What are the symptoms of Newcastle Disease (ND) in brown layer flocks and its effect on eggshells?

Newcastle Disease, caused by a virulent avian paramyxovirus-1, is one of the most contagious and devastating viral diseases in global poultry. The virus targets the respiratory, nervous, and digestive tracts, but also exhibits a strong affinity for the reproductive system. In laying flocks, the most striking sign is an immediate, catastrophic drop in egg production. The virus severely infects the oviduct, destroying the epithelial cells responsible for albumen and shell calcification. Consequently, the few eggs laid during an ND outbreak are completely deformed, exhibiting rough, soft, thin, or entirely shell-less surfaces, accompanied by a complete loss of brown pigment (chalky white shells) and watery albumen. Strict biosecurity is mandatory. Farmers can consult emergency guides in the Poultry Encyclopedia, buy ND vaccines on Poultry Plaza, monitor daily rates on Poultry Rates, and use Murghi Mandi.