COMPARATIVE STUDY ON PATHOGENS FOUND IN SPECIFIC PATHOGEN FREE “ SPF “ AND COMMERCIAL EGGS

Abstract

The embryo transmitted diseases were especially relevant to the development of SPF flocks because one first needed to break the cycle of transmission or identify uninfected parent flocks in order to derive pathogen­ free chicks. However, even those infectious disease not known to be transmitted vertically were of interest because SPF flocks needed also to be free of antibodies to as many diseases as possible. So, the aim of this investigation was to test and evaluate both SPF eggs and chickens produced by SPAFAS. It was concerned with examination of imported SPF eggs used for vaccine production and researches in VSVRI and those necessary for quality control experiments in CLCVB. Different tests were applied, following International Standards, to prove freedom of SPF eggs and chickens from extraneous viral, bacterial, fungal and mycoplasmal contaminants that may affect vaccine production and quality control tests. 400 fertile chicken eggs were obtained from SPAFAS, Incorporated, Norwich, CT, and 100 fertile commercial egg samples were taken randomly from 4 batches and incubated until hatching, or for 7, 14, 18 days for preparation of embryo homogenates and CEF cultures as well as for collection of albumin and yolk samples before incubation. These material were tested for the presence of AE, ALV, CAV, EDS-75, Reo and REV antigens and/or antibodies by ELISA and IFA.