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1.
The lead poisoning incidents in cattle investigated by the Veterinary Laboratories Agency between 1990 and 2003 are reviewed. Lead poisoning was most commonly encountered in young calves, but cattle of all ages were affected. The lead was derived mainly from lead paint, lead accumulator batteries and lead in soil from old mine workings. Paint was responsible for the majority of cases of poisoning in young calves; yearling animals were most at risk from discarded batteries, and adult cows were most commonly poisoned by geochemical sources of lead. There was a marked seasonal incidence, with most cases occurring after turnout in the spring and early summer.  相似文献   

2.
Lead poisoning in cattle and other food animals is of public health significance because of the potential for human exposure to lead through ingestion of contaminated meat and milk products derived from lead-poisoned animals. In Michigan, lead poisoning in livestock is a reportable disease, and positive cattle are quarantined until they test negative (<0.05 ppm blood lead). There is surprisingly little information on blood lead kinetics in cattle. The half-life has been variably reported as 9 weeks and 1-2 months. Because these data did not fit those obtained from cases received at the Michigan State University Animal Health Diagnostic Laboratory, a retrospective study was conducted to review all cases of accidental lead poisoning in cattle between 1990 and 1998. This information is needed to estimate when quarantined lead-poisoned cattle can be released. The results showed that the half-life of blood lead was quite variable and ranged from 48 to 2,507 days. The shortest half-lives (48, 56, and 57 days) were found in a lactating herd of 20-month-old heifers. The longest half-life, 2,507 days, was found in a 9-month-old castrated bull, which ingested a discarded automobile battery. Of the 24 animals monitored, only 8/24 (33%) had half-lives between 6 and 14 weeks. In conclusion, the half-life of blood lead is difficult to predict in accidental cases of cattle poisoning.  相似文献   

3.
Lead poisoning continues to be a problem in cattle. The toxicologic significance of blood lead levels requires the differentiation of background blood lead from toxic levels. A ten-fold variation of background blood lead levels reported in previous studies has prompted us to conduct our own survey. Our results indicate significantly lower background blood lead levels in New York State cattle analyzed in 1986 than in those levels previously reported elsewhere.  相似文献   

4.
Lead poisoning was the most common toxicosis diagnosed in cattle by Alberta Animal Health Laboratories between 1964 and 1985 (n = 738 cases, = 33.5 cases per year). Seasonal variation in incidence was evident, and occurrence was frequently associated with change in housing or pasture. Discarded batteries or used crankcase oil were implicated in more than 80% of cases for which the source of lead was determined.

Pulmonary congestion, marked congestion and hemorrhage of thymus and heart, and presence of oil or lead particles in the ingesta were the most common postmortem findings. Eighty-six percent of cases were confirmed by elevated lead levels in tissues.

Lead poisoning represents a significant, unnecessary loss to producers. Increased producer awareness and improved waste management on farms could significantly reduce the incidence of lead poisoning in cattle.

  相似文献   

5.
The thiamin status (thiamin concentration in whole blood, plasma, and erythrocytes; erythrocyte transketolase activity) of normal cattle consuming varying diets did not differ from that of cattle with polioencephalomalacia or lead poisoning. Dairy cattle had higher ruminal content of thiamin and lower thiamin destroying activity than did beef cattle. Renal oxalosis was no more frequent in cattle which had polioencephalomalacia than in postnatal calves. In normal beef cattle, approximately 75% of total blood thiamin is in erythrocytes and the remainder in plasma.  相似文献   

