The immune surveillance and pullorum quarantine have been conducted in layer flocks of a poultry breeding farm in Guizhou province.

• 通过对贵州省某种禽场蛋鸡群进行的免疫监测和白痢检疫,结果表明,在3个被检的蛋鸡群中,鸡白痢的隐性感染率分别为69%25(2/29)、193%25(6/31)、0%25(0/41)。