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1.
The objective of the present study was, to investigate the effect of varying conditions of differential centrifugation of duodenal content on the isolation of bacteria (B-fraction) and feed particles + protozoa (FP-fraction). The treatments at low-speed centrifugation were as follows: 100 x g/5 min, 400 x g/10 min, 1000 x g/10 min and 2000 x g/10 min, high speed conditions were 30,000 x g/30 min/4 degrees C. The results of three experiments are given. Analytical examination gave similar results for N-contents for all treatments, the mean values being 7.90 +/- 0.27% (n = 12) for B-fractions and 6.53 +/- 0.73% (n = 12) for FP-fractions. Increasing the low-speed from 100 x g to 2000 x g lead to increasing DAP-contents and decreasing N:DAP-ratios of the bacterial isolates, the values being 2.43, 3.02, 3.22 and 3.39 mg DAP/g DM and 32.0, 27.4, 25.0 and 23.0 N:DAP-ratio. Decreased isolation of bacterial material in the B-fraction in conjunction with increased incorporation in the FP-fraction resulted in rising the speed of the low speed centrifugation. The rates of loss of DAP, measured by comparison with the total amount were 10, 32, 48 and 70% respectively. It was concluded to prefer the isolation of bacteria from rumen fluid. 相似文献
2.
旨在研究不同饲粮条件下湖北黑头羊瘤胃细菌多样性及群落结构。选取15只健康的湖北黑头山羊公羊,随机分为5组,每组3只,分别饲喂花生藤(A组)、苜蓿(B组)、苜蓿+花生藤(C组)为粗饲料来源的颗粒型全混合日粮以及进口苜蓿草颗粒(D组)和新疆苜蓿草颗粒(E组),试验期共45 d,其中预试期15 d。在试验结束后第1天,经口腔抽取瘤胃液抽提基因组DNA,采用Illumina Miseq PE300平台对瘤胃细菌进行分析。结果表明:1)在97%相似性水平下,5组样品共产生851个操作分类单元(OTU),共享295个OTU,占瘤胃液细菌总OTU数目的34.67%,D组在各组中α多样性指数指标(Ace指数、Chao1指数和Shannnon指数)最高,而3组颗粒型全混合日粮中A、C组高于B组(P<0.05,P<0.01);2)瘤胃中拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)、无壁菌门(Tenericutes)为各组优势菌门,D组中的拟杆菌门显著高于B组(P<0.05),而厚壁菌门显著低于D组(P<0.05),而A、B、C组间拟杆菌门、厚壁菌门含量差异不显著(P>0.05);3)普雷沃氏菌属1(Prevotella_1)、1种未鉴定的属(Unidentified genus)、理研菌属RC9(Rikenellaceae_RC9_gut_group)为优势菌属,其中D组普雷沃氏菌属含量较高,A组与C组,D组与E组的遗传距离更接近。综合得出,苜蓿草颗粒品质和颗粒型全混合日粮中精料含量能影响湖北黑头羊瘤胃细菌的多样性;全苜蓿饲粮条件下湖北黑头羊瘤胃存在独特的细菌群落结构,细菌多样性最高。 相似文献
3.
The goal of this study was to determine the effects of the fermented juice of epiphytic lactic acid bacteria (FJLB) on the quality of total mixed ration (TMR) silage containing agricultural by-products, its digestibility, rumen fermentation, and nitrogen balance in ewes. TMR was prepared from rice straw, corn stover silage, brewer grain, tofu waste, steam-flaked corn, and a mineral mixture. The treatments consisted of silage additives added to TMR: CON (no silage additive), FJLB, COM (commercial additive), and MIX (FJLB + COM). Four cannulated ewes were assigned to the 4 × 4 Latin square design. The MIX treatment produced a lower (P < 0.01) pH than did the CON and FJLB treatments and a higher (P < 0.01) lactic acid concentration than did the other treatments. The fiber content in the COM treatment was lower (P < 0.05) than that in the other treatments. The FJLB treatment had similar fermentation quality and chemical composition to those of the CON and COM treatments in all parameters observed. Although the silage quality index (Fleig point) was higher in the MIX and COM treatments than in the CON treatment, all silages had good quality. No silage additives affected intake, digestibility, rumen fermentation, or nitrogen balance. In conclusion, the TMR silage prepared from agricultural by-products mixed with wet-type food by-products with or without FJLB added resulted in well-preserved fermentation, and this product might be used as a ruminant feed. 相似文献
4.
