放牧与舍饲条件下苏尼特羊肉品质的变异和机理研究

With the policy implementation of the animal husbandry limited and grazing prohibition in the degraded grassland, the key problem of the development of mutton industry in China is to solve the problem of meat quality degradation of grazing sheep breeds under the condition of lot-feeding and to develop the technology to improve meat quality of lot- feeding lamb. The carcasses grade、meat quality、physical and chemical index, changes of nutrients and flavor of grazing lamb and lot-feeding lamb will be measured，and the muscle fibre characteristics and the microbial flora in the gastrointestinal tract characteristics be analyzed,to determine the effect of different feeding management conditions on meat quality and explore the methods of improving the meat quality of lot-feeding Sunite lamb. The relationship between the relative abundances of microbial communities and meat quality indexes, fat content, fatty acid composition and flavor substances will be researched by metagenomic analysis to found the main influence factors and the functional pathways. The influence mechanism of Grazing and lot-feeding on meat quality will be studied based on micro ecological changes of gastrointestinal tract flora and using the experimental animals test. The results will provide the experimental data and theoretical support for the Consumption and processing of Sunite lamb and the development of new feeding management technology to improve meat quality of lot-feeding lamb by means of adjustment the gastrointestinal tract microbial flora.

随着国家退化草地限牧或禁牧封育政策的实施，解决放牧绵羊禁牧舍饲后造成的羊肉品质劣化难题是目前我国羊肉业发展的面临的关键性问题。通过测定传统放牧和舍饲圈养条件下苏尼特羊胴体质量、羊肉感官品质、理化指标、营养成分和风味组成的不同，分析不同条件下羊肉肌纤维特性发生的变化和羊体胃肠道微生物菌群结构的变化规律，研究放牧和舍饲条件对苏尼特羊肉品质的影响，探讨改善舍饲羊肉品质的方法。利用宏基因组功能性测定技术，分析细菌微生物相对丰度与羊肉品质指标、脂肪含量、脂肪酸组成和风味物质的相关性，发现主要影响因素和作用途径。进行基于胃肠道菌群微生态变化的放牧与圈养对羊肉品质影响作用机制的研究，并利用试验动物进行机理验证。该研究的结果为苏尼特羊的合理利用和进行开发通过改变胃肠道微生物菌群结构从而达到改善圈养羊肉品质的饲养管理技术提供试验数据和理论支持。

随着国家退化草地限牧或禁牧封育政策的实施，改善舍饲羊肉品质是我国羊肉业发展面临的关键性问题。通过分析苏尼特羊在不同饲养条件（草原放牧和舍饲）下生产性能和肉用品质的差异，得出草原放牧和舍饲羊肉品质差异的物质基础（营养成分、功能成分和风味物质组成），为以后的研究奠定了基础。通过对羊胃肠道微生物多样性的研究，发现了不同饲养条件下胃肠道菌群结构、组成和优势菌群的变化规律，并分析了菌群结构和羊肉营养物质的沉积和风味成分的相关关系，证明了胃肠道菌群与饲养条件肉品质存在着较强的相关关系，为揭示不同饲养下苏尼特羊肉品质差异的机理提供了理论依据和数据支持。通过在日粮中添加亚麻籽和乳酸菌以及运动训练对羊的风味、脂肪酸代谢、胃肠道菌群结构、肌纤维组织学特性等进行了调控，发现改变日粮营养组成或给予一定的运动训练，可以改变肌纤维组成，丰富风味物质的种类，提高瘤胃菌群丰富度，有利于改善苏尼特羊胃肠道微生物健康和提高肠道免疫性能，从而达到了改善苏尼特羊肉品质的目的，对提高农牧民养羊积极性、提高养羊效益、促进农牧民增产增收和带动地区经济具有重要意义。