【摘要】 【目的】本试验旨在研究日粮精粗比对育肥藏羊小肠真菌多样性的影响。【方法】选择210只健康且体况相近早期断奶藏羔羊,随机分成7组,每组30只,分别对其饲喂精粗比为20∶80、30∶70、40∶60、50:50、60∶40、70∶30和80∶20的基础日粮,预饲期10 d,试验期90 d。试验结束后,每组随机选择3只试验羊屠宰,采集肠道食靡。试验采用16S rDNA基因测序测定肠道菌群,分析肠道真菌丰度和多样性指数。【结果】(1)OTU分布:在97%的物种相似度水平下,7组检测样本共得到499个OTU,其中有351个为7组共有OUT。除E组外各组之间OTU组成差异较小,相似度较高;E组肠道真菌特有OTU最高,有76个。(2)Alpha多样性:E组Shannon指数显著高于B、C组(P<0.05);B、C组Simpson指数显著高于其余各组(P<0.05);B组ACE指数显著高于其余各组(P<0.05);Chaol指数中F组显著高于其余各组(P<0.05)。(3)真菌物种分布:门水平下,子囊菌门是各处理组的优势菌门,占肠道真菌比例超过34%,且C、D和F组显著高于A、B组(P<0.05);担子菌门是次优菌门,B组显著高于其余各组(P<0.05);被孢霉菌门A、B组显著高于其余处理组(P<0.05)。科水平下,被孢霉菌科为藏羊肠道真菌中优势菌科,最高占比超过18%,且A、B组中占比较高(P<0.05);丝孢酵母菌科C、D组显著高于其余各组(P<0.05);黏毛菌科则在低精料处理组(F和G组)中分布较广(P<0.05);酵母菌科则B组显著高于其余各组(P<0.05);G组中红菇科相较其他处理组有较多分布(P<0.05)。【结论】综上所述,日粮精粗比对育肥藏羊肠道真菌菌群定植和结构构建具有显著影响。更多还原

【Abstract】 【Objective】This experiment aimed to study the effect of dietary concentrate to roughage ratio on the diversity of intestinal fungi in fattening Tibetan sheep.【Method】 210 healthy and similar early weaned Tibetan lambs were randomly divided into 7 groups, 30 in each group, they were fed basal diet with concentrate to roughage ratio of 20∶80,30∶70,40∶60,50∶50,60∶40,70∶30 and 80∶20 respectively, the pre feeding period was 10 days, and the experimental period was 90 days.At the end of the experiment, 3 sheep in each group were randomly selected to slaughter and collected intestinal food.16 S rDNA gene sequencing was used to determine the intestinal flora, and the abundance and diversity index of intestinal fungi were analyzed.【Result】(i)OTU distribution: At the 97% species similarity level, a total of 499 OTUs were obtained from 7 groups, among which 351 were shared by 7 groups.Except for group E,the difference of OTU composition among groups was small, and the similarity was high; Group E had the highest OTU of intestinal fungi, with 76 OTUs.(ii) Alpha diversity: Shannon index of group E was significantly higher than that of group B and group C(P<0.05); Simpson index of group B and group C was significantly higher than that of other groups(P<0.05); ACE index of group B was significantly higher than that of other groups(P<0.05); The Chao1 index of group F was significantly higher than that of other groups(P<0.05).(iii) Species distribution of fungi: At the phylum level, Ascomycota was the dominant flora in each treatment group, accounting for more than 34% of intestinal fungi, and the number of Basidiomycetes in groups C,D and F was significantly higher than that in groups A and B(P<0.05); Basidiomycota was the second best flora, which was significantly higher in group B than that in other groups(P<0.05); Group A and group B were significantly higher than those in other groups in Mortierellomycota(P<0.05).At the family level, Mortierellaceae was the dominant family of intestinal fungi in Tibetan sheep, accounting for more than 18%,and the proportion of group A and group B was higher(P<0.05); The distribution of Aspergillaceae in group C and D was significantly higher than that in other groups(P<0.05); Myxotrichaceae was widely distributed in low concentrate treatment groups(F and G)(P<0.05); In group B,Nectriaceaewas significantly higher than that in other groups(P<0.05); In group G,Russulaceae was more distributed than that in other treatment groups(P<0.05).【Conclusion】In conclusion, dietary concentrate to roughage ratio has significant effects on colonization and structure construction of intestinal fungal flora in fattening Tibetan sheep.更多还原