同源湖羊在不同生长环境条件下生长性能和瘤胃内容物微生物组成的差异

Differences of Growth Performance and Rumen Content Microbial Composition of Homologous Hu Sheep under Different GrowingEnvironmental Conditions

本试验旨在探讨不同生长环境对同源湖羊生长性能、瘤胃内容物微生物组成及生物信息的影响。选择遗传背景相似、同胎次的1岁左右的湖羊90只(公∶母=1∶8),其中45只运输至青海省海晏某肉羊繁育基地饲养繁育,另外45只留在山东高密某牧业有限公司饲养繁育。当年配种,次年产羔。2个地方所产的羔羊均75日龄断奶,标记,作为备选试验对象。试验分为2组,山东组(sdlw组)和青海组(qhlw组)。每组按照体重相近的原则挑选90日龄健康湖羊40只,随机均分至4个饲养栏中(公母混养),开始常规饲养试验。预试期10 d,正试期150 d。试验结束后每组随机选取4只公羊剖杀并采集瘤胃液,应用16s RNA技术分析细菌菌群差异及Tax4Fun功能预测。结果表明:1)在饲粮营养物质基础相近的情况下,青海组和山东组平均日增重差异显著(P<0.05),料重比差异显著(P<0.05);饲养在山东和青海的湖羊瘤胃内容物菌群丰富度无显著差异(P>0.05)。2)基于Unweighted Unifrac距离主成分分析(PCoA)发现,山东组和青海组组内物种相似性较大,组间物种多样性方面存在较大差异。3)物种分析发现,2组在门水平上,优势菌门有拟杆菌门、厚壁菌门、绿弯菌门,在属水平上,优势菌属为未鉴定普雷沃氏菌科、未鉴定瘤胃菌科、拟杆菌属;优势菌种为普雷沃菌、瘤胃杆菌、栖瘤胃普雷沃菌。在门水平上,山东组绿弯菌门相对丰度显著高于青海组(P<0.05),在属水平上,青海组未鉴定普雷沃氏菌科相对丰度显著高于山东组(P<0.05);而未鉴定瘤胃菌科相对丰度显著低于山东组(P<0.05)。4)通过LEfSe分析发现,青海组中起重要作用的为普雷沃菌属、普雷沃氏菌科,而山东组中起重要作用的为瘤胃菌科、g_Flexilinea、厌氧绳菌纲、c_Anaerdlineales、绿弯菌纲、厌氧绳菌科。5)通过对生物代谢通路一级功能层分析发现,山东组在环境信息处理、细胞代谢和新陈代谢等代谢通路的基因表达丰度较青海组高;对二级功能层分析发现,山东组在转录、氨基酸代谢、碳水化合物代谢、膜运输、脂质代谢、细胞群落原核生物、新陈代谢、细胞过程和信号传导等方面基因表达丰度明显高于青海组。综上所述,在饲粮营养物质基础相近的情况下,青海组和山东组湖羊平均日增重差异显著,料重比差异显著;不同生长环境可以显著改变同源湖羊瘤胃内容物微生物组成与多样性;饲喂在山东的湖羊在转录、营养物质代谢、氨基酸代谢、碳水化合物代谢、脂质代谢、新陈代谢、膜运输、细胞群落原核生物、细胞过程和信号传导等方面基因丰度的表达优于饲喂在青海的湖羊。

The purpose of this experiment was to investigate the effects of different growing environments on the growth performance,rumen content microbial composition and biological information of the homologous Hu sheep.A total of 90 Hu sheep(male∶female=1∶8)about 1-year-old with similar genetic background and the same birth order were selected and randomly divided into two groups.One group with 45 sheep were transported to a sheep rearing and breeding base in Haiyan,Qinghai province for breeding.Another group with 45 sheep were transported to a sheep rearing and breeding base in Gaomi,Shandong province.They mated in that year and produced lambs in the next year.Lambs produced from both places were weaned at 75 days of age,labeled,and used as candidate test subjects.The experiment was divided into two groups,Shandong group(sdlw group)and Qinghai group(qhlw group).In accordance with the principle of similar weight,40 healthy 90-day-old Hu sheep were selected for each group,and randomly divided into 4 rearing stalls(mixed breeding between male and female)to start the routine feeding experiment.The pre-test period was 10 days,and the formal period was 150 days.At the end of the experiment,4 rams were randomly selected from each group to be dissected to collect rumen fluid,and 16s RNA technology was used to analyze the differences in bacterial microflora of two groups and predict the function of Tax4Fun.The results showed as follows:1)when the dietary nutrient bases were similar,the average daily weight gain in sdlw and qhlw groups is significantly different(P<0.05),and the difference in feed/gain is significant(P<0.05).Besides,the observed species index and Shannon indexe were not significantly different between sdlw and qhlw groups(P>0.05).2)According to the analysis of Unweighted Unifrac distance PCoA,it was found that species in sdlw and qhlw groups were more similar,and species diversity was different between groups.3)According to the species analysis,the dominant species at the level of phylum mainly included Bacteroidetes,Firmicutes and Chloroflex,and the dominant species at the level of genus were the unidentified_Prevotidae,unidentified Rumenaceae and Bacteroides.The dominant species were Prevotella_sp_DJF_CP65,Rumen_Bacterium_NK4A214 and Prevotella_Ruminicola.The relative abundance of Chloroflex in sdlw group was significantly higher than that in qhlw group(P<0.05).However,the relative abundance of unidentified_Prevotellaceae in the qhlw group was significantly higher than that in the sdlw group(P<0.05),and the relative abundance of unidentified_Rumenaceae in the sdlw group was significantly higher than that in the qhlw group(P<0.05).4)LEfSe analysis revealed that the f_Ruminococcaceae,g_Flexilinea,c_Anaerolineae,p_Chloroflexi and f_Anaerolineaceae played an important role in sdlw group.Prevotella_sp_DJF_CP65)and f_Prevotellaceae played an important role in the qhlw group.5)Through the analysis of the first-level functions of biological metabolic pathways,it was found that the gene expression abundance in sdlw group was higher than that in qhlw group in the four biological metabolic pathways of environmental information processing which were metabolism,cellular processes,environmental information_processings and unclassified function,and the gene expression abundance in qhlw group was higher in the aspects of genetic information processing,human disease and organic system.By analyzing the secondary functional layer,it was found that the gene expression abundance in sdlw group was significantly higher than that in qhlw group in transcription,aging,carbohydrate metabolism,biosynthesis of other secondary metabolites,membrane transport,lipid metabolism,cellular community prokaryotes,metabolism of other amino acids,metabolism,cellular processes and signaling,cell motility,cancers,xenobiotics,biodegradation and metabolism,nervous system,amino acid metabolism,signal transduction,genetic information processing.In summary,it was found that in the case of similar dietary nutrient bases,the average daily weight gain of Hu sheep in qhlw and sdlw groups is significantly different,and the feed/gain is significantly different;the regional differences can significantly affect the richness and diversity of Hu sheep.Function prediction shows that the biological metabolism pathway gene expression abundance of Hu sheep fed in Shandong are obviously better than those of Hu sheep fed in Qinghai in transcription,amino acid metabolism,carbohydrate metabolism,membrane transport,lipid metabolism,community prokaryote cells,metabolism,cell signaling,cell activity process and biological degradation et al.