6.
Lead poisoning is commonly diagnosed in cattle. In this study, 3 groups of cattle from different herds accidentally exposed to discarded lead batteries on pasture were intensively studied to determine the extent and severity of exposure. The losses from acute death due to lead toxicity were substantial in all the 3 study groups at 12%, 17%, and 4%. Blood samples were taken from all cattle around the time of the first diagnosis and then later in 2 of the 3 herds to monitor the change in lead concentrations over time. Asymptomatic lead toxicosis was observed in these herds. In these 3 groups, between 4% and 12% of asymptomatic cattle had blood lead concentrations consistent with acute lead poisoning (> 0.35 ppm), and between 7% and 40% of these asymptomatic animals were in the high-normal range (0.1-0.35 ppm). Because of the consistently high number of asymptomatic cattle with elevated lead levels, all cattle potentially exposed to a lead source should be tested before sale or slaughter to minimize the entry of lead into the food chain. The blood lead concentrations, which were monitored for months after the initial diagnosis, decreased slowly after the cattle were removed from the lead source. The prolonged retention of lead may be due to continued release and absorption of lead from metal particles in the reticulum or rumen. The mean reduction in the lead level was 0.046 ppm (95% CI, 0.017-0.075 ppm) every 30 days for these 2 herds. Using a single-component exponential model, the half-life of lead in the animals retested from Herds 1 and 2 was highly variable. The median half-life was 63 days (interquartile range, 34-107 days). One out of 8 pregnant heifers with high blood levels had a stillborn calf. There were no abortions or calf mortalities in this group. Blood samples were'collected from the calves around the time of birth. The concentrations of lead in the blood of the calves exposed in utero were low (0.010-0.095 ppm).  相似文献   

7.
Four of 10 heifers that survived an episode of lead poisoning caused by an old broken battery in the pasture were periodically monitored from days 14 to 205 after the episode, with the aim of (i) determining the time-course of lead clearance from blood; and (ii) assessing whether the exposed cattle showed changes in haematological parameters or serum markers of hepatic and renal function (e.g. serum creatinine level) that might be useful as indicators of subclinical toxicity. On the first sampling day, lead levels in blood varied between 0.478 and 0.758 mg/l. The half-life of lead in blood was rather variable, ranging from 68 to 266 days. Despite the high blood lead levels, no significant changes were detected in haematological parameters or hepatic/renal markers, all of which remained within normal ranges. In conclusion, these cattle that survived an episode of lead poisoning may constitute a risk for human consumers, but do not appear to have suffered severe health consequences themselves.  相似文献   

8.
为了提高春季黄牛嫩绿牧草亚硝酸盐中毒的防制意识和诊治水平,杜绝亚硝酸盐中毒给黄牛养殖带来重大损失,文章阐述了黄牛亚硝酸盐中毒的发病机理,分析了病因,描述了现场检查方法,提出了急救措施,具体了源头预防,对防制黄牛亚硝酸 盐中毒有一定的实际指导意义。  相似文献   

9.
Conditioned feed aversion was investigated as a means to prevent tulp (Homeria pallida) poisoning in cattle on tulp-infested grazing. Aversion treatment with a combination of epoxyscillirosidin and lithium chloride together with a tulp-hexane extract, which served as identification factor for tulp, resulted in a significantly lower (P < 0.001) proportion of severe tulp poisoning. In a first trial where 21 averted and 21 non-averted control cattle were exposed to a tulp-infested grass pasture, only two of the averted cattle were severely poisoned compared to 13 of the non-averted control cattle. In a second trial, with cattle being exposed to a pure stand of tulp supplemented with maize residues, only two of 21 averted cattle were severely poisoned compared to 14 of 21 non-averted control cattle. Occurrence of mild tulp poisoning, however, did not differ much between averted and non-averted control cattle. The results show that conditioned feed aversion effectively restricted severe poisoning in cattle on tulp-infested grazing.  相似文献   

10.
The normal values of lead in the organs and tissues of clinically healthy slaughter cattle were determined by the method of atomic absorption spectrophotometry and by the polarographic method. Animals of various age categories came from several farms of the East-Slovakian region. The lead found in the liver of young fattened cattle was not determined polarographically, since its concentration was under the threshold of sensitivity of the method (1.0 ppm). In the older category of animals (4-16 years old dairy cows) the following lead levels were revealed by the method of atomic absorption spectrophotometry: liver: (n = 76) 1.4 ppm, kidney cortex (n = 51) 1.5 ppm, bone tissue (n = 37) 3.3 ppm, muscle (n = 24) 1.0 ppm. The animals coming from different places had diverse amounts of lead in their tissues. The fact that the organs and tissues of slaughter cattle contained lead as a non-biogenic element is attributed mainly to environment pollution. The normal concentrations of lead, as determined in our study, can be used in chemical diagnosis of poisoning and in the evaluation of the hygienic safety of foodstuffs of animal origin.  相似文献   