本文旨在研究不同剂量的瘤胃细菌培养物对荷斯坦奶牛瘤胃发酵及菌体蛋白(BCP)含量的影响。试验采用单因素试验设计,选用4头装有永久性瘤胃瘘管,体况相近的荷斯坦奶牛,取其瘤胃液混匀,添加不同剂量的瘤胃细菌培养物进行体外培养,分别为:对照组(0 CUF/g),试验Ⅰ组(添加量为3%,4.4×108CUF/g),试验Ⅱ组(添加量为5%,7.8×108CUF/g),试验Ⅲ组(添加量为10%,1.2×109CUF/g),每组分别设2、4、8、12、24、36、48 h 7个指标测定时间点,每个时间点3个重复。结果表明:(1)添加瘤胃细菌培养物使瘤胃液pH有所降低,但始终在6.5~7.0,对瘤胃内环境无不良影响;(2)添加3%的瘤胃细菌培养物显著降低氨态氮(NH3-N)的含量(P<0.05),显著增加了培养液BCP的浓度(P<0.05);(3)添加3%的瘤胃细菌培养物可一定程度增加总挥发性脂肪酸(TVFA)和乙酸浓度,但对其他各挥发性脂肪酸及乙酸/丙酸比值无显著影响。由此可见,添加3%剂量的瘤胃细菌培养物可改变瘤胃的发酵环境,提高BCP浓度。 相似文献
5.
试验通过研究不同酸度的乳酸菌添加剂对6月龄梅花鹿的采食量、氮平衡、消化率以及小肠微生物氮流量的影响,确定乳酸菌添加剂在梅花鹿饲喂中的适宜酸度。结果表明:添加不同酸度的乳酸菌可明显提高梅花鹿对DM、OM、CF、CP以及氮采食量(P<0.05),其中以未调酸的乳酸菌组各种营养成分采食量最高;DM、OM、CF采食量,各组间差异显著(P<0.05),氮的采食量,除调酸组与未调酸组间差异不显著外(P>0.05),其余各组间差异显著(P<0.05)。不同酸度的乳酸菌饲料添加剂可提高梅花鹿DOM、DCF、氮沉积以及小肠微生物氮流量,未调酸组的DOM、DCF、氮沉积以及小肠微生物氮流量显著高于对照组(P<0.05)。 相似文献
6.
结合体外发酵和瘤胃尼龙袋法,研究了本地山羊瘤胃厌氧真菌对木质素含量不同底物(黑麦草叶、黑麦草茎、稻草秸、花生壳,木质素含量依次上升)的附着及发酵特性.结果表明,随体外发酵的进行,真菌数量逐渐增加,以黑麦草叶、黑麦草茎、稻草秸为底物时,瘤胃真菌数量均在48 h达到最大值,且真菌数量的最大值随底物木质素含量的上升呈下降趋势.显微观察显示,体外发酵前72 h附着于稻草秸表面孢子囊数量均显著高于黑麦草叶和黑麦草茎(P<0.05),而切缘孢子囊数量三者差异不显著.瘤胃内培养结果表明,稻草秸切缘和表面孢子囊数量均在48 h时最大,72 h后数量显著下降(P<0.05),而黑麦草茎切缘和表面上的孢子囊数量均在24 h 时最大,72 h后数量显著下降(P<0.05);稻草秸切缘和表面上孢子囊数量均要高于黑麦草茎上的数量.不同底物进行厌氧真菌体外发酵时其累计产气量、干物质消失率和纤维素消失率差异均不显著,但在瘤胃内培养时,各底物的干物质消失率则随底物木质素含量的上升而显著下降(P<0.05). 相似文献
7.
