仔猪肠道黏膜免疫及其营养调控

肠道是营养物质消化吸收的主要场所,也是机体最大的免疫器官,构成仔猪肠黏膜免疫系统的重要组成部分.本文从仔猪肠道黏膜免疫系统的组成、肠道免疫细胞、肠道微生物及病原识别受体、肠黏膜免疫对肠道健康的影响、仔猪肠黏膜免疫的营养调控等方面综述了近年来仔猪肠道黏膜免疫的研究进展,为未来仔猪肠道健康和营养调控的研究以及益生菌等抗生素替代物在仔猪生产中的合理应用提供理论依据.     

仔猪肠道发育与内环境调控技术(一)

肠道是营养物质消化、吸收的主要场所以及营养物质代谢的重要器官,同时也是仔猪免疫的第一道屏障,其发育对动物生长具有重要意义。文章从肠道结构与功能、黏膜免疫和微生物区系等方面综述了仔猪肠道发育与内环境调控技术的研究现状,为调控仔猪生长发育及养猪生产提供参考。     

仔猪肠道免疫与肠道健康

肠道黏膜免疫系统是仔猪体内最大的黏膜免疫器官,在识别和清除有害物质的过程中发挥着重要作用,同时能够对营养物质和肠道益生菌形成免疫耐受,与仔猪的健康关系最为密切。随着养殖业进入全面减抗、限抗的时代,养猪业面临巨大的挑战。仔猪肠道健康决定了猪场的生产效益,正确认识仔猪肠道免疫系统,科学调节肠道免疫,提高仔猪抗病能力,是决定养猪生产能否成功的重要因素。     

早期菌群干预在仔猪肠道健康中的应用

仔猪肠道健康与仔猪的生长性能息息相关。肠道微生物在对营养物质的消化吸收、维护仔猪肠道屏障的完整性和刺激肠黏膜免疫的发育方面发挥着重要的作用。断奶仔猪肠道内有害菌的大量增殖,破坏了仔猪肠道的菌群平衡,引发仔猪腹泻。因此,尽早建立稳定的微生物群对于维护仔猪肠道健康显得尤为重要。本文通过不同方法干预仔猪肠道微生物的建立进行了综述,并分析比较了各方法的利弊,旨在为广大养殖户提供理论依据。     

影响断奶仔猪肠道发育的因素及营养调控措施

仔猪的肠道不仅是营养物质消化、吸收的重要场所,还是营养物质代谢的重要器官,对维持仔猪的健康生长具有重要作用。本文从断奶仔猪肠道发育的生理特点出发,分析影响断奶仔猪肠道发育的因素,并从营养角度阐述了其调控措施,从而为提高断奶仔猪的饲养水平和养殖效益提供参考依据。     

外源多胺对断奶仔猪肠道结构和功能的作用及机制

多胺(腐胺、精胺、亚精胺等)是原核生物和真核生物的生长因子.科学地添加外源多胺能促进断奶仔猪肠道的生长发育和营养物质的吸收,对其黏膜的生长、发育、成熟、修复损伤有重要作用.适量的外源多胺可以缓解由断奶对仔猪肠道结构和功能产生的损伤,帮助仔猪更好地适应由哺乳到采食的过渡.本文将围绕多胺对断奶仔猪肠道结构和功能的作用及机制进行综述.     

断奶仔猪肠黏膜免疫与功能性氨基酸的营养

黏膜免疫系统是机体抵抗病原体入侵的第一道免疫屏障,文中综述了肠黏膜免疫系统的结构和功能、肠黏膜免疫应答过程、功能性氨基酸的营养与免疫作用。断奶仔猪日粮的合理配制需考虑胃肠道的发育和功能性氨基酸的添加,研究促进肠道黏膜免疫的营养物质并探讨其作用机理具有重要意义。     

饲料添加剂对仔猪生产性能及消化吸收功能的影响

<正>仔猪对营养物质的消化吸收主要在肠道进行,肠道健康与否直接影响动物对营养物质的摄取。各种应激尤其是断奶应激对肠道形态、结构和功能产生极大影响。牛磺酸作为饲料添加剂可以促进肠道对糖、蛋白质和脂类物质的消化吸收,从而达到促生长作用。试验在仔猪饲粮中添加牛磺酸以改善断奶仔猪肠道黏膜,以提高其生产性能,为科研和生产提供理论参考。1材料与方法1.1试验动物试验动物为(28±1)日龄断奶、平均体重为     

