Effects of yolk sac infection in chicken

The most prevalent and the commonest cause of early chick mortality in Pakistan (and around the world) is yolk sac infection. Various effects of yolk sac infection on health status of chicken are discussed in this review. Yolk sac infection affects weight and contents of yolk sac, body weight and immune status of the chicks. This anomaly results not only in increased yolk sac weight with marked pathological changes in yolk but also in reduced weight gain and lowered immune response in chicks.