Dalmau Antoni, Sánchez-Matamoros Almudena, Molina Jorge M, Xercavins Aida, Varvaró-Porter Aranzazu, Muñoz Israel, Moles Xènia, Baulida Berta, Fàbrega Emma, Velarde Antonio, Pallisera Joaquim, Puigredon Alba, Contreras-Jodar Alexandra
Animal Welfare Program, Institute of Agrifood Research and Technology, Barcelona, Spain.
HIPRA, Girona, Spain.
Front Vet Sci. 2021 Aug 11;8:715260. doi: 10.3389/fvets.2021.715260. eCollection 2021.
The aim of the present study was to compare intramuscular injection with a needle and intradermic needle-free vaccinations against porcine reproductive and respiratory syndrome (PRRS) in piglets at 28 days old by studying behavioral and physiological reactions. A total of 72 piglets divided into 2 sex-balanced batches were assessed. Within each batch, the piglets were divided into three treatments, which were Hipradermic (0.2 ml of UNISTRAIN® PRRS vaccine administered with an intradermic needle-free device), Intramuscular (IM, 2.0 ml of vaccine), and Control (not vaccinated). Before the vaccination, the piglets were trained to cross a 4-m-long raceway to perform an aversion learning test. The day of vaccination, the time taken to cross the raceway was registered for each piglet at different times: prior to the vaccination and 10 min, 2, 24, 48, and 72 h after the vaccination, to measure variations in these times as signs of aversion to the vaccination process. Vocalizations, as potential signs of pain, were recorded as well at the end of this raceway to analyze their frequency (Hz), duration, and level of pressure (dB) at the moment of vaccination. Salivary cortisol, as a sign of the HPA-axis activity, was assessed 10 min after the vaccination. In addition, activity budgets, local reaction to the vaccine, and serological titer were also considered in the study. Ten minutes after the vaccination, the IM piglets took longer ( < 0.001) to cross the raceway than did the Hipradermic and Control piglets. Vocalizations were significantly different between the three treatments: the Control piglets produced vocalizations with the lowest frequency ( < 0.001) and level of pressure ( < 0.001), and IM with the highest, with Hipradermic in a significant intermediate position ( < 0.001). Accordingly, the day of the vaccination, IM and Hipradermic animals were lying on the side of the vaccine administration a greater proportion of time than were the Control piglets (10, 11, and 6%, respectively; = 0.027). Salivary cortisol was not significantly different between treatments. The serum titer of antibodies against the PRRS was higher ( < 0.001) in both vaccinated treatments in comparison to the Control piglets. It is concluded that the Hipradermic needle-free vaccination may result in a less aversive experience in piglets than did intramuscular vaccination.
本研究的目的是通过研究行为和生理反应，比较28日龄仔猪肌肉注射针头疫苗和皮内无针疫苗预防猪繁殖与呼吸综合征（PRRS）的效果。总共评估了72头仔猪，分为2个性别均衡的批次。在每个批次中，仔猪被分为三种处理组，分别是皮内无针注射组（使用无针皮内注射装置注射0.2毫升UNISTRAIN® PRRS疫苗）、肌肉注射组（IM，注射2.0毫升疫苗）和对照组（不接种疫苗）。在接种疫苗前，训练仔猪穿过一条4米长的跑道以进行厌恶学习测试。接种疫苗当天，记录每头仔猪在不同时间穿过跑道所需的时间：接种疫苗前以及接种后10分钟、2小时、24小时、48小时和72小时，以测量这些时间的变化作为对疫苗接种过程厌恶的迹象。在跑道末端也记录了叫声，作为潜在疼痛迹象，以分析接种疫苗时叫声的频率（Hz）、持续时间和压力水平（dB）。接种疫苗10分钟后评估唾液皮质醇，作为下丘脑-垂体-肾上腺（HPA）轴活动的指标。此外，研究中还考虑了活动预算、对疫苗的局部反应和血清效价。接种疫苗10分钟后，肌肉注射组仔猪穿过跑道的时间比皮内无针注射组和对照组仔猪更长（P<0.001）。三种处理组的叫声存在显著差异：对照组仔猪叫声的频率（P<0.001）和压力水平（P<0.001）最低，肌肉注射组最高，皮内无针注射组处于显著的中间位置（P<0.001）。因此，在接种疫苗当天，肌肉注射组和皮内无针注射组动物侧卧在疫苗注射侧的时间比例比对照组仔猪更高（分别为10%、11%和6%；P = 0.027）。各处理组之间唾液皮质醇无显著差异。与对照组仔猪相比，两种接种疫苗处理组中抗PRRS抗体的血清效价更高（P<0.001）。结论是，皮内无针疫苗接种可能比肌肉注射疫苗给仔猪带来的厌恶体验更少。
