有机酸对断奶仔猪肠道菌群调控的研究进展

现代集约化养殖生产中,仔猪早期断奶综合征所引发的采食下降、生长缓慢和腹泻等一系列问题对养猪业造成了较大的经济损失。引起这些症状的主要原因之一就是断奶应激造成的肠道菌群紊乱,因此,研究仔猪肠道微生态区系及其调控技术,对于预防仔猪早期断奶综合征具有重要意义。有机酸具有显著的调节肠道菌群的功能,在预防仔猪早期断奶综合征中有广泛的应用。本文针对断奶仔猪胃肠道菌群变化、有机酸作用原理及常用有机酸对肠道微生态区系的调控等研究进展进行了综述。     

益生菌对断奶仔猪肠道黏膜屏障功能的调控作用及可能机制

早期断奶仔猪，由于饮食、环境的改变以及自身消化系统、免疫系统的不完善，易引发断奶应激综合征，造成肠道屏障功能紊乱。有效修复因断奶应激引发的肠道屏障功能紊乱，提高仔猪肠道消化吸收及免疫机能对促进仔猪生长、防治腹泻具有重要意义。益生菌是一类安全、绿色、高效的新型饲料添加剂，具有抗菌、抑炎、免疫调节等作用。研究表明，益生菌能够维护断奶仔猪肠道屏障功能，缓解断奶应激。本文综述了益生菌对断奶仔猪肠道健康影响的研究进展，总结了其调控断奶仔猪肠道屏障功能的可能机制，以期为断奶仔猪肠道健康的营养调控提供理论依据。 [关键词] 益生菌|断奶仔猪|肠道屏障|作用机制     

丁酸梭菌调控断奶仔猪肠道屏障功能的研究进展

饮食、环境的改变断奶仔猪易引发断奶应激综合征,造成肠道屏障功能紊乱。丁酸梭菌是一种安全、绿色、高效的新型饲料添加剂,可有效维护断奶仔猪肠道屏障,对断奶仔猪生长发育具有重要意义。文章综述了丁酸梭菌对断奶仔猪肠道屏障的研究进展,总结了丁酸梭菌调控断奶仔猪肠道屏障的作用机制,以期为丁酸梭菌在改善断奶仔猪肠道健康方面提供参考。     

仔猪肠道损伤修复营养调控及其机制和应用

仔猪早期断奶是现代养猪业中的一项重要技术措施,但断奶应激又导致仔猪出现早期断奶综合征,尤其是肠道损伤.肠道正常的功能依赖肠道黏膜上皮屏障、免疫屏障、生物屏障的完整性来维持.断奶应激会导致仔猪肠道黏膜形态结构改变、肠上皮屏障通透性增加、消化吸收功能降低、黏液层厚度下降、肠道pH升高、免疫抑制、肠道微生物菌群失衡等,甚至造成肠道功能的继发性损伤和功能紊乱.因此,肠道损伤修复及其营养调控研究日益受到关注.直接或间接调控因子主要包括:1)多肽类生长因子.主要包括表皮生长因子(EGF)、胰高血糖素样肽-2 (GLP-2)、胰岛素样生长因子-Ⅰ(IGF-Ⅰ)和转化生长因子(TGF)等.本文介绍了本团队制备的猪胰高血糖素样肽-2(pGLP-2)长效化产物对降低仔猪肠道炎性反应,提高黏膜屏障功能的作用.2)微生态调控剂.包括益生菌制剂和抗菌肽.猪饲粮中常用益生菌有屎肠球菌、芽孢杆菌、植物乳杆菌、乳球菌、酵母菌等.已报道用于仔猪饲粮的抗菌肽主要有天蚕素、防御素、抗菌肽buforinⅡ、抗菌肽P5及复合肽等.3)营养代谢调控剂.报道较多的氨基酸及其衍生物有谷氨酰胺及其替代品α-酮戊二酸、L-精氨酸、N-乙酰半胱氨酸等.研究较多的其他调控剂还有短链脂肪酸、壳聚糖、植物多糖、锌和硒等.本文对上述各类损伤修复调控因子研究进展进行了综述.     

