Stress relief and weight gain effects of needle-free injection for foot-and-mouth disease vaccine in pigs

Abstract

This study compared the immune responses, stress relief and weight gains of needle or needle-free intramuscular and needle-free intradermal vaccination in pigs. When the same amount of a foot-and-mouth disease (FMD) vaccine was administered to pigs, antibody titers at 4 weeks after the 1st and 2nd FMD vaccination were not significantly different between the needle (IM-S) and needle-free (NM-P250) intramuscularly vaccinated groups, but the weight gain of NM-P250 was significantly increased compared to that of IM-S at 8 weeks after the 2nd FMD vaccination (p<0.05). In addition, serum cortisol concentrations of NM-P250 were considerably decreased compared to those of IM-S on the 5th and 7th day after the 1st and 2nd FMD vaccination (p<0.05). However, the antibody titers of IM-S vaccinated with 2 mL of FMD vaccine were significantly increased compared to those of the needle-free intradermal vaccinated group with 0.5 mL of FMD vaccine at 4 weeks after the 1st and 2nd FMD vaccination (p<0.05). In conclusion, the needle-free intramuscular injection for the FMD vaccination can be chosen for weight gain and stress relief in pigs.