Abstract:Maggot is not only a high quality feed protein, but also a new immune enhancer. To evaluate the effect of maggot protein mixture on the non-specific immunity of American eel Anguilla rostrata, seven hundred and fifty American eels with average initial body weight of (95.0±5.0) g were randomly divided into five groups with three replicates per group and 50 fish per replicate, were reared at water temperature of 25—28 ℃ and fed basal diet supplemented with 0 (control group), 5%, 10%, 15% and 20% (converted from housefly maggot protein mixture) of maggot protein, respectively. After 60 d rearing, the activities of lysozyme, acid phosphatase, alkaline phosphatase, superoxide dismutase, glutamic-pyruvic transaminase and glutamic-oxaloaletic transaminase and contents of complement 3 and 4 were measured in serum of American eel, and the mortality also tested after American eels were infected with Aeromonas hydrophila. The results showed that the contents of complements 3 and 4 in serum were significantly increased with the increase maggot protein mixture in diets (P<0.05). The highest levels of contents for complements 3 and 4 were found in the 15% and 20% maggot protein added groups, respectively. The activities of the serum lysozyme, acid phosphatase, alkaline phosphatase and superoxide dismutase were increased first and then decreased with increasing maggot protein mixture supplementation, and significantly higher than those in the control group except the activity of alkaline phosphatase for the 5% maggot protein added group (P<0.05). The highest activities of lysozyme, acid phosphatase and superoxide dismutase were all exhibited in the 15% maggot protein added group. The activity of alkaline phosphatase reached the highest level in fish fed diet containing 10% maggot protein. Although the activity of the serum glutamic-pyruvic transaminase increased initially and then decreased with increasing maggot protein mixture supplementation, no significant difference was observed when supplementing maggot protein ratio was lower 20% (P>0.05). The activity of the serum glutamic-oxaloaletic transaminase was gradually decreased with the increase in supplementing maggot protein mixture, significant decrease compared to the control group when supplementing maggot protein mixture ratio was higher 15% (P<0.05). The challenge test revealed that there was significantly lower accumulated mortality and higher relative immune protective rate for American eel in the 15% maggot protein added group than that in control group. The findings indicated that dietary supplementation of maggot protein mixture elevated the non-specific immunity and disease resistance of American eel. It is suggested that supplementation with 15% maggot protein in diet is optimal for American eel.
陈杰, 陈子廷, 赵甜, 王方海, 李广宏. 蝇蛆蛋白混合物对美洲鳗鲡非特异性免疫功能的影响[J]. 水产科学, 2023, 42(1): 39-47.
CHEN Jie, CHEN Ziting, ZHAO Tian, WANG Fanghai, LI Guanghong. Effects of Maggot Protein Mixture on Non-Specific Immune Function of American Eel Anguilla rostrata. Fisheries Science, 2023, 42(1): 39-47.