In ovo applications in poultry: A review

The various methods employed for the in ovo administration of different materials for promoting the health and productivity of poultry are discussed in this review article. The amnion has proven to be an effective site for injection and the timing of in ovo injection has commonly occurred at transfer. However, the volumes and dosages or concentrations of the materials administered vary depending on bird type, egg size, timing and site of injection, incubation system and regimen, and the type of material. Both manual and automated injections have been shown to be effective. Nevertheless, commercial application mandates automation. Materials described in the literature over the past 20 years or more for in ovo use in avian species include vaccines, drugs, hormones, competitive exclusion cultures and prebiotics, and supplemental nutrients. Vaccines approved for in ovo delivery include those for Marek's disease, infectious bursal disease, fowl pox, Newcastle disease, and coccidiosis. Some of the materials listed above have been shown to be viable candidates for enhancing immunity and for promoting embryonic and posthatch development. Several reports have indicated that probiotics may be effectively used to fight intestinal bacterial infections, and folic aid, as well as egg white protein and various amino acids, including L-arginine, L-lysine, L-histidine, HMB, and threonine alone or in combination, have been shown to benefit embryonic development or posthatch performance. Furthermore, CpG oligodeoxynucleotides, vitamins C and E, and thyme and savory have the potential to enhance immunity, carbohydrates can be used to increase tissue glycogen stores, and creatine can be used to promote muscle growth. Trace minerals and vitamin D3 have shown potential to improve bone strength, and potassium chloride may be an effective alternative electrolyte in vaccine diluent. The in ovo application of these and other materials will continue to expand and provide further benefits to the poultry industry.