The effect of Earth worm ( Eisenia fetida) difference levels on growth performance and body composition and Nutrition and Digestive Enzymes of Rainbow trout (Oncorhynchus mykiss)

This experiment was designed to investigate the use of live Eisenia fetida as a nutritional supplement on growth performance and carcass composition The purpose of this study was to evaluate the nutritional efficiency and changes in digestive enzymes of rainbow trout (Oncorhynchus mykiss). Fish were placed with average weight 58 g in a completely randomized design in 4 treatments and each with 3 replications. Rainbow trout with different levels of 0, 25, 50 and 75% (control, T1, T2 and T3) diet (including 50% moisture) of live worm for 8 weeks. At the end of the experiment, growth performance and body biochemical analysis were and of the experiment, nutritional function and digestive enzyme analyzes were performed. There was a statistically. Comparison of mean values obtained from final weight, weight gain, daily growth rate and specific growth rate showed a significant difference between experimental treatments. The highest amount of final weight was obtained in treatment 2 (109.24 ± 0.96 g) and the lowest in control (89.22 ± 1.21 g). The protein and lipid content of carcass was significantly different between the control and experimental treatments. The highest amount of protein and lipid in treatment 2 and 1 were 66.12 ± 0.29 and 25.73 ± 0.07 respectively. There was a statistically significant difference in the amount of feed conversion ratio (FCR) between different treatments, so that was obtained the lowest in W2 (1.50 ± 0.01) and the highest in W3 (1.95 ± 0.03). The analysis of gastrointestinal enzymes showed that amylase, protease and lipase had a statistically significant difference between control treatment and experimental treatments. The highest values obtained from them in W2 treatment were 732.68 ± 50.16, 79.33 ± 4.50 and 34.33 ± 5.35, respectively. The lowest amount of these enzymes was observed in control treatment. The results showed that using 50% of worm instead of the base diet can improve growth and carcass composition and of the base diet could lead to increased food productivity and activation of digestive enzymes.