Heavy metal, polychlorinated biphenyl and organochlorine pesticide residues in marine organisms: risk evaluation for consumers

This survey provides information on the levels of heavy metal, polychlorinated biphenyl and organochlorine pesticide residues in marine organisms to ascertain whether these concentrations exceeded the prescribed legal limits. In order to assess the potential human health impact, the weekly intake was estimated. Most of the organisms analysed showed higher levels of mercury than the maximum permissible limit, while cadmium and lead were below the proposed permissible limits in all samples. The estimated intake was far above the established Provisional Tolerable Weekly Intake for all metals, except for total mercury.     

Heavy Metal,Polychlorinated Biphenyl and Organochlorine Pesticide Residues in Marine Organisms: Risk Evaluation for Consumers

This survey provides information on the levels of heavy metal, polychlorinated biphenyl and organochlorine pesticide residues in marine organisms to ascertain whether these concentrations exceeded the prescribed legal limits. In order to assess the potential human health impact, the weekly intake was estimated. Most of the organisms analysed showed higher levels of mercury than the maximum permissible limit, while cadmium and lead were below the proposed permissible limits in all samples. The estimated intake was far above the established Provisional Tolerable Weekly Intake for all metals, except for total mercury.

     

Dioxin concentration in milk and tissues of cows and sheep related to feed and soil contamination

If cows or sheep are grazing on areas known for a higher dioxin level of the soil, respectively, dry cows are fed with feedstuffs produced on such areas, the dioxin concentration in food, in this case in cows' milk and livers of sheep could reach or exceed maximum levels. Furthermore large amounts of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzo-p-furans (PCDD/F) can be excreted with the faeces. But there are chances for farmers to prevent or at least to minimize the dioxin load of feed and with it of food (including the harvesting technique and the feeding strategy).     

Animal-derived feeds as possible vectors for bovine spongiform encephalopathy (BSE) in Germany. 1. Comparative risk assessment for a single animal food of animal origin

The occurrence of BSE cases in Germany after the ban of meat and bone meal for ruminant feed in 1994 requires a detailed investigation of animal derived feedstuffs regarding their specific risks as vectors for the disease. Accepting the theory that BSE is a prion transmitted disease, the theoretical infectious potential was calculated for animal derived feedstuffs. This calculation was based on the assumption, that risk material (brain, spinal cord) of one clinically diseased cattle was rendered in the process as established in Germany (133 degrees C, 3 bar, 20 min) or, alternatively, that one diseased animal was slaughtered resulting in normal processing of the by-products for human food production. From this risk assessment it became obvious that meat and bone meal was one, but probably not the most important source for the spreading of BSE. Taking into account the high sensitivity of calves it can be speculated that certain products, e.g. from bone processing (bone meal) and fat melting (mixed animal fats), commonly used for the formulation of milk replacers, might have been more important as pathways. As it can't be excluded retrospectively that infected meat and bone meal was imported from the UK, this non-calculable influence may have been related to the significance of the other products. The calculation model underlines that efficient removal of specified risk material (brain, spinal cord) and adequate processing (133 degrees C, 3 bar, 20 min) or alternatively other equivalent treatments of fats are prerequisites for minimising the risk of feed borne transmission of BSE by animal derived feedstuffs. The epidemiological consequences are part of a subsequent paper.     

Fungi isolated from bovine udders,and their possible sources

AIM: To identify fungi isolated from infections of the bovine mammary gland, and establish their possible sources.

METHODS: From a herd of 420 cows, milk samples were collected from all quarters at calving and cultured to detect causative organisms. Quarters identified as infected with fungi were further sampled during early lactation. Samples from feedstuffs, the feed pad and ends of teats were also collected and analysed for the presence of fungi.

RESULTS: Eleven of 420 cows were diagnosed with intramammary infections (IMI) caused by yeasts (nine cows, 10 quarters) and moulds (two cows, three quarters). Six of the yeast species had previously been reported as being responsible for mastitis. Elevated somatic cell counts (SCC) were observed in many quarters, but most infections were eliminated spontaneously. Two of the fungi isolated from milk samples were also isolated from feedstuffs and teat swabs, and seven other fungi isolated from milk samples were not isolated from feed, the feed pad or cows' teats.

