Dpto. de Anatomía e Histología Humanas, Universidad de Zaragoza, C/Domingo Miral S/n, 50009, Zaragoza, Spain; Centro de Encefalopatías y Enfermedades Transmisibles Emergentes, C/ Miguel Servet 177, 50013, Zaragoza, Spain; Instituto Agroalimentario de Aragón - IA2 (CITA-Universidad de Zaragoza), C/ Miguel Servet 177, 50013, Zaragoza, Spain.
Instituto Agroalimentario de Aragón - IA2 (CITA-Universidad de Zaragoza), C/ Miguel Servet 177, 50013, Zaragoza, Spain; Centro de Investigación y Tecnología Agroalimentaria (CITA) de Aragón, Avda. Montañana 930, 50059, Zaragoza, Spain.
Theriogenology. 2020 Jan 1;141:211-218. doi: 10.1016/j.theriogenology.2019.07.019. Epub 2019 Jul 19.
Castration reduces aggressive and sexual behaviour and provides better carcass quality in bull calves. Vaccination against gonadotrophin-releasing hormone (GnRH) is used as an alternative to surgical castration for the purposes of reducing pain and distress in the animals. Currently, no anti-GnRH vaccine has been authorized for use in cattle in the European Union. The aim of the present study was to assess the effect of an anti-GnRH swine-specific vaccine (Improvac®, Zoetis, USA) on the morphology, structure and function of bull testes. Animals were vaccinated at days 1, 21 and 104 of the experimental period and were classified based on their live weight into the following two groups: LIGHT (172.9 ± 30.00 kg) and HEAVY (323.8 ± 37.79 kg). The scrotal circumference was measured on day 1 and prior to slaughter (day 164). At slaughter, the sperm motility and concentration in the caudae epididymis were assessed. Testes were weighed, measured and examined using ultrasound, and then tissue samples were collected and fixed in formalin. Histological and immunohistochemical studies were performed on the testes to measure the diameter of the seminiferous tubules and assess the testicular cell populations. The results revealed that suppression of testicular development was associated with the use of the Improvac® vaccine, which resulted in a smaller size of the testes and impaired spermatid production. However, the effect of Improvac® was more pronounced and consistent in calves vaccinated at a low live weight than at a heavy live weight, which suggested that vaccination is more effective when calves are vaccinated before or early during puberty. However, testes from calves vaccinated at a low live weight were more prone to the development of intraluminal concretions in the seminiferous tubules.
去势可减少公牛犊的攻击性行为和性行为，并改善胴体质量。促性腺激素释放激素 (GnRH) 疫苗接种被用作手术去势的替代方法，以减少动物的疼痛和不适。目前，尚无 GnRH 疫苗被授权用于欧盟的牛。本研究旨在评估一种抗 GnRH 猪特异性疫苗（Improvac®，Zoetis，美国）对公牛睾丸形态、结构和功能的影响。动物在实验期的第 1、21 和 104 天接种疫苗，并根据活体重分为以下两组：LIGHT（172.9±30.00kg）和 HEAVY（323.8±37.79kg）。在第 1 天和屠宰前（第 164 天）测量阴囊周长。在屠宰时，评估尾侧附睾中的精子活力和浓度。测量睾丸重量、大小并使用超声进行检查，然后收集组织样本并固定在福尔马林中。对睾丸进行组织学和免疫组织化学研究，以测量精小管的直径并评估睾丸细胞群。结果表明，睾丸发育抑制与使用 Improvac®疫苗有关，导致睾丸体积减小和精子发生受损。然而，在低活体重时接种疫苗的小牛中，Improvac®的作用更为明显和一致，这表明在小牛青春期前或早期接种疫苗效果更好。然而，在低活体重时接种疫苗的小牛的睾丸更容易在精小管内形成管内结石。
