Zinc is a trace element which participates in various fundamental biochemical processes in vertebrates. Zinc deficiency in animals results in oxidative damage by oxygen free radicals. Thus, appropriate zinc absorption is essential for maintaining normal growth and development in animals. Largemouth bass, an important carnivorous economic fish, is extensively reared in southern China because of its high nutritional value and promising economic benefits. In the present study, we explored the regulatory effects of zinc treatment in modulating growth, antioxidant capacity and lipid storage, as well as comparing the difference of such effects in fish fed with organic or inorganic zinc.
Sul120 and Bio120 groups showed significantly higher weight gain and specific growth rate than Con group (Table 2), with Bio60 group obtaining the lowest viscerosomatic index and hepatosomatic index (Table 3). Up-regulation of hepatic SOD, GSH-PX and CAT activities and decline of MDA contents indicated augmented antioxidant capacities by organic zinc (Table 4). The alterations in whole body and liver crude lipid contents illustrated the regulatory effect of zinc on lipid storage (Table 5).
These findings demonstrated the capabilities of zinc in potentiating growth and morphological performance, antioxidant capacity as well as regulating lipid storage in M. salmoides. Organic zinc exhibited higher efficiency than inorganic