KINETICS OF ANTIBODY-TITERS IN EGG-YOLK AND SERUM TO 4 AVIAN VIRUSES IN 5 BREEDER HEN FLOCKS

This study was undertaken to establish antibody profiles for 4 avian viruses in broiler breeder hens during the laying period, using egg yolk and serum as a source of antibody. Five flocks were monitored from 27 to 57 weeks of age. Paired samples of blood and egg were collected from the same hen for a total of 12 pairs per flock and each flock was sampled 6 times during the production period. Commercially available ELISA kits were used to measure the antibody titers to each of the following viruses : infectious bursal disease virus, infectious bronchitis virus, Newcastle disease virus and avian reovirus. The serum antibody profile was similar to that of egg yolk and on the whole, the serum titres were lower than the egg yolk titres for all four viruses throughout the laying period. A slight increase in both antibody titers was observed towards the end of the laying period.