仔猪肠道健康的营养调控技术及其应用

<正>仔猪饲养是养猪业的关键,在一般情况下,仔猪健康与其营养状况密切相关。仔猪的肠道是消化吸收的主要场所,对维持仔猪的健康生长至关重要。1仔猪胃肠道健康的影响因素首先是病原微生物,仔猪的胃肠道功能尚未发育完善,若肠道内微生物结构受到破坏时,很容易破坏其胃肠道黏膜,影响仔猪的采食量,增大了外部细菌感染的几率。其次是加工饲料,仔猪的肠道修复能力较差,若饲料中营养物质或粗纤维含量较多时,其肠道会很容易受到侵害。由     

精氨酸对仔猪肠道的保护机理及作用

正精氨酸是仔猪的必需氨基酸,可以直接或间接影响仔猪肠道机械屏障,对仔猪肠道黏膜生长、绒毛高、细胞生长、肠道通透性等方面均有重要作用。肠道具有将肠道内物质与机体内环境隔离开的功能,称为肠道屏障功能,主要由肠黏膜屏障实现,可防止肠道内致病抗原及有毒有害物质侵入机体。肠黏膜屏障由机械屏障、化学屏障、免疫屏障与生物屏障共同构成,其中最为关键的是机械屏障和免疫屏障。肠道机械屏障由肠道黏膜上皮细胞,细胞间紧     

规模化猪场仔猪腹泻病防治

规模化养猪场中仔猪发生腹泻病是比较普遍的问题,饲喂不善会给消化系统造成不可逆损伤,尤其是仔猪体质较差,各种组织和器官发育不完善,消化机能先天性比较脆弱,主动免疫功能还未健全,再加上环境条件潮湿、阴冷及奶水质量较差等应激情况,均会引起仔猪发生腹泻病。该文分析仔猪发生腹泻的几种原因,提出防治措施。     

饲粮不同能量来源对断奶仔猪肠道黏膜功能的影响

仔猪早期断奶常常导致仔猪能量摄入不足,使肠道黏膜细胞处于"饥饿状态",影响仔猪正常的肠道功能,从而加剧断奶应激,因此满足肠道黏膜细胞的能量供给至关重要。本文就谷氨酰胺(Gln)、葡萄糖(Glu)、脂肪这3种肠黏膜细胞主要的供能物质来分别论述它们对于断奶仔猪肠道黏膜功能的影响。     

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。     

Nutritional interventions to prevent and rear low‐birthweight piglets

Selection for hyperprolific sows, as a means of increasing litter size and profit, has resulted in an increased number of low‐birthweight (LBW) piglets. These LBW piglets might suffer from increased morbidity and mortality during the early neonatal period. In addition, they show reduced growth performance, meat and carcass quality, which leads to an important economic loss for the farmer in the post‐natal period. Therefore, nutritional interventions can be undertaken to prevent and rear LBW piglets. In the first part of this review, the preventive strategies at the sow level will be discussed. Approaches in preventing LBW piglets are to optimize the intrauterine environment via supplementing the sow during gestation. In the second part of this review, the interventions at the piglet level will be described. To increase the survival and growth rates of LBW piglets, one must focus on ensuring adequate colostrum and milk intake. Interventions include supplementing piglets, split nursing, split weaning and cross‐fostering. Additional interventions increasing the probability of optimal post‐natal food intake will be discussed.     

Estimating the incidence of influenza-virus infections in Dutch weaned piglets using blood samples from a cross-sectional study