CONCLUSIONS: Isolation of fungi from the udder is rarely reported in dairy cows in New Zealand. In this herd, contamination of the end of the teat originating from feedstuffs and possibly exacerbated by the use of a feed pad may have led to the establishment of IMI caused by fungi.

CLINICAL RELEVENCE: Fungi are infrequently if ever reported in mastitis trial data or surveys in New Zealand and are probably of little clinical significance.     

Fungi isolated from bovine udders , and their possible sources

AIM: To identify fungi isolated from infections of the bovine mammary gland, and establish their possible sources. METHODS: From a herd of 420 cows, milk samples were collected from all quarters at calving and cultured to detect causative organisms. Quarters identified as infected with fungi were further sampled during early lactation. Samples from feedstuffs, the feed pad and ends of teats were also collected and analysed for the presence of fungi. RESULTS: Eleven of 420 cows were diagnosed with intramammary infections (IMI) caused by yeasts (nine cows, 10 quarters) and moulds (two cows, three quarters). Six of the yeast species had previously been reported as being responsible for mastitis. Elevated somatic cell counts (SCC) were observed in many quarters, but most infections were eliminated spontaneously. Two of the fungi isolated from milk samples were also isolated from feedstuffs and teat swabs, and seven other fungi isolated from milk samples were not isolated from feed, the feed pad or cows' teats. CONCLUSIONS: Isolation of fungi from the udder is rarely reported in dairy cows in New Zealand. In this herd, contamination of the end of the teat originating from feedstuffs and possibly exacerbated by the use of a feed pad may have led to the establishment of IMI caused by fungi. CLINICAL RELEVENCE: Fungi are infrequently if ever reported in mastitis trial data or surveys in New Zealand and are probably of little clinical significance. KEY WORDS: Fungi, yeast, mould, bovine, intramammary infection, somatic cell count, mastitis.     

Levels of trace elements in liver from Norwegian moose, reindeer and red deer in relation to atmospheric deposition

The levels of antimony, arsenic, cadmium, copper, lead, mercury, molybdenum, selenium and zinc were determined in liver of moose, reindeer and red deer from differen localities in Norway. Reindeer had considerably higher levels of mercury, lead and arsenic than moose and red deer. These findings are considered to be related to differences in feeding habits since reindeer on highland plateaus feed mainly on lichens which have been shown to accumulate trace elements. The levels of arsenic, and to some extent also selenium and cadmium, in moose and reindeer liver showed a north-south gradient closely related to the regional distribution of these elements in the forest moss. As regards lead, a north-south gradient and a relationship to moss levels, were found in moose liver only. It therefore seems that atmospheric deposition of the elements mercury, lead, arsenic, cadmium and selenium contribute to the body burden of these elements in cervides in Norway. There was no evidence of these elements accumulating to toxic levels.     

柞蚕雄蛾重金属污染物的含量测定与对比分析

为验证柞蚕雄蛾的食用安全性,对柞蚕雄蛾粉中的重金属污染物进行了测定。结果发现,柞蚕雄蛾中汞、铬、铅、镉、砷的含量低于谷物、蔬菜、肉、蛋食品的相关限量标准。     

市售乳扇和乳饼中8 种有害元素污染状况分析

对市售乳扇和乳饼样品中8 种有害元素污染情况进行调查分析。对某市部分区县具有代表性的农贸市场及超市的乳扇和乳饼进行采样,并将样品通过石墨湿法消解,采用电感耦合等离子体质谱法检测,内标法定量,同时测定分析样品中砷（As）、铅（Pb）、汞（Hg）、镉（Cd）、铬（Cr）、硼（B）、铝（Al）、钡（Ba）8 种有害元素。结果表明：市售乳扇和乳饼样品未受金属元素Hg和Cd的污染,受元素B、As、Ba及Pb污染程度相对较轻,但乳扇样品被元素Al和Cr污染较严重,乳饼中Ba元素污染程度相对较高;乳扇和乳饼样品中普遍含有Cr、Ba和Pb元素,乳扇中元素污染程度大于乳饼,相关部门应加强对乳扇和乳饼作坊的监管,规范生产工艺,严格把关污染环节,加强生产环节污染监管力度,确保此类乳制品的质量安全。     