谷氨酰胺营养及其对早期断奶仔猪的作用

早期断奶是提高养猪生产效率的重要手段,但是早期断奶往往造成以仔猪断奶后生长缓慢和腹泻为主要特征的“早期断奶综合症”。产生这一后果的生理基础是由于断奶应激影响了仔猪肠道组织的形态结构和消化道微生态区系的平衡。此外,还影响免疫系统和酶系统的发育和健全。国内外的营养学家对这一问题做了大量的工     

改善早期断奶仔猪肠道健康和功能的营养策略研究进展

商业化生产中仔猪早期断奶（3~4周龄）恰是肠道功能发育的关键时期,断奶应激带来的持续性肠道屏障功能损伤是断奶仔猪细菌性和病毒性肠炎及断奶后腹泻的主要诱因。饲料端“禁抗”背景下,运用营养策略改善早期断奶仔猪肠道功能的研究是研究者关注的焦点问题。从早期断奶对仔猪肠道屏障功能的影响及多种营养策略对断奶仔猪肠道功能改善的作用,综述了早期断奶致仔猪肠道屏障功能损伤的机理及氨基酸、抗菌肽、益生菌、膳食纤维、低聚糖、有机酸、微量营养素和脂质营养等营养策略改善仔猪肠道功能的作用机制,为通过营养策略改善断奶仔猪肠道功能相关研究提供参考。     

仔猪早期断奶对肠道免疫功能的影响

肠道不仅是动物体内最大的消化吸收器官，同时也是体内最大的免疫器官。早期断奶造成断奶后仔猪食欲不振、消化不良、增重缓慢、腹泻等表现的早期断奶综合征。引发这一后果的主要原因是断奶应激对仔猪肠道屏障的破坏，进而造成仔猪肠道免疫功能受损。通过对早期断奶仔猪肠造的生理特性及肠道的免疫机制的综述，进而阐述了早期断奶对仔猪肠道免疫功能的影响。     

仔猪早期断奶对肠道屏障损伤机制研究进展

肠道不仅是体内最大的消化吸收器官，同时也是体内最大的免疫和内分泌器官。作为外界接触微生物最多的部位，肠道扮演着双重角色：既是病原体入侵机体的主要门户，又是阻止肠道微生物感染的第一道屏障。现代养猪生产中，仔猪早期断奶技术促进了养猪水平的提高．但是早期断奶使仔猪肠道屏障损伤产生的仔猪腹泻给养猪业造成了巨大的经济损失。此文就猪肠道屏障及早期断奶屏障损伤机制进行综述。     

谷氨酰胺对早期断奶仔猪肠黏膜免疫的调节作用

作者综述了早期断奶仔猪肠黏膜免疫系统、谷氨酰胺的营养生理功能、早期断奶对仔猪肠黏膜免疫的影响,以及谷氨酰胺对早期断奶仔猪肠黏膜免疫系统的结构和功能、肠道屏障功能、肠道抗氧化能力及生产性能的影响。     

断奶仔猪肠道健康与免疫调控

断奶应激一直是困扰现代养猪业的难题,由于幼龄仔猪消化系统和免疫系统都尚未发育成熟,早期断奶容易造成仔猪胃肠道功能紊乱,诱发仔猪断奶综合征。肠道是断奶仔猪消化食物、吸收营养的主要场所,也是体内最大的免疫器官之一。因此,通过研究仔猪肠道健康,阐明仔猪肠道生理结构及功能的发育规律,分析仔猪断奶前后肠道免疫调控特点,为不同日龄断奶仔猪确定合理的营养对策具有十分重要的意义,文章就近年来国内外仔猪肠道生理及免疫调控的研究进展进行综述。     

