Effects of Infectious Bronchitis in Baby Chicks

INFECTIOUS bronchitis commonly causes a drastic and usually sudden decrease in egg production. Mortality is slight, seldom amounting to more than 5% of the laying flock. The most damaging effect is the failure to return, after several weeks pause, to what is considered a profitable rate of lay. In addition, abnormality of egg shape, shell strength, and texture, and of poor interior quality, further reduce the profitability of a recovered flock. In parent flocks, hatchability is considerably reduced. These conditions following the occurrence of the disease in a mature flock make infectious bronchitis one of the most costly diseases of the poultry industry. During the past four years the authors have had occasion to observe field cases in which flocks, having recovered from infectious bronchitis at a very early age (3 days to 3 weeks), failed ever to reach a satisfactory rate of lay. Thirty-five such farm flocks so affected …