日粮结构对羊瘤胃原虫种群及吞噬速率的影响

本文以4只瘤胃瘘管山羊为试验动物,研究碳水化合物结构对山羊瘤胃发酵、原虫种群结构及吞噬速率的影响。设置精粗比为10∶90、30∶70、50∶50、70∶30的4种日粮(A、B、C、D组),其干物质中中性洗涤纤维(NDF)分别为54.87%、44.23%、33.72%、23.23%。采用4×4拉丁方设计,使用荧光标记细菌技术测定原虫吞噬细菌的速率。结果表明:日粮结构影响瘤胃发酵,以B组微生物活力较强、NDF降解率较高、pH也相对稳定;原虫吞噬速率与日粮NDF含量间呈三次方曲线关系(Y=-0.183065X2-0.003092X3+467.117113,R2=0.86795)。吞噬速率与细菌(原虫)密度呈负(正)相关关系,方程为Y=445.514-3.078X1+1.864X(2R2=0.839、Y为吞噬速率;X1和X2为细菌和原虫密度)。日粮结构显著影响原虫种群结构,内毛虫和等毛虫随NDF含量降低而增高,而双毛虫和头毛虫则相反。内毛虫与双毛虫和头毛虫的吞噬速率分别为361.9、606.3个/h和607.5个/h,种属间差异显著,但不同种属吞噬速率随日粮结构变化的趋势基本一致。综上所述,日粮结构可以引起瘤胃发酵状态的改变,从而影响原虫种群结构和吞噬速率。     

用荧光标记细菌法研究丝兰提取物对瘤胃原虫对细菌吞噬的影响

采用荧光染色标记细菌(fluorescence labeled bacteria,FLB)技术,研究山羊瘤胃中原虫对细菌的吞噬速率.试验选用3头装有永久瘘管的徐淮山羊作为瘤胃液供体,采用体外培养法研究在精粗比为1:9的情况下,探讨不同丝兰提取物水平(A组0 mg/L、B组35 mg/L、C组70 mg/L)对瘤胃原虫吞噬细菌速率的影响.荧光镜检与回归分析结果表明:原虫吞噬细菌的速率:A组:339.9 cells/(cell·h);B组:314.7 cells/(cell·h);C组:339.9 cells/(cell·h).结果表明荧光标记细菌技术能够应用于瘤胃原虫吞噬细菌速率的研究.[动物营养学报,2009,21(3):417-422][中文全文见<动物营养学报>网站(www.ChinaJAN.com)中文版2009年21卷3期]     

4种油脂对瘤胃原虫群体和纤维降解菌的影响

试验旨在研究不同油脂对体外培养瘤胃原虫群体结构、纤维降解菌及纤维素降解性能的影响。以3头瘤胃瘘管山羊为瘤胃液供体,分对照、菜籽油(A)、豆油(B)、玉米油(C)、花生油(D)5组体外培养。结果表明:各组间原虫密度差异显著(P<0.05),A到D组有依次上升的趋势;内毛虫、等毛虫、双毛虫、前毛虫等类群原虫组间变化显著(P<0.05)。4种油脂对产琥珀酸拟杆菌、白色瘤胃球菌、生黄瘤胃球菌的影响不大,B组溶纤丁弧菌显著高于对照组(P<0.05)。A组的4种纤维降解菌基本都显著低于对照组与其他试验组(P<0.05)。总之,添加4%的油脂除菜籽油外对纤维降解性能没有明显的负面影响,均对微生物的群体结构有不同程度的影响。     

蛋白质来源对瘤胃细菌和原虫群体结构的影响

以4只瘘管山羊为试验动物,采用4×4拉丁方设计,使用克隆测序、遗传指纹以及细胞显微计数等技术,研究以羽毛粉(A)、玉米蛋白粉(B)、豆粕(C)和鱼粉(D)4种蛋白补充料分别配合的混合日粮对瘤胃细菌和原虫群体结构的影响。结果表明:细菌的R.flavefaciens、R.bromii、R-7、Roseburia faecalis、Uncultured T33H60F48、Uncultured GRANT42及1个尚不能定性的类群在组间存在显著差异(P<0.05);原虫的内毛虫、前毛虫、头毛虫、等毛虫4个类群在处理间差异显著(P<0.05)。综上可见,蛋白质源对瘤胃细菌和原虫类群结构有显著影响。     

