A growth study was conducted to determine the dietary threonine requirement of juveniles of the Indian major carp (Cirrhinus mrigala) known as “mrigal”. Diets containing casein and gelatin as sources of intact proteins were supplemented with crystalline amino acids to obtain a crude protein content of 40%. Six diets with different levels of threonine (1.0, 1.3, 1.5, 1.7, 1.9 and 2.1%) were fed ...