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1.
H9亚型禽流感在我国家禽中广泛流行,给养禽业造成巨大经济损失的同时,也严重威胁着公共卫生安全。H9亚型禽流感病毒(avian influenza virus,AIV)具有高度遗传变异性,导致流行株和疫苗株之间抗原匹配性差,从而影响疫苗的临床保护效果,急需研发一种高效、具有交叉保护性的通用型H9亚型禽流感疫苗。马赛克疫苗是针对遗传多样性病原体设计,通过整合所有抗原序列获得一条抗原表位覆盖最广泛的嵌合蛋白,并制备疫苗。本研究参考mosaic疫苗设计原则,设计、优化并合成了一条H9亚型禽流感病毒的mosaic血凝素(hemagglutinin,HA)基因序列,采用反向遗传操作技术,以H1N1亚型流感病毒PR8株为骨架,以mosaic H9HA序列替换PR8株的HA片段,获得重组病毒rPR8-HAm/H9。将其制备为灭活疫苗并免疫SPF雏鸡,监测抗体水平、攻毒保护效果,评价其交叉保护效果。结果表明,重组病毒rPR8-HAm/H9灭活疫苗免疫SPF雏鸡,可诱导机体产生较高水平的HI抗体和中和抗体,可显著抑制攻毒后病毒的脱落,对H9N2 AIV JM0305株的攻毒保护率为80%。rPR8-HAm/H9灭活疫苗可以对异源H9N2 AIV JM0305株产生较好的交叉攻毒保护,为研发基于马赛克技术的禽流感通用疫苗提供了前期基础。  相似文献   

2.
在研究1998-2008年中国H9N2亚型禽流感病毒(AIV)分离株HA基因的进化时,发现在25个毒株中有2个致病性最强的毒株因HA基因第145位氨基酸的突变导致产生1个潜在的糖基化位点,从而使其不与单抗H6、F6等反应。为进一步探究这类变异毒株HA基因变异对H9亚型AIV的抗原性和免疫原性的影响,本试验对12株HA蛋白S145N变异的H9N2AIV进行了交叉中和试验和交叉攻毒试验。结果显示,不同H9N2S145N变异株与疫苗株间在抗原性上变化不大,或无显著差异(0.5≤R≤0.67)。但参照现有的H9灭活疫苗效力检验方法对HP疫苗免疫鸡进行攻毒,用HP株攻毒对照组0/5保护,免疫组保护≥9/10,达到了H9灭活疫苗质量标准要求;但用S145N变异株N3攻毒,仅保护2/10~6/10,且随免疫量剂量的增加,抗体水平的提高,攻毒保护也依次升高。对H9变异株疫苗(N1、N2、N3、N8)免疫鸡用N3攻毒,仅保护2/5~4/5,N3同源抗体也不能有效地阻止其攻毒后的排毒。用N3、N6 2个变异株交叉攻毒,采用与疫苗株攻毒相同的剂量作攻毒试验也得到类似结果。表明高于6log2的抗体能抵抗疫苗株和大多数流行毒株攻毒后的排毒,但不能抵抗S145N变异株攻毒后的排毒。这类毒株免疫原性上的变化与病毒HA基因的变异密切相关。因HA基因145~147aa位增加了1个NGT,导致三维空间构象的变化,并影响其邻近的受体结合位点,从而使这类毒株致病性提高,免原性发生改变。虽然这一类变异株或免疫逃逸毒株仅占当前流行毒株总数的5%~7%,但在强大的免疫压力和自然选择下有可能逐步成为优势毒株,造成更大的危害,这为该病的防控提出了新的挑战。  相似文献   

