Subclinical avian hepatitis E virus infection in layer flocks in the United States.

The objective of this study was to determine patterns of avian HEV infection in naturally infected chicken farms. A total of 310 serum samples and 62 pooled fecal samples were collected from 62 chicken flocks on seven commercial in-line egg farms in the Midwestern United States and tested for avian HEV circulation. Serum samples were tested for the presence of anti-avian HEV IgY antibodies by a fluorescent microbead immunoassay (FMIA) which was developed for this study.

The effect of inoculating Enterococcus faecalis into the yolk sac on chick quality and maternal antibody absorption.

Four hundred thirty-two 1-day-old specific-pathogen-free chicks were randomly divided into 36 groups of 12. All chicks were given 0.2 ml of Newcastle disease antiserum (hemagglutination-inhibition [HI] titer 1:5120) by injection into the yolk sac at hatch.

Investigation of bacterial resistance to hatchery disinfectants.

Three commercial chicken hatcheries were sampled for environmental bacteria. Isolated bacteria were tested for resistance to commercial preparations of quaternary ammonia, phenolic, and glutaraldehyde liquid disinfectants. Bacterial isolates were exposed to several disinfectant dilutions bracketing the dilutions recommended by the manufacturer for 5-, 10-, and 15-min exposure periods before subculturing to broth medium.