常见霉菌毒素的危害及检测方法

饲料被霉菌毒素污染会导致营养价值降低,引起动物疾病,并直接或间接危害人类健康,所以应当建立相应的体系对其监控。本文概述了常见霉菌毒素的危害及检测方法。     

猪霉菌毒素中毒及防控措施

饲料中的霉菌毒素是引发猪饲料中毒的主要原因之一,严重影响着猪的生长发育、母猪生产、繁殖性能以及仔猪的成活率,还可以引起免疫抑制,使猪的抵抗力下降,诱发多种疾病,甚至引起死亡。残留于猪肌肉、内脏中的霉菌毒素还可能通过食物链传递给人,造成更大的危害。因此,饲料霉菌毒素对养猪生产的危害应引起养殖者的重视。目前饲料检测到的毒素已超过350种,饲料中各种霉菌毒素之间有协同作用,猪采食了由霉菌毒素污染的饲料,引发抵抗力下降,继而容易继发各种传染病。     

饲料及畜禽产品中霉菌毒素快速检测技术研究进展

霉菌毒素是某些霉菌的次级代谢产物,在自然界中分布极为广泛,可污染动物饲料及畜禽产品,对动物和人类健康造成巨大危害。作者介绍了饲料与畜禽产品中常见的霉菌毒素及其对动物和人类的危害,总结了近年来快速检测技术在霉菌毒素检测方面所取得的进展,分析了霉菌毒素抗体制备的主要影响因素,并对霉菌毒素快速检测技术发展前景作出展望。     

饲料中霉菌毒素的危害及防治措施

霉菌毒素污染不仅能够造成畜牧业经济损失，部分霉菌毒素还具有致癌性或致畸性作用，通过肉、蛋、奶等食物链对人类健康产生危害。动物采食被霉菌毒素污染的饲料可引起免疫抑制和繁殖紊乱，但是饲料中霉菌毒素的污染及其造成的危害目前仍是养殖者容易忽略的问题。     

饲料中霉菌毒素的检测方法研究

近年来,畜产品安全逐渐受到广大消费者的关注,而畜产品的安全受到饲料安全的直接影响。饲料被霉菌毒素污染会导致其营养价值降低,引起动物疾病,并直接或间接地危害人类健康。同时,加强饲料中霉菌毒素的监测关系到整个饲料产业及养殖业的健康发展。本文综述了霉菌毒素常见检测方法的研究方法和应用。     

霉菌毒素对养猪业的危害及防治措施

霉菌毒素是霉菌的二级代谢产物，大多是由曲霉菌属（aspergillus）、青霉菌属（penicillium）和镰刀菌属（fusarium）的霉菌产生。它们在谷物和饲草收获前后产生。因为它们的毒性效果和协同作用。霉菌毒素对人和动物是有害的。人和动物对霉菌毒素的代谢过程很复杂，其中包括生物灭活和去毒。去毒过程是在人和动物的细胞内或消化道内微生物酶的作用下进行生物转化。一些毒素或它们的代谢产物会在人和动物的组织中被固定下来，但是大多数通过尿、粪和乳汁排出。在动物中，霉菌毒素的毒性是慢性的，很少引起动物死亡，但是它们会引起动物采食量下降，影响生产力。而且，霉菌毒素在畜产品（肉、奶、下水）中的残留还会对人的健康产生影响。国际组织对饲料和乳制品中各种霉菌毒素的可允许最大含量做出了规定。霉菌毒素的危害可以通过检测植物产品中的霉菌污染程度、改进作物的栽培、收获和存贮方法、稀释已污染的饲料原料、使用霉菌毒素吸附剂等措施得到控制或者减轻。作者将就对养猪业产生危害的几种主要的霉菌毒素的产生、危害及霉菌毒素的防治措施做一综述。     

浅谈猪霉菌毒素中毒的防治

<正>霉菌广泛存在于饲料原料和配合饲料中,因其污染饲料程度的不同和养殖场中综合防治措施的因素,其危害程度有轻有重。霉菌毒素是霉菌产生的有毒代谢产物的统称,其中对动物有严重伤害性。不同的霉菌毒素对动物造成的危害各异,各霉菌毒素之间具有相互协调作用。霉菌毒素进入动物机体后可长期蓄积,引发临床症状复杂难辨的慢性中毒,确诊霉菌毒素中毒病必须结合饲料史和实验室的霉菌毒素检测。1临床症状1.1急性中毒猪群按断乳仔猪、架子猪、育肥猪、种猪的先     

奶牛养殖中霉菌毒素的危害及其防控方法研究进展

近年来,霉菌毒素污染饲料已经引起饲料行业的高度重视。奶牛采食被霉菌毒素污染的饲料后很容易引发各种疾病,有些霉菌毒素还会代谢进入牛奶中对人们的健康造成威胁。本文主要就霉菌毒素对奶牛的危害及其防控方法的研究进行综述,以期为生产实践中降低霉菌毒素的危害提供理论参考。     

山东地区2013年饲料原料霉菌毒素污染情况调查

<正>霉菌毒素是产毒霉菌在谷物的田间生长、收获和储藏时或饲料加工过程中产生的次生代谢产物,它是一种天然的生物性污染物,通过污染饲料、垫料对动物造成极大的危害。饲料霉变是畜牧业生产中不可忽视的问题。饲料中各种霉菌在适宜的温度、湿度和营养环境下迅速生长而使饲料发热、结块、发霉,甚至改变颜色并产生霉菌毒素。动物饲喂含霉菌毒素的饲料后会引起中毒、致癌、致畸等,甚至可通过多种途径污染食品和饲料,直接或间接进入人类食物链,威胁     

饲料中霉菌毒素的毒害机理、检测方法和控制措施

霉菌毒素是真菌代谢生成的次级代谢物,主要在丝状真菌的孢子和菌丝体内存在,可导致多种物质如饲料、食品、粮食等发生污染。饲料在加工或者贮存的过程中稍不注意就会污染霉菌,从而使其含有大量的霉菌毒素,导致饲料营养价值降低,动物长时间饲喂或者大量采食这种饲料就会发生急性或者慢性中毒,同时动物产品中残留的霉菌毒素还会危害人类的健康。现概述饲料中霉菌毒素的毒害机理、常用检测方法以及控制措施。     

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