3.
以国内欧洲禽源H1N1亚型猪流感病毒流行株A/swine/Shanghai/1/2014(H1N1)(SH1)为材料,RT-PCR扩增HA和NA基因并将其克隆至PBD载体中,构建HA和NA基因的重组质粒。将HA和NA基因重组质粒及来源于流感病毒高产株PR8的6个内部基因(PB2、PB1、PA、NP、M和NS)重组质粒共转染293T细胞,从而成功构建了重组欧洲禽源H1N1亚型猪流感病毒疫苗株SH/PR8。以相同病毒剂量接种MDCK细胞,检测不同时间点的血凝效价,绘制病毒生长曲线,结果表明,重组病毒SH/PR8相对于原始野生株SH1在MDCK细胞上具有更高的病毒滴度。重组病毒SH/PR8制备的灭活疫苗经过一免和二免小鼠后,检测血清中血凝抑制抗体、中和抗体和IgG抗体,结果显示首免后抗体效价持续升高,4周后抗体效价达到峰值。小鼠攻毒试验结果表明,免疫组体质量下降不明显且未出现死亡,而非免疫组小鼠体质量持续下降并且于攻毒后6d小鼠出现100%死亡。肺脏组织病毒含量滴定以及组织病理学观察结果显示,免疫组能够有效抑制SH1病毒在肺脏中的复制,减轻肺脏病理变化。总之,本研究表明重组SH/PR8疫苗候选株相对于原始毒株SH1在MDCK细胞上具有更高的复制能力,制备的重组灭活疫苗能够诱导机体产生高水平的抗体,能够针对欧洲禽源H1N1亚型猪流感病毒的攻击提供很好的免疫保护。  相似文献   

4.
为评估当前应用的Re-8株种毒相关禽流感灭活疫苗对野鸟源H5N8流感病毒的免疫预防效果,本研究将重组禽流感病毒(AIV)H5亚型Re-8株灭活疫苗(H5N1亚型,Re-8株)和重组AIV(H5+H7)灭活疫苗(H5N1Re-8株+H7N9 H7 Re-1株)分别以0.3 m L/只的剂量接种3周龄SPF鸡,免疫3周时进行HI抗体检测和攻毒试验。结果显示,上述2种疫苗免疫的SPF鸡血清中针对H5亚型Re-8株抗原的HI抗体均在8 log2以上,以105EID50的剂量、鼻腔感染途径攻击野鸟源H5N8病毒BHG/QH/2/16和BHG/Tibet/3/16后,所有免疫组鸡在14 d观察期内均全部健活,不排毒,而对照组鸡在攻毒后4 d内全部发病、死亡、排毒。现地免疫重组AIV H5亚型三价灭活疫苗(Re-6株+Re-7株+Re-8株)的商品蛋鸡直接进行HI抗体检测和攻毒试验,结果显示,免疫蛋鸡血清中针对Re-8株抗原的HI抗体平均滴度为8.3 log2,以相同攻毒方式和剂量分别攻击2株H5N8病毒后,免疫鸡也获得完全免疫保护,不发病、不死亡、不排毒。本研究结果表明,含有重组AIV H5 Re-8株抗原的灭活疫苗可有效防控野鸟源H5N8流感病毒,为我国及其他国家H5N8亚型禽流感免疫防控提供了科学依据。  相似文献   

5.
为研究H9N2亚型禽流感病毒(AIV)对哺乳动物的致病力,本研究选取了2009年~2010年从我国南方地区分离到的6株H9N2 AIV,测定分析了其基因组序列及在小鼠体内的复制能力。HA基因分析显示:6株病毒均属于A/CK/BJ/94谱系,HA均含有人样受体结合位点Leu226。PB2基因分析表明,6株H9N2 AIV分离株均具有AIV低致病力的分子特征(Glu627和Asp701)。对BALB/c小鼠感染试验显示:感染组无任何临床症状及增重;病毒仅局限于小鼠呼吸道复制。本研究结果有助于全面了解近年我国H9N2 AIV分子进化情况,并对评估H9N2AIV对哺乳动物的潜在威胁提供参考。  相似文献   

6.
为了验证电化学基因芯片技术检测A型流感亚型的可行性,应用建立的电化基因芯片方法分别检测了9株不同亚型的A型流感病毒抗原、1株新城疫病毒抗原和10份临床样品。结果为电化学基因芯片均能特异检出相应的A型流感病毒亚型,与新城疫病毒抗原无交叉反应;临床样品中,检出5份为H6N6亚型流感病毒核酸阳性、2份为H6H2亚型禽流感病毒核酸阳性、3份为H9H2亚型禽流感病毒核酸阳性。结果表明,电化学基因芯片方法适合A型流感病毒各亚型的鉴别,具有快速、特异的特点。  相似文献   

7.
本研究分析了免疫鸡群H5N1和H9N2亚型禽流感病毒混合感染中H9N2亚型分离毒株A/chicken/Yuyao/01/2010(H9N2)的基因组特征。氨基酸序列分析显示,HA蛋白裂解位点为PSRSSR/GL,具有低致病性禽流感病毒特征,HA受体结合位点出现了人流感病毒结合位点226L,D基因出现了S31N的突变。遗传分析表明,A/chicken/Yuyao/01/2010病毒的HA基因、NA基因和NS基因在进化上属于CK/BJ/94-Like谱系,D基因和PB2基因属于G1-Like谱系,NP基因、PA基因和PB1基因属于Ck/SH/F/98-Like谱系。结果表明,从H5N1和H9N2亚型混合感染鸡体内分离的H9N2亚型禽流感病毒是一株来源于CK/BJ/94-Like谱系、G1-Like谱系和Ck/SH/F/98-Like谱系的重组病毒。  相似文献   

