Use of an automatic needle-free injection device for foot-and-mouth disease vaccination in dairy heifers.

The foot-and-mouth disease (FMD) vaccination of Thai dairy cows is routinely conducted to control and prevent the disease. In Thailand, FMD control strategies include a subcutaneous route (s.c.) vaccination with 2 ml of inactivated FMD vaccine 2-3 times a year produced by the Department of Livestock Development (DLD). A new way of vaccination was introduced in the form of an automatic needle-free injection device. This technology has several important advantages, such as requiring less animal restraint, reduced time and labour with high precision, and a consistent delivery system. Here, the effectiveness of an automatic needle-free injection (ANFI) device was evaluated in 30 dairy heifers (randomly divided into three groups, 10 in each group) in the FMD vaccine delivery. The first group was subcutaneously (s.c.) vaccinated using a conventional hypodermic needle with 2 ml of the vaccine, the second group received the same, but using a CO-powered ANFI device, and the third group received the vaccine using the same ANFI device, but administered intradermally (i.d.) with only 1 ml of the vaccine. The blood samples collected up to 120 days post-vaccination revealed that both injection methods resulted in a similar serological response. The results suggest that the i.d. and s.c. ANFI systems are effective and safe. Moreover, the i.d. use of the ANFI enabled the possibility to half the vaccination dose with the same efficacy. Therefore, the ANFI can be used as an alternative approach for FMD vaccination by s.c. or i.d. routes in dairy cows in Thailand. Ultimately, reducing the use of restraint devices and labour will improve the vaccination for the prevention and control of FMD and may improve the cows' welfare.