11.
Larkspur poisoning is a major cause of acute death of cattle on mountain and high plains rangelands of western United States. A nonlethal method to quantify dose response in cattle is needed to better estimate the toxicity of larkspur plants and the response of cattle to larkspur poisoning and to provide a basis for reference during studies. A numerical system of rating the clinical signs of larkspur poisoning was developed and used to describe the response of 10 Hereford cows given a repeated single daily dose of larkspur (Delphinium occidentale x barbeyi) by gavage. Larkspur poisoning resulted from a short-term cumulative effect, and a statistically significant increase in score was essentially maximal by 4 days. At the dose given, this effect did not persist for more than 4 days after cessation of dosing. Poisoning was most severe between 5 and 9 hours after dosing. Early signs of poisoning can be subtle and sometimes brief. The effect of larkspur poisoning can be exacerbated temporarily by exertion. Therefore, cattle could probably repeatedly consume an otherwise toxic daily dose, without manifesting marked signs of poisoning, if consumption decreased to a sufficient degree intermittently at 2- to 4-day intervals.  相似文献   

12.
Diquat poisoning of dairy cattle by topical application   总被引:2,自引:0,他引:2       下载免费PDF全文
This case report describes poisoning of dairy cattle from a dermal challenge of 50 to 100 mg/kg body weight diquat. Five of 36 cattle exposed, demonstrated clinical signs of intoxication, dehydration, and death over 5 days. Diquat poisoning of cattle by the dermal route has not previously been reported.  相似文献   

13.
Autumn crocus poisoning of cattle is characterized by severe diarrhea caused by alkaloid colchicine. Previously, we examined pathologically this poisoning in cattle and reported that enterotoxic lesions were closely associated with apoptosis. To examine enterotoxicity of autumn crocus more precisely, a reproductive study was performed using guinea pigs and mice, and pathological findings associated with autumn crocus poisoning were compared with those of colchicine. Each group of guinea pigs given the bulb of autumn crocus or colchicine exhibited severe diarrhea. Histopathological findings in intoxicated guinea pigs were entirely consistent with those in the autumn crocus-poisoned cattle. In contrast, each group of mice administered with the bulb or colchicine did not develop diarrhea. Our results confirmed that the toxicity of autumn crocus bulb is attributable to the toxicity of ingredient colchicine, and revealed that the guinea pig has high reproducibility of autumn crocus poisoning in cattle and colchicine poisoning in humans. It has been reported that the physiological mechanism of the apoptotic process for eliminating the enterocytes in the mouse and rat differs from that of the guinea pig, monkey, cattle and horse. Taking the observation that the former animals do not develop diarrhea, whereas the latter animals do so in the autumn crocus or colchicine poisoning into consideration, it would seem that the species-difference in enterotoxicity of autumn crocus may be closely associated with the physiological mechanism of eliminating the effete enterocytes.  相似文献   

14.
硒(Se)是动物必需的微量元素。缺硒会引起一系列疾病,硒过量则会导致硒中毒,而适量补硒则具有多方面的有益影响。硒在牛生产中的作用重大。日粮补硒不仅可以提高血液、牛奶及牛肉的硒含量,还能改善牛的繁殖性能、增强机体免疫力,同时改善牛肉品质。日粮补硒的效果受牛的生理状况、补硒前的硒状况、补饲硒的形态及补饲量的影响。目前,补硒对动物的生理影响研究较为深入,但硒在动物体内的吸收及具体代谢途径有待于进一步研究,这将有助于从机理层面解释硒对动物生理产生的影响。文章系统地综述硒元素的功能以及补硒对牛的影响。  相似文献   

