عنوان مقاله [English]
This study was conducted to evaluate the effects of dietary XTRACT on growth, survival and body composition of Carassius gibelio. For this purpose, goldfish fry with a mean weight of 7.53±0.17 gr and a length of 8.34±0.26 cm in 6 treatments with three replicates were distributed randomly in 18 aquaria with 80 liters water capacity. The commercial XTRACT diet was added to diets at levels of 100 (X100), 200 (X200), 300 (X300), 400 (X400), 500 (X500) mg / kg and control diet without XTRACT. The breeding period was considered to be 12 weeks. Growth indices, including weight gain, specific growth rate, body weight gain, status index, feed conversion ratio, survival rate, protein yield, and fat yield were measured for growth indices and comparison between treatments at the end of breeding period. The results showed that the treatment fed 200 mg/kg diet of commercial XTRACT material had significant differences with the control group in the final weights, weight gain, body weight gain percentage, specific protein yield, protein yield, lipid yield and reduction in feed conversion ratio (P<0.05). In terms of survival rate of fish, the highest survival rate was observed in treatments containing different levels of commercial matter. The analysis of the chemical composition showed that the highest protein and moisture content were in X200 and X100 mg/kg of XTRACT commercial feed and also the highest mean muscle fat in the control treatment. As a general conclusion, it can be stated that the use of 200 mg/kg of commercial XTRACT in the goldfish diet can increase and improve the growth and survival index in goldfish. The addition of commercial XTRACT to 200 mg / kg of feed for goldfish is suggested.