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黄曲霉毒素B1在乳畜中的转化 总被引：1，自引：0，他引：1
黄曲霉毒素主要是由曲霉菌产生的一类具有高致癌性的次级代谢产物,我国饲料及饲料原料普遍受到黄曲霉毒素B1污染。乳畜摄入黄曲霉毒素B1后,代谢生成的羟基化产物黄曲霉毒素M1可通过乳汁污染乳及乳制品,并因这两种毒素都具有极强的毒性越来越受到人们的关注。黄曲霉毒素B1在乳畜的肝脏、瘤胃和乳腺等部位均可代谢转化,黄曲霉毒素M1向乳中的转移受到多种因素的影响。文章从黄曲霉毒素B1的代谢与转移排泄、影响黄曲霉毒素M1的转化因素以及黄曲霉毒素B1对乳腺上皮细胞和瘤胃微生物的影响进行论述。 相似文献
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饲料及原料中不可避免地存在霉菌毒素污染,给畜禽养殖业及饲料工业带来极为不良的影响。南京奥迈科技有限公司霉菌毒素分析中心对2013年上半年霉菌毒素检测结果进行分析,结果表明:饲料及原料总体上黄曲霉毒素污染较轻,玉米赤霉烯酮和呕吐毒素污染严重;玉米副产物霉菌毒素污染最严重;玉米和配合饲料主要污染玉米赤霉烯酮和呕吐毒素;小麦、麸皮的主要污染物为呕吐毒素;饼粕类特别是花生粕黄曲霉毒素污染较严重。 相似文献
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家禽黄曲霉毒素中毒 总被引：2，自引：0，他引：2
黄曲霉毒素中毒(Aflatoxicosis)是畜禽的一种严重疾病,病因是食入被黄曲霉菌污染的饲料。这种真菌能产生一组极毒的代谢物,其中黄曲霉毒素B_1(aflatoxin B_1,AFB_1)的毒性最大。各类家禽,尤其是仔鸡、仔鹅、雏鸭和小火鸡对黄曲霉毒素B_1的毒性易感性最强。黄曲霉毒素主要损害肝脏,表现为肝坏死、胆管增生、黄疸和出血。家禽慢性中毒的特征是体重降低、饲料利用效率和产蛋量下降,易患传染病。肝细胞肿瘤的发生,尤其在雏鸭,被认为是黄曲霉毒素中毒的严重后果之一。被黄曲霉毒素污染的饲料,可用不同的方法去除污染,主要是对饲料中的毒素进行物理排除或化学钝化。此外,饲料添加剂,例如活性炭、苯巴比妥、半胱氨酸、谷胱甘肽、β-胡箩卜素、非瑟酮和硒,据报导也可有效地降低家禽的黄曲霉毒素中毒。黄曲霉毒素不仅对家禽有害,而且其存在于禽肉和蛋中的残毒,对人类健康也有危害,本文是讨论黄曲霉毒素B_1的急性和慢性中毒的重要特征,并介绍黄曲霉毒素中毒的预防和减轻中毒的方法。 相似文献
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李凯年 《畜牧兽医科技信息》2004,(12):34-35
黄曲霉(Aspergillus flavus)是一种能够引起饲料严重污染的霉菌，黄曲霉产生的黄曲霉毒素(anatoxin)毒性极强，不易破坏，能够对畜禽造成严重的危害。畜禽摄入被黄曲霉毒素污染的饲料可以出现生长不良，饲料转化率降低，死亡率增加，对疾病易感，而且黄曲霉毒素可以在动物源性食品中残留，给人类健康带来极大的安全隐患。此外，黄曲霉毒素对微营养状态的影响也引起了人们的关注。据报告， 相似文献
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1 饲料质量对畜产品质量安全的影响
1.1 饲料自身因素
饲料自身含有的毒素,有些饲料自身含有一些不利因子如棉饼中的棉酚和环丙烯类脂肪酸等对动物具有毒性,使鸡蛋的蛋白部分呈粉红色,蛋黄也不正常,鸡蛋不耐储存;猪长期食用这类饲料,猪肉表面就会出现大小不等的灰、黄斑块,影响肉的品质;加热不足的大豆饼含有抗胰蛋白酶、凝集素和皂角等抗营养因子对畜禽及人类健康造成危害;饲料发霉,玉米、花生饼、菜饼等饲料极易被黄曲霉菌污染,产生黄曲霉毒素,黄曲霉毒素B1有致癌作用,被黄曲霉毒素污染的饲料能导致畜禽出现病变,畜产品质量下降,人食用这类的畜产品会致癌;饲料中某种物质过量也会影响肉品质,饲喂过量苜蓿、胡萝卜等造成黄色素沉着造成黄脂肉;饲料中若含不饱和脂肪酸程度过高,畜禽肥育后期食用会引起体脂和肌肉变软,不利加工和储存,进而影响畜产品品质. 相似文献
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黄曲霉毒素是一种霉菌产生的毒素，易存在各类饲料和食品中。本研究采用免疫亲和柱-荧光光度法对牛奶中的黄曲霉毒素M1进行测定，而饲料中的黄曲霉毒素B1采用酶联免疫法检测，研究结果发现：本实验中的黄曲霉毒素M1的荧光光度计的最佳光谱发射波长为450 nm，分析阴性牛奶产品的黄曲霉毒素M1含量，确定数据的精确性，牛奶回收率为76.67%～93.33%，变异系数为0.45%～2.8%，满足我国制定的检测标准，该方法操作简单、快速和安全。奶牛饲料中青绿饲料、粗饲料、能量饲料和蛋白饲料样品的黄曲霉毒素B1的测定率为100%，奶牛饲料中被检测的青绿饲料、粗饲料、能量饲料和蛋白质饲料阳性样品中黄曲霉毒素B1的含量分别为11.45、4.25、5.24和7.58 μg/kg，均小于20μg/kg（国家卫生部门制定标准），属于轻度污染|不同类型牛奶样品中阳性最高值为0.201 μg/kg，阳性最低值为0.004 μg/kg，平均值最大为0.084 μg/kg，严重超过我国卫生部门制定的标准。
[关键词]饲料|黄曲霉毒素|牛奶品质 相似文献
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Subacute ruminal acidosis (SARA) is a significant production disease of dairy cattle. Previous concerns have been raised over the occurrence of SARA in pasture-fed dairy cattle and the potential consequences of laminitis and lameness. Highly digestible perennial rye grass contains high concentrations of rapidly fermentable carbohydrate and low concentrations of physical effective fibre that may result in SARA. This study conducted a point prevalence survey of rumen health status in grazing Irish dairy cattle fed predominantly perennial rye grass-based pasture. The survey assessed rumen fluid, animal health status, milk production data and pasture composition. A total of 144 cows between 80 and 150 days in milk were sampled on 12 farms. Eleven percent of cows were classified as affected with SARA (pH < or = 5.5), 42% were marginal (pH 5.6-5.8) and 47% were normal (pH>5.8). The study showed that low rumen pH is prevalent in grazing Irish dairy cattle consuming perennial rye grass-based pasture and raises concerns regarding effective pasture utilisation and possible consequences for animal health. 相似文献
