饲料污染物呕吐毒素对单胃动物家禽和猪肠道的影响

正食品和饲料安全是世界性的重大课题,它提升了人们对控制食品和饲料霉菌毒素污染的关注,因为霉菌毒素污染会影响动物和人类的健康。呕吐毒素(DON)是镰刀霉菌毒素中的一种,对人体和多种动物有毒,猪对这种毒素最为敏感,鸡的耐受性最高。在欧洲,谷物通常含有呕吐毒素,因此是镰刀菌毒素污染的指标之一。人和动物摄入呕吐毒素通常会产生多种中毒症状,如肠道黏膜刺激或坏死、腹泻、呕吐及、食量下降、增重下降和免疫功能改变。根据污     

饲料原料中呕吐毒素靶向降解的研究进展

呕吐毒素(Vomitoxin),也称脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON),是由镰刀菌产生的代谢产物,对食用受污染食品的人类和食用受污染的饲料的动物构成严重的健康风险。通常会引起腹泻、呕吐和人类和动物的胃肠道炎症。随着我国自然灾害的频繁爆发,呕吐毒素的污染也随之增加,所以控制呕吐毒素的污染已刻不容缓。本文表述了DON的化学性质、危害作用及生物脱毒方面的研究进展,为降解粮食和饲料中DON含量提供科学依据。     

饲料中呕吐毒素的危害和生物脱毒方法研究进展

呕吐毒素又称脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)是谷物中最为常见的一种真菌毒素,其降低畜禽的生产性能,并且对动物免疫系统、 细胞信号传导和基因的表达均有不同程度的影响.随着我国灾害气候的频频发生,呕吐毒素的污染程度呈现加剧趋势,因此呕吐毒素污染的控制迫在眉睫.传统控制脱氧雪腐镰刀菌烯醇的方法主要有物理法和化学法,但上述两种方法都具有局限性.本文阐述了脱氧雪腐镰刀菌烯醇的化学性质、 毒性作用以及生物脱毒方面的研究进展,为研究生物学方法控制粮食与饲料中呕吐毒素含量提供参考.     

脱氧雪腐镰刀菌烯醇的免疫毒性研究进展

脱氧雪腐镰刀菌烯醇（deoxynivalenol,DON）是一种单端孢霉烯族毒素,主要由禾谷镰刀菌、尖孢镰刀菌、串珠镰刀菌、拟枝孢镰刀菌、粉红镰刀菌、雪腐镰刀菌等镰刀菌产生,由于它可以引起猪的呕吐,故又名呕吐毒素（vomitoxin,VT）。DON纯品1970年首先从日本香川县感染赤霉病的大麦中分离到并命名。这种毒素广泛存在于霉变的小麦、大麦、燕麦、玉米等谷类作物、发霉的饲料以及被污染的肉、奶等动物性食品中,人畜摄入了被DON污染的食物后,会导致厌食、呕吐、腹泻、发烧、站立不稳和反应迟钝等中毒症状,严重时损害造血系统造成死亡（Plattneretal,2003;敖志刚和陈代文,2008）。     

饲料中DON的污染及其对畜禽的危害

脱氧雪腐镰刀菌烯醇(DON)是谷物受镰刀菌污染而产生的一种常见的霉菌毒素。脱氧雪腐镰刀菌烯醇经动物吸收后能快速地排泄而在动物组织中很少残留。但该毒素对动物的采食量以及生长性能有一定影响。     

脱氧雪腐镰刀菌烯醇(DON)检测方法研究进展

脱氧雪腐镰刀菌烯醇(DON)是一种霉菌毒素,也是谷物中的主要污染物之一,对农产品生产、人类健康、国际贸易交流和社会经济发展均有重要影响。适宜的检测方法是确定毒素含量是否符合相关限量标准、制定谷物饲料和食品中毒素污染控制措施的关键。本文就脱氧雪腐镰刀菌烯醇的毒性特征,分子结构特点,常用检测方法及最新研究进展进行综述。     

