This study evaluated the influence of administering different levels of L-arginine into eggs of 0-day-old Japanese quail embryos. On day 0 of incubation, 480 eggs (120 for each treatment group) were injected with 0% arginine (C group), 1% arginine (T1), 2% arginine (T2) or 3% arginine (T3). After hatching, 336 quail chicks (84 chicks produced from each in ovo injection treatment) were placed in an experimental quail house and allocated to four treatment groups of three replicates, with 16 quail chicks for each replicate. Traits involved in this study were hatchability rate, initial body weight (7 days of age), final body weight (42 days old), feed intake, weight gain, feed conversion ratio and blood serum glucose, protein, cholesterol, total lipids, triglycerides, calcium and phosphorus concentrations, and proportional weights of the carcass, breast, legs, backbone, wings, neck, abdominal fat, liver, heart and gizzard. Results revealed that in ovo injection with different levels of L-arginine on day 0 of incubation resulted in significant increases in the hatchability rate, initial body weight, final body weight, feed conversion ratio, and blood serum glucose, protein, total protein, calcium and phosphorus concentrations, as well as the proportional weights of the carcass, breast, legs, liver, heart and gizzard. However, there was no significant difference in feed intake between treatment groups. Significant decreases were recorded in blood serum cholesterol, total lipids and triglyceride concentrations, and proportional weights of the backbone, wings and abdominal fat. In conclusion, the inoculation of different levels of L-arginine into eggs of 0-day-old quail embryos, especially at the levels of 2% and 3% arginine, resulted in a significant improvement in the productive and physiological performance of the quail. Hence in ovo injection with L-arginine could be used as a tool for enhancing the hatchability rate and productive performance of quail hatched from the egg.
