1993 Volume 41 Issue 3 Pages 359-365
This experiment was conducted to confirm the effects of dietary digestible energy (DE) and available phosphorus (Av. P) contents on reduction of total amount of nitrogen excretion (T-N) from carp, Cyprinus carpio using simple methods for calculation of DE and Av. P contents in diet. Carp fingerlings (an initial body weight; 13.1 g or 31.3 g) were fed 18 kinds of experimental diets for 4 weeks.
Growth rate was better in fish fed the diet containing more than 350 kcal DE or more than 0.7 % Av. P. The Av. P deficient diet resulted in low growth rate and feed efficiency together with low protein efficiency ratio. When protein contents were same, the T-N was affected by Av. P of the diet. Dietary DE of 340-350 kcal and Av. P greater than 0.7 % was confirmed to be appropriate for reduction of the T-N and improved growth. The simple method used for calculation of dietary DE and Av. P contents was found to be effective for evaluation of practical carp feed quality from the viewpoint of environmental impact.