Research Advances on Intestinal Microflora Regulationin by Several Feed Additives in Piglets

In modern pig production,early weaning is a bottleneck problem which are restricting the development of pig industry.It can lead to early weaning syndrome in piglet,such as low appetite,growth inhibition,diarrhea and so on.One of the reasons induced these symptoms is impairment of intestinal mucosal barrier in piglets.The intestinal microflorais is one of the important parts of intestinal mucosal barrier.Therefore,study on the intestinal microflora of weaning piglets and nutritional regulations have been attracted more and more attentions,and it has an important influence on avoiding diarrhea,promoting the healthy growth and improving growth performance.The change of intestinal microflora in weaning piglets and research development of some common feed additives（microecologics,plant polysaccharide,acidulant,microelement,Chinese herbal medicine and plant extracts）for intestinal microflora were reviewed in this paper.     

Study on Relationship between Intestinal Epithelium Tight Junction Proteins mRNA Expression and Piglets Weaning Diarrhea

The experiment was carried out to compare diarrhea status between Min pig and Landrace pig in a week after weaning, detect two varieties piglets jejunum, ileum and colon tight proteins Zonula occludens-1(ZO-1)and Occludin mRNA expression before and after weaning. The intention was to discuss the relationship between tight proteins expression and piglets weaning diarrhea. The results showed that Min piglets diarrhea rate, diarrhea frequency were very significantly lower than Landrace pig within one week after weaning (P<0.01), diarrhea days was significantly lower than Landrace pig within one week after weaning (P<0.05);Min piglets not weaning group ileum and colon ZO-1 and Occludin mRNA expression was very significantly higher than Landrace pig not weaning group (P<0.01);Min piglets weaning diarrhea group ileum and colon ZO-1 and Occludin mRNA expression was significantly higher than weaning health group (P<0.05). The results indicated that Min piglets intestinal tight junction proteins mRNA high expression before weaning might be had relation with guarantee piglets intestinal health and decrease occurrence diarrhea;Min pig fast recover intestinal mucosa function and rehabilitation by increased tight junction proteins mRNA expression after weaning. So tight junction proteins mRNA high expression before and after weaning had an important significance for piglets to resist weaning diarrhea.     

断奶应激引发仔猪肠道损伤及重建机制研究进展

肠道的发育与成熟状况是制约幼畜快速生长的关键因素。断奶是仔猪必须经历的一个应激过程,而断奶应激主要的靶点就是仔猪的肠道,特别是小肠的损伤尤为严重。因此,本文从仔猪肠道的形态和结构、肠道消化和代谢相关酶活性、肠道黏膜屏障、肠道功能基因和蛋白的表达及调控、断奶激活的肠道应激信号通路、应激蛋白家族在肠道中的差异表达等多个层面探讨断奶应激导致仔猪肠道损伤及重建的机制。为今后采用各种营养调控手段改善仔猪肠道健康、促进其快速生长提供理论基础和支持。     

壳聚糖对断奶仔猪的生物作用研究进展

为了展示壳聚糖对断奶仔猪生物学作用的研究动态,综述了壳聚糖对断奶仔猪肠道微生态环境、肠道形态结构、免疫力、肠道酶活性、仔猪生长和腹泻等方面的影响,以为其在养猪生产中的研究和应用提供理论指导和参考。     

Mechanisms Involved in the Growth Promotion of Weaned Piglets by High-level Zinc Oxide

