壳寡糖对妊娠母猪、泌乳母猪及新生仔猪健康调控机理研究

The efficiency of our country sows produce piglets is only 50% of the U.S. and Europe, How to improve sow eugenics and efficient productive capacity of Chinese pig farming industry is facing problems to be solved. Chitooligosacchrides comes from Chitin, which is a polysaccharide isolated from the outer skeleton of insects, crabs and shrimps. Because of chitooligosacchrides showed good biological activity and the characteristics of "green" , it has become increasingly favored by the livestock keepers. There were a certain amount of research and application on chitooligosacchrides as a feed additive. To add a new of chitooligosaccharides feed additives in pregnant sows compound , a large number of experiments found that chitooligosaccharides can improve the new piglet amount, at the same time increase the total litter weight, and significantly improve the reproductive performance of sows, but its mechanism of action is not yet clear, also no reports in the international arena. This experimental study will intend to be the basis of the existing work of the applicant team, utilizing chitooligosaccharides derived from marine organisms as experimental material, to do some research on the health of the pregnant sow reproductive performance, lactation performance of lactating sows and newborn piglets growth performance, immune indicators, cytokines, etc. To look forward to improving sow reproduction and piglet health standards, finally clarifying its mechanism of action and target as the theoretical basis for the chitooligosacchrides feed additives in a wider range of applications.

我国母猪年产仔猪的效率仅为欧美发达国家的50%左右, 提高母猪高效多产能力是我国生猪养殖业面临亟待解决的问题。壳寡糖由生物降解源于虾/蟹壳的壳聚糖获得，已发现作为饲料添加剂具有促进仔猪生长、提高仔猪免疫及替代抗生素等功能。在前期工作中, 申请者以自行研制的壳寡糖作为饲料添加剂, 对怀孕母猪作了大量研究, 首次发现壳寡糖可以提高窝仔数和总窝量，明显改善母猪繁殖性能的功效。目前, 这种功效的作用机理和作用途径尚不清楚, 也未见国内外同行有相关报道。 本申请拟在申请者团队现有工作的基础上,以源于海洋生物的壳寡糖为实验材料，从糖链变化入手, 在基因和蛋白质水平上研究壳寡糖对妊娠母猪繁殖性能、泌乳母猪泌乳性能及新生仔猪生长性能、免疫指标、细胞因子等的影响，明确壳寡糖干预母猪繁殖能力和增强仔猪健康水平的作用机理和作用途径, 为寡糖饲料添加剂在生猪养殖领域的广泛应用，促成我国母猪的高效多产提供理论支撑。

我国是世界上第一养猪大国，但并不是养猪强国，主要的原因之一就是我国母猪年产仔猪的效率仅为欧美发达国家的50%左右, 提高母猪繁殖性能和新生仔猪存活率是我国生猪养殖业面临亟待解决的问题。壳寡糖是通过生物法降解虾/蟹壳来源的壳聚糖制备获得，2006年获得我国农业部审批，作为新饲料添加剂可以用于畜禽和水产养殖。壳寡糖作为饲料添加剂具有促进仔猪生长、提高仔猪免疫及替代抗生素等功能。本项目将壳寡糖应用于母猪的妊娠和泌乳阶段，首次发现壳寡糖具有提高窝仔数和总窝重，明显改善母猪繁殖性能的功效。针对此发现，按照基金的资助计划书，本研究从三个方面开展：（1）壳寡糖对妊娠母猪生产性能与免疫功能影响的研究，发现壳寡糖显著提高妊娠母猪35天血清孕激素水平，增加了绒毛膜中瘦素（Leptin）（P<0.01）和血管内皮生长因子VEGFA（P<0.05）基因的相对表达量，同时提高了35天胎儿BMP2, BMP4, PPARγ等基因的表达，羊水代谢组学结果显示壳寡糖影响母猪葡萄糖代谢、氨基酸代谢以及三羧酸循环，可改善早期胚胎发育，促进胎儿生长；（2）壳寡糖对泌乳母猪生产性能及免疫功能影响的研究，发现壳寡糖可以有效增加泌乳母猪血清中IgG、初乳中乳糖和非脂固形物含量，揭示了壳寡糖调控母猪及新生仔猪健康的机制，同时建立猪乳游离寡糖库，共鉴定游离寡糖41种，解析了乳蛋白N-糖链寡糖结构42种，明确了壳寡糖对猪乳营养调控的理论基础；（3）探索了壳寡糖对断奶仔猪生产性能、肠道发育及免疫功能的影响，首次发现壳寡糖添加具有明显的“母体效应”。相关研究结果共计发表SCI收录论文9篇（累计影响因子29.8，单篇最高4.81）。本项目阐明壳寡糖对妊娠母猪繁殖性能、泌乳母猪泌乳性能及对新生仔猪健康水平的影响，明确其作用机理和靶点，有效提高母猪繁殖能力和仔猪健康水平，最终为发挥壳寡糖饲料添加剂在我国生猪健康养殖中的应用奠定理论基础。