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生产中为了追求高产,反刍动物不可避免地需要饲喂高精料饲粮来满足其生产需要,而反刍动物饲喂高精料饲粮易诱发瘤胃胀气和瘤胃酸中毒,显著降低动物的生产性能,甚至还会导致动物死亡,给养殖业造成重大经济损失。早期研究认为瘤胃产气过多过快是高精料饲粮诱发瘤胃胀气的主要原因,但随着科技的进步,越来越多的研究表明,瘤胃气体被泡沫包裹无法正常排放才是高精料饲粮诱发瘤胃胀气的根本原因。瘤胃泡沫形成的确切机制还有待研究,来源于饲粮的、瘤胃微生物合成的以及瘤胃微生物酵解饲粮产生的蛋白质、多糖和羧酸盐可能充当了瘤胃泡沫的起泡剂或泡沫稳定剂。 相似文献
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B. Stefańska W. Nowak J. Komisarek M. Taciak M. Barszcz J. Skomiał 《Journal of animal physiology and animal nutrition》2017,101(4):694-702
The aim of this study was to estimate the prevalence of subacute ruminal acidosis (SARA) in Polish high‐yielding dairy herds. Also, the relationships between the chemical composition of the diet and the feed particle size, ruminal pH and the occurrence of this metabolic disease and the fermentation profile were determined. Rumen fluid samples were obtained from a total of 213 cows from nine dairy herds (≥20 cows per herd) via rumenocentesis. Almost 14% (30/213) of cows as acidotic (pH<5.6) were found, which is indicative of SARA. Moreover, 44% of the herds were classified as SARA‐positive and 56% as SARA‐negative. Results of the current study suggested that the physically effective NDF (NDF>1.18 mm)‐to‐starch ratio could be better indices than peNDF>1.18 mm to preventing the occurrence of SARA, and their level should not be lower than 1.00. Also, linear negative relationships between rumen fluid pH and concentration of propionate, valerate and total VFA were determined. According to the herd's SARA status and rumen fluid biochemical indices, there were significant differences between the pH of rumen fluid (p ≤ 0.01), concentrations of acetate (p ≤ 0.05), propionate (p ≤ 0.05), n‐butyrate (p ≤ 0.01), n‐valerate (p ≤ 0.01), the sum of VFA (p ≤ 0.01) and ammonia (p ≤ 0.05) in SARA‐positive herds compared to SARA‐negative herds. The better understanding the strategy of ruminant nutrition to coordinate energy conversion and the role of the ruminal pH in regulating N‐NH3 production, absorption through rumen mucosa, urea secretion, the more successfully we can utilize these processes with due recognition of animal needs and welfare, as well as prevention of SARA occurrence. 相似文献
