In Ovo Administration of Innate Immune Stimulants and Protection from Early Chick Mortalities due to Yolk Sac Infection

SUMMARY Omphalitis or yolk sac infection (YSI) and colibacillosis are the most common infectious diseases that lead to high rates of early chick mortalities (ECMs) in young chicks. Out of numerous microbial causes, avian pathogenic Escherichia coli (APEC) or extraintestinal pathogenic E. coli infections are considered the most common cause of these conditions. YSI causes deterioration and decomposition of yolk, leading to deficiency of necessary nutrients and maternal antibodies, retarded growth, poor carcass quality, and increased susceptibility to other infections, including omphalitis, colibacillosis, and respiratory tract infection. Presently, in ovo injection of antibiotics, heavy culling, or after hatch use of antibiotics is practiced to manage ECM. However, increased antibiotic resistance and emergence of “super bugs” associated with use or misuse of antibiotics in the animal industry have raised serious concerns. These concerns urgently require a focus on host-driven nonantibiotic approaches for s...