Lipids

脂质
  • 文章类型: Journal Article
    在大多数蛋白质组关联研究(PWAS)中,蛋白质编码基因附近的变体(±1Mb),也称为顺式单核苷酸多态性(SNP),用来预测蛋白质水平,然后测试与表型的关联。然而,蛋白质可以通过顺式区域之外的变体进行调节。鉴定蛋白质数量性状基因座(pQTL)的中间GWAS步骤允许在蛋白质水平预测模型中的顺式区域之外包含反式SNP。这里,我们评估了妇女健康倡议(WHI)对1002名个体中540种蛋白质的预测,平均分成一组GWAS,弹性网络训练集,和一套测试。我们比较了使用这种提出的方法在测量和预测的蛋白质水平之间的测试r2,仅使用顺式SNP测试r2。这两种方法通常导致相似的测试r2,但是一些蛋白质在用我们的方法测试r2时显示出显著的增加。例如,对于软骨酸性蛋白1,测试r2从0.101增加到0.351。我们还证明了在没有蛋白质组学数据的WHI参与者中预测的蛋白质与脂质和血细胞特征的相关性的可重复发现,以及在英国生物银行中利用我们的PWAS权重。
    In most Proteome-Wide Association Studies (PWAS), variants near the protein-coding gene (±1 Mb), also known as cis single nucleotide polymorphisms (SNPs), are used to predict protein levels, which are then tested for association with phenotypes. However, proteins can be regulated through variants outside of the cis region. An intermediate GWAS step to identify protein quantitative trait loci (pQTL) allows for the inclusion of trans SNPs outside the cis region in protein-level prediction models. Here, we assess the prediction of 540 proteins in 1002 individuals from the Women\'s Health Initiative (WHI), split equally into a GWAS set, an elastic net training set, and a testing set. We compared the testing r2 between measured and predicted protein levels using this proposed approach, to the testing r2 using only cis SNPs. The two methods usually resulted in similar testing r2, but some proteins showed a significant increase in testing r2 with our method. For example, for cartilage acidic protein 1, the testing r2 increased from 0.101 to 0.351. We also demonstrate reproducible findings for predicted protein association with lipid and blood cell traits in WHI participants without proteomics data and in UK Biobank utilizing our PWAS weights.
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  • 文章类型: Editorial
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  • 文章类型: Journal Article
    纯合子家族性高胆固醇血症(HoFH)的特征是由于高低密度脂蛋白胆固醇(LDL-C)负担而导致的早发性动脉粥样硬化性心血管疾病。无效低密度脂蛋白受体(LDLR)变异的患者反应不佳,如果有的话,他汀类药物和前蛋白转化酶枯草杆菌蛋白酶/kexin9型抑制剂,它通过上调LDLR表达式来发挥作用。3期ELIPSEHoFH(纯合型家族性高胆固醇血症患者的Evinacumab脂质研究;NCT03399786)研究的24周双盲治疗期(DBTP)表明,HoFH患者的LDL-C显着降低;无效LDLR突变的患者也观察到LDL-C降低。
    这项研究的目的是从ELIPSEHoFH研究中评估evinacumab在HoFH患者中的长期疗效和安全性。
    接受稳定降脂治疗(LLTs)±脂蛋白单采和筛查LDL-C≥70mg/dL且完成DBTP的HoFH患者进入24周开放标签治疗期(OLTP),每4周接受15mg/kg静脉注射evinacumab。对OLTP结果进行描述性总结。
    共有64名患者完成了DBTP并接受了开放标签的evinacumab。尽管有多个LLT,DBTP进入时的平均基线LDL-C为250.5±162.3mg/dL.从基线到第48周(OLTP结束),evinacumab使平均LDL-C降低46.3%(平均降低,134.3±117.3mg/dL),无效(47.2%)和非无效变异(45.9%)的患者的LDL-C平均降低相似。47例(73.4%)患者发生了不良事件;4例(6.3%)患者经历了与evinacumab相关的不良事件(药物超敏反应,输液相关反应和虚弱,全身性瘙痒,和肌肉痉挛)。
    在HoFH患者中,evinacumab显示出显著和持续的LDL-C降低,无论LDLR功能如何,一般耐受性良好。
    UNASSIGNED: Homozygous familial hypercholesterolemia (HoFH) is characterized by early-onset atherosclerotic cardiovascular disease due to the high low-density lipoprotein cholesterol (LDL-C) burden. Patients with null-null low-density lipoprotein receptor (LDLR) variants respond poorly, if at all, to statins and proprotein convertase subtilisin/kexin type 9 inhibitors, which act by upregulating LDLR expression. The 24-week double-blind treatment period (DBTP) of the phase 3 ELIPSE HoFH (Evinacumab Lipid Studies in Patients with Homozygous Familial hypercholesterolemia; NCT03399786) study demonstrated significant LDL-C reductions in patients with HoFH; LDL-C reductions were also observed in those with null-null LDLR mutations.