8.
H9亚型禽流感病毒SD96株HA蛋白特异性单抗的制备及鉴定   总被引:1,自引:1,他引:0  
本研究用H9N2亚型禽流感病毒分离株A/Chicken/Shandong/6/1996(CK/SD/6/96)免疫6周龄BALB/c雌性小鼠,取免疫后小鼠脾细胞与骨髓瘤细胞SP2/0融合。采用血凝抑制(HI)和ELISA方法筛选阳性细胞克隆,连续多次克隆培养后获得3株能稳定分泌H9亚型HA特异性单抗的细胞株1F4C4、9F12D1、2C5H12。3株阳性杂交瘤细胞的培养上清及腹水对CK/SD/6/96的HI效价分别为2^6、2^4、2^1和2^12、2^10、2^7。特异性试验表明该3株单抗均不与其他主要禽类病毒和其他14个HA亚型的禽流感病毒发生交叉反应。1F4C4和2C5H12抗体亚类为IgG2b,9F12D1为IgG2a。这3株单抗对H9亚型不同抗原群流感毒株有不同程度的中和作用,表现出单抗识别抗原住点的差异性,为进一步研究H9亚型流感病毒的抗原性差异以及抗原识别提供了物质基础和条件。  相似文献   

9.
为了解我国野鸟中H9N2亚型禽流感病毒的分布与特征,2015—2016年对鄱阳湖与青海湖地区野鸟中的H9N2病毒进行监测,结果共分离到12株H9N2亚型禽流感病毒。对分离的病毒进行HA和NA基因序列测定、受体分析和SPF鸡、Balb/c小鼠的感染性试验,结果显示:12个分离株的HA裂解位点基序均为PSRSSR/GLF,符合低致病性禽流感病毒的分子特征;HA蛋白受体结合位点处第226位氨基酸残基为亮氨酸(L),具有结合人样流感病毒受体的分子特征;受体结合试验表明,分离毒株既能结合禽样受体,也能结合人样受体;SPF鸡攻毒试验表明,分离株为低致病性毒株;Balb/c小鼠的感染性试验表明,分离株只在小鼠的上呼吸道鼻甲和肺中有限复制,未见明显临床症状。  相似文献   

10.
为了解H5N3亚型流感病毒的生物学特性,本研究对2017年浙江省分离到的一株H5N3亚型禽流感病毒(AIV)[DK/ZJ/S1368/2017(H5N3)]进行了遗传演化分析及小鼠感染性实验。遗传演化分析结果显示,该株病毒的HA蛋白裂解位点处仅含一个碱性氨基酸,属于低致病性AIV。同时,该病毒的血凝素(HA)基因与H5N7亚型流感病毒亲缘关系较近;聚合酶碱性蛋白2(PB2)基因和核蛋白(NP)基因与H10N7亚型流感病毒亲缘关系较近;碱性聚合酶蛋白1(PB1)基因与H1N1亚型流感病毒亲缘关系较近;酸性聚合酶蛋白(PA)基因与H6N2亚型流感病毒亲缘关系较近;神经氨酸酶(NA)基因与H10N3亚型流感病毒亲缘关系较近;基质蛋白(M)基因与H3N8亚型流感病毒亲缘关系较近;非结构蛋白(NS)基因与H1N1亚型流感病毒亲缘关系较近。表明其基因来源复杂。小鼠感染实验结果显示,该分离株无需提前适应即可以在小鼠肺脏和鼻甲中复制,小鼠感染病毒后无明显临床症状,与对照组相比其体质量变化不明显,表明该病毒对小鼠呈低致病性。本研究通过对该H5N3亚型AIV的生物学特性的分析,发现该病毒基因来源复杂,无需提前适应就可以在小鼠体内复制,具有感染哺乳动物的潜在威胁,提示应当持续加强对H5N3亚型AIV的监测和相关生物学特性的研究工作。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

14.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

15.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

16.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

17.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

18.
The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.  相似文献   

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20.
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.  相似文献   

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