~(15)N标记法研究不同精粗比底物对山羊瘤胃内原虫与细菌间蛋白质微循环的影响

以4头安装永久瘤胃瘘管的徐淮山羊为试验动物,运用15N稳定性同位素示踪技术,研究了1∶9(A)、3∶7(B)、5∶5(C)、7∶3(D)四种精粗比底物下瘤胃原虫与细菌间蛋白质微循环的影响。结果表明:不同精粗比底物显著影响瘤胃内原虫的吞噬量及微生物蛋白(MCP)的微循环,A、B、C、D四组吞噬N量分别为:18.11×105、21.16×105、20.95×105、30.34×105pg/(mL·h)。每天每头山羊由于原虫的吞噬造成的细菌蛋白循环量分别为:1.09、1.27、1.26、1.82g,其中以C组循环率最大(2.79%),D组蛋白质循环量最高,而B组循环率最低(1.94%),且蛋白质周转量仅为D组的69.78%,可有效减少菌体蛋白循环量。     

用荧光标记法研究瘤胃原虫吞噬细菌的初探

采用荧光染色技术研究山羊瘤胃中原虫对细菌的吞噬速率。试验设置精粗比分别为10:90和50:50的A、B两组,结果表明:吞噬速率A组、B组分别为106.2、184.2cells(/cell.h),换算为细菌N为0.57、0.99pgN(/cell.h);而每天每头羊由原虫在瘤胃内循环中带出的细菌N损失A组、B组分别为4.32、32.07mgN(/d.只)。     

荧光光度法在瘤胃原虫对细菌吞噬作用研究中的应用

本试验旨在探讨荧光光度法研究瘤胃原虫对细菌吞噬作用的可行性.试验选用4只装有永久性瘤胃瘘管的徐淮山羊采集瘤胃液以获取瘤胃原虫和细菌,以4,6-二脒基-2-苯基吲哚(DAPI)标记细菌的荧光强度为主要测定指标,研究山羊瘤胃中原虫对细菌的吞噬作用.结果表明,DAPI标记的瘤胃细菌浓度与其荧光强度之间存在线性相关(R2=0.995 2).在日粮粗精比为7:3的条件下,徐淮山羊瘤胃原虫对细菌的吞噬速率为370.89 cells/(cell·h),瘤胃内原虫对细菌的吞噬速率存在一定的波动性,吞噬量在60 min达到饱和,其最大吞噬量为370,89 ceIls/cell.结果提示,荧光光度法可应用于瘤胃原虫对细菌吞噬作用的研究.     

不同长链脂肪酸组合对体外瘤胃细菌发酵和群体结构的影响

本试验旨在研究不同长链脂肪酸组合对体外培养瘤胃细菌发酵和群体结构的影响。以3头瘤胃瘘管奶牛提供瘤胃液,对照(A)组底物含5%脂肪酸钙,试验组培养底物中硬脂酸、油酸、亚油酸和亚麻酸的含量分别为1.5%、1.0%、0.5%和1.5%(B组),1.5%、1.0%、1.5%和1.0%(C组),1.0%、1.5%、1.5%和0.5%(D组)以及1.5%、0.5%、0.5%和1.0%(E组)。在培养后0、3、6、12、18、24 h采集培养液,测定p H、氨氮浓度和瘤胃细菌含量。结果表明:1)培养液p H在组间的差异不显著(P0.05);C组的培养液氨氮浓度显著高于B、D组(P0.05)。2)除白色瘤胃球菌,其他菌属含量在组间存在显著差异(P0.05)。其中琥珀酸拟杆菌、生黄瘤胃球菌、蛋白溶解梭菌和嗜淀粉瘤胃杆菌含量在B组较高;C组溶纤维丁酸弧菌、埃氏巨球菌、降解淀粉瘤胃球菌以及瘤胃总细菌含量显著高于其他各组(P0.05)。培养液埃氏巨球菌含量最高,为优势菌。综合得出,脂肪酸组合对瘤胃总细菌和大部分细菌种属含量有显著影响,这与发酵模式有关。     

