Chicken Infectious Bursal Disease (IBD) is a viral infection that primarily affects young chickens, particularly those between three and six weeks old. The disease is caused by the Infectious Bursal Disease Virus (IBDV), which targets the bursa of Fabricius, an important organ for the immune system in birds. Infected chickens may show symptoms such as lethargy, diarrhea, and a decrease in feed intake. The disease can lead to significant economic losses in poultry farming due to increased mortality rates and reduced growth. Vaccination is a common preventive measure, helping to protect flocks from the virus and maintain overall health in poultry operations.