Abstract Introduction The objective of this research was to evaluate the antibody response to multiple doses of an inactivated mixed vaccine against Histophilus somni, Pasteurella multocida, and Mannheimia haemolytica, and to investigate the influence of age at time of vaccination in the field. Material and Methods Healthy female Holstein calves received the vaccine at the age of 5–12 days and 2, 3, or 4 weeks later in the first experiment or at 1, 2, or 3 weeks of age and 4 weeks later in the second. Blood samples were collected at each vaccination and 3 weeks after the booster dose. Based on the antibody titres after the vaccinations, calves were divided into positive and negative groups for each of the bacteria. Calves in the control group were vaccinated only once at the age of 19–26 days. Results Antibody titres against H. somni and P. multocida were significantly increased by the booster. After the second vaccinations, the titres against each bacterium were higher than those of the control group, and the M. haemolytica-positive percentage in calves with high maternal antibody levels (MAL) exceeded that in calves with low MAL. In the first experiment, a majority of the M. haemolytica-positive calves tended to have received the primary dose at seven days of age or older. Conclusion A booster dose of the inactivated bacterial vaccine in young Holstein calves increased antibody production and overcame the maternal antibodies. Calves should be vaccinated first at seven days of age or older.

中文翻译：

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在幼年荷斯坦犊牛中对牛呼吸道细菌进行初步和加强剂量灭活疫苗的现场试验

摘要 简介 本研究的目的是评估多剂量灭活混合疫苗对嗜睡组织杆菌、多杀性巴斯德氏菌和溶血曼海姆氏菌的抗体反应，并调查现场接种疫苗时年龄的影响。材料和方法 健康雌性荷斯坦小牛在第一次实验中在 5-12 天和 2、3 或 4 周后接种疫苗，或者在第二次实验中在 1、2 或 3 周龄和 4 周后接种疫苗。在每次接种疫苗时和加强剂量后 3 周收集血样。根据疫苗接种后的抗体滴度，将小牛分为每种细菌的阳性组和阴性组。对照组的小牛在 19-26 天时只接种了一次疫苗。结果针对 H. somni 和 P. 的抗体滴度。助推器显着增加了多杀性。第二次接种后，每种细菌的滴度均高于对照组，且母体抗体水平（MAL）高的小牛溶血性分枝杆菌阳性百分比超过了低MAL的小牛。在第一个实验中，大多数溶血分枝杆菌阳性小牛倾向于在 7 天或更大时接受主要剂量。结论 在幼年荷斯坦犊牛中加强剂量的灭活细菌疫苗增加了抗体的产生并克服了母体抗体。犊牛应在 7 天或以上时首先接种疫苗。高母体抗体水平 (MAL) 的小牛溶血阳性百分比超过低 MAL 的小牛。在第一个实验中，大多数溶血分枝杆菌阳性小牛倾向于在 7 天或更大时接受主要剂量。结论 在幼年荷斯坦犊牛中加强剂量的灭活细菌疫苗增加了抗体的产生并克服了母体抗体。犊牛应在 7 天或以上时首先接种疫苗。高母体抗体水平 (MAL) 的小牛溶血阳性百分比超过低 MAL 的小牛。在第一个实验中，大多数溶血分枝杆菌阳性小牛倾向于在 7 天或更大时接受主要剂量。结论 在幼年荷斯坦犊牛中加强剂量的灭活细菌疫苗增加了抗体的产生并克服了母体抗体。犊牛应在 7 天或以上时首先接种疫苗。结论 在幼年荷斯坦犊牛中加强剂量的灭活细菌疫苗增加了抗体的产生并克服了母体抗体。犊牛应在 7 天或以上时首先接种疫苗。结论 在幼年荷斯坦犊牛中加强剂量的灭活细菌疫苗增加了抗体的产生并克服了母体抗体。犊牛应在 7 天或以上时首先接种疫苗。