The In Ovo feeding technique as a recent aspect of poultry farming

Abstract

The incubation period of chicken eggs is 21 days; for meat-type birds, this represents approximately 60% of their life. In most cases, chicks are shifted from the hatchery when the majority (approximately 95%) of the chicks have hatched. This period time, added with the time required to transport the chicks to rearing farms, means that chicks can be deprived of water and feed for 2-3 days. Due to the specificity of the embryogenesis process and the unique avian eggshell structure, the development of the embryo could be directly manipulated via a small window that is cut into the egg-shell to allow access to the embryo. This ability has been used to develop the in ovo technique as a biotechnology approach, i.e. direct injection of bioactive and nutritional substances during the incubation process. Recent studies have shown major developments in the utilisation of this technique for early feeding and supply of carbohydrates and amino acids (more than 2.5% weight enhancement for broilers) or vaccination (Newcastle, Mareks Disease, with more than 2% immunity enhancement) in several commercial poultry farms particularly in Europe, United States and Brazil. Additionally, the injection of IGF type I (100 ng/egg from human origin) on the 3rd day of incubation increased the efficiency of growth and development of muscle during the first weeks of life resulting in more than 12% weight enhancement for broiler. The amniotic site has been considered the most effective for supplements injection, while the 18th day of chicken egg incubation is the most effective time. This review integrates recent aspects that could influence traits of interest for in ovo feeding in the poultry industry.