Zhang Qianru, Cui Chenchen, Zhang Siyu, Deng Xiaohong, Cai Xuehui, Wang Gang
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
College of Veterinary Medicine, Xichang University, Xichang 615000, China.
Vet Sci. 2022 Dec 25;10(1):12. doi: 10.3390/vetsci10010012.
Porcine reproductive and respiratory syndrome (PRRS) is a devastating disease that affects pigs and is responsible for severe economic losses. The commercial PRRSV-inactivated vaccine (CH-1a strain) in China was recently selected to control PRRS in large populations of PRRS-positive sows and was found to effectively reduce the rate of stillbirth abortion based on clinical observations. However, stress from vaccine inoculation (e.g., fever, anorexia, abortions, and slow body weight gain) usually appears after immunization on many swine farms. In this study, we fed piglets a diet medicated with tylvalosin tartrate during PRRSV-inactivated vaccine immunization. We found that tylvalosin tartrate attenuated the increase in total white blood cells induced by immunization at day one post-immunization (DPI) and induced an increase in monocyte counts after seven DPI. There was also attenuation in the intensity of the inflammatory response induced by vaccination and elevation of serum IFN-γ concentrations at three and seven DPI after immunization. The administration of tylvalosin tartrate could also attenuate the reduction in the percentage of CD8 T cells induced by PRRSV-inactivated vaccine immunization at seven DPI. These results demonstrated that in addition to tylvalosin tartrate being able to control respiratory and enteric bacterial infections in swine farms, it can also improve the stress status of swine herds during PRRSV-inactivated vaccine immunization.
猪繁殖与呼吸综合征（PRRS）是一种影响猪的毁灭性疾病，会造成严重的经济损失。中国的商业性PRRSV灭活疫苗（CH-1a株）最近被用于控制大量PRRS阳性母猪群中的PRRS，基于临床观察发现其能有效降低死胎流产率。然而，在许多养猪场，疫苗接种后的应激反应（如发热、厌食、流产和体重增加缓慢）通常会在免疫后出现。在本研究中，我们在PRRSV灭活疫苗免疫期间给仔猪喂食含酒石酸泰万菌素的日粮。我们发现，酒石酸泰万菌素在免疫后第1天（DPI）减弱了免疫诱导的总白细胞增加，并在7 DPI后诱导单核细胞计数增加。免疫后3和7 DPI时，疫苗接种诱导的炎症反应强度也有所减弱，血清IFN-γ浓度升高。酒石酸泰万菌素的给药还可以减弱PRRSV灭活疫苗免疫在7 DPI时诱导的CD8 T细胞百分比降低。这些结果表明，酒石酸泰万菌素除了能够控制养猪场的呼吸道和肠道细菌感染外，还可以改善PRRSV灭活疫苗免疫期间猪群的应激状态。
