Abstract
Two feeding experiments were conducted for both practical and experimental scales to develop low-protein high-energy diets (less-polluting diets) for practical carp culture in order to reduce the total nitrogen excretion from the fish.
Results of both the experiments have demonstrated that diets containing 32-37% crude protein (CP) with digestible energy (DE) above 340kcal/100g diet enriched with carbohydrate or lipid were found to be better than a commercial cazp diet containing CP above 40% in growth and feed efficiency. This fact indicated that CP content in practical carp feeds can be reduced from 40% to around 30% without reduction of growth rate and feed efficiency, if a high quality protein is used as protein source and DE content is increased by carbohydrate or lipid to about 340kcal/100g diet.
The total nitrogen excretion from carp was also found to be reduced by 30-48% of the present value by feeding these low protein-high energy diets.