An anaerobic in vitro study of tyrosine (Tyr) metabolism by rumen bacteria (B), protozoa (P) and their mixture (BP) was conducted using an HPLC analytical method to obtain some basic and systematic information on aromatic amino acid metabolism in the rumen. Most of the Tyr (> 96%) disappeared after 12 h incubation in B and BP, but only 58% in P. Tyr was converted mainly to p‐hydroxyphenylacetic acid (HPA) in all microbial suspensions. About 45% of disappeared Tyr in B and P, and about 35% in BP were converted to HPA. An appreciable amount of phenylalanine (Phe), 13 and 3% of disappeared Tyr, and a small amount of tryptophan (Trp), 8 and 1% of disappeared Tyr, were also produced from Tyr by rumen bacteria and protozoa, respectively. Small amounts of p‐hydroxyphenylpyruvic acid (about 4 and 6% of disappeared Tyr) were produced from Tyr in B and P, respectively. A moderately large amount of phenylacetic acid (14% of disappeared Tyr) was produced from Tyr in P which was 1.9 times higher than that in B. Phenylpropionic acid and p‐hydroxybenzoic acid were produced only in B and BP. It was concluded that the Tyr degradation ability of rumen bacteria was about 1.5 times higher than that of rumen protozoa. Degraded Tyr mainly produces HPA and then two other aromatic amino acids, Phe and Trp, which are considered essential amino acids for ruminants. Therefore, it is speculated that the requirement for Phe and Trp in ruminants may be partially fulfilled if Tyr is sufficiently supplied in rations. 相似文献
8.
In different experiments, the nutritive value of maize silage associated with urea was compared with that of the same forage associated with soybean meal. The ammonia concentration in the rumen fluid was measured with two dry cows fitted with a permanent rumen cannula. Urea gave rise to much higher NH3 concentrations compared with soybean meal. The duodenal N flow was measured with two dry cows fitted with a re-entrant cannula at 10 cm from the pylorus. Adding increasing amounts of either of the two N supplements to the maize silage showed that they were equivalent with low N intakes. However, clearly more N reached the intestine with soybean meal than with urea when the N intake increased. With 33 cows in the second part of lactation, the substitution of soybean meal for urea decreased the urinary N loss. At the same time, it significantly increased the mammary protein secretion and the milk production. The increase of the dietary metabolizable energy density noted under these feeding conditions corresponded to about two thirds of the increase of the milk production. Milk composition was only slightly affected. 相似文献
9.
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. 相似文献
10.
对6株溶磷菌和4株固氮菌混合培养,选择最适培养条件即温度,pH和盐分,为确定促生菌的最佳发酵条件和生态适应性评价提供依据。结果表明:溶磷菌和固氮菌单独培养或混合培养最适温度在25-35℃,混合培养较单独培养生长良好;溶磷菌和固氮菌单独培养或混合培养最适pH为6.5~7.5,在pH7.5~8.5偏碱性环境下,混合培养生长... 相似文献
11.
此研究表明豆粕、鱼粉总氨基酸与粗蛋白的比例较高,分别为92.13%和83.26%;而玉米蛋白粉相对较低,为63.34%。必需氨基酸含量鱼粉最高,为48.7%;豆粕次之,为41.4%;玉米蛋白粉最低,为37.21%。此外,不同饲料蛋白质的瘤胃消失规律不尽相同。豆粕蛋白质瘤胃消失率在2h就已经很高,以后直线上升,48h时基本完全降解;鱼粉和玉米蛋白粉的蛋白质消失率在48h前一直很低,降解缓慢。在2h、6h和12h时间点组间比较,豆粕与鱼粉具有非常相似的瘤胃降解率,而玉米蛋白粉则在此期间内具有更低的瘤胃降解率。从72h时间点的瘤胃降解率可以看出,豆粕降解最高(98.12%)、玉米蛋白粉次之(96.67%)、鱼粉最低(82.36%)。 相似文献
12.
