Effect of phytase addition and citric acid on the production parameters of feed for Common Carp (Cyprinus carpio L.)

The aim of the experiment was to evaluate the effect of addition phytase enzyme together with citric acid to Feed conversion ratio (FCR) and a Specific growth rate (SGR) in feed for common carp. The phytase addition increases the digestibility of phytate phosphorus from plant components in feed mixtures. The addition of citric acid (CA) optimize a pH level in guts for the phytase enzyme. For the experiment was prepared five types of feed. The basic component was a commercial mixture for carp (KP1) with 10% share of soybean meal. This mixture was fed to the control group. Next 4 experimental mixtures were prepared by addition of 500 FTU, 1000 FTU, 500 FTU + 3% of CA and 1000 FTU + 3% of CA. The test was made in 10 tanks (5 groups with one replication) with 15 specimens in each group. The test lasted 72 days. Results show statistically insignificant differences of production parameters in groups 500 FTU and 1000 FTU, but differences of FCR and SGR were statistically significant in groups 500 FTU+CA and 1000 FTU + CA. FCR of these groups decreased by 20% over the control group (one–way ANOVA: F=24, df=4, P=0.002). SGR increased by 11% over the control group (one–way ANOVA: F=17.93, d.f.=4, P=0.004).