Dietary supplementation with high levels of zinc oxide (ZnO) is an effective method to prevent diarrhea and promote growth in weaned piglets. However, the mechanisms behind these beneficial effects are not well understood. Recent advances in this field indicated that the effects of ZnO on piglet growth are achieved through multiple regulatory pathways rather than a single pathway. This review focuses on recent advances in the effects of high level ZnO on: 1) Zn status in weaned piglets; 2) intestinal microbe flora regulation; 3) intestinal structure and function; 4) ion secretion in the intestine epithelium; 5) intestinal immunology; and 6) secretion of brain-intestine peptides. ZnO appears to regulate the intestinal microflora and decreases the release of histamine to prevent diarrhea. ZnO also increases the expression of intestinal insulin-like growth factor-1 (IGF-1) and the IGF-1 receptor to ameliorate intestinal injury associated with weaning, and mediates secretion of brain-gut peptides to stimulate food intake, to promote the growth of piglets. Better understanding of the underlying mechanisms should inspire us to supplement the diet for weaned piglets with ZnO and investigate new approaches to prevent diarrhea and enhance growth.     

缓释复合酸化剂对断奶仔猪消化道酸度及肠道功能的影响

本试验选用28 R龄断奶、平均体质量(7.00±0.10)kg的长白猪(♂)×大白猪(♂)二元杂交仔猪64头,按单因索试验设计原则,研究在玉米一豆粕一膨化大豆型基础日粮中添加不同类型(包被未包被)复合酸化剂对断奶仔猪胃肠道酸度、生产性能、肠组织形态、消化酶活性、肠道微生物菌群及肠黏膜抗体SIgA的影响.试验设4个处理,每个处理4个重复,每个重复4头猪(公母各半),饲养试验时间为35 d.结果表明,微胶囊型缓释复合酸化剂可以极显著降低断奶仔猪胃和小肠pH(P＜0.01);极显著提高空肠绒毛高度和隐窝深度的比值(P＜0.01);断奶前期,显著提高小肠蔗糖酶和乳糖酶活性(P＜0.05);断奶后期,极显著提高仔猪盲肠和结肠中乳酸杆菌数量,降低大肠杆菌数量(P＜0.01);微胶囊型缓释复合酸化剂还有增加仔猪肠黏膜抗体SIgA分泌量的趋势(P＞0.05).结果提示,在断奶仔猪日粮中添加微胶囊型缓释复合酸化剂,可以通过降低肠道pH,优化肠道微生物区系,改善肠组织形态和功能,从而提高断奶仔猪肠道的消化力和适应性,并促进仔猪生长.     

Mechanisms Involved in the Growth Promotion of Weaned Piglets by High-level Zinc Oxide

Dietary supplementation with high levels of zinc oxide (ZnO) is an effective method to prevent diarrhea and promote growth in weaned piglets. However, the mechanisms behind these beneficial effects are not well understood. Recent advances in this field indicated that the effects of ZnO on piglet growth are achieved through multiple regulatory pathways rather than a single pathway. This review focuses on recent advances in the effects of high level ZnO on:1) Zn status in weaned piglets;2) intestinal microbe flora regulation;3)intestinal structure and function;4 )ion secretion in the intestine epithelium;5) intestinal immunology; and 6) secretion of brain-intestine peptides. ZnO appears to regulate the intestinal microflora and decreases the release of histamine to prevent diarrhea. ZnO also increases the expression of intestinal insulin-like growth factor-1 (IGF-1) and the IGF-1 receptor to ameliorate intestinal injury associated with weaning, and mediates secretion of brain-gut peptides to stimulate food intake, to promote the growth of piglets. Better understanding of the underlying mechanisms should inspire us to supplement the diet for weaned piglets with ZnO and investigate new approaches to prevent diarrhea and enhance growth.     

仔猪早期肠道微生物变化特点与饲养管理

仔猪早起肠道微生物菌群的变化对于仔猪的生长发育有重要的作用。为提高仔猪的存活率,在了解仔猪早期肠道微生物变化特点的基础上,采取科学的饲养管理措施,为仔猪提供干净、舒适的生长环境,保障仔猪的健康生长发育具有重要的科学价值和应用价值。该文主要论述仔猪早期肠道微生物变化特点出发,提出一套仔猪的饲养管理方式,为仔猪的饲养管理提供可靠的技术支持。