Carryover effects of dietary arginine on productive performance and blood biochemistry in Japanese quail (Coturnix japonica).

Early nutritional programming can affect later development in birds, yet the carryover effects of dietary arginine in Japanese quail remain poorly understood. Arginine is an essential amino acid for birds, as they cannot synthesise it endogenously, and it plays a vital role in growth and metabolism. This study aimed to evaluate the effect of dietary arginine restriction or supplementation on body mass change, reproduction, and plasma biochemistry in Japanese quail after the dietary treatment was discontinued for two consecutive weeks. Birds were fed either a low-arginine diet (25% below recommendations), a control diet (recommendations), or a high-arginine diet (25% above recommendations) at the early reproductive stage and adult stage and were then subsequently returned to a standard diet for two weeks. Overall, in comparison with the immediate effects of dietary arginine, no significant residual effects of dietary arginine were observed on body mass change, average daily body mass gain, feed conversion ratio, and egg production after the withdrawal period. However, age-dependent responses were observed, and adult birds showed a significant decrease in body mass change as compared to early reproductive stage birds. In addition, cholesterol showed age-related differences, whereas alanine aminotransferase (ALT/GPT) and aspartate aminotransferase (AST/GOT) showed both age- and treatment related difference with adult birds exhibiting lower concentrations than early-reproductive-stage birds. These findings suggest that early-life dietary arginine manipulation has a limited influence on growth and reproduction after withdrawal but may induce age-dependent changes in selected biochemical parameters in Japanese quail.