Effect of adding phytase enzyme and formic acid to diets of common carp Cyprinus carpio L. on coefficient of digestibility and growth rates.

Abstract

The study aimed to add phytase enzyme and formic acid at different percentages of control (0) and (1, 2, 3)% in the diets of common carp Cyprinus carpio L.to know their effect on the total digestibility coefficient and growth rates of fish.Common carp fish were used at weight rates of 230±1.53 g/fish, which were randomly distributed in (40×60×40) cm3 glass tanks equipped with aeration and air filtration system and in controlled laboratory conditions. The results showed significant differences (P≤0.05) between treatments and there was a decrease in the coefficient of digestion of protein, fat, carbohydrates and ash for the control treatment T1 compared to all experimental treatments and it amounted to (60.54, 70.39, 32.95, 51.84), respectively. The two treatments T2 and T3 excelled in the coefficient of protein digestion, reaching (85.22 and 86.63), respectively, while no significant differences were recorded between treatments T3, T4, T5, T6, and T7 in the coefficient of fat digestion, and the coefficient of carbohydrate digestion increased (71.43, 74.94, 67.23, respectively, and the ash digestibility factor (84.28, 89.63, 79.21), respectively, for each of the treatments T2, T3, T4.The T1 control treatment recorded the lowest results in weight gain rates of 46.71 g, daily growth rate of 0.57 g/day, relative growth rate of 19.36%, specific growth rate of 0.12 g/day, and food conversion efficiency of 21.19% compared to the experimental treatments, and T3 treatment significantly outperformed the rest of the treatments in daily growth rates. 1.73 g/day, and the relative growth rate and feed conversion efficiency were increased for T3 and T4 treatments.We conclude from this research that it is possible to use diets supplemented with phytase enzyme and formic acid with 1%, 2% and 3% acid as a source of animal protein in the diets of common carp without negative effects on digestion and growth rates.