    UNASSIGNED: The purpose of this study was to evaluate longer-term efficacy and safety of evinacumab in patients with HoFH from the ELIPSE HoFH study.
    UNASSIGNED: Patients with HoFH on stable lipid-lowering therapies (LLTs) ± lipoprotein apheresis and screening LDL-C ≥70 mg/dL who completed the DBTP entered the 24-week open-label treatment period (OLTP) and received intravenous evinacumab 15 mg/kg every 4 weeks. OLTP results were summarized descriptively.
    UNASSIGNED: A total of 64 patients completed the DBTP and received open-label evinacumab. Despite multiple LLTs, the mean baseline LDL-C at DBTP entry was 250.5 ± 162.3 mg/dL. From baseline to week 48 (end of OLTP), evinacumab reduced mean LDL-C by 46.3% (mean reduction, 134.3 ± 117.3 mg/dL), with similar mean LDL-C reductions for patients with null-null (47.2%) and non-null variants (45.9%). Adverse events occurred in 47 (73.4%) patients; 4 (6.3%) patients experienced adverse events considered evinacumab-related (drug hypersensitivity, infusion-related reaction and asthenia, generalized pruritis, and muscle spasms).
    UNASSIGNED: In patients with HoFH, evinacumab demonstrated substantial and sustained LDL-C reduction regardless of LDLR function, and was generally well tolerated.
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  • 文章类型: Journal Article
    血脂异常是一种异常脂质浓度在血液中循环的疾病。该疾病常见于2型糖尿病患者(T2D),并与T2D合并症有关。尤其是心血管疾病。T2D中的血脂异常通常以升高的血浆甘油三酯和低的高密度脂蛋白胆固醇(HDL-C)水平为特征。关于非洲农村地区血脂异常的文献存在显著差距,通过常规监测可能无法捕获血脂谱。这项研究旨在描述Ganadougou农村社区T2D中血脂异常的患病率和演示图形特征,马里。我们在2021年11月至2022年3月期间对Ganadougou的104名T2D受试者进行了横断面研究。通过横断面调查和血清学分析收集人口统计学和血脂谱。T2D患者血脂异常的总体患病率为87.5%(91/104),性别没有差异(P=.368)。高低密度脂蛋白胆固醇(LDL-C)是最常见的血脂异常(78.9%,[82/104])。血脂异常与年龄和高血压状态相关(分别为P=.013和.036)。高总和高LDL-C参数与高血压显著相关(分别为P=.029和.006)。在资源匮乏的地区,如马里农村,迫切需要改善常规血脂异常筛查的基础设施,以指导其预防和干预方法.在甘达杜古观察到的高血脂异常率,与非洲的心血管疾病伴随增加相一致,建议在非洲农村地区的T2D患者的常规医疗护理中应纳入血脂状况评估.
    Dyslipidemia is a disorder where abnormally lipid concentrations circulate in the bloodstream. The disorder is common in type 2 diabetics (T2D) and is linked with T2D comorbidities, particularly cardiovascular disease. Dyslipidemia in T2D is typically characterized by elevated plasma triglyceride and low high-density lipoprotein cholesterol (HDL-C) levels. There is a significant gap in the literature regarding dyslipidemia in rural parts of Africa, where lipid profiles may not be captured through routine surveillance. This study aimed to characterize the prevalence and demo-graphic profile of dyslipidemia in T2D in the rural community of Ganadougou, Mali. We performed a cross-sectional study of 104 subjects with T2D in Ganadougou between November 2021 and March 2022. Demographic and lipid profiles were collected through cross-sectional surveys and serological analyses. The overall prevalence of dyslipidemia in T2D patients was 87.5% (91/104), which did not differ by sex (P = .368). High low-density lipoprotein cholesterol (LDL-C) was the most common lipid abnormality (78.9%, [82/104]). Dyslipidemia was associated with age and hypertension status (P = .013 and.036, respectively). High total and high LDL-C parameters were significantly associated with hypertension (P = .029 and .006, respectively). In low-resource settings such as rural Mali, there is a critical need to improve infrastructure for routine dyslipidemia screening to guide its prevention and intervention approaches. The high rates of dyslipidemia observed in Gandadougou, consistent with concomitant increases in cardiovascular diseases in Africa suggest that lipid profile assessments should be incorporated into routine medical care for T2D patients in African rural settings.
