Synonyms Egg Drop, Egg Drop Syndrome 76, EDS-76 [PDF]

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Egg Drop Syndrome Synonyms egg drop, egg drop syndrome 76, EDS-76



The egg drop syndrome - 1976 (EDS 76) • is an infectious disease in layer hens manifested by a quick drop in egg production, failure to reach peak production, irregularly shaped eggs, soft-shelled or shell-less eggs and de-pigmentation



Causative agent • • • •



adenovirus Type 3 The incubation period is 3- 5 days the disease course is 4- 10 weeks. The cause has been identified as denovirus BC14, 127, first isolated in Northern Ireland in 1976.



Species affected: • The natural hosts for EDS virus are ducks and geese, No illness has been observed in ducks. • Chickens of all ages and breeds are susceptible. The disease is most severe in broiler-breeders and brown-egg layer strains.



Clinical signs: • There are no reliable signs other than egg drop at peak or failure to peak. • Healthy appearing hens The first sign is the loss of egg pigmentation, rapidly followed by the appearance of soft-shelled, shell-less of deformed-shell eggs and poor internal quality. • The drop could be sudden or prolonged. Usually, it lasts for 4-10 weeks and the egg production is reduced by about 10-40%. • Transient diarrhea and dullness occur prior to egg shell changes. • Fertility and hatchability are not affected



loss of egg pigmentation



appearance of soft-shelled



shell-less of deformed-shell eggs



The shells may also be rough or" chalky.”



Misformed and soft shelled eggs



Non-peaking effect of early EDS ’76 infection



Egg drop by infection during lay



Post-mortem lesion • inactive and atrophied oviducts, edema in uterus



Transmission: • It is believed that the syndrome was first introduced into chickens from contaminated vaccine. • Vertical transmission occurs from infected breeders to chicks. Newly hatched chicks excrete the virus in the feces. • Horizontal transmission.



diagnosis • Poor eggshell quality and a decrease in egg production, in an otherwise healthy flock. • isolation and identification of the virus • ELISA, HI, Serum Neutralization • polymerase chain reaction (PCR)



Differential diagnosis • Infectious diseases - infectious bronchitis - Newcastle disease - avian influenza • Nutritional deficiency as D as well as calcium, phosphorus • intoxication by sulphonamides, insecticides or nicarbazin.



Treatment There is no successful treatment. Induced molting will restore egg production. Soluble multivitamins may be recommended



Prevention Prevention involves a good biosecurity program. Vaccination with inactivated vaccine prior to lay