Ảnh hưởng của tỷ lệ lysine và arginine trong thức ăn trên cá bớp (Rachycentron canadum) giai đoạn giống

Juvenile cobia (8.4±0.1 g  initial body weight) were fed to satiation with three test diets of high  plant  protein-based ingredients  and  different  lysine  to  arginine  ratios,  and  one commercial diet as a control (CT) for growth in a recirculation system for 6 weeks. The test diets contained 206 g marine ingredients kg-1, including fishmeal, krill meal, and fish protein concentrate  (in  order of  high  to  low inclusion),  while  the  rest of  the  dietary protein  was  a blend  of  soya and  pea  protein  concentrate,  wheat  protein,  and  sunflower meal.  Crystalline lysine and arginine were added in the test diets to produce either a balanced lysine to arginine ratio  (BL/A;  1.1)  and  a  high  or  low  lysine  to  arginine  ratio  (HL/A;  1.8  and  LL/A;  0.8, respectively). The test diets contained 505-529 g protein and 90.2-93.9 g lipid kg-1  dry matter, while  that  in  the  CT  diet  was  550  and  95  g  kg-1,  respectively.  There  were  no  significant differences in final body weight, weight gain, feed conversion ratio or protein gain between cobia fed BL/A- and commercial control diet (CT). However, cobia fed the BL/A diet showed higher feed intake, and protein and lipid gain, compared to cobia fed either the HL/A- or the LL/A  diet.  Cobia  fed  BL/A  diet  performed  better  in  final  body  weight,  weight  gain,  feed conversion ratio than fish fed either HL/A- or LL/A diet.