What is the economic impact of Infectious Coryza (Haemophilus paragallinarum) outbreaks on the lay rate of brown layers?

Infectious Coryza, caused by the bacterium Avibacterium paragallinarum (formerly Haemophilus), is an acute respiratory disease of chickens. It spreads rapidly through aerosol droplets and contaminated drinking water, especially in high-density farming zones like Lahore and Faisalabad. Swelling of the infraorbital sinuses ("swollen head"), foul-smelling nasal discharge, and conjunctivitis prevent birds from eating and drinking. The direct economic consequence is an immediate, severe drop in egg production (up to 40%) and a massive increase in downgraded, thin-shelled eggs. Even after recovery, flocks rarely return to their peak lay curve, forcing farmers to cull birds early. Implementing strict biosecurity and multi-valent Coryza vaccination is essential. Farmers can read treatment protocols in the Poultry Encyclopedia, buy antibiotics and vaccines on Poultry Plaza, monitor daily egg prices on Poultry Rates, and trade flocks on Murghi Mandi.