肠道菌群及代谢物调控宿主肠道免疫的研究进展

肠道菌群是一个稳定且复杂的微生态系统,其在长期进化过程中与宿主建立了稳定的共生关系,且微生物的活动直接影响着宿主的健康。它们不仅在宿主营养物质的消化代谢和机体发育等方面发挥重要作用,而且与宿主的免疫和疾病密切相关。肠道菌群和机体免疫系统之间的相互作用机制十分复杂,受多种环境因素的影响,至今尚未完全阐明。微生物代谢物及微生物-机体共代谢物对调控免疫功能具有重要作用,逐渐引起研究者们的重视。因此,本文在介绍肠道及其在宿主防御中的作用的基础上,就肠道微生物及肠道内代谢产物如何促进宿主免疫系统发育、调节宿主免疫反应等进行了综述。旨在为进一步研究肠道微生物及代谢物与机体免疫系统互作提供参考,同时为改善畜禽肠道健康的营养措施提供理论依据。

高职院校毕业生留温就业意愿的影响因素探究——基于温州425份样本的实证分析

近年来,东部沿海城市普遍存在高素质技能型人才流失等现象,为鼓励人才留温,温州于2020发布“高校毕业生510计划”,留温就业率受到前所未有的重视。为此,文章对温州职业技术学院的425名毕业生进行问卷调查,使用SPSS20.0软件,以微观心理学为视角进行实证研究,结果显示:温州户籍、政治面貌为群众的毕业生留温就业意愿显著较高(p<0.05);基础设施环境、区域人才政策、城市发展状况、家庭经济压力和父母支持留温等五个变量能显著改善学生的就业意向(p<0.05)。高职院校应以党建为引领,全员参与精准指导就业,政校企行四方携手做好引才留才服务,获得毕业生和家长支持,与县域政府合作扩大办学,加大与本地中学的合作力度,保障企业技术人才供应,服务非中心城市经济发展。

Effect of Different Roughages on Milk Protein and Milk Fat Synthesis in Dairy Cows

The main purpose of this study was to determine the effect of a corn straw or mixed diet on milk production, milk composition and the expression of genes associated with lactation in mid-lactation Chinese Holstein cows. In this study, 10 healthy Chinese Holstein cows were randomly assigned to two groups and fed with different diets respectively, corn straw （CS） or mixed forage （MF） diet. CS group was fed roughage consisting of 53.8% corn straw only and the forge to concentrate （F ： C） ratio [dry matter （DM）] was about 40： 60. MF group was fed roughage consisting of 3.7% Chinese wildrye and 23.4% alfalfa hay, the forge to concentrate （F ： C） ratio （DM） was 70： 30. All the cows were fed 8 weeks and body weight, dry matter intake, body condition score, fat, protein, lactose, milk yield, total solid and somatic cell count （SCC） were recorded. Quantitative real-time PCR （qRT-PCR） was used to analyze cow mammary gland samples representing two different diets. The results suggested that different diet types had significant effects on milk yield, lactose, milk fat, milk protein, dry matter intake and somatic cell count in dairy cows, and cows fed MF diet improved milk production and lactation performance clearly （P〈0.05）. In addition, mRNA expression of genes ACC, roTOR, STATS, CSN2, PPAR）,, FABP3 and PTEN in MF group was extremely significantly higher than that in CS group （P〈0.05）. mRNA expression ofAKT1, FAS, SCD and SREBPlc in MF group was significantly higher than that in CS group （P〈0.01）. In summary, the milk yield and composition in mixed forage group were significantly improved than those in corn straw group.

沙棘提取物的生物学功能及其在畜禽生产中的应用

沙棘富含多糖类、黄酮类、鞣质、萜类、脂肪酸、维生素等活性成分,具有抗氧化、抗菌、抗炎、抗肿瘤、保肝利胆等生物学功能,可以增强畜禽机体免疫力与抗氧化功能,改善生长性能,提高畜禽产品品质。饲粮中添加沙棘果渣、籽、叶或提取物可不同程度地提高猪、羊、奶牛和肉鸡生产性能,降低饲料成本,增加养殖经济效益,但沙棘提高畜禽生产性能的活性成分和分子机制并不明确。文章综述了沙棘的活性成分、生物学功能及其在畜禽生产中的应用,为沙棘促进畜禽生产的机制研究、生产应用与开发提供参考。