Three sources of N fertilizer (urea, limestone ammonium nitrate (LAN) and ammonium sulphate) showed no consistent significant trends in terms of the dry matter yield and nitrogen or nitrate‐N content of midmar ryegrass. Ammonium sulphate was found to acidify the soil markedly, relative to urea, with LAN showing the least acidifying effect. 相似文献
13.
本研究以4头装有永久性瘤胃瘘管的徐淮山羊为试验对象,利用体外培养法研究了不同氨基酸模式(A 组:微生物蛋白必需氨基酸模式,B组:90%微生物蛋白必需氨基酸模式+10%山羊肌肉必需氨基酸模式,C组:80%微生物蛋白必需氨基酸模式+20%山羊肌肉必需氨基酸模式.D组:70%微生物蛋白必需氨基酸模式+30%山羊肌肉必需氨基酸模式)对瘤胃微生物生长及其发酵特征的影响.结果表明:氨基酸模式影响瘤胃微生物发酵.培养液pH值、氨氮(NH3-N)浓度以及尿素(氧)(UN)各组间存在显著差异(P<0.05).并且随培养时间的动态变化模式也是不一致的;培养液中总挥发性脂肪酸(TVFA)以C组最高,从乙酸/丙酸值来看,乙丙比接近3:1,乙酸和丙酸处于相对平衡的状态,各组间差异不显著(P>0.05).原虫/细茵(P/B)值以及游离氨基酸(AA-N)各组之间差异显著(P<0.05).氨基酸模式对瘤胃微生物的生长有一定影响,B组的氨基酸模式对微生物生长促进作用最大.综合以上试验结果可以认为氨基酸组成的不同可以影响瘤胃微生物生长以及发酵. 相似文献
14.
An in vitro study was conducted to quantitatively investigate the metabolism of pipecolic acid (Pip), a neuromodulator, by mixed rumen bacteria (B), mixed rumen protozoa (P), a combination of B and P (BP), species‐enriched rumen protozoal suspension ( Polyplastron sp., Diploplastron sp., entodinia and Entodinium caudatum) and pure cultures of several isolates of rumen bacteria ( Prevetolla bryantii, Prevetolla albensis, Streptococcus bovis, Veillonella parvula, Megasphaera elsdenii and Ruminococcus albus). Only P produced Pip from L‐lysine (1.0 mmol/L L‐Lys) at a rate of 83.5 ± 1.6 µmol/L/h and even in BP, Pip was produced from L‐Lys by P and increased at a rate of 31.2 ± 3.8 µmol/L/h. Pip production by P was highest when the substrate (L‐Lys) concentration was 6 mmol/L and then the rate was 580 ± 36 µmol/L/h. Pipecolic acid production by P suspension enriched with different species of protozoa showed that Polyplastron sp. had the highest Pip production rate of 0.907 ± 0.092 µmol/L/mg protozoal protein per h, and Diploplastron sp. had the lowest rate of 0.55 ± 0.13 µmol/L/mg protozoal protein per h. The addition of D‐Lys (1.0 mmol/L) as a substrate to the P suspension revealed that P were also able to produce Pip from D‐Lys, though at a lower rate (1/3) compared with L‐Lys (1.0 mmol/L), suggesting the presence of epimerases in P. It was confirmed that B were unable to produce Pip from L‐ or D‐Lys. Only B degraded Pip (1.0 mmol/L) after a lag phase at a rate of 56.0 ± 1.5 µmol/L/h. The B suspension was able to degrade D‐Lys, though the products were not identified. Pip degradation by pure culture of some species of rumen bacteria showed that P. bryantii and R. albus had the highest rate followed by P. albensis, S. bovis and M. elsdenii with a low rate of Pip degradation. Veillonella parvula showed no ability to degrade Pip. The results suggest that a fairly large proportion of rumen‐produced Pip is likely to be absorbed by the host animal before degradation by rumen bacteria. 相似文献
16.
