棕榈油和亚麻油混合添加对内蒙古白绒山羊肌肉脂肪酸组成的影响与机理研究

As a result of the limitation of natural grassland resources, the limit of grazing and grazing prohibition policy implementation and the increasing demand of mutton, stall feeding becomes one of the main producing ways for mutton production,leading to bad mutton quality,which is a problem of restricting the healthy development of mutton production.The experimental animals of this project are Inner Mongolia white cashmere goats experiencing satll feeding.Whether the improving effect of fatty acids in mutton by feeding the blend of palm oil and linseed oil is better than feeding palm oil or linseed oil alone can be revealed and the main fatty acids which could improve fatty acids composition of mutton can be clarifed according to the changes of fatty acids in muscle tissues as well as fattening performance and meat quality of white cashmere goats. By using the analyse of metabonomics ,microbe diversity in rumen and RT PCR to disscuss the main fatty acids,metabolic pathway and important microbes which have a large difference in rumen. And combining with analysing the enzyme activities, genes and proteins expression related to the fatty acid mechanism to systematically study the regulation mechanism of feeding the blend of palm oil and linseed oil in modifying fatty acid profile from the cellular, molecular and metabolic pathway. The results of the research provides theoretical basis for utilizing plant oils to reasonably regulate fat metabolism and effectively improve fatty acids composition in mutton, thereby improving mutton quality. All this findings have an important theoretical and practical significance to improve goats heath under stall feeding mode,increase meat performance and produce the mutton that are benefit to humen health.

摘要. 由于天然草地资源的限制及羊肉市场需求的增加，舍饲育肥成为了绒山羊羊肉生产的主要方式，由此引起的羊肉品质降低成为了制约羊肉生产健康发展的瓶颈问题之一。羊肉脂肪酸（FA）组成是影响肉产品品质的主要因素之一。项目以舍饲育肥的内蒙古白绒山羊为研究对象，根据肌肉组织FA组成变化揭示棕榈油与亚麻油混合添加对羊肉FA组成的改善效果是否优于单独添加，阐明可优化羊肉FA组成的主要FA种类；采用代谢组学、微生物多样性分析和实时定量PCR分析技术探讨瘤胃内差异显著的标志性FA种类、代谢过程及关键微生物，结合肌肉组织中FA代谢相关酶活性、基因与蛋白质的表达，从细胞、分子和代谢水平系统地研究棕榈油与亚麻油的混合添加对绒山羊羊肉FA组成具有优化作用的调节机理。研究结果为在生产中合理使用植物油脂调控山羊的脂类代谢、有效改善羊肉FA组成进而改进羊肉品质提供理论依据。

天然草场资源的限制、草地生态环境的恶化等因素使得舍饲育肥成为了绒山羊目前具有代表性的育肥方式之一，由此而引起的羊肉产品中C18:3n3和n-3长链多不饱和脂肪酸（n-3 LCPUFA）如C20:5n3和C22:6n3等含量的下降导致了羊肉品质的降低，成为了制约羊肉生产健康发展的瓶颈问题之一。补充富含C18:3n3的亚麻油是促进体组织n-3LCPUFA生成以改善羊肉脂肪酸（FA）组成的重要途径，但C18:3n3不稳定，易于发生氧化和瘤胃氢化；富含C18:1c9的棕榈油通常被用作富含不饱和脂肪油脂的保护剂，与亚麻油混合添加可以显著提高亚麻油的抗氧化能力。然而，棕榈油和亚麻油的混合添加对绒山羊FA组成的优化改善效果是否优于单独的亚麻油处理尚不清楚，其影响机制均需要进一步探讨。鉴于此，项目利用体外法结合体内法阐明了棕榈油与亚麻油的混合添加对绒山羊羊肉FA组成的优化作用，并从细胞、分子和代谢水平系统地揭示了其优化作用的调节机理。结果显示亚麻油与棕榈油的混合添加对绒山羊体组织C18:3n3、C20:5n3、C22:6n3、n-3 PUFA和n-3 LCPUFA含量的促进效果优于亚麻油，可以促进体组织C18:3n3和n-3 PUFA的含量，并增加部分组织内C20:5n3的含量，降低n-6/n-3。Pseudobutyrivibrio参与C18:3n3的氢化，Succinivibrio、 Succinivibrionaceae UCG-002和unclassified_f_ Bacteroidetes参与C18:1n9c的氢化。与亚麻油相比，混合油增加了瘤胃内参与C18:1c9氢化的菌的丰度；降低了参与C18:3n3氢化的菌的丰度，即混合油通过增加瘤胃内C18:1c9的氢化降低了C18:3n3的氢化，同时通过降低组织内C18:3n3的氧化对C18:3n3起到了保护效果；促进了肝脏、肌肉和脂肪组织内参与n-3 LCPUFA合成相关的转录因子与酶的活性和基因表达；促进了肌肉和脂肪组织对从肝脏合成分泌入血的n-3 LCPUFA的吸收。取得的研究成果不仅丰富了反刍动物的脂类代谢与调控理论，同时也为在生产中合理使用植物油脂调控反刍动物的脂类代谢、有效改善羊肉脂肪酸组成进而改进羊肉品质提供了新思路，对在舍词模式下改善山羊的健康、提高产肉性能并生产有益于人体健康的山羊羊肉具有重要的理论与实际意义