Document Type : scientific research article
Authors
1
Department of Aquatics Production and Exploitation, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
2
Dept. of Aquaculture Gorgan University of Agricultural Sciences and Natural Resources
3
Department of Fisheries, Faculty of Natural Resources and Environment, Malayer University, Malayer, Hamedan, Iran.
4
Department of Clinical Sciences, Faculty of Veterinary Medicine, Razi University, Kermanshah, Iran
Abstract
In fish farming industry, the use of nutritional supplements, including enzymes, is recognized as a vital strategy to enhance nutritional performance and growth. This study aimed to evaluate the effect of enzymatic extract from pyloric appendages on the growth performance and body composition of rainbow trout fry. Four dietary treatments were prepared, including a control diet (A: without enzyme) and three diets containing different levels of enzyme extract (B: 0.5 g/kg, C: 1 g/kg, and D: 2 g/kg of feed) with uniform protein and energy content. The results indicated that diets D and C exhibited the best growth performance compared to other experimental diets. These diets significantly outperformed others in terms of body weight increase and daily growth rate. Moreover, they showed the best feed conversion ratio, indicating efficient feed utilization. Additionally, diet D showed the highest specific growth rate and condition factor, while diet C exhibited the highest survival rate, although these differences were not statistically significant. The ash content in diet D was also significantly higher compared to other diets. Diets D and C significantly increased protein efficiency ratio and lipid efficiency ratio. The findings suggest that the inclusion of 2 g/kg enzymatic extract from pyloric appendages can improve the growth and nutritional performance of rainbow trout fry.
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