研究探讨日粮添加花生油、玉米油和大豆油对绵羊瘤胃发酵和营养物质表观消化率的影响.选取4只雄性、健康且安装有永久性瘤胃瘘管的成年东北半细毛羊×陶赛特杂交绵羊,体重(40±1)kg,采用4×4拉丁方试验设计,预饲期10 d,正试期6 d,4个处理组分别为不添加油脂组(CK组)、添加4%花生油(PO组)、2.84%玉米油(CO组)和2.86%大豆油(SO组)的加油组,日粮精粗比均为40:60,经测得3个加油组亚油酸水平一致.结果表明:添加植物油后,对绵羊瘤胃液pH值、NH3-N浓度、VFA没有影响(P>0.05),花生油处理组原虫数量比对照组降低了42.18%(P<0.05),玉米油和大豆油处理组原虫数量分别比对照纽降低28.07%、29.81%(P>0.05);对DM、CP和NDF的瘤胃动态降解率没有影响(P>0.05);对日粮DM、CP、NDF和ADF的全消化道表观消化率没有影响,显著提高了EE的全消化道表观消化率(P<0.05).日粮添加植物油对瘤胃发酵没有负面影响,并显著提高了EE的全消化道表观消化率. 相似文献
17.
通过对高寒牧草内生细菌的分离培养方法研究,得出了优化的分离培养条件,即牧草不同组织器官用0.19/6SDS浸泡15min、3%NaClO浸泡3min、0.1%升汞浸泡10min、75%酒精1~2min处理后(各步间均用无菌水冲洗3~4次),研磨并稀释至10^-3,涂布于TSA培养基上,置28℃恒温条件下培养5—7d,可从高寒牧草组织中分离获得数量、种类较多的内生细菌。用此方法,已从5种牧草不同组织器官(根、茎、叶、花)中分离获得大小、形态、颜色各异的内生细菌315株。 相似文献
18.
Background: Corn stover(CS) is an abundant source of feed for livestock in China. However, it is low in nutritional value that we have been seeking technologies to improve. Previous studies show that non-fiber carbohydrate(NFC)might limit the utilization of a CS diet by lactating dairy cows. Thus, this study was conducted to investigate the lactation performance and rumen fermentation characteristics in lactating cows consuming CS with two contents of NFC compared to an alfalfa hay-containing diet. Twelve Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments:(1) low-NFC diet(NFC = 35.6%, L-NFC),(2) high-NFC diet(NFC = 40.1%,H-NFC), and(3) alfalfa hay diet(NFC = 38.9%, AH).Results: Intake of DM was lower for cows fed H-NFC compared to L-NFC and AH, while the milk yield was higher in AH than in H-NFC and L-NFC(P 0.01). The feed efficiency(milk yield/DM intake, 1.15 vs. 1.08, P 0.01) were greater for cows fed H-NFC than L-NFC. The contents of milk protein and lactose were not different among the groups(P 0.11), but milk fat content was higher for cows fed H-NFC and L-NFC compared to AH(P 0.01). The rumen ammonia nitrogen concentration and the concentrations of urea nitrogen in blood and milk were lower for cows fed H-NFC and AH compared to L-NFC(P 0.05). The concentrations of rumen propionate and total volatile fatty acids were different among groups(P 0.05) with higher concentration for cows fed AH compared to H-NFC and L-NFC, and acetate concentration tended to be different among groups(P = 0.06).Conclusions: From the results obtained in this study, it was inferred that the increased NFC content in a diet containing corn stover can improve the feed efficiency and benefit the nitrogen conversion. 相似文献
19.
