EXPERIMENTAL TRANSMISSION OF HYDROPERICARDIUM SYNDROME AND PROTECTION AGAINST IT IN COMMERCIAL BROILER-CHICKENS

Liver collected aseptically from broiler chickens suffering from natural outbreaks of hydropericardium syndrome was homogenised in phosphate buffered saline (1:5) or normal saline (1:10). A dose of 0.25 ml of 800 g supernatant (inoculum S) in the first case or homogenate without centrifugation (inoculum T) in the second case was injected subcutaneously into 12- to 15-day-old broiler chickens. Lesions similar to natural outbreaks of the syndrome appeared in 2 to 5 days. Inoculum S inactivated with 0.1% formalin for 24 h (Vac S) or inoculum T inactivated with 0.5% formalin for 72 h (Vac T) was injected into commercial broiler chickens at 10 or 15 days of age. The birds were challenged with inoculum S or inoculum T at 20 or 25 days of age. Experimentally both vaccines gave satisfactory protection, but under field conditions, Vac T was superior. © 1964, Taylor & Francis Group, LLC. All rights reserved.