体外驱除瘤胃厌氧真菌对绵羊和山羊细菌、原虫及稻草干物质降解率的影响

选择体况良好、体重30kg左右、安装有永久性瘤胃瘘管的内蒙古白绒山羊和内蒙古土种去势绵羊各3只作为供体羊,为体外批次培养提供瘤胃液。比较研究了驱除瘤胃厌氧真菌对绵羊和山羊细菌、原虫及稻草干物质降解率的影响。结果表明:对照组(F0组)绵羊瘤胃液中真菌游动孢子数量多于对照组山羊瘤胃液;且在培养的2、4、6、48、72小时差异显著(P<0.05)。在培养初期(0～12小时)山羊F0组和F2组(驱真菌组)细菌总数均高于绵羊;绵羊和山羊驱真菌组(F2组)细菌总数均高于对照组(F0组)。山羊F0组(对照组)原虫数量各时间点的平均数显著高于绵羊F0组(P<0.05)。驱除厌氧真菌后绵羊和山羊对稻草干物质降解率显著下降,分别下降了12.06%和8.62%。这说明瘤胃厌氧真菌在纤维物质降解过程中的确发挥了重要作用。     

荧光染色标记细菌法对瘤胃原虫吞噬细菌速率的研究

采用荧光染色标记细菌(fluorescence labeled bacteria,FLB)技术研究山羊瘤胃中原虫对细菌的吞噬速率。试验设置精粗比为30:70的试验日粮,结果表明:原虫吞噬细菌速率为207个/h,换算为细菌N为1.118pgN/h;而每头羊由原虫在瘤胃内循环中带出的细菌N损失为53.654mgN/d,或者细菌蛋白损失为0.335gPr/d。结果证明,荧光染色标记细菌技术可以应用于瘤胃原虫对细菌吞噬速率的研究。     

Fatty acid composition of ruminal bacteria and protozoa, with emphasis on conjugated linoleic acid, vaccenic acid, and odd-chain and branched-chain fatty acids

Knowledge of the fatty acid profile of microbial lipids is of great nutritional importance to the animals and, subsequently, their products. This study was conducted to examine the fatty acid profiles of mixed rumen bacteria and protozoa. Bacterial and protozoal cells were isolated by differential centrifugation of rumen contents. The main fatty acids were palmitic (16:0) and stearic (18:0) in both the bacterial and protozoal fractions. Palmitic acid was 74% greater in the protozoal fatty acids than in the bacterial fatty acids, whereas bacteria had 2.25-times greater stearic acid (18:0) proportions compared with protozoa. The total odd-chain plus branched-chain fatty acids were 16.5% of bacterial fatty acids and 11.0% of protozoal fatty acids. The anteiso-17:0 proportions in bacterial and protozoal fatty acids were 1.4 and 2.9%, respectively. The most abundant trans-18:1 isomer, vaccenic acid (18:1 trans-11), was 6.6% of total fatty acids in protozoa and 2.0% of total fatty acids in bacteria. The cis-9, trans-11 CLA was 8.6-times greater in the protozoal fraction (1.32% of total fatty acids) than in the bacterial fraction (0.15%). These results suggest that the presence of protozoa in the rumen may increase the supply of CLA and other unsaturated fatty acids for lower gut absorption by ruminants.     

Amino acid and fatty acid composition of microorganisms passing into the abomasum of sheep

The bacterial and protozoal fractions were isolated by a differential centrifugation method from daily samples of chyme passing into the abomasum from the forestomach of sheep. The mean values for the nitrogen content (percentage of dry matter) were 8.3 ± 0.2% for the bacterial fraction and 5.3 ± 0.2% for the protozoal fraction. They were not significantly affected by the different products, methionine, lysine or starch, added to the basal ration. The amino acid composition of the bacterial and protozoal proteins was relatively constant, though some slight variations in certain amino acids were observed in relation to the nature of the supplements.The total lipid content ranged from 5.42 to 8.85% of the dry matter for the bacterial fraction. Its mean value was 9.63% for the protozoal fraction. It was not affected significantly by the supplements. Free fatty acids dominate the lipid composition of bacteria and phospholipids dominate in that of protozoa. The principal fatty acids of protozoal lipids were palmitic acid (41.32%) and oleic acid (19.33%).     