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  • 文章类型: Journal Article
    这项研究描述了用于从铜绿假单胞菌中制备硒纳米颗粒的方法,以及将其给予羔羊进行脂质分布检查的方法,在羔羊中使用硒纳米颗粒作为药物会导致低脂血症。
    该研究旨在研究硒纳米颗粒在改善羔羊脂质分布中的潜力。
    选择年龄和体重相似的健康羔羊(n=10)进行研究。将动物饲养在单独的围栏中,自由接触水和标准饮食。将羔羊随机分为对照组(n=5)和治疗组(n=5)。对照组接受标准饮食,而治疗组接受相同的饮食和口服0.1mg/kg体重的硒纳米颗粒。每天进行给药,持续8周。在研究开始时(基线)和2周治疗期结束时,从每只羔羊的颈静脉收集血样。将样品收集在vacutainer管中并使其凝结。通过在3,000rpm下离心分离血清10分钟,并在-80°C下储存以评估脂质概况总胆固醇(TC)。甘油三酯,高密度脂蛋白(HDL),低密度脂蛋白(LDL)。血清样品用于使用酶比色法估计脂质分布水平。使用分光光度计在540nm处测量吸光度。
    结果显示血清TC显著下降,甘油三酯,补硒后极低密度脂蛋白胆固醇水平与对照组相比(p<0.05),结果表明,与对照组相比,纳米硒补充后血清HDL水平显着增加(p<0.05)。这表明硒纳米颗粒补充对降低羔羊的TC水平具有有益作用。
    结论部分将总结研究结果,并强调硒纳米颗粒在改善羔羊脂质分布方面的潜力。将讨论这项研究对动物营养和健康的影响,随着这方面进一步研究的需要。
    UNASSIGNED: This research describes the methodology used for the preparation of selenium nanoparticles from Pseudomonas aeruginosa and their administration to lambs for lipid profile checking, administration of selenium nanoparticles as a medication in lambs results in hypolipidemia.
    UNASSIGNED: The study aimed to investigate the potential of selenium nanoparticles in improving lipid profiles in lambs.
    UNASSIGNED: Healthy lambs (n = 10) of similar age and weight were selected for the study. The animals were housed in individual pens with free access to water and a standard diet. The lambs were randomly divided into two groups: the control group (n = 5) and the treatment group (n = 5). The control group received a standard diet, while the treatment group received the same diet and oral administrated with selenium nanoparticles at 0.1 mg/kg body weight. The administration was carried out daily for a period of 8 weeks. Blood samples were collected from the jugular vein of each lamb at the beginning of the study (baseline) and at the end of the 2 weeks treatment period. The samples were collected in vacutainer tubes and allowed to clot. Serum was separated by centrifugation at 3,000 rpm for 10 minutes and stored at -80°C for estimation of lipid profile total cholesterol (TC), triglyceride, high-density lipoprotein (HDL), and low-density lipoprotein (LDL). The serum samples were used for the estimation of lipid profile levels using an enzymatic colorimetric method. The absorbance was measured at 540 nm using a spectrophotometer.
    UNASSIGNED: The results showed a significant decrease in serum TC, triglyceride, and very-low-density lipoprotein cholesterol levels after selenium nanoparticle supplementation compared to the control group (p < 0.05), the results indicated a significant increase in serum HDL levels after selenium nanoparticle supplementation compared to the control group (p < 0.05). This indicates that selenium nanoparticle supplementation has a beneficial effect on reducing TC levels in lambs.
    UNASSIGNED: The conclusion section will summarize the findings of the study and highlight the potential of selenium nanoparticles in improving lipid profiles in lambs. The implications of the study for animal nutrition and health will be discussed, along with the need for further research in this area.
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  • 文章类型: Editorial
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  • 文章类型: Journal Article
    背景:在标准的常规血脂检查中,最终决定是快速还是不快速,健康人群尚不清楚。而美国和欧洲的协议规定,禁食定期血脂分析是不必要的,北美和中国指南仍建议在常规血脂检测前禁食.
