The YS-400 strain was non-pathogenic to pigs when given orally and induced high VN titers (132-1128) 6 weeks post-administration. Of the pigs given the ADV bait vaccine twice or three times, 40% were seropositive by 2 weeks, and 100% were seropositive by 7 weeks after the first dose. Pigs that consumed the AD bait vaccine three times developed VN titers that were slightly higher than those of pigs given the vaccine twice.