Iodine concentration in the blood serum of milk cows from Saxony as well as in cows' milk and milk products (baby food)

Within the framework of investigations into the metabolism of Saxon dairy-cows, more than 3300 analyses of blood serum total iodine concentrations have been carried out between 1997 and 2003. The total iodine concentration proved as suitable parameter for the recognition of the iodine supply situation of the milk cows. While to first two years 28,5 % of the samples were rated below the recommended minimum level (0,04 mg/l), thus indicating deficiencies, the total iodine concentration then rose demonstrably, even indicating an oversupply in some herds (> or = 0,20 mg/l). The iodine concentration in 117 independently tested milk samples (official food monitoring) confirmed this situation. An adequate iodine supplementation in feedstuffs is of great significance for the bovine metabolism as well as for the iodine concentrations in milk and therefore the iodine intake of the population. Of the negative consequences of an uncritically excessive iodine supplement particularly for high milk-yield cows one warns. This can lead to precariously high iodine concentrations in milk and dairy products. Further tests of blood total iodine levels in dairy herds on selective animals as well as analysis     

Farming practices in Sweden related to feeding milk and colostrum from cows treated with antimicrobials to dairy calves

Background

Milk produced by cows in receipt of antimicrobial therapy may contain antimicrobial residues. Such antimicrobial-containing waste milk must be withdrawn from human consumption and is therefore sometimes used as calf feed. Unfortunately, this approach might promote selection of antimicrobial resistant bacteria in the calves’ intestinal microbiota. The objectives of this study were therefore to obtain an overview of waste milk feeding practices on Swedish dairy farms and to investigate if these practices were associated with certain farm characteristics. A representative group of 457 Swedish dairy farmers participated in a web-based survey with questions about the use of colostrum and milk from cows treated with antimicrobials at dry off or during lactation, respectively, as calf feed.

Results

Colostrum (milk from the first milking after calving) and transition milk (milk from the second milking to the fourth day after calving) from cows treated with antimicrobials at dry off was fed to calves on 89% and 85% of the farms in the study, respectively. When antimicrobial therapy was given to cows during lactation, 56% of the farms fed milk that was produced during the course of treatment to calves, whereas milk that was produced during the subsequent withdrawal period was fed to calves on 79% of the farms. Surveyed farmers were less prone to feed such milk if the antimicrobial therapy was due to mastitis than other infections. In Sweden, a majority of antimicrobial treatments during lactation are systemic administration of benzylpenicillin and thus, the bulk of waste milk in Sweden is likely to contain residues of this drug. Feeding waste milk to calves was more common on non-organic farms, and on farms located in Southern Sweden, and was less common on farms with cows housed in cold free stalls barns.

Conclusions

Waste milk that may contain antimicrobial residues is, at least occasionally, used as feed for calves on a majority of surveyed Swedish dairy farms. Future work should focus on the effect of waste milk feeding on the occurrence of antimicrobial resistant bacteria in the calves’ intestinal microbiota.     

Suspected white kidney bean (Phaseolus vulgaris) toxicity in horses and cattle

Thirty-four mixed breed horses from two separate farms showed signs of abdominal discomfort, pyrexia and dehydration after being exposed to a new batch of 14% complete horse feed. A new batch of cattle feed from the same manufacturer resulted in dairy cows showing depression, a drop in milk production and diarrhoea. Examination of both diets revealed the presence of white kidney beans (Phaseolus vulgaris). Inclusion of raw beans of this genus in animal feeds is to be avoided.     

