Effects Of Dietary Different Vitamin E Levels On Growth Performance, Immunity, Meat Quality And Heat Stress Of New Zeanland Rabbits

Experiment one and experiment two were conducted to assess the influence of different dietary VE levels on growth performance,VE deposition in organism, immunity performance, meat quality and antioxygen performance of organism to weaned~2month and 2~3month old New zealand rabbits. One hundred and twenty weaned New zealand rabbits were randomly allotted to six trentments of twenty rabbits each, in which they were fed each diet with different VE levels (0mg/kg, 40mg/kg, 80 mg/kg, 160 mg/kg, 320 mg/kg, 640 mg/kg). In experiment three, tewenty four rabbits were selected and allotted to three treatments,and were fed dietary of three different VE levels(0mk/kg,320mg/kg and 640mg/kg), and they were dealt with acute heat stress.The results were as follows:Experiment one: Vitamin E supplement had no significant influence on growth performance (P>0.05),however, with the VE levels increasing, ADG of weaned~2month old rabbits rose and then reduced and F/G had the opposite tendency, first reduced and then increased, the best addition level is 80mg/kg. Concentration ofα- tocopherol in serum and tissues increased with VE levels increased. There was no significant influence on immunity performance to weaned~2month old rabbits with vitamin E supplementation increasing. The thymus index,spleen index in different treatments had no significant regularity changes and there was no improvement to antibody production and raise with vitamin E supplementation increasing. However IgG 14 days after injected the vaccine in serum had augment tendency (P=0.337) with VE levels increased .There were no significant differences of SOD activity in serum and tissues. MDA in serum and liver had decreasing tendency, but both didn't attain the significant levels compared with control group. When VE levels in dietary feed exceeded 40mg/kg, content of MDA in muscle decreased significantly (P<0.01); There were no significant effect on blood biochemical indexes with the VE supplement in dietary, however, TG and CHO had an decreasing trend. In conclusion, the appropriate dietary VE levels to weaned~2months old rabbits was 40~80mg/kg.Experiment two With the increasing levels of VE, F/G of 2~3months rabbits showed decreasing and then increasing tendency, when the addition level was 80mg/kg ,the F/G was the lowest, but had no significant differences compared with the control group; ADI and ADG had no significant change tendency. Concentration ofα-tocopherol in serum and tissues of 2~3month old rabbits increased more than that of weaning ~2 month old rabbit , and the content ofα-tocopherol in serum, liver and muscle in indifferent treatments increased significantly with the increasing of VE levels compared with the control group (P<0.01);The dressing percentage rose first and then reduced with the increasing levels of VE in dietary feed of trial rabbits. The effect was the best when the addition level was 80mg/kg,there were significant differences compared with control group(P<0.05).VE supplement can improve PH of meat, and high concentration of VE levels (320mg/kg,640mg/kg) reduced drip loss significantly (P<0.05). When VE levels in dietary attain 80mg/kg, it could improve meat tenderness significantly (P<0.05), and lowered down the production of MDA of stored meat. VE supplement had an improvement for the immunity performance of 2~3 months old rabbits. VE supplement in dietary was able to decrese the TG and VLDL content, and there was an significant decease compared with the control and 40mg/kg group when VE levels arrived at 160mg/kg, and there was an increasing intendcy in HDL; VE supplement had no effect on CHO and LDL(P>0.05). VE supplement had no significant influence to SOD activity in serum and tissues, and reduced the concentration of MDA significantly in serum and tissues of 2~3 month old Newzealand rabbits (P<0.01). To sum up, the appropriate VE addition level to 2~3 months rabbit was 80mg/kg. In experiment three, VE supplement in andvance had no effect on SOD activity, and had an significant improvement in T-AOC and decreasing MDA production (P<0.05).