1. Taiwan Provincial Research Institute for Animal Health, Tamsui, Taiwan, R.O.C.
2. Department of Veterinary Medicine, College of Agriculture, National Taiwan University.
Using neutralization test, the hog cholera antibodies of thirteen Jitters of piglets from four breed herds in I-Lan and Yun-Lin counties were determinated. Serum samples were obtained from each pig at 3, 6 and 9 weeks after birth. The relationships between antibody titers and suitable age for vaccination were also studied by computer analysis.