呕吐毒素对畜禽肠道健康的影响及相关研究进展

呕吐毒素是饲料原料中最为常见，对畜禽健康危害最大的一种霉菌毒素，其给畜牧业生产造成极大经济损失。大量研究结果发现，动物肠道可能是呕吐毒素进入机体内产生毒理作用的重要靶器官，因此，呕吐毒素诱导的动物肠道健康损伤也成为目前的一个研究热点。本文结合近年来国内外相关研究进展，综述了饲料中呕吐毒素污染对畜禽肠道健康的影响与毒理机制，以及相关防治措施，为饲料生产及畜禽健康养殖提供一些参考。 [关键词] 饲料|呕吐毒素|畜禽|肠道健康     

怀孕后期和哺乳期呕吐毒素通过胎盘和母乳传递给仔猪

呕吐毒素污染的饲料会引起猪的生长性能下降、拒食、免疫抑制和其他诸多健康问题。仔猪在出生前和哺乳期可分别经过胎盘和母乳接触和摄入呕吐毒素(Deoxynivalenol,DON)。然而,人们对仔猪早期接触呕吐毒素的情况并未完全了解。本文旨在调查研究呕吐毒素在怀孕后期如何通过胎盘和哺乳(初乳与常乳)传递给仔猪。试验选取44头怀孕后期(93 d±1 d)的母猪,饲喂由天然污染呕吐毒素的燕麦制成的饲料,直到仔猪断奶结束。试验日粮中的呕吐毒素含量分为三个水平:(1)对照组(DON 0.2 mg/kg);(2)DON-L1组(DON1.4mg/kg);(3)DON-L2组(DON2.17mg/kg)。选取15头母猪,每窝选取5头仔猪,重复采集母猪的母乳与血液以及仔猪血液进行检测;计算仔猪/母猪血液DON浓度比和母乳/母猪血液DON浓度比(M/P)以评估呕吐毒素的转移状况。仔猪血液/母猪血液DON浓度比在仔猪出生时为2.14,分娩后12 h～36 h为1.21,分娩后7 d为0.08,分娩后21 d为0.16,断奶时为0.20;母猪母乳与母猪血液中DON浓度比则分别为0.92、1.11、0.94、1.21和0.90。研究结果表明,DON能够通过胎盘和母乳高效传递给仔猪。尽管母乳/母猪血液中呕吐毒素浓度比较高且能够有效分泌DON到母乳中,但研究表明,仔猪/母猪血液DON浓度比较低时,哺乳仔猪在生长早期具有足够抵抗呕吐毒素的能力。     

饲料中霉菌毒素对猪生产繁殖的影响

霉菌毒素在饲料中很常见,母猪对霉菌毒素高度易感。摄入含有霉菌毒素的饲料之后会对母猪的生育繁殖造成较大影响,引起多种症状。影响的严重程度往往同霉菌毒素的种类、含量以及母猪的健康状态等有关。常见的霉菌毒素有黄曲霉毒素、麦角生物碱、单端抱霉烯族毒素以及玉米赤霉烯酮等。     

一起玉米赤霉烯酮及呕吐毒素中毒引起猪繁殖障碍的病例报告

2012年4月,山东某规模猪场暴发疾病,母猪受胎率、产仔数、健仔数等繁殖性能指标显著下降,猪群表现出不同程度的霉菌毒素中毒症状。经初步调查,发现该猪场所饲喂的饲料被霉菌毒素污染,进一步采取原料玉米及饲料样品通过高效液相色谱法鉴定霉菌毒素种类及含量,结果显示,原料玉米中赤霉烯酮、呕吐毒素及烟曲霉毒素含量均超标。经更换饲料和采用脱霉剂后,母猪繁殖性能指标显著恢复。     

猪场如何选择合理的饲料脱霉剂

<正>近年来,饲料中的霉菌毒素污染日趋严重,给养猪业带来较大经济损失。猪一旦食用了被霉菌毒素污染的饲料,常常会发生免疫抑制性疾病,甚至会造成母猪产死胎、木乃伊胎,流产和不孕等等。据相关资料报道,目前危害谷物饲料的霉菌毒素主要有六种,分别是黄曲霉毒素、呕吐毒素、烟曲霉毒素、赭曲霉毒素、T2毒素、玉米赤霉烯酮。针对这些霉菌毒素,国内外饲料     

