Dietary Arginine Requirement of Fingerling Indian Major Carp, Catla catla (Hamilton)

Dietary arginine requirement of fingerling Catla catla (3.55 +/- 0.05cm; 0.61 +/- 0.02g) was determined by feeding casein-gelatin-based isonitrogenous (33% crude protein) and isocaloric (3.40kcal/g digestible energy) amino acid test diets containing six graded levels of l-arginine (1, 1.25, 1.5, 1.75, 2, and 2.25% dry diet) for 12wk. Maximum absolute weight gain (6.93g/fish), protein efficiency ratio (2.13), protein deposition (0.36), arginine retention efficiency (78%), and best feed conversion ratio (1.42) were recorded in fish fed 1.75% arginine of the dry diet. Maximum carcass protein (15.57%) and RNA/DNA ratio (4.79) were also recorded for the group fed 1.75% arginine of the dry diet. Quadratic regression analysis at 95% maximum or minimum response of above growth parameters yielded optimum arginine requirement of fingerling C. catla at 1.67% of the dry diet. On the basis of the above analysis of the growth parameters, it is recommended that the inclusion of dietary arginine at 1.67% of the dry diet is optimum for formulating arginine-balanced, cost-effective quality feeds for the mass culture of fingerling C. catla.