Milk odd- and branched-chain fatty acids as biomarkers of rumen function-An update
Milk odd- and branched-chain fatty acids as biomarkers of rumen function-An update
复制标题
DOI：
10.1016/j.anifeedsci.2011.12.008
复制
发表时间：
2012-02-28
影响因子：
3.2
通讯作者：
Vlaeminck, B.
中科院分区：
文献类型：
--
作者：
Fievez, V.;Colman, E.;Vlaeminck, B.
乳牛乳中主要的单链和支链脂肪酸(OBCFA)是十三酸(等C13：0)、十四酸(等C14：0)、十五酸(C15：0、等C15：0和等C15：0)、十六酸(等C16：0)和十七酸(C17：0、等C17：0和等C17：0)的异构体。建议使用OBCFA来反映瘤胃功能(例如，瘤胃发酵模式，包括甲烷、十二指肠微生物蛋白流动和酸中毒)。这取决于它们的主要来源，即离开瘤胃的细菌。OBCFA是由瘤胃细菌从头合成的，并结合在他们的细胞膜上，这表明与细菌的生物量有直接的关系。它们作为十二指肠标志物的潜力因其与细菌N含量在不同细菌群上的持续关系而得到加强。从一个有限的数据库中，有证据表明牛奶OBCFA产量与瘤胃微生物蛋白流量之间存在有用的关系，但还需要更多的研究来阐明不同饮食方案下的一些差异。此外，报道了纯瘤胃细菌OBCFA谱的变化，在当前的综述中，OBCFA谱与其代谢产物的产生有关。由此可以推测，瘤胃发酵模式与瘤胃OBCFA谱有关，这似乎与牛奶OBCFA相一致。瘤胃挥发性脂肪酸和甲烷之间密切的化学计量关系进一步为使用牛奶中的OBCFA图谱来量化甲烷排放开辟了前景。无论采用何种建模方法，OBCFA对预测模型的贡献是：ISO C14：0和ISO C15：0，它们与乙酸盐和甲烷呈正相关，与丙酸呈负相关；以及C15：0和C17：0，它们显示出相反的关系。Anteiso C15：0似乎只与丁酸比例的预测有关。由于瘤胃微生物种群的变化(例如，牛链球菌优势增加)，有时会引发一系列事件，最终可能导致(亚急性)瘤胃酸中毒。乳脂中的OBCFA可作为早期检测瘤胃酸中毒的候选物质。C17：0+C17：1cis-9升高和iso C14：0浓度降低有可能作为亚急性酸中毒的指标或在急性酸中毒临床症状出现前就已明显。目前正在收集更多的实验数据，以开发更稳健的模型，以连续的概率类别来分类瘤胃健康，而不是离散的酸中毒和非酸中毒病例。(C)2012爱思唯尔B.V.保留所有权利。
The main odd- and branched-chain fatty acids (OBCFA) in milk of dairy cows are isomers of tridecanoic acid (iso C13:0), tetradecanoic acid (iso C14:0), pentadecanoic acid (C15:0, iso C15:0 and anteiso C15:0), hexadecanoic acid (iso C16:0) and heptadecanoic acid (C17:0, iso C17:0 and anteiso C17:0). OBCFA are suggested to reflect rumen function (e.g. ruminal fermentation pattern, including methane, duodenal flow of microbial protein and acidosis). This relies on their predominant origin, i.e. bacteria leaving the rumen. The OBCFA are synthesized de novo by ruminal bacteria and incorporated in their cell membrane, suggesting a direct relation with bacterial biomass. Their potential as duodenal markers to quantify bacterial protein is strengthened by their constant relation with bacterial N content over a diversity of bacterial groups. From a limited database, evidence was shown of a useful relation of milk OBCFA yield with microbial protein flow from the rumen, but more research is needed to elucidate some discrepancies under diverse dietary regimes.Further, variation in the OBCFA profile of pure strains of ruminal bacteria were reported and are, in the current review, linked with their production of metabolites. From this, it can be assumed that the rumen fermentation pattern is related to the rumen OBCFA profile, which seems consistent for milk OBCFA. The close stoichiometric relation between ruminal VFA and methane further opens perspective for the use of OBCFA profiles in milk to quantify methane emissions. OBCFA consistently contributing to the predictive models, irrespective of the modeling approach are: iso C14:0 and iso C15:0, which positively relate to acetate and methane and negatively to propionate; and C15:0 and C17:0 which show an inverse relationship. Anteiso C15:0 seemed only relevant in the prediction of butyrate proportions. As changes in the ruminal microbial population (e.g. increased dominance of Streptococcus bovis) sometimes initiate a chain of events that eventually might lead to (sub-acute) ruminal acidosis. OBCFA in milk fat are targeted as candidates for the early detection of ruminal acidosis. Increasing C17:0 + C17:1 cis-9 and decreasing iso C14:0 concentration show potential as indicators of sub-acute acidosis or were obvious before clinical symptoms of acute acidosis occurred. Collection of more experimental data is currently on-going for the development of more robust models to classify rumen health in continuous probability classes rather than discrete acidotic vs. non-acidotic cases. (C) 2012 Elsevier B.V. All rights reserved.