4种海藻多糖对鲫鱼生长免疫影响的探究

Effects of Dietary Supplementation of Four Alga Polysaccharides on Growth and Disease Resistance in Crucian Carp Carassius auratus

为研究4种海藻多糖对鲫鱼生长和免疫的影响,将鲫鱼[(50±5)g]暂养2d,随机分为普通饲料组、浒苔组、条斑紫菜组、铜藻组、坛紫菜组5组,每组4个重复,每个平行10尾,准确记录体质量。养殖60d后,注射菌体密度为10~7cfu/mL嗜水气单胞菌,24h后称取鱼的体质量,解剖脾脏称量质量,并取鱼血测定碱性磷酸酶、谷草转氨酶、谷丙转氨酶、总蛋白、球蛋白活性。试验结果显示,浒苔组、条斑紫菜组、铜藻组鱼的质量增加率相比普通饲料组有所提高,其中浒苔组效果最好,质量增加率为47.50%。浒苔组、条斑紫菜组、铜藻组、坛紫菜组鲫鱼的脾体比均有所增加,且浒苔组和条斑紫菜组较好,脾体比增加量分别为23.76%和27.73%,4组培养基中菌落数较普通饲料组有所减少。血液生化检测结果,浒苔组的总蛋白和球蛋白含量均高于普通饲料组。由结果数据分析可以看出,4种海藻多糖在一定程度上可促进鲫鱼生长并能提高其抗病能力。

Crucian carp Carassius auratus were randomly divided into four groups and fed diet containing polysaccharides from algae Enterornorpha proli f era , Porphyra yezoensis , Sargassum horneri and P. hai- tanensis to research effects of four alga polysaccharides on growth and immunity of the fish. After 60 day culture, the body weight was recorded again, and the speen in some samples was also weighted after dis- section. The rest fish were injected with Aeromonas hydrophila at 107cfu/mL and reared for another one day. The bacterial number and activities of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase, and total protein and globulin levels were analyzed in blood. The results showed that there were higher weight gain rates in the fish fed the diets containing E. prolifera,P, yezoensis and S. horneri than that in control group, with the maximum of 47. 5% in E. prolifera group. The spleen--so- matic index in all groups were elevated, especially in the E. prolifera （23. 8%） and P. yezoensis （27. 7%） groups. On the contrary, the number of A. hydrophila in blood was lower in all groups than that in control group. The biochemical test indicated that the content of total protein and globulin in blood of the fish in E. prolifera group were to some extent higher than that in other groups. It is concluded that all the four kinds of seaweed polysaccharides have potential to promote the growth and immunity of crucian carp.