1. Diet preparation
Commercial meal diets (Nutrena
8000 by Cargill Siam Ltd.) with 40% protein
and 12% lipid, were used as basal diets
.
Astaxanthin (200 mg kg
-1
) from marigold
flower was added to one treatment diet (with
supplementation). Another treatment diet
had no astaxanthin added. Approximately
60% distilled water per kg was added, and
diets were thoroughly blended. Pelleted
diets were dried in hot air oven at 60°C
.
Diets were stored in plastic bags at a constant
temperature of -20°C