脱氧雪腐镰刀菌烯醇致动物厌食和呕吐机制的探讨

脱氧雪腐镰刀菌烯醇(DON)是一种由镰刀菌产生的霉菌毒素,其广泛存在于食品和饲料中,严重威胁着人类的健康和食品安全。DON又称呕吐毒素,它可对动物的肠道、大脑以及神经系统产生毒害作用,致使动物产生厌食和呕吐反应。本文综述了DON诱导厌食和呕吐反应的机制,并阐述了肠道微生物和DON诱导厌食和呕吐反应的潜在联系,以期为更深层次研究DON诱导厌食和呕吐反应的机制提供新思路。     

饲料中的霉菌毒素(续完)

单端孢霉烯毒素 单端孢霉烯毒素(trichothecene)是包含200～300种化合物的一类毒素,其中包括T-2毒素、二乙酰藨草镰刀烯醇(diacetooxyscirpenol,DAS)和脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON),这些毒素常见于农产品中(Desjardins等,1993).它们通过在核糖体水上抑制蛋白质的合成而发挥其毒性作用,具有免疫抑制性和细胞膜毒性,可诱使细胞凋亡(Sharma,1993;Shifrin和Anderson,1999).单端孢霉烯毒素的毒性作用包括对胃肠道的影响,如引起呕吐、腹泻和肠炎;此外,贫血、白细胞减少、皮肤刺激、拒食、生长减缓和繁殖障碍等症状也很普遍.若干种镰刀菌及相关属的真菌会产生单端孢霉烯毒素.看来,除了DON外,大多数单端孢霉烯毒素污染发生在谷物收割前.     

呕吐毒素生物降解机制研究进展

呕吐毒素（DON）是全球农业领域最为关注的食源性真菌毒素之一,主要由镰刀菌产生。谷物类农产品一旦被污染,很难通过普通工艺将其消除。生物降解法消除农产品及其加工制品中的呕吐毒素是近年来的备受学者关注。一批新颖的降解菌、降解酶和降解机制被先后发现,为DON生物降解和防治技术的开发提供了新的切入点。文章根据DON不同的生物降解机制,梳理了近十年的相关研究进展,以便更好地了解呕吐毒素生物降解研究现状、存在的问题以及发展趋势。     

国内饲料及饲料原料中呕吐毒素的消减技术

正饲料工业和畜牧业生产中的饲料霉变是全球面临的难题,中国也因此造成了严重的经济损失,霉菌毒素含量过高的饲料是不安全饲料,最受关注的霉菌毒素包括了黄曲霉毒素(AFB)、玉米赤霉烯酮(ZEN)、脱氧雪腐镰刀菌烯醇(DON,又称呕吐毒素)、伏马毒素B1(FB1,又称烟曲霉毒素)、赭曲霉毒素(OTA)等,其中以DON的检出率最高。在养殖场环节,饲料及其原料中DON的消减方法可分为包括物理法、生物法、功能营养素法、脱     

Feeding trials with vomitoxin (deoxynivalenol)-contaminated wheat: effects on swine, poultry, and dairy cattle

Nutritional and toxicologic feeding trials with 3 species of farm animals demonstrated that decreased feed consumption and reduced weight gains in pigs are the main effects of ingestion of a diet with low vomitoxin (deoxynivalenol; DON) content, eg, 2 mg of DON/kg of feed, ie, 2 ppm. The feeding trials indicated that swine can ingest up to 2 mg of DON/kg of feed without serious adverse effects. Poultry can tolerate at least 5 mg of DON/kg feed. In fact, at concentrations up to 5 mg of DON/kg feed, some beneficial effects on poultry were observed. In dairy cattle, feed consumption decreased slightly when a wheat-oats diet containing 6 mg of DON/kg was fed at the rate of 1% of body weight/day, with hay offered ad libitum. In surveys of Canadian grains carried out during the past 3 years, the DON content (maximum of 8.5 mg/kg) in eastern Canadian wheats probably was not high enough to account for reports of feed refusal, vomiting, and reproductive problems in livestock operations. This conclusion is based partly on the fact that even at the highest concentrations of DON found in wheat, formulated diets comprise, at maximum, about 70% to 80% wheat. Consequently, the actual DON content of diets fed to farm animals would be much lower.     