    目的:本研究旨在解开全球不同血脂检测方案之间的矛盾,阐明饮食对血脂检测的影响,健康人口。
    方法:文献检索到2024年5月。分析包括从2000年至今进行的研究,因为在此期间首次出现了血脂谱测试指南的矛盾。使用美国国立卫生研究院(NIH)质量测量工具对观察性队列进行计划的内部有效性评估,案例控制,受控介入,和横断面研究。根据RevMan5.3合成数据。
    结果:纳入了8项研究,共有244,665名参与者。六项研究中胆固醇的标准化平均差异表明,空腹和非空腹状态之间的总体效应存在显着差异(P<0.00001),高密度脂蛋白胆固醇(P<0.00001)。同时,关于甘油三酯和低密度脂蛋白胆固醇,禁食状态和非禁食状态之间的总体效应存在显著差异(分别为P<0.00001和P≤0.001)。
    结论:这项荟萃分析得出的结论是,在进行血脂检测时,空腹作为一种保守的模型是优选的,以减少变异性并增加患者代谢状态的一致性。
    BACKGROUND: The final decision to fast or not fast for routine lipid profile examination in a standard, healthy population is unclear. Whereas the United States and European protocols state that fasting for regular lipid analysis is unnecessary, the North American and Chinese guidelines still recommend fasting before routine lipid testing.
    OBJECTIVE: This study aimed to unravel the contradiction between the different protocols of lipid profile testing worldwide and clarify the effect of diet on lipid profile testing only in a regular, healthy population.
    METHODS: A literature search was conducted through May 2024. The analyses included studies performed from the date 2000 until now because the contradiction of guidelines for lipid profile testing appeared for the first time in this period. A planned internal validity evaluation was performed using the National Institute of Health (NIH) quality measurement tools for observational cohort, case‒control, controlled interventional, and cross-sectional studies. The data were synthesized according to RevMan 5.3.
    RESULTS: Eight studies with a total of 244,665 participants were included. The standardized mean difference in cholesterol in six studies showed significant differences in overall effect among fasting and nonfasting states (P < 0.00001), as did high-density lipoprotein cholesterol (P < 0.00001). At the same time, with respect to triglycerides and low-density lipoprotein cholesterol, there were notable variations in the overall effect between the fasted and nonfasted states (P < 0.00001 and P ≤ 0.001, respectively).
    CONCLUSIONS: This meta-analysis concluded that fasting for lipid profile testing is preferred as a conservative model to reduce variability and increase consistency in patients\' metabolic status when sampling for lipid testing.
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  • 文章类型: Journal Article
    背景:消化系统癌症代表了重大的全球健康挑战,并归因于人口统计学和生活方式变化的结合。脂质组学已成为癌症研究的关键领域,提示脂质代谢的改变与癌症的发展密切相关。然而,特定血脂谱与消化系统癌症风险之间的因果关系尚不清楚.
    方法:使用双样本孟德尔随机化(MR)方法,我们阐明了脂质体谱与五种消化系统癌症风险之间的因果关系:胃,肝脏,食道,胰腺,和大肠癌。这项研究的目的是利用来自GWAS目录和英国生物银行等公共数据库的数据,研究发展脂质分布对消化系统癌症风险的影响。使用逆方差加权(IVW)方法和其他严格的MR方法来评估潜在的因果关系。此外,我们进行了敏感性分析和反向MR分析,以确保结果的稳健性.
    结果:在某些脂类性状与发生消化系统癌症的风险之间确定了显著的因果关系。鞘磷脂(d40:1)水平升高与胃癌发病风险降低相关(比值比(OR)=0.68,P<0.001),而磷脂酰胆碱水平升高(16:1_20:4)会增加患食管癌的风险(OR=1.31,P=0.02)。相反,磷脂酰胆碱(18:2_0:0)对大肠癌有保护作用(OR=0.86,P=0.036)。双向分析并未表明癌症风险与血脂水平之间存在反向因果关系。严格的MR方法证明了上述因果关系的稳健性。
    结论:我们的发现强调了特定的脂质组学特征与发生各种消化系统癌症的风险之间的显着因果关系,强调脂质分布在癌症预防和治疗策略中的潜力。这些结果加强了MR在解开复杂的脂质-癌症相互作用中的价值,为研究和临床应用提供了新的途径。
    BACKGROUND: Digestive system cancers represent a significant global health challenge and are attributed to a combination of demographic and lifestyle changes. Lipidomics has emerged as a pivotal area in cancer research, suggesting that alterations in lipid metabolism are closely linked to cancer development. However, the causal relationship between specific lipid profiles and digestive system cancer risk remains unclear.
