低出生重的宫内生长受限（IUGR）猪不仅哺乳期死亡率高，而且后期饲料利用效率降低，平均出栏时间延长。由于对IUGR猪的营养素代谢特征不清楚，目前生产上通过简单地增加营养素浓度或根据其体重阶段进行饲喂等调控措施效果有限。本项目拟综合运用消化道瘘管、血插管、血浆代谢组、组织蛋白质组及肠道微生物组等分析技术，系统揭示IUGR猪的营养素消化、吸收与沉积规律，鉴定体液中营养素盈缺的代谢标记物并建立完善猪营养参数体液代谢组谱型识别模型，评价IUGR猪的营养满足程度，探讨IUGR猪的营养优化方案。项目研究成果不仅对于揭示猪的营养代谢规律具有重要理论意义，还将对通过分类管理和亚群体营养改善IUGR猪的生长具有实践指导价值。

My research is mainly focused on the developmental defects, nutritional provision and growth regulation of intrauterine growth restriction (IUGR) pigs. The previous results indicated that the relative weights of both gastrocnemius muscle and small intestine are reduced in newborn IUGR piglets compared with normal littermates. Decreased concentration of glucose and amino acids such as Arg and Gln in umbilicial vein during gestation mainly account for the progress and formation of the IUGR fetus. As a consquence, supplementation of Arg to gestating diet increased the litter size by 2 and supplementation of Gln decreased the occurrence of IUGR by 10%, as well as the beneficial role of Gln, Arg, zinc oxide and Lactobacillus fermentation on weaned piglets. Here, I would like to extend my research to improve the feed efficiecy of IUGR pigs. To address this problem, the characteristics of IUGR pigs in digestion, absorption and desposion of nutrients will be firstly determined by analyzing the metabolites in plasma at different locations and the proteome of improtant tissues involved in nutrient metabolism. Secondly, the systematic identification of metabolic biomarkers related to specific nutrients such as energy, proteion or amino acids in plasma will be conducted and the pattern recognization model will be setup and improved. Finally, the provision of nutrients for IUGR pigs will be optimized based on their metabolic charactaristics and actual nutritional status.

低出生重（IUGR）仔猪新生期死亡率高且后期生产性能差，而且，由此所造成的生长猪个体生产性能变异大又在一定程度上增加了饲养管理的成本以及猪场“全进全出”管理制度的落实。本研究从猪出生重和个体生产性能变异的角度出发，利用多层次血插管技术，研究了IUGR猪的营养消化吸收和代谢特征；建立了基于断奶仔猪血浆代谢组的猪全期生长性能预测模型，并研究了不同饲料利用效率生长猪营养代谢差异及其血浆代谢物分型。研究结果发现，1) 仔猪出生重与其断奶成活率、断奶体重和同期出栏体重呈密切正相关；2）通过分析差异代谢物，可将全期生产性能较好的猪从大群中鉴定出来，且建立的模型可以预测猪群的后期生长情况；3）综合运用股动脉-肠系膜静脉-门静脉-股静脉多层次血插管技术，通过测定血流量及进出特定组织的代谢物浓度差计算了相应器官的代谢物进出量、定量研究了各种营养物质与代谢物在特定器官或组织中的产生、利用和沉积规律。通过监测生长猪采食淀粉酪蛋白纯合日粮和玉米-豆粕型日粮后不同时间点营养素和血浆代谢物的盈缺与变化规律，发现两种日粮条件下血浆中谷氨酸，甘氨酸在餐后0.5小时均呈下降的趋势；而生长猪在采食玉米豆粕型日粮后，血浆中亮氨酸和异亮氨酸在餐后0.5小时显著下降。此外，血浆代谢组学结果显示，生长猪在采食上述两种日粮后的不同时间点共存在94种差异代谢物。综上所述，本研究建立了基于血浆代谢组的猪营养参数识别模型，准确评价了低出生重仔猪的生理发育特点、营养需要特点及实际营养状态；鉴定了不同日粮条件下生长猪的营养代谢规律，为猪群实现精准化营养干预奠定了理论基础。