Immune Factor On Carassius Auratus Of Mannatide

α-Mannatide was a kind of polysaccharide that was obtained from deep cultured and fermented α-hemolytic streptococcui 33#. It was used on improving immufunction and antitumor on human beings. And it was used for domestic animals and poultry to improve resistance to disease ,and to promote the use and absorbtion of nutrition .The experiment use different dose of to feed Carassius auratus, and study the effect on Carassius auratus through checking Hemoglobin(Hb), Erythroeyte(RBC), agglutinating antibody titer, SOD activities, phagocytic activity of Leucocytes and bactericidal activity of phagocytes. Then we use the best dose of α-Mannatide to find out the best period to provide materials for producing immunopotentiator, green production and health feeding. 1. Through the pre-experiment, we confirmed that the 0.75-3.00 mg/kg was the best dose. We set 4 groups which were 0.75 mg/kg,1.50 mg/kg,3.00 mg/kg and control group. Through compared on the detecting of Hb with control group, the result of 0.75 mg/kg group was raised from 7.56 g/100mL to 10.10 g/100mL. The 1.50 mg/kg group was raised from 7.50 g/100mL to 11.07 g/100mL. The 3.00 mg/kg group was raised from 7.55 g/100mL to 11.28 g/100mL. However the maximum result of the control group was 9.06 g/100mL. On RBC, the maximum result was 1.02×10~6 cell/mm~3, but the 1.50 mg/kg group was twiced to the control group. On agglutinating antibody titer, the 1.50 mg/kg and 3.00 mg/kg group were raised 2~4 and 2~5. On SOD activities, the control group's maximum result was 41.07 U/mL, 1.50 mg/kg group was 91.77 U/mL, 3.00 mg/kg group was 107.93 U/mL. On phagocytic activity and bactericidal activity, the results of the experiment groups were raised by 45%　and　300%. The experiment groups were significant difference (P<0.05) or more　significant difference (P<0.01) from control group. Among the experiment groups, the 1.5mg/kg group and 3.0mg/kg group were the gratifying groups, but there was no significant difference between the two groups. So we think that the 1.5mg/kg is the best dose in daily production. 2. We use the successively dose of 1.5mg/kg to feed the Carassius auratus, we set 4 groups to feed Carassius auratus for 7 d, 14 d, 21d and 28 d. And we feed Carassius auratus with normal forage to the 68th days after using up the forage to determine the best period. The result states that, all the factors were to the maxium in 2 to 3 weeks: the Hb was 11.4 g/100mL; the number of RBC was 2.30×10~6 cell/mm~3; agglutinating antibody titer was 2~7; SOD activities was 92.5 U/mL; phagocytic activity and bactericidal activity can be kept over one month after the activity to the climax. It was fit for the practical production. So we think that feeding Carassius auratus successively for 21 days was the best feeding-cycle.