Effects of Dietary Phosphorus Levels and Citric Acid on Growth and Mineral Availability in Common Carp, Cyprinus Carpio Fed Low Fish Meal Diets

摘要

The effects of dietary phosphorus (P) levels and citric acid (CA) supplementation on growth and mineral utilization of common carp fed low fishmeal diets were investigated. Six experimental diets were formulated and designated as OPOCA, 1POCA, 2POCA,OP 1 CA, 1P1 CA and 2P1 CA, the first 3 diets were supplemented with 0, 1 and 2% monocalcium phosphate respectively whereas rest of the 3 diets were supplemented with 1 % CA plus 0,1 and 2% monocaicium phosphate respectively. Duplicate groups of carp (size 3.77±0.6 g) were fed the test diets to satiation, four times a day, six days a week throughout the trial for 8 weeks. A higher whole body lipid and lower P and Ca confirmed the deficiency of the dietary P in OPOCA and OP 1 CA test diets. P supplementation in the test diets increased fish growth significantly (P<0.05). Carcass Cu content increased significantly (P<0.05) in all the groups supplemented with citric acid. P and N retention (%) increased with P supplementation in IPOCA and2P0CA groups butCA supplementation reduced the P andN retention (%) in 1 P1CA and 2P1CA groups. Citric acid has no effect on improvement of growth and phosphorus utilization and 2% monocalcium phosphate supplementation almost safisfies the P requirement of carp in lowfishmeal based diet.