玉米赤霉烯酮对母猪的繁殖毒性研究进展

玉米赤霉烯酮（zearalenone,ZEA）是一种具有雌激素活性的真菌毒素,是猪生产中最常见的霉菌毒素之一。玉米赤霉烯酮广泛存在于谷物原料和配合饲料中,食入被其污染的饲料可导致母猪繁殖障碍,严重影响母猪的生产潜力和生产性能。本文就ZEA在猪饲料中的污染现状、对母猪的繁殖毒性以及毒性作用途径等方面进行综述,为进一步研究提供参考。     

青海省部分地区猪饲料中霉菌毒素污染情况调查分析

为了解青海省部分地区猪饲料中霉菌毒素的污染情况,应用ELISA方法对2012年采集的青海省部分地区205份猪饲料样品进行了赭曲霉毒素A （OTA）、黄曲霉毒素B1（AFB1）、呕吐毒素（DON）、玉米赤霉烯酮（ZON）的检测与分析.结果表明.156份商品化饲料中,OTA、AFB1、DON、ZON阳性率分别为7.05％、16.03％、83.33％和69.87％,49份自制饲料中,OTA、AFB1、DON、ZON阳性率分别为6.12％、28.57％、85.71％和73.4％;156份商品化饲料中,总单污率为11.54％,总混污率为79.49％,在49份自制饲料中,总单污率为8.16％,总混污率为91.84％;试验显示,青海省部分地区饲料中存在霉菌毒素的污染,且混合污染现象严重,同时自制饲料的污染程度较商品化饲料高.     

2018年山东省饲料原料及配合饲料霉菌毒素污染状况调查

为了解山东省饲料原料及配合饲料中霉菌毒素含量及污染状况,随机采集于山东各地饲料原料2 237份,配合饲料1 432份,利用上转发光竞争抑制免疫层析法分别测定了黄曲霉毒素B1(AFB_1)、玉米赤霉烯酮(ZEN)和呕吐毒素(DON)含量。结果表明:饲料原料中AFB_1污染率为39.20%,超标率为7.18%;ZEN污染率为43.23%,超标率为12.82%;DON污染率为62.58%,超标率为1.79%。玉米及副产物应重点关注3种毒素的污染,小麦及副产物和米糠重点关注DON污染,花生饼粕重点关注AFB_1的污染;配合饲料中AFB_1污染率为45.88%,超标率为2.74%;ZEN污染率为57.05%,超标率为4.04%;DON污染率为77.37%,超标率为0.81%。配合饲料应关注鸭饲料及猪饲料3种毒素的污染,雏鸡饲料应关注AFB_1污染,生长及产蛋鸡饲料应关注ZEN含量,奶牛精料补充料应关注DON和AFB_1的污染。     

Phytate and phytase in fish nutrition

Phytate formed during maturation of plant seeds and grains is a common constituent of plant-derived fish feed. Phytate-bound phosphorus (P) is not available to gastric or agastric fish. A major concern about the presence of phytate in the aquafeed is its negative effect on growth performance, nutrient and energy utilization, and mineral uptake. Bound phytate-P, can be effectively converted to available-P by phytase. During the last decade, phytase has been used by aqua feed industries to enhance the growth performance, nutrient utilization and bioavailability of macro and micro minerals in fish and also to reduce the P pollution into the aquatic environment. Phytase activity is highly dependent on the pH of the fish gut. Unlike mammals, fish are either gastric or agastric, and hence, the action of dietary phytase varies from species to species. In comparison to poultry and swine production, the use of phytase in fish feed is still in an unproven stage. This review discusses effects of phytate on fish, dephytinisation processes, phytase and pathway for phytate degradation, phytase production systems, mode of phytase application, bioefficacy of phytase, effects of phytase on growth performance, nutrient utilization and aquatic environment pollution, and optimum dosage of phytase in fish diets.     

