Effects of Yucca schidigera extract on the growth performance, feed efficiency, body composition of Common Carp (Cyprinus carpio, Linnaeus 1758) and culture water quality

One of the important goals in the aquaculture industry is to increase fish production with the least stress from ammonia secretion. Yucca plant(Yucca schidigera) was composed of steroidal saponins, polysaccharides, and polyphenols, which have increase the intestinal flora activity to improving the digestive process, also great absorption capacity for harmful volatile compounds, such as ammonia and hydrogen sulfide. Therefore, the aim of this study was to evaluate the effects of different Yucca schidigera extract levels on the Cyprinuscarpio growth, feed performance, body composition and culture water quality for 60 days. Experimental treatments were designed which include: T₁ (control without extracts), T₂, T₃ and T₄ treatments (containing 0.5, 1 and 1.5% Yucca extract respectively). In a completely randomized design, 360 Common carp fish with weight of 2.40±0.04 g and length of 5.47±0.05 cm were reared in twelve 40-L plastic tanks. Different levels of extract were sprayed on commercial food and consumed at 4 times daily. There was significantly higher final body weights in T₄ (p<0.05) compared with control (T₁) and other experimental treatments (T₂ and T₃). Similarly, significantly better (p<0.05) feed conversion ratio (FCR), 2.01±0.37 and protein efficiency ratio (PER), 0.17±0.01 was noticed in T₄ compared to control (FCR 2.71±0.31 and PER 0.14±0.01). The biochemical composition of carcass had a significant difference between treatments (p<0.05). The body chemical composition analysis showed that the low levels of crude protein and the high levels of crude lipids in T₄ treatment were 62.87±2.63% and 26.29±1.55%, respectively. The physical and chemical parameters were within the recommended range for C.carpio. The experiment treatments had the lowest amount of ammonia and the highest amount of nitrate compared to the control treatment in culture water. The results of this experiment showed that the use of Yucca extract can improve the growth, feed performance, body composition and the water quality of the common carp culture system.