    METHODS: Using a two-sample Mendelian randomization (MR) approach, we elucidated the causal relationships between lipidomic profiles and the risk of five types of digestive system cancer: stomach, liver, esophageal, pancreatic, and colorectal cancers. The aim of this study was to investigate the effect impact of developing lipid profiles on the risk of digestive system cancers utilizing data from public databases such as the GWAS Catalog and the UK Biobank. The inverse‒variance weighted (IVW) method and other strict MR methods were used to evaluate the potential causal links. In addition, we performed sensitivity analyses and reverse MR analyses to ensure the robustness of the results.
    RESULTS: Significant causal relationships were identified between certain lipidomic traits and the risk of developing digestive system cancers. Elevated sphingomyelin (d40:1) levels were associated with a reduced risk of developing gastric cancer (odds ratio (OR) = 0.68, P < 0.001), while elevated levels of phosphatidylcholine (16:1_20:4) increased the risk of developing esophageal cancer (OR = 1.31, P = 0.02). Conversely, phosphatidylcholine (18:2_0:0) had a protective effect against colorectal cancer (OR = 0.86, P = 0.036). The bidirectional analysis did not suggest reverse causality between cancer risk and lipid levels. Strict MR methods demonstrated the robustness of the above causal relationships.
    CONCLUSIONS: Our findings underscore the significant causal relationships between specific lipidomic traits and the risk of developing various digestive system cancers, highlighting the potential of lipid profiles in informing cancer prevention and treatment strategies. These results reinforce the value of MR in unraveling complex lipid-cancer interactions, offering new avenues for research and clinical application.
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  • 文章类型: Journal Article
    中度升高的白蛋白尿(30-300mg/g)是肾功能障碍的标志,也是心血管疾病的危险因素。此外,最近的几项研究报道了中度升高的白蛋白尿与甘油三酯(TG)水平之间的关系。因此,我们旨在评估尿白蛋白与肌酐比值(UACR)和总胆固醇(TC)之间的关系,TG,和高密度脂蛋白C(HDL-C)水平。我们分析了韩国国家健康和营养检查调查中2011-2014年和2019-2020年的19,340名患者的数据。多元线性回归分析显示,在韩国女性和男性中,UACR与TC和TG水平呈正相关,与HDL-C水平呈负相关。根据蛋白尿的程度(正常,中度升高的白蛋白尿,和严重升高的白蛋白尿(≥300mg/g))。我们发现UACR与TC和TG水平之间存在正相关关系,但与HDL-C水平呈负相关,除了TC(中度升高的白蛋白尿)和HDL-C(中度升高的白蛋白尿)在韩国男性和TC(严重升高的白蛋白尿),TG(严重升高的白蛋白尿),和HDL-C(正常范围白蛋白尿)在韩国妇女。随着白蛋白尿从正常转变为严重升高的白蛋白尿,白蛋白尿与脂质特征之间的相关性变得更加明显。因此,我们的多元线性回归分析表明,血脂(TG,TC,和HDL-C水平)与UACR相关。
    Moderately elevated albuminuria (30-300 mg/g) is a marker of renal dysfunction and a risk factor of cardiovascular disease. Additionally, several recent studies have reported a relationship between moderately elevated albuminuria and triglyceride (TG) levels. Therefore, we aimed to evaluate the relationship between the urine albumin-to-creatinine ratio (UACR) and total cholesterol (TC), TG, and high-density lipoprotein C (HDL-C) levels. We analyzed data from 19,340 patients from the 2011-2014 and 2019-2020 from the Korea National Health and Nutrition Examination Surveys. Multivariate linear regression analysis showed that the UACR was positively associated with TC and TG levels and negatively associated with HDL-C levels in both Korean women and men. These results were reanalyzed according to the degree of proteinuria (normal, moderately elevated albuminuria, and severely elevated albuminuria (≥ 300 mg/g)). We found a positive relationship between UACR and TC and TG levels, but a negative association with HDL-C levels, except for TC (moderately elevated albuminuria) and HDL-C (moderately elevated albuminuria) in Korean men and TC (severely elevated albuminuria), TG (severely elevated albuminuria), and HDL-C (normal range albuminuria) in Korean women. The correlation between albuminuria and lipid profiles became more evident as albuminuria shift from normal to the severely elevated albuminuria. Thus our multivariate linear regression analysis showed that lipid profiles (TG, TC, and HDL-C levels) were associated with the UACR.
