EFFECTS OF DIETARY VITAMIN A AND E ON GROWTH PERFORMANCE AND ANTIOXIDANT STATUS IN BLOOD OF JUVENILE RAINBOW TROUT (ONCORHYNCHUS MYKISS, W. 1792) EXPOSED TO FLOW RATE STRESS
G. T. Keleştemur and Y. Özdemir
Fisheries Faculty, Firat University, Department of Aquaculture, Elazig, Turkey
Corresponding Author E-mail: email@example.com, firstname.lastname@example.org
The present study investigated the effects of vitamin A and E supplementation in diets of juvenile rainbow trout subjected to two different flow rates with or without flow stress (0.9 and 2.1 l/min, respectively) on growth performance, vitamin A and E concentrations in serum, malondialdehyde (MDA) level in serum as well as plasma SOD (superoxide dismutase) activity. Fish fed with the three experimental diets (30E+A, 60E+A, –E+A ) during 12 weeks. In the unstressed groups, WG (weigth gain) of fish did not differ among the diets groups (p>0.05). Lower WG was observed in fish fed the vitamin E-free diet in stressed groups (p<0.05). In stress and unstressed groups, SGR (specific growth rate) was not different among all dietary treatments (p<0.05). In stressed group, SUR (survivor rate) was highly significant in A+60E and A+30E groups and lower SUR was observed in fishes in the A-E group (P<0.05). Both flow rate trials, there was no significant difference in serum vitamin A concentration of all diet groups (p>0.05). In the unstressed and stressed groups, serum vitamin E concentration was lowest in fish fed with A-E diets (p<0.05). In the unstressed and stressed groups, serum MDA (malondialdehyde) level was highest in fish fed the A-E diet (p<0.05). In the unstressed group, SOD activity were similarly affected by 30 and 0 mg/kg vitamin E supplemented diet groups and in both stress conditions plasma SOD (superoxide dismutase) enzyme activity increased in A+60E diet group.
Key words: rainbow trout, stress, growth performance, antioxidan status.