Ingestion of low doses of deoxynivalenol does not affect hematological, biochemical, or immune responses of piglets

Deoxynivalenol (DON), a mycotoxin produced by Fusarium spp., is a frequent contaminant of cereals. Because of their rich cereal diet, pigs could be exposed to this mycotoxin. Pigs are among the animal species showing the greatest sensitivity to DON. Effects of intermediate to high levels of DON on pigs are well known and include feed refusal, decreased feed intake, and alteration of the immune response. Effects of low levels of DON, which are commonly detected in contaminated feed, remain unknown. The aim of this study was to investigate the effect of a diet naturally contaminated with a low concentration of DON (0, 280, 560, or 840 microg/kg of feed) on performance of weanling piglets and on 34 hematological, biochemical, and immune variables. Low doses of DON did not alter the animal performances (feed intake and BW gain). Such low levels of DON did not modify the 9 hematological variables measured (including white blood cell, red blood cell, and platelet counts, relative numbers of neutrophils and lymphocytes, and hematocrit and hemoglobin concentrations) or the 18 biochemical variables tested (including cations, glucose, urea, creatinine, bilirubin, cholesterol and triglyceride concentrations, and plasma enzyme activity). Similarly, no effect of low doses of DON was observed on the immune responses of the animals (immunoglobulin subset concentration, lymphocyte proliferation, and cytokine production).     

饲料原料粉碎过细引起猪胃肠溃疡的病例分析

笔者在养猪技术服务过程中发现一个现象：农村相当多的中小型养猪场的饲料生产车间，基本是所有阶段的猪只仅使用一个规格的玉米筛片，而且是选择最细（大多孔径为1.5 mm）的筛片来破碎饲料原料，也有的是部分小型饲料加工厂的老板为迎合部分使用者"饲料粉碎越细，消化利用率越高"的需求而为之。这种做法是不讲究科学的表现，也是对猪的身体健康十分有害的，作为饲料生产厂家不按科学要求生产饲料，这也是对养猪用户及其不负责任的具体体现。文章就"饲料原料粉碎过细引起猪胃肠溃疡"的典型案例进行简单的描述与分析，以期对部分中小型猪场饲料粉碎工艺提供技术及理论依据。     

Deoxynivalenol-contaminated wheat in swine diets

Two studies were conducted using Fusarium graminearum-infected (scabby) wheat containing 6.8 ppm deoxynivalenol (DON), commonly called vomitoxin, substituted for normal wheat in starter pig diets to give varying levels of DON. After 3 wk on experimental treatments, one-half of the pigs in trial one were sacrificed to evaluate the effects of DON on heart, kidney, spleen and liver. Analyses for DON residues in these tissues were also performed. The remaining 16 pigs were placed on a conventional diet for 4 wk to evaluate effects of DON on subsequent animal performance. A different sample of scabby wheat containing 4.9 ppm of DON was substituted for sorghum grain in growing-finishing pig diets to give varying concentrations of DON. At the end of the 42-d feeding period, eight pigs were slaughtered to evaluate the effects of DON on selected tissues. Results of the three trials suggest that feed intake was reduced when DON concentrations in the swine diets neared or exceeded 1 ppm. No apparent signs of disease, including vomiting, were observed in experimental animals. Histological evaluation revealed no significant lesions or abnormalities related to DON ingestion in tissues examined. Traces of DON (8 to 28 ppb, wet weight) were found in kidney, liver, spleen and heart of starter pigs consuming the diets containing DON up to time of slaughter. No DON was found in tissues of growing-finishing pigs that were withdrawn from feed about 12 h before slaughter.