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  • 文章类型: Journal Article
    没有单一的肠道CH4缓解策略一直有效或易于适用于草地系统中的反刍动物。当CH4缓解策略在放牧条件下有效时,缓解充其量是轻度至中度。进行了一项研究,以评估将两种被认为可行的CH4缓解策略结合在放牧奶牛中的潜力。甲烷生成抑制剂3-硝基氧丙醇添加剂(3-NOP)和棉籽补充剂(CTS),寻求增强他们个人的CH4缓解潜力。在连续放牧研究中评估了48头奶牛,并补充了淀粉基浓缩物(STA)或含有棉籽的浓缩物(1.75kgDM/d;CTS),和19g/d的10%3-NOP(Bovaer®)或添加剂载体(安慰剂),在2×2阶乘排列的处理中。将处理与浓缩物补充剂(5kg/d作为饲料)混合提供,并在挤奶时以两种相等的口粮提供。使用六氟化硫示踪气体技术在第4周和第8周测量了5天的甲烷排放量。3-NOP和CTS处理倾向于与绝对CH4相互作用,使得3-NOP与STA一起使CH4降低13.4%,但是3-NOP和CTS没有缓解。还获得了CH4产量的处理相互作用,当供应STA时,3-NOP倾向于降低CH4,并倾向于用CTS增加它。CTS饮食中CH4产量的增加是由DM摄入量的数字减少驱动的。甲烷强度不受3-NOP或CTS处理的影响。瘤胃液中的总挥发性脂肪酸不受3-NOP补充的影响,但是乙酸盐的减少和丙酸盐比例的增加,导致乙酸盐:丙酸盐减少。3-NOP添加剂减少了草的摄入量;然而,能量校正的产奶量和乳成分在很大程度上不受影响.牛奶尿素随着3-NOP的补充而增加。当饲喂放牧奶牛时,每天两次补充3-NOP和CTS并不能增强其CH4缓解潜力。与总混合口粮的研究相比,3-NOP对CH4产生的抑制作用相对较低,可能是由于分娩方式(每天两次脉冲给药)和实验处理和在3-NOP补充后将动物转移到牧场引起的时间间隔在挤奶室中,这可能会损害瘤胃中添加剂的存在与围场中草的摄入量之间的同步性。
    No single enteric CH4 mitigating strategy has been consistently effective or is readily applicable to ruminants in grassland systems. When CH4 mitigating strategies are effective under grazing conditions, mitigation is mild to moderate at best. A study was conducted to evaluate the potential of combining two CH4 mitigation strategies deemed feasible to apply in grazing dairy cows, the methanogenesis inhibitor 3-nitrooxypropanol additive (3-NOP) and cottonseed supplementation (CTS), seeking to enhance their individual CH4 mitigating potential. Forty-eight dairy cows were evaluated in a continuous grazing study and supplemented with either a starch-based concentrate (STA) or one that contained cottonseeds (1.75 kg DM/d; CTS), and with either 19 g/d of 10% 3-NOP (Bovaer®) or the additive\'s carrier (placebo), in a 2 × 2 factorial arrangement of treatments. Treatments were supplied mixed with a concentrate supplement (5 kg/d as fed) and offered in two equal rations at milking. Methane emissions were measured on weeks 4 and 8 using the sulphur hexafluoride tracer gas technique over a 5-d period. The 3-NOP and CTS treatments tended to interact on absolute CH4 such that 3-NOP decreased CH4 by 13.4% with STA, but there was no mitigation with 3-NOP and CTS. Treatment interactions were also obtained for CH4 yield, where 3-NOP tended to decrease CH4 when supplied with STA, and tended to increase it with CTS. The increase in CH4 yield with the CTS diet was driven by a numerical decrease in DM intake. Methane intensity was not affected by the 3-NOP or CTS treatments. Total volatile fatty acids in ruminal fluid were not affected by 3-NOP supplementation, but a reduction in acetate and an increase in propionate proportion occurred, resulting in decreased acetate: propionate. The 3-NOP additive decreased grass intake; however, energy-corrected milk yield and milk composition were largely unaffected. Milk urea increased with 3-NOP supplementation. Combining twice daily supplementation of 3-NOP and CTS did not enhance their CH4 mitigation potential when fed to grazing dairy cows. The relatively low inhibition of CH4 production by 3-NOP compared to studies with total mixed rations may result from the mode of delivery (pulse dosed twice daily) and time gap caused by experimental handling and moving of animals to pasture after 3-NOP supplementation in the milking parlour, which could have impaired the synchrony between the additive presence in the rumen and grass intake in paddocks.
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