哺乳母猪霉菌毒素中毒一例

饲料或者饲料的原料在运输、加工和贮存过程中由于环境温度和湿度的改变,可导致霉菌的生长和霉菌毒素的污染,给动物带来不利的影响.目前已知在饲料中黄曲霉毒素、烟曲霉毒素、呕吐毒素、玉米赤霉烯酮、赭曲霉毒素和T-2毒素的污染是最为常见,并且多种霉菌毒素同时存在.2007年11月,某养猪专业户饲养的哺乳母猪发生霉菌毒素中毒,临诊报告如下.     

饲料霉菌毒素对猪的危害

饲料霉菌毒素主要来源于原材料霉菌毒素生长过程或饲料后期贮存过程的霉菌,霉菌毒素对各个生长阶段的猪都存在极大的危害,尤其是怀孕母猪。现将霉菌毒素的研究情况,及其对生猪养殖过程中的毒性作用进行阐述。     

北京地区饲料及饲料原料呕吐毒素污染情况调查

本研究旨在了解目前北京市养猪场所用饲料原料和全价饲料受呕吐毒素的污染情况、检出频率和特点,为广大饲料生产和动物养殖企业提供基础数据参考。采集北京市15个猪场131个饲料原料及全价配合饲料,采用免疫亲和柱-高效液相色谱法测定其中呕吐毒素的含量。结果表明:玉米、麸皮、豆粕、DDGS和配合饲料中呕吐毒素的检出率分别为92.9%、92.3%、54.5%、100%和97.4%,平均含量分别为1.01、0.44、0.05、1.36 mg/kg和0.65mg/kg,超标率分别为57.1%、0.0%、0.0%、88.2%和15.8%。结果提示,饲料原料中玉米和DDGS呕吐毒素平均含量较高,超标率也较高;麸皮、豆粕及配合饲料也受呕吐毒素不同程度的污染。     

上海地区蛋鸡养殖场夏秋季全价饲料黄曲霉毒素和呕吐毒素污染情况调查

本研究旨在调查夏秋炎热潮湿季节后,上海郊区蛋鸡养殖场饲料中黄曲霉毒素和呕吐毒素污染情况,为鸡场的毒素污染预防和治理提供相关数据。选择上海郊区及周边蛋鸡场鸡舍内可能受污染的区域采集具有代表性的10批饲料样品,使用美国Affinitech公司酶联免疫试剂盒对样品毒素含量进行检测。结果表明,被检的全价饲料中黄曲霉毒素和呕吐毒素的检出率都为100%,其中黄曲霉毒素检出率虽然很高,但是都没有超标,检测样品的黄曲霉毒素平均值为4.03!g/kg,属于轻度污染;呕吐毒素的超标率为80%,其中呕吐毒素含量在1.0~5.0mg/kg,属于中度污染的样品数为8个,是污染上限的2~4倍。2种毒素都没有检出重度污染。结果提示,酶联免疫法(ELISA)操作简单和便捷,有利于在广大饲料生产企业和蛋鸡养殖企业中推广使用。广大饲料生产企业和蛋鸡养殖企业也要做好原料质量控制并在饲料中使用有效的霉菌毒素吸附剂,同时建立相应常规采样检测制度,以预防和防治霉菌毒素的污染。     

母猪繁殖障碍的原因调查及防制措施

<正>母猪繁殖障碍就是母猪不能正常繁殖,临床上引起母猪繁殖障碍的常见疾病和多发因素可分为病毒性疾病(猪瘟、猪繁殖与呼吸综合征、伪狂犬、细小、乙脑),寄生虫病(弓形体、猪附红细胞体),饲料霉菌毒素超标(黄曲毒素、呕吐毒素、),营养性疾病(能量过剩使母猪过肥导致其返情及妊娠失败、跟母猪繁殖相关的多种营养缺乏)以及产科疾病(母猪乳房炎及子宫内膜炎)等,要根据具体情况及时解决具有繁殖     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein