Abstract
A 20% reduction in hatchability continued in a hatchery for about 2 months. Bacteria identified as Serratia marcescens were isolated uniformly from all the samples collected from dead embryos. Bacterial isolates were derived from the feces, but not from any reproductive organ of layer hen in the affected hatchery.
The Serratia isolate was lethal to embryonating hen's eggs, but not pathogenic for chicks or mice. Bacteria were recovered from the feces of birds with experimental infection.
The agglutinating titers of serum samples against Serratia antigen were 1:80 to 1:640 in layer hens which had laid unhatched eggs, 1:20 to 1:80 in experimentally infected chickens, and 1:5 or less in a majority of serum stock obtained from various regions.
The occurrence of death among chick embryos in this hatchery could be attributed to the transmission of Serratia marcescens from carrier hens through contaminated feces to the eggs that they laid. The source of the infection is unknown.
