In‌ ovo feeding of nutraceuticals and its role in adjusting the gastrointestinal tract, antioxidative properties, immunological response, and performance in poultry: An updated review

Nutraceuticals are food ingredients that provide extra health advantages that expand above their nutritional value. Nutraceuticals comprise amino acids, antioxidants, minerals, vitamins, probiotics, prebiotics, synbiotics, enzymes, organic acids, fatty acids, medicinal plants, etc. Recently, nutraceuticals have acquired much attention in poultry industry by reason of their potential effects on establishing the normal physiological status, supporting the immune system, and disease prevention, which consequently enhances productivity. The technique of in ovo feeding (IOF) of nutraceuticals holds several promises in poultry industry. The vital benefits of IOF of nutraceuticals are enhancement of intestinal development, establishment of a balanced microbial population in the gut, support of intestinal physiology and health. Interestingly, IOF of nutraceuticals participates in improving the antioxidative properties and energizing the immune system, which thereby translated into greater performance and bigger resistance to diseases, especially in early life challenges. The current review attempts to throw more light on the fresh results associated with the profits of IOF of nutraceuticals on intestinal histomorphology, intestinal microbiota, antioxidative properties, immune responsiveness, hatchability, chick quality, and growth performance in poultry.