نوع مقاله : مقاله پژوهشی
1 انستیتو تحقیقات بین المللی ماهیان خاویاری، موسسه تحقیقات علوم شیلاتی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، رشت، گیلان، ایران
2 گروه شیلات، واحد تالش، دانشگاه آزاد اسلامی، تالش، ایران
عنوان مقاله [English]
An investigation was carried out to find the effects of different Smizyme phytase levels on growth indices, body composition and nutrient digestibility of farmed Siberian sturgeon, Acipenser baerii. One hundred and eighty fish (average weight 1.19 ± 0.017 kg) were distributed in nine concrete tanks (20 fish in each tank; area = 4 m2; depth = 80 cm) and divided to 3 treatments (F0, F1000 and F2000). Fish were fed for 62 days. Results showed that physaem addition in 2000 IU (F2000) to sturgeon commercial diet (38% protein and 12.5% crude fat) leads to significant increase in final weight, daily growth rate, specific growth rate and the decreased feed conversion ratio compared to the other two groups (p<0.05). Significant raises in protein and dry matter digestibility were observed in the enzyme-fed fish compared to control diet (p<0.05). However, no significant difference in fat digestibility was observed between experimental treatments (p>0.05). Body protein was declined in F1000 and F2000, while body lipid was elevated in F2000 (p<0.05). The highest body carbohydrates was observed in F1000 (p<0.05), while no significant difference was observed in the fish body moisture fed with different diets (p>0.05). Based on the results obtained from growth indices and digestibility coefficient, we suggest adding 2000 IU/kg Smizyme phytase in the fish diet.