凹凸棒石对锦鲤生长、消化及其肠道菌群的影响

Effects of Attapulgite on Growth,Digestion and Intestinal Flora of Koi Carp Cyprinus carpio

为探明不同凹凸棒石添加量对锦鲤生长性能、消化酶、肠道菌群及组织结构的影响,选取平均体质量为(115.48±3.72)g的健壮无病的锦鲤240尾,随机分成4组,每组3个平行,每个平行20尾,投喂凹凸棒石添加量分别为0%、3%、5%、8%的饲料,试验周期28 d,测定上述指标。试验结果表明:日粮中添加凹凸棒石对锦鲤生长性能无显著影响(P>0.05);凹凸棒石可提高肠道α淀粉酶、脂肪酶、胰蛋白酶活性,3%添加时影响显著(P<0.05);与对照组相比,试验组均提高了肠黏膜皱襞高度和肌层厚度,在3%、5%添加量时效果显著(P<0.05);各组样本测序覆盖率均为99.8%,且稀释曲线逐渐平缓,可知测序结果合理可靠;在门水平上各组共有优势菌有厚壁菌门、变形菌门、梭杆菌门等,在属水平上优势菌为琼杆菌属、芽孢杆菌属、消化链球菌属等,而在不同分类水平上0%、3%添加时群落组成相似度较高,分析显示凹凸棒石可促进有益菌繁殖,改善肠道菌群组成及分布。

In order to investigate the effects of different attapulgite additions on the growth performance,digestive enzyme activities,and intestinal flora and histological structure of koi carp Cyprinus carpio,240 healthy and disease-free koi carp with body weight of(115.48±3.72)g were randomly divided into 4 groups with 3 replicates in each group and 20 fish in each replicate,and fed the basic diet containing 0%(control group),3%,5%and 8%of attapulgite for 28 days.The results showed that dietary attapulgite led to increase the activities of intestinalα-amylase,lipase and trypsin,with significant effect at 0%and 3%groups(P<0.05),even though without significant effect on the growth performance of koi carp(P>0.05).There were increase in the intestinal mucosal fold height and muscle thickness in the test groups compared with the control group,with significant effect at 3%and 5%groups(P<0.05).There were sequencing coverage of 99.8%in samples in each group,and the gradually gentle dilution curve,indicating that the sequencing results were reasonable and reliable.At the phylum level,the dominant bacteria were found to be Firmicutes,Proteobacteria,and Fusobacteria in each group,with the dominant bacteria of Cetobacterium,Bacillus,and Peptostreptococcus at the genus level.At different classification levels,the higher similarity of community composition was observed in the 0%and 3%groups,and the analysis showed that attapulgite promotes the reproduction of beneficial bacteria and improves the composition and distribution of intestinal flora.