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Rumen contents of 2 heifers with acute polioencephalomalacia (cerebrocortical necrosis) were compared with rumen contents from a healthy steer fed a fibrous diet. Also examined were (i) the quantitative nature of the predominant rumen microflora, (ii) the distribution of morphologic types of bacteria in the rumen contents, (iii) the extent that morphologic groups produced or degraded thiamine, and (iv) the cumulative effects of metabolic activities of the predominant rumen bacteria concerning the net production or degradation of thiamine. The differences in the frequency of occurrence of particular bacterial morphologic groups, the extent of growth, and the amount of thiamine metabolism in relationship to growth were also evaluated. The cumulative thiamine metabolism of the predominant bacteria associated with the rumen of polioencephalomalacia-affected heifers led to substantial net thiamine destruction, whereas metabolism associated with the rumen of a normal steer led to thiamine production. Polioencephalomalacia may occur as a consequence of alteration of the metabolic activities of the predominant resident ruminal bacteria associated with diseased cattle. 相似文献
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反刍动物是畜牧业中的重要支柱，研究瘤胃微生物在幼龄反刍动物上的定植过程，并利用其中的定植规律采取科学的早期调控措施，以此提高反刍动物的生产效率，对于维持畜牧业高效、健康、可持续发展具有重要意义。瘤胃微生物的定植过程伴随着幼龄反刍动物瘤胃的发育和饮食结构的巨大变化。在幼龄反刍动物哺乳时，瘤胃由于食管沟反射的存在而不发挥功能，发育缓慢，此时只有部分功能菌群逐渐定植；随着日龄的增长，幼龄反刍动物大量摄入固体饲料，瘤胃在固体饲料的刺激下迅速发育直至成熟，此时大量菌群定植，瘤胃发酵逐渐活跃，且优势菌及其丰度与前期相比发生较大变化。同时，大量瘤胃发酵产物的积累又进一步刺激了瘤胃的发育。反刍动物在幼龄阶段经历了从非反刍到反刍的生理过渡，是其最敏感和可塑性最强的时期，可以在此阶段对反刍动物瘤胃微生物采取人工调控措施，以保证机体的健康和后续生长发育。作者综述了反刍动物瘤胃早期发育过程、瘤胃内微生物的种类、来源及其在幼龄反刍动物瘤胃中的定植过程，阐明瘤胃微生物在反刍动物消化代谢、生产性能以及畜体健康方面的重要功能，并归纳了常用的瘤胃微生物调控技术，从而为生产中对幼龄反刍动物的饲养管理、营养调控提供参考。 相似文献
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Factors limiting the maintenance of recombinant ruminal bacterium in the rumen were evaluated in vitro , using batch culture prepared from rumen fluid of sheep. Butyrivibrio fibrisolvens expressing a foreign xylanase gene ( B. fibrisolvens NO4) was used as a tested recombinant that was selectable on an erythromycin-containing agar medium. The recombinant tended to reduce its level slowly in the rumen fluid of sheep on a high hay diet, while its initial decrease was more apparent in the rumen fluid of sheep on a high concentrate diet. Incubation with cell-free ruminal fluid revealed a significant decrease of inoculated recombinant, suggesting the presence of antibacterial factors limiting maintenance of the recombinant. In particular, during the first 12 h of incubation this inhibition was more notable in culture prepared from rumen fluid of sheep given the high concentrate diet. Autoclaving the cell-free rumen fluid inactivated the inhibition. Numbers of the recombinant for inoculation did not influence the final level of survived recombinant, that is, the initial depression was larger as more recombinant was inoculated. Subculturing with xylan before inoculation and/or direct addition of xylan to the batch culture did not improve survival of the recombinant. From these results it is suggested that the level of survived recombinant is limited to 102–4 /mL of in vitro batch culture with restricted energy supply and that initial depression of the recombinant is mainly caused by the heat-sensitive antibacterial factors not associating with microbial cells in the rumen. 相似文献