生猪不同养殖阶段粪便中金属残留及富集分析

为探究集约化生猪养殖过程中不同养殖阶段粪便中金属残留量及其对环境的影响效应.试验选取正常饲养条件下保育、育肥、后备、妊娠和泌乳5个阶段的猪饲料及粪便样品进行了铜、锌、镉、铅、铬、汞和砷等7种常见超标元素的检测和分析.试验表明:不同养殖阶段猪粪便样品中铜、锌含量差异较大,所有样品中均未检出铅、铬、汞、砷等元素,仅在后备和...     

Mycotoxins and reproduction in domestic livestock.

Molds are parasitic plants that are ubiquitous in livestock feedstuffs. Even though molds themselves reduce the quality of grains, their synthesis of chemical substances termed mycotoxins causes the greatest monetary loss to the animal industry. Five major mycotoxins that impair growth and reproductive efficiency in North America are aflatoxins, zearalenone, deoxynivalenol, ochratoxin, and ergot. Aflatoxins are produced by Aspergillus flavus and Aspergillus parasiticus. Consumption of grains containing aflatoxins by swine affects reproduction indirectly by reducing feed intake and growth. In swine, aflatoxins impair liver and kidney function, delay blood clotting, increase susceptibility to bruising, and interfere with cellular humoral immune systems. Ruminants are comparatively resistant to aflatoxicosis, but presence of aflatoxins in milk of dairy cows is closely monitored for human safety. Depending on environmental conditions, Fusarium roseum can produce either zearalenone or deoxynivalenol. Days 7 to 10 postmating seem to be a critical period of gestation for zearalenone to exert its detrimental actions on early embryonic development. Presence of deoxynivalenol in swine feedstuffs decreases feed intake, causes feed refusal, and induces occasional vomiting. Several species of Penicillium and Aspergillus produce ochratoxin, a mycotoxin that causes necrosis of kidney tissue. Ergot alkaloids produced by Claviceps purpurea on wheat can cause reproductive problems and are associated with lactational failure in swine. Various methods have been developed to remove mycotoxins from infected feedstuffs. Chemical analyses in laboratories as well as diagnostic kits suitable for use at the elevator or farm can be used successfully to identify which mycotoxins are present in suspect feedstuffs.     

Fly ash, basic slag and Glenbrook slag toxicity in cattle

In case studies of two herds of dairy cattle, a herd of 270 Friesian cows and heifers and a herd of 256 Jersey cows and heifers experienced high death rates and a protracted course of illness when fly ash was broadcast as a fertiliser over the farms at a rate of about 1 tonne per hectare. The onset of weakness, lassitude and diarrhoea in the cattle first appeared within 4-5 days and both fertility and milk fat production fell off dramatically. In the following 7 months, 51 animals died in the Friesian herd and a similar death rate and performance losses occurred in the Jersey herd. Emaciation and hepatic fibrosis were consistently reported from autopsies. Heavy metal poisoning was eliminated from the possible diagnosis. The slags and fly ash used as fertiliser had several features in common. They contained 29-40% calcium as calcium oxide, 15-35 grams of iron per kg, they were all extremely alkaline and concentrations of lead and arsenic were low. The effect of adding fly ash to rumen contents in vitro was to raise the pH to greater than 7.2, at which point fermentation was markedly-reduced.     

污染指数及危害系数(HQ)评价生乳中重金属残留风险分析方法研究

本研究建立了应用单项污染指数及内梅罗综合污染指数法评价生乳中重金属的污染情况的方法,以分析不同地区的污染情况;并且对于生乳中低浓度的重金属残留及没有残留限量的重金属残留,以慢性非致癌性风险HQ值进行描述,与参考剂量相比较,进而确定其对于成人饮用的安全性。对中国2个奶业主产区的20个生乳中的砷、铅、铬、汞、铝、镍进行了污染分析及危害描述,证明了本方法的合理性和适用性。     

Heavy metals (cadmium, copper, lead and mercury) in common eiders (Somateria mollissima) from Denmark

