Why is the vaccination program against Avian Encephalomyelitis (AE) mandatory before brown pullets reach 15 weeks of age?

Avian Encephalomyelitis (AE) is a viral disease caused by a picornavirus that targets the nervous system of young chicks and the reproductive organs of mature layers. If an unvaccinated flock is infected with AE during active lay, the virus replicates in the ovary and oviduct, causing a sudden, temporary drop in egg production (up to 15%) and a severe loss of internal egg quality, resulting in watery albumen and pale, chalky shells. More critically, the virus is vertically transmitted through the egg to the embryo, causing epidemic tremors, ataxia, and mass mortality in day-old chicks at the hatchery. To prevent this, breeders and commercial layer farmers must administer a live AE vaccine (often combined with Fowl Pox) via drinking water or wing-web puncture between 10 and 15 weeks of age. This allows the flock to build permanent immunity well before the onset of lay, securing both maternal antibody transfer and stable egg production. Farmers can access vaccine schedules in the Poultry Encyclopedia, buy certified AE vaccines on Poultry Plaza, check live egg rates on Poultry Rates, and trade on Murghi Mandi.