregnancy rate was evaluated in 195 heifers submitted to FTAI protocols and divided into two groups: FSH (n = 97) and eCG (n = 98). In Experiment I, the ultrasound examination showed that the maximum diameter of the dominant and preovulatory follicles and the ovulation time were similar between the FSH and eCG groups (p > 0.05). However, the ovulation rate was higher in the eCG group when compared to FSH (p = 0.014). In Experiment II, females that received eCG presented a higher pregnancy rate (58.1%) when compared to FSH (40.2%) (p = 0.012). The use of eCG in the FTAI protocol in Nellore heifers promoted a higher ovulation rate and increased pregnancy rate and may be the most suitable alternative to increase conception rates in animals that are raised in an extensive system under tropical conditions in the Amazon.
本研究旨在评估接受与马绒毛膜促性腺激素（eCG）或促卵泡激素（FSH）相关的定时人工授精（FTAI）方案的内洛尔小母牛的卵泡动态和妊娠率。使用了259头内洛尔小母牛，分为两项研究。实验I评估了64头接受不同FTAI方案（每组n = 32）的内洛尔小母牛的卵巢卵泡动态，这些方案分别使用FSH或eCG。在实验II中，评估了195头接受FTAI方案的小母牛的妊娠率，这些小母牛分为两组：FSH组（n = 97）和eCG组（n = 98）。在实验I中，超声检查显示，FSH组和eCG组之间优势卵泡和排卵前卵泡的最大直径以及排卵时间相似（p > 0.05）。然而，与FSH组相比，eCG组的排卵率更高（p = 0.014）。在实验II中，接受eCG的母牛的妊娠率（58.1%）高于FSH组（40.2%）（p = 0.012）。在内洛尔小母牛的FTAI方案中使用eCG可提高排卵率并增加妊娠率，可能是提高在亚马逊热带条件下粗放养殖系统中的动物受孕率的最合适选择。
