饲料中灵芝提取物对异育银鲫生长、饲料利用、免疫应答及抗病的影响

通过生长实验探求饲料中添加灵芝提取物饲料对异育银鲫（6.720.11） g生长、饲料利用及免疫应答的影响，以及停止灵芝提取物饲料后，使用效果的持续性。在实验进行的第21天（D21）、第46天（D46）、第65天（D65）进行取样，结果表明所有的灵芝提取物组的特定生长率在饲喂65d后与对照组无显著差异（P0.05）。摄食率随着灵芝提取物在饲料中含量的增加而增加（P0.05），饲料效率则有着相反的趋势（P0.05）。在D46和D65时，随着灵芝提取物的含量增高，吞噬活力略有增高，但无显著差异（P0.05）。在D21、D46和D65时，呼吸暴发活力随着灵芝提取物的含量增高而增高（P0.05），在D21时，（0.6%-21d、0%-44d）处理组和（3%-21d、0%-44d）处理组其呼吸暴发活力高于对照组（P0.05）。在D65时，（0.6%-21d、0%-44d）处理组和（3%-21d、0%-44d）处理组其呼吸暴发活力仍高于对照组（P0.05），但差异不显著。D21、D46和D65时，替代途径补体溶血活力随着灵芝提取物的增高而降低（P0.05）。所有处理组溶菌酶活力在D21时没有产生显著差异。在D46时，对照组溶菌酶活力比最高添加组低但高于低添加组（P0.05），（3%-1d、0%-44d）处理组也仍高于对照组（P0.05）。在D65时，所有添加组的溶菌酶活力均低于对照组（P0.05）。在D65时，髓过氧化物酶活力随着灵芝提取物的添加剂量升高而升高（P0.05），（0.6%-21d、0%-44d）处理组仍高于对照组（P0.05）。灵芝提取物的能提高白细胞呼吸暴发活力，且在在高剂量摄入21d后（D46时），仍可以保持较高的活力，说明灵芝提取物对免疫应答有一定时间延续效应。随着灵芝提取物添加量的升高，异育银鲫在经爱德华氏菌攻毒后的存活率显著提高。最高存活率组为3%添加组，显著高于对照组（P0.05）。实验周期为65d时，饲料中灵芝提取物推荐添加剂量为3%。  

EFFECTS OF DIETARY INCLUSION OF EXTRACTS FROM GANODERMA LUCIDUM ON GROWTH PERFORMANCE,IMMUNE RESPONSE AND DISEASE RESISTANCE IN GIBEL CARP (CARASSIUS AURATUS GIBELIO)

To investigate the effects of the administration of a glucan extract from Ganoderma lucidum to gibel carp (Carassius auratus gibelio) on non-specific immune parameters, growth and disease resistance, 5 different treatments were conducted: a) a control diet without any glucan extract for 65 days (0%-65d); b) the control diet with 0.6% glucan extract for 21 days and then switched on the control diet for 44 days (0.6%-21d, 0%-44d); c) the control diet with 0.6% glucan extraction for 65 days (0.6%-65d); d) the control diet with 3.0% glucan extract for 21 days and then switched on the control diet for 44 days (3%-21d, 0%-44d); and e) the control diet with 3.0% glucan extract for 65 days (3%-65d). Each diet was allocated randomly to triplicate groups of fish with an average basal weight of 6.72 g, and each tank (300 L) was stocked with 45 fish. Growth, serum lysozyme, alternative pathway of complement hemolytic activity, blood leucocyte phagocytic activity, respiratory burst, and myeloperoxidase activity were monitored at Day 21, 46 and 65. We observed that glucan extract had no significant effects on s growth rate (SGR) at the end point of the feeding trials (P0.05). In addition, dietary glucan extract increased the respiratory burst (P0.05) while reduced the alternative pathway of complement hemolytic activity (P0.05). The -glucan extract enhanced leucocyte phagocyitc activity in a dose-dependent pattern (P0.05). On Day 65, fish in Treatment C showed the highest survival rate for the challenge of Edwardsiella tarda (P0.05). These results suggested that dietary 3.0% glucan extract supplementation may enhance immunity and disease resistance for gibel carp.