In an examination of 50 Danish common eiders, the liver and kidney content of cadmium, copper, lead and mercury was determined. Eiders were chosen for analysis, because this species feed almost exclusively on the common mussel (Mytilus edulis), which is known to accumulate heavy metals. The concentrations recorded of cadmium, copper, and mercury were lower than what is usually regarded as toxic for birds, except for one eider which carried more than 2000 mg copper/kg liver tissue (dry weight). Of the 42 eiders analysed for lead, four had toxic levels, i.e., more than 7 mg per kg liver wet weight, and two other had increased levels, i.e., 3-7 mg lead per kg liver wet weight. The mean Cd concentration was 3.3 mg/kg liver (ww). This means that by consumption of ab. 160 gram liver from the common eider, the weekly tolerable intake of cadmium suggested by FAO/WHO would be exceeded.     

Concentrations of ketones in milk in early lactation, and reproductive performance of dairy cows

Samples of blood and milk were taken from clinically ketotic cows at 12-hour intervals before and after treatment The concentration of beta-hydroxybutyrate was determined in plasma and milk, and the concentration of acetone was determined in milk. Measurement of milk acetone had the optimal combination of sensitivity, specificity and positive predictive value to identify ketotic cows and was subsequently used in a comparison of the fertility of ketotic and normal cows. Two samples of milk were taken approximately two weeks apart, between 12 and 60 days after calving, from 410 cows on three farms and the concentration of acetone in the milk was measured. Thirty cows with milk acetone concentrations of at least 0.4 mmol/litre were compared with paired control cows with milk acetone concentrations less than 0.3 mmol/litre. The ketotic cows had a significantly longer calving-to-conception interval and a significantly higher culling rate due to a failure to conceive (P<0.05).     

Trends in the quantity of foreign substances in feed mixtures and in pigsty dust at large pig farms

In the period from January 1983 to December 1985 we examined thirty-five samples of commercial feed mixtures for pigs and thirty samples of pigsty dust deposition from large pig-houses in a region with extensive mining (lignite extraction) situated in the Hodonín district. In comparison with the contents of contaminants in the feed mixtures over the period from January 1983 (1/83) to June 1984 (6/84), the zinc and lindane concentrations increased to 213.3% (P less than 0.01) and 133.3%, respectively, from July 1984 (7/84) to December 1985 (12/85). The concentrations of copper, manganese, lead, cadmium, mercury (P less than 0.05), DDT (P less than 0.01) and aflatoxin B1 in the feed mixtures decreased. The highest permissible amount of contaminants in the feed mixtures was exceeded in the 1/83-6/84 period in cadmium (limit value 0.3 mg per kg) and mercury (limit value 0.1 mg per kg), in the 7/84-12/85 period only in zinc (limit value 250 mg per kg). In comparison with the values of contaminants in pigsty dust deposition recorded from January 1983 to June 1984, the lead concentration increased to 555.5% in the 7/84-12/85 period, lindane concentration rose to 569.0% (P less than 0.01), zinc concentration to 220.5% (P less than 0.01), the copper, manganese, cadmium, mercury concentrations (P less than 0.05) decreased, and the concentrations of DDT, aflatoxin B1 and polychlorinated biphenyls also dropped. It is desirable to evaluate in regular intervals the spectrum of contaminants both in feed mixtures and in pigsty dust deposition and to monitor other potential sources of contaminants in the pig-houses.     

Performance and limitation of two dairy production systems in the North western Ethiopian highlands

In order to characterise the dairy production systems as well as the productive and reproductive performance of dairy cows in the study area, a total of 256 and 54 dairy farms were used for survey and monitoring data collection, respectively. Based on breed, land size, feed and market accessibility, two major dairy production systems were identified: a rather specialized, urban, and a peri-urban dairy production system. Urban farmers owned larger herds but farmed less land, and sold a greater proportion of liquid milk than peri-urban farmers, who processed more milk. Purchased feed played a more important role for the feed supply of urban than peri-urban farms. Significant breed effects were found for productive and reproductive performance traits. It is concluded that improved breeding and health management, genetic improvement of local breeds and supplementation of poor quality feed resources are the key factors for enhancing productivity of dairy cows and thereby increasing family income from milk production.