母源添加连翘酯苷对仔猪断奶应激的影响及其传递途径的研究

Plant extracts have been the research focus in Animal Nutrition field due to the bacteriostasis and oxidation resistance. Our laboratory has demonstrated that Fructus forsythia can relieve the oxidative damage of young animals and improve their health condition under different kinds of stressors in the recent ten years. Most of the research focused on how to reduce weaning stress of piglets and less attention was paid to maternal plant extract supplementation to improve piglet health and the transfer rule is not clear until now. Recently, with the popularization and application of microorganism high throughput sequencing and metabonomics, the research on maternal transfer rule has abundant technical support. Therefore, the applicant aims to utilize sequencing technique and analyze intestinal bacterial diversity and dominant bacterial community difference from pregnance to weaning period by adding forsythiaside into the sow diet, and analyze forsythiaside, metabolites change of diet and pig using metabonomics to investigate the potential maternal transfer path of forsythiaside (microbial flora transfer/undiscovered active constituent of forsythiaside transfer through umbilical cord blood and breast milk/or regulate matrix metabolites directly through umbilical cord blood and breast milk). According to metabonomics and high thoughput sequencing, we screen potential biomarker or important microflora to provide new theory and scientific basis for maternal transfer regulation on the offspring health.

植物提取物因具有良好的抑菌抗氧化作用，已成为动物营养界的研究热点。我们实验室近十年来已研究证实，连翘提取物可以缓解不同应激源所致幼龄动物的氧化损伤，提高机体健康水平。诸多研究侧重于如何减缓仔猪的断奶应激，而对母源添加植物提取物提高仔猪健康关注较少，且传递规律并不清晰。近年来，随着微生物高通量测序和代谢组学技术的推广应用，母源性传递途径的研究有了技术保障。因此，申请人拟在母猪日粮中添加连翘酯苷，追踪妊娠至仔猪断奶饲养过程，利用测序技术分析母猪和仔猪肠道微生物菌群多样性和优势菌群的差异；同时结合组学技术分析连翘酯苷、日粮及猪的组织代谢产物的变化，探讨连翘酯苷可能的母源传递途径（微生物菌群传递/连翘酯苷本身未知活性成分经脐带血或母乳传递/或直接调控母体代谢产物经血液或母乳传递），筛选影响仔猪健康的母源性生物标记或关键菌群，为母源调控仔猪生长提供新的理论和科学依据。

针对项目研究目标，通过三个试验探究妊娠和哺乳期日粮中添加以连翘酯苷为主效成分的连翘提取物（Forsythia suspensa extract，FSE）对母猪繁殖性能、乳成分、抗氧化活性、免疫细胞因子、血清激素水平和肠道菌群结构的影响及可能的母源性传递途径，并取得如下进展：1）发现妊娠后期添加FSE可通过改善母猪养分消化率、初乳成分、抗氧化活性和免疫性能，从而减少死胎率，增加初生窝重，改善产仔性能。同时，妊娠后期添加FSE还可调节母猪生殖激素水平和改善分娩时粪便菌群结构。2）发现哺乳期添加FSE可改善哺乳母猪乳成分、抗氧化活性、炎症反应和肠道菌群结构，缓解哺乳期氧化应激，提高其繁殖性能，促进仔猪生长。此外，哺乳期母源添加FSE可改善哺乳仔猪抗氧化免疫性能、肠道形态、屏障功能和菌群结构。该研究结果为解决母猪妊娠后期和哺乳期生产中的氧化应激并改善仔猪肠道健康提供可行性方案。3）发现哺乳期母源添加FSE可通过改善抗氧化酶活性、免疫性能和肠道健康，缓解仔猪断奶应激，促进仔猪生长。在促生长、改善肠道形态和菌群结构方面，哺乳期母源添加FSE对仔猪的效果优于单独在保育仔猪日粮中添加，而在提高抗氧化免疫水平方面，哺乳期和保育期添加FSE效果相当。综上，FSE可通过提高妊娠后期母猪机体抗氧化和免疫力，减少死胎率，提高初生窝重；同时，通过改善母乳成分和仔猪肠道绒毛形态，促进仔猪生长。另外，哺乳期母源添加FSE，通过改善血液、乳汁及肝脏抗氧化和抗炎活性，减少炎性因子的释放，改善肠道菌群结构、屏障功能，进而改善母猪繁殖性能和断奶仔猪生长。