A cross-sectional study was carried out on 32 Dutch breeding herds to estimate the incidence of influenza-virus infections in piglets before the start of the finishing period, at the age of approximately 10 weeks. Longitudinal studies on two herds (8 and 10 litters, respectively) were done to obtain an average decay function for maternal antibodies.Each participating farm in the cross-sectional study was visited twice within 5 months; each time, blood samples were taken randomly from one compartment (a separate room with separate air flow) of 4-5-week-old piglets and one compartment of 8-9-week-old piglets. These blood samples (a total of 2598; 16-23 per compartment, depending on its size) were tested in a haemagglutination inhibition test for antibodies against influenza-virus subtypes H1 and H3. Samples from 8-9-week-old piglets from the first sampling period (n=660) were also tested in an IgM ELISA.For each individual herd and each influenza-virus subtype separately, the decay function derived from the longitudinal studies was used to calculate an expected seroprevalence in 8-9-week-old piglets, which was then compared to the observed seroprevalence. Depending on subtype and sampling period, between 10 and 15 of the 32 herds were suspected of virus circulation during the weaning period because the observed seroprevalence was significantly higher than the expected seroprevalence (P<0.05). In the first sampling period the IgM ELISA confirmed six of these outbreaks. However, due to the small window of detection of the IgM ELISA (compared to the length of the weaning period), it will always underestimate the number of infections. Infections in the first half of the weaning period will no longer be detectable because IgM antibodies have already disappeared.In individual pigs, an incidence of 16-17% was estimated for each subtype over a 4-week period between the age of 4-5 and 8-9 weeks. For each influenza subtype, 80% of the piglets will enter the finishing facilities without antibodies or with decaying maternal antibodies. These piglets may be susceptible to an infection with influenza virus.     

Iron Poisoning in Piglets Autopsy Findings in Experimental and Spontaneous Cases

An account is given of the autopsy findings in 78 piglets which died from iron poisoning. They belonged to an experimental series which included a further 6 piglets that also died but will not be accounted for here. The experiment was designed to study why iron treatment causes occasional deaths among piglets. The results will be reported in full elsewhere (Tollerz, in press).In 63 piglets, the sows had been fed special experimental diets, and in 8 piglets from a field case where deaths occurred after conventional iron treatment to prevent anaemia, the predominant autopsy finding was waxy degeneration of the skeletal muscles, which appeared irrespective of whether iron dextran or iron dextrin was injected intramuscularly, or whether ferrofumarate or ferous sulphate was given orally. Only one piglet had slight heart-muscle degeneration, and hydropericardium was not present.The remaining 7 piglets received ferrous sulphate orally, which resulted in catarrhal to necrotizing gastroenteritis. Three of these piglets had waxy degeneration of the skeletal muscles, but in the other 4 the musculature was intact, which indicates another mechanism of toxicity than that in the cases of muscle degeneration.     

临床病猪铁异位沉积的病理组织学观察

采集，临床病猪的病料，采用冰冻切片技术和组织化学染色方法，对猪铁异位沉积的组织学变化进行了显微观察。结果显示，一些病猪的淋巴结、淋巴索和淋巴窦内的淋巴细胞数量显著减少，巨噬细胞的数量大幅度增加；大量吞噬有含铁血黄素颗粒的巨噬细胞聚集在一起，连成一片，致使细胞轮廓不清；它们的趋化运动能力和吞噬处理抗原的机能丧失。证明仔猪过量补充铁制剂，可以引起铁的异位沉积；铁在巨噬细胞内的沉积导致机体的免疫机能下降，使仔猪易患各种传染病。     

易与猪大肠杆菌病混淆的腹泻类疾病鉴别诊断

新生仔猪腹泻是猪场常见的疾病。因为新生仔猪免疫系统、消化系统发育不完全,抵抗力低下,一旦感染相关病原,发生腹泻,死亡率较高,对猪场造成巨大的经济损失。能导致仔猪发生腹泻的病原很多,虽然临床症状都为腹泻,但是表现出的具体症状有所区别。文章对不同病原引起的临床症状进行总结,为猪场的相关人员进行诊断提供依据。     

肠黏膜免疫研究进展和仔猪营养调控

断奶仔猪的营养是养猪业中的一个焦点问题。本文较系统的综述了肠黏膜免疫系统的结构与功能、肠黏膜免疫应答过程、断奶对仔猪肠黏膜免疫功能的影响、活性物质对断奶仔猪肠黏膜免疫调控的影响。肠道黏膜免疫机理的充分研究对断奶仔猪的营养调控具有重要意义。     

菊粉在断奶仔猪中的研究进展

断奶仔猪在心理、环境及营养应激下，出现“仔猪早期断奶综合症”，严重影响养猪生产效益。而菊粉作为一种新型的饲料添加剂，可选择性促进肠道有益菌增殖，抑制有害菌生长，从而提高动物的生产性能和免疫力。作者概述了菊粉及其提取工艺，以及菊粉对断奶仔猪肠道菌群和免疫功能等的影响，以期为仔猪的健康养殖提供理论依据。