چکیده مقالات:
Abstract
This study conducted to evaluate the effect of dietary zinc (Zn) levels on feed utilization, tissue Zn composition and serum enzyme activities of juvenile Siberian sturgeon,
Acipenser baerii. Five isoenergetic and isonitrogenous semi-purified diets were formulated with increasing Zn sulphate (ZnSO4.5H2O) level to provide the actual Zn values of
14.7 (control), 20.8, 27.3, 37.7 and 46.4 mg/kg diet. Each diet was assigned to three
groups of 20 experimental Siberian sturgeons with uniform size (initial weight of
26.52 ± 0.94 g) for a period of 8-week feeding trial. Results showed that growth performance and muscle protein content were significantly increased with increasing dietary Zn level up to 27.3 mg/kg (p < .05), beyond which they remained significantly
unchanged (p > .05). Muscle lipid content significantly declined with increasing dietary
Zn level. While muscle and serum Zn contents were not significantly changed among
treatments (p > .05), liver Zn content tended to rise with increasing dietary Zn supplementation. Alkaline phosphatase, superoxide dismutase and glutathione peroxidase
activities were also raised with increasing dietary Zn level. The adequate amount of
dietary Zn requirements for the Siberian sturgeon was estimated to be 28.24 mg/kg
based on the relative growth rate and 34.60 mg/kg based on the liver Zn content.
مشخصات نشريه:
سال: 2017