The effects of low and high nitrogen diets on amino acid levels were studied in hydrolyzates of ruminal bacteria adhered to four topographically different anatomic parts of the ruminal wall (dorsal, ventral and caudal parts as well as reticulum) in 18 sheep + of the Slovak Merino breed divided into three experimental groups. The epimural bacteria of the dorsal and ventral parts of the ovine rumen revealed the most sensitive reaction to the varying amounts of nitrogen ingested with the diet. In hydrolyzates of ruminal bacteria adhered to the dorsal and ventral epithelium, 15 and 14 amino acids were changing (Figs. 1, 2). In hydrolyzates of epimural bacteria, a sensitive reaction was observed in the following amino acids: alanine, histidine, thyroxin, arginine and proline (Tabs. I-IV). In all topographical and anatomical parts of the rumen, both alanine and histidine levels in hydrolyzates of epimural ruminal bacteria significantly increased with the diet with high-nitrogen content fed, but was falling in sheep fed with low-nitrogen diet. Changes in alanine concentrations may be explained by the fact that alanine forms a part of the mechanism for short-time storage of ammonia in bacterial cells (Bartos, 1987). The fact that alanine is in its lack deaminated to pyruvate (Havassy, 1976) is explained by significant fall in alanine contained in hydrolyzates of bacterial proteins when fed low nitrogen diets. Significant fall in alanine in shortage of amino acid bound nitrogen can be explained by the fact that under these conditions, the alanine skeleton is being incorporated in to 80% of amino acids synthetized de novo by ruminal bacteria (Syv?oja and Kreula, 1980). When sheep flock was fed the high-nitrogen diet, thyroxin and proline levels were significantly reduced in hydrolyzates of epimural bacteria from all parts of the rumen, while low-nitrogen diet significantly increased the concentrations of both given amino acids in comparison with the control. Bartos (1987) gives in his study the table containing weight representation of different amino acids in proteins of bacteria of the ruminal content compiled on the basis of data of several authors. These data principally correspond to the results of our measurements in hydrolyzates of epimural bacteria. The highest weight representation of amino acids in hydrolyzates of epimural bacteria was found for glutamic acid, aspartic acid and arginine, while the lowest ones were detected for thyroxin, proline and phenylalanine.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
20.
This experiment was carried out to examine the effect of grapeseed oil (GSO) on performance, rumen fermentation, antioxidant status and subcutaneous adipose fatty acid (FA) profile in lambs. Eighteen Baluchi lambs, 196 ± 14 days of age and 39.8 ± 1.7 kg body weight, were randomly assigned to three experimental diets: (i) diet without GSO (control), (ii) diet containing 2% of GSO (GSO2) and (iii) diet containing 4% of GSO (GSO4) for 42 days. Results showed that the experimental diets had no significant effect on dry matter intake and performance (p > 0.05). The supplemented diets with GSO had no effect on pH and NH3‐N of rumen fluid (p > 0.05), but GSO4 increased (p = 0.003) the concentration of propionic acid and reduced (p = 0.002) the concentration of acetate acid compared to the control. Inclusion 4% of GSO to the diet increased total antioxidant activity and decreased malondialdehyde in serum and muscle (p < 0.001). The level of blood glutathione peroxidase in diets containing GSO was higher than control diet (p = 0.02), but diets had no effect on superoxide dismutase in blood and muscle tissues (p > 0.05). The concentration of vaccenic acid, rumenic acid and linoleic acid and thus polyunsaturated fatty acid in subcutaneous fat was affected by experimental diets (p < 0.001), as control had the lowest amount of these FAs and GSO4 had the highest amount of them. Therefore, it can be concluded that the use of GSO up to 4% improves the antioxidant status and adipose fatty acid profile in lambs without effects on performance. 相似文献
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