15.
桃树是我国广泛分布的树种,当牛在放牧或圈养时食用了较多的桃树枝叶,可引起中毒,以春季新鲜牧草缺乏时发病较多,且不分品种和年龄均可发病,多于采食后数小时至数天内发病。笔者从医几年来,偶遇两例牛误食桃树枝叶中毒病例,现将诊治体会分享如下。  相似文献   

16.
1前言湖南省洞口县第二例牛尿素中毒,制做了简易竹洞针,进行左赚部套洞针(竹洞针)穿刺术放气,灌入食醋,葡萄糖输液等抢救和治疗方案。牛场存栏328头,239头中毒,发病率72.9%,治疗239头,治愈216头,治愈率90.4%,较首例牛尿素中毒病例治愈率100%,降低9.6个百分点,瘤胃膨气病病牛128头,治愈105头,治愈率82.0%,较洞口县首例牛尿素中毒病例治愈率100%,下降18.0个百分点;并对牛瘤胃膨气病最佳抢救时间和尿素养牛正确用量用法进行了探索,供同行参考。  相似文献   

17.
Lead (Pb) poisoning of cattle has been relatively common in Australia and sump oil has been identified as an important cause of Pb toxicity for cattle because they seem to have a tendency to drink it. Lead-free petrol has been available in Australia since 1975, so the aim of this study was to assess the current risk to cattle from drinking used automotive oils. Sump or gear box oil was collected from 56 vehicles being serviced. The low levels of Pb found suggest that the removal of leaded petrol from the Australian market as a public health measure has benefited cattle by eliminating the risk of acute poisoning from used engine oil.  相似文献   

18.
Lead poisoning was diagnosed in three cattle along with increased mercury levels in the liver and kidney tissues of two of these animals. The clinical signs were different in each case and included salivation, anorexia, delayed menace response, delayed withdrawal reflex, head pressing, localized muscle fasciculation, reduced tongue tone, ataxia, rumen atony and seizures. Blood lead concentration was increased in all three cases to 0.76, 0.37 and 0.454ppm. Post mortem changes characteristic of lead poisoning were only recognized in one case and included cerebro-cortical oedema, cortical neuronal necrosis and endothelial proliferation, especially at the tips of the cerebral gyri. The animals were poisoned by ingestion of lead-contaminated ash residues from a bonfire. The abnormal levels of mercury in the liver and kidney tissues of two animals may also be at least partly attributable to the intake of the metal in the ash residues. The levels of mercury in the three samples from the ash residue were relatively low (1.31, 0.7 and 2.1ppm).  相似文献   

19.
Extract

The July 1973 issue of the New Zealand Journal of Agriculture discussed the Tama revolution. No mention was made of the possibility of nitrite poisoning in cattle grazing ‘Grasslands Tama’ (tetraploid westerwolds) ryegrass. There have been deaths from nitrite poisoning in cattle grazing Tama ryegrass and other crops in many districts this year, and this experience with a brief discussion on nitrite/nitrate poisoning is presented for the guidance of those who may be considering Tama ryegrass as a fodder crop.  相似文献   

20.
棉酚中毒是由于长期、过量饲喂含游离棉酚超标的棉副产品,引起的以出血性胃肠炎、血红蛋白尿以及雄性生殖毒性和母畜流产为主要特征的中毒病。新疆是我国的棉花主产区,棉花加工过程中产生了大量的棉籽饼、棉籽粕、棉壳等副产品,这些副产品是优质的动物饲料来源,具有产量多、来源广、价格便宜、适口性好的特点,广泛应用于肉牛和肉羊的育肥。本文通过对育肥牛棉酚中毒的诊断与治疗,重点阐述棉酚中毒的发病机理、治疗手段与预防措施,以期为棉酚中毒的预防治疗及有效脱毒合理饲喂提供一定的参考。  相似文献   

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