Fatty acid composition of ruminal bacteria and protozoa,and effect of defaunation on fatty acid profile in the rumen with special reference to conjugated linoleic acid in cattle

Objectives of this study were to compare fatty acid (FA) composition of ruminal bacterial (B) and protozoal (P) cells, and to investigate effect of protozoa on FA profile in the rumen of cattle. Three cows were used to prepare ruminal B and P cells. Four faunated and three defaunated cattle (half‐siblings) were used to study effect of protozoa on ruminal FA profile. Proportions of C16:0 and C18:0 in total fatty acids in B cells were 20.7% and 37.4%, whereas those in P cells were 33.4% and 11.6%, respectively. Proportions of trans‐vaccenic acid (VA) and cis‐9, trans‐11 conjugated linoleic acid (CLA) in B cells were 3.9% and 1.0%, and those in P cells were 5.5% and 1.6%, respectively, being higher in P cells. Proportions of C18:1, C18:2 and C18:3 in P cells were two to three times higher than in B cells. Proportions of unsaturated fatty acids, VA and CLA in B cells of faunated cattle were higher than those of defaunated. VA and CLA in the ruminal fluid of faunated were also 1.6 to 2.5 times higher than those of defaunated. This tendency was similar for cell‐free fraction of ruminal fluid. These results indicate that protozoa contribute greatly in VA and CLA production in the rumen.     

日粮不同蛋白质来源对山羊瘤胃微生物氨基酸组成的影响

本文主要研究不同蛋白质饲料对瘤胃微生物蛋白产量及其氨基酸(AA)组成模式影响的规律.以4只瘘管山羊作为试验动物,分为A组(羽毛粉组)、B组(玉米蛋白粉组)、C组(豆粕组)和D组(鱼粉组)4个组,进行4×4拉丁方试验.结果表明:不同蛋白质饲料显著影响瘤胃微生物蛋白的量,以豆粕组最高,为13.975 0 mg/mL,羽毛粉组最低,为10.765 0 mg/mL(P<0.01).微生物蛋白中AA-N的含量也受蛋白质来源的影响,豆粕组AA-N比例最低,而鱼粉组最高.进一步回归分析表明AA-N的含量与细菌(原虫)蛋白有负(正)相关关系,回归方程为Y=15.469-1.098X1+1.498X2(R2=0.944).研究还发现微生物蛋白的AA组成模式在不同蛋白质处理以及微生物区系间有差异.原虫蛋白的Val含量高于细菌,而细菌蛋白的Lys含量则高于原虫.细菌蛋白的Arg含量,原虫蛋白的Met、Leu和His含量在各组间差异显著.AA的变化与微生物类群的变化有一定的关联.因此,日粮蛋白质对瘤胃微生物蛋白产量和微生物从组成都有一定的影响.     

In vitro effects of individual fatty acids on protozoal numbers and on fermentation products in ruminal fluid from cattle fed a high-concentrate, barley-based diet

