增喂无根萍对全州禾花鲤生长、营养及肠道菌群的影响

Effects of Dietary Fresh Wolffia Wolffia globosa on Growth,Nutrition Quality and Intestinal Microbita of Common Carp Cyprinus carpio var.Quanzhounensis

为探究增喂鲜活无根萍对全州禾花鲤生长性能、营养成分、抗氧化能力、肠道菌群结构及其消化酶活性的影响,在相同养殖条件下,将全州禾花鲤幼鱼[体质量(2.44±1.11)g]分为两组,试验组每日投喂饲料+鲜活无根萍,对照组每日仅投喂饲料,养殖期12周后测定全州禾花鲤生长性能、营养成分、抗氧化能力、肠道菌群结构及消化酶活性。试验结果显示,两组全州禾花鲤的肥满度、饲料系数及性腺指数差异不显著(P>0.05),试验组增喂无根萍的全州禾花鲤体质量增加率、特定生长率、肝体指数和肠体指数极显著高于对照组(P<0.01),脾体指数也显著高于对照组(P<0.05)。与对照组相比,增喂无根萍的全州禾花鲤肌肉中粗蛋白和粗脂肪含量显著升高(P<0.01),粗灰分和胆固醇的含量显著降低(P<0.01)。试验组增喂无根萍的全州禾花鲤的肝胰腺总抗氧化能力显著高于对照组(P<0.01)。增喂无根萍对全州禾花鲤肠道菌群的物种多样性、丰富度以及绝对优势菌的菌门数量无影响(P>0.05),显著提高了与粗脂肪和总抗氧化能力正相关的肠球菌属的相对丰度,降低了与胆固醇和粗灰分正相关的弯曲杆菌属的相对丰度;增强了肠道的物质降解、代谢、复制、修复与消化等功能;提高了前肠胰蛋白酶活性(P<0.01)。试验结果表明,日常养殖过程中,增喂鱼体质量2%的鲜活无根萍,可通过提高全州禾花鲤肠道菌群对物质的降解、代谢与消化功能,提高胰蛋白酶活性和总抗氧化能力,进而提高全州禾花鲤生长性能,改善肌肉营养结构,无根萍可作为养殖全州禾花鲤的优质生物增喂饵料。

To investigate the effects of dietary fresh wolffia Wolffia globosa on the growth performance,nutritional composition,antioxidant capacity,gut microbiota structure,and digestive enzyme activity of common carp Cyprinus carpio var.Quanzhouensis,juvenile fish with body weight of(2.44±1.11)g was raised in a 6.55 m×1.58 m×0.90 m aerated cement tank and fed 3%granular feed and 2%fresh wolffia daily at water temperature of(23.00±0.72)℃(experimental group),while in the control group the fish was fed 5%formulated feed per day for 12 weeks when the growth performance,nutritional composition,antioxidant capacity,intestinal microbiota structure,and digestive enzyme activity of the carp were measured.The results showed that there were very significant higher increase in body mass,specific growth rate,hepato-somatic index,and intestinal-somatic index in the common carp in the experimental group than those in the control group(P<0.01),without significant differences in condition factor,feed conversion ratio and gonado-somatic index between the two groups(P>0.05).The spleen-somatic index was significantly higher than those in the control group(P<0.05).Compared with the control group,the contents of crude protein and crude fat in the muscle of the common carp in the experimental group were increased significantly(P<0.01),while the contents of crude ash and cholesterol decreased significantly(P<0.01).The total antioxidant capacity of hepatopancreas(T-AOC)of the fish fed with fresh W.globosa were significantly higher than those of the control group(P<0.01).The W.globosa had no effect on the species diversity and abundance of intestinal microbiota of the common carp and the number of absolute dominant bacteria(P>0.05),but the relative abundance of enterococci positively related to crude fat and total antioxidant capacity were significantly increased,while the relative abundance of campylobacter positively related to cholesterol and crude ash were significantly decreased,the functions of intestinal material degradation,metabolism,replication,repair and digestion were enhanced;while the activity of trypsin in foregut were increased(P<0.01).To sum up,all results suggest that dietary 2%fresh W.globosa can improve the degradation,metabolism and digestion functions of intestinal microbiota of the common carp,promote its trypsin activity and T-AOC,thereby improving its growth performance and the nutritional structure of muscle.W.globosa could be used as a high-quality biological feed for the fish fed in industrial and paddy field cultivation.