不同纤维组分影响生长猪净能生成与分配利用的规律

不同纤维原料生长猪代谢能转化为净能的效率（k值）存在较大差异，对其规律性的把握是在猪日粮配方中合理使用纤维原料的关键，而纤维原料k值的不同取决于其所含纤维组分在净能生成和分配利用规律方面的差异。本项目拟以纤维素、半纤维素、阿拉伯木聚糖、β-葡聚糖和木聚糖等纤维原料中平均含量高且变异系数大的单一纤维组分为研究对象，在无纤维日粮的基础上，首先结合消化道瘘管、血插管和外源双指示剂等技术，揭示特定纤维组分影响生长猪净能生成的规律；其次整合间接测热、能量消化代谢和分子生物学分析等技术，研究特定纤维组分及其不同比例组合影响生长猪净能分配利用的规律；最后通过在玉米-豆粕型日粮基础上添加等代谢能不等k值的纤维组分组合，结合生长试验和比较屠宰对该规律予以验证，并形成新的纤维应用方案。在揭示日粮纤维生长猪净能生成和分配利用规律性的基础上，为实现非粮饲料和农业副产物在生长猪日粮配方中的合理使用提供理论指导。

Our preliminary studies have shown that there is great variation in the efficiency of metabolizable energy to net energy (k value) for different fibrous ingredients fed to growing pigs, and understanding these regularity is vital for the appropriate utilization of dietary fiber in swine formulation. The difference in k value of fibrous ingredients could be mainly attributed to the discrepancy in generation, partition and utilization of net energy. This project is going to take the fiber components with high contents and great coefficient of variation in fibrous ingredients as research subjects, which include cellulose, hemicellulose, arabinoxylan, β-glucan and xylan. On the basis of fiber-free diets, the techniques of gastrointestinal fistula, blood catheter and exogenous double indicators will be combined firstly to explore the generation of the net energy of specific fiber component fed to growing pigs. Then the techniques of indirect calorimetry, energy digestion and metabolism and molecular biology analysis will be integrated to determine the effects of different fiber components and their combinations in different ratios on the partition and utilization pattern of net energy in growing pigs. Lastly, combinations of fiber components with equal metabolizable energy and different k values will be added into the corn-soybean meal diet, with growth trial and comparative slaughter techniques being used to validate the above patterns, and create new application cases for dietary fiber. This project will help to reveal the regularity of the net energy generation, partition and utilization of dietary fibers fed to growing pigs, and provide theoretical guidance for the rational utilization of the non-cereal feed resources and agricultural by-products in swine formulation.