The objective of this study was to investigate the effects of sodium salts of individual fatty acids on protozoal numbers and ruminal fermentation variables in vitro. Ruminal inoculum was obtained from two heifers fed a finishing diet consisting of (DM basis) 90% rolled barley grain, 4% barley silage, 5% soybean meal, and 1% mineralized salt. Fatty acids (FA) were included individually in the inoculum as follows: C6:0, C8:0, and C10:0 at concentrations (wt/vol) of 0.0625, 0.125, and 0.25%; C14:0 and C18:0 at concentrations of 0.125, 0.25, and 0.5%; and C12:0, C16:0, C18:1, C18:2, and C18:3 at concentrations of 0.25, 0.5, and 1.0%. 15N-Labeled casein was included as a N tracer. In the presence of medium-chain saturated FA (particularly C10:0 and C12:0), no ciliate protozoa (99.8%Entodinium spp.) were recovered from the incubation medium. Long-chain unsaturated FA (C18:3, C18:2, C18:1) also decreased (P < 0.05) protozoal numbers. At all concentrations tested, C10:0 and C12:0 decreased (P < 0.05) ammonia and total VFA concentrations (by 29 and 22%, respectively) and increased (P < 0.05) concentrations of total free amino acids, reducing sugars, and soluble protein. At the greatest concentrations of these FA, xylanase and amylase activities of the incubation media were decreased (P < 0.05). The C18 unsaturated FA increased (P < 0.05) the polysaccharide-degrading activities of the media. These in vitro results suggest that long-chain unsaturated FA in combination with medium-chain saturated acids have the potential to decrease protozoal numbers and ruminal ammonia utilization in cattle fed high-grain diets.     

ITS1 rDNA序列用于瘤胃原虫研究可行性的探讨

文章主要探讨瘤胃原虫rDNA序列的ITS1区段用于其群体研究的可行性和有效性。试验1由3只瘘管山羊提供瘤胃液、以不同结构碳水化合物底物(可溶性淀粉/滤纸纤维:A,100:0、B,70:30、C,50:50、D,30:70、E,0:100)进行体外培养;试验2以4只瘘管山羊为试验动物,以A(鱼粉)、B(羽毛粉)、C(玉米蛋白粉)和D(豆粕)等蛋白质饲料配制的4种等氮日粮进行4×4拉丁方试验,采用ITS1rDNA序列的遗传指纹检测及细胞计数技术研究原虫群体组成的变化。遗传指纹检测结果表明,在试验1不同碳水化合物结构底物培养条件下或在试验2不同蛋白日粮条件下,原虫群体组成都发生了变化。细胞计数的研究结果与之一致。依据本研究结果可见,ITS1rDNA序列是原虫研究的良好素材。     

不同油脂对瘤胃原虫、细菌蛋白质及DNA影响的研究

试验旨在研究饱和程度不同的油脂对瘤胃原虫、细菌蛋白质及DNA的影响。试验以3头瘘管山羊提供瘤胃液,设置对照组、花生油、菜油、玉米油和豆油等进行体外培养0、4、8、16、24 h取样,TCA法测定原虫与细菌的蛋白质,二苯胺显色法测定其DNA。结果表明:除细菌蛋白外,细菌DNA、原虫蛋白和DNA、微生物蛋白和DNA、原虫/细菌区系等指标的均值在组间差异都不显著(P>0.05),但各项指标随培养时间延长在取样时点间都有显著或极显著的纵向差异(P<0.05、P<0.01)。各组微生物蛋白或DNA在数值上的高低顺序基本一致,皆为豆油>玉米油>花生油>对照组>菜籽油;而原虫/细菌则以对照组最高,菜籽油组次之,玉米油、豆油组较低。相关分析表明,细菌蛋白与DNA间、微生物蛋白与DNA间皆相关显著(2-tail<0.05)。     

Incorporation of soya oil hydrolysate in the diet of defaunated or refaunated sheep: effect on rumen fermentation in vitro

The effects of incorporation in the diet of 7% soya oil hydrolysate (SOH) on in vitro incubations of cellobiose + maltose, maize starch and casein by rumen microbes were studied using defaunated and refaunated sheep as rumen fluid donors. Feeding refaunated sheep the SOH supplemented diet lowered the protozoal numbers in the rumen from 1.61 10(6)/ml to 6.1 10(5)/ml. SOH addition reduced in vitro methane production, rather by a depletion of methanogens is than by a simple inhibition of their activity. This reduction seemed to be independent of protozoa depletion. With cellobiose-maltose and maize starch incubations, SOH supplementation increased molar proportion of propionate while acetate decreased. Both variations could be linked to the inhibition of methanogenesis. Volatile fatty acid production from casein was strongly reduced by SOH supplementation with or without protozoa in the rumen of the donors animals.