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1.
Levels of arsenic, cadmium, copper, mercury and lead were determined in approximately 650 samples of liver and kidney from cattle, swine and poultry slaughtered in Canada during 1979-81. In addition zinc levels were determined in livers and kidneys from swine, and selenium and zinc levels were determined in the livers and kidneys from cattle. Depending on the element several methods of atomic absorption spectroscopy were used to analyze samples including flame, hydride generation, cold vapour generation and graphite furnace atomization. Analyses were also done by plasma emission spectroscopy. Levels of arsenic over 2.0 micrograms/g were detected in 0.9% of swine livers and 0.3% of swine kidneys. Cadmium levels higher than 1.0 micrograms/g were detected in 0.3% of cattle livers, 10.8% of cattle kidneys, 1.8% of swine kidneys, 0.4% of poultry livers and 0.3% of poultry kidneys. Levels of copper over 150 micrograms/g were detected in 0.4% of cattle and swine livers. Levels of lead over 2.0 micrograms/g were detected in 1.4% of poultry livers and 1.6% of poultry kidneys. The highest level of mercury detected in all species was 0.25 micrograms/g and the highest level of selenium was 1.9 micrograms/g. Zinc levels of over 100 micrograms/g were detected in 1.7% of cattle livers, 0.2% of cattle kidneys and 5.0% of swine livers.  相似文献   

2.
Effectiveness of 2 concentrations of a monovalent vaccine containing Leptospira interrogans serovar hardjo type hardjo-bovis was evaluated for protection of heifers from infection with type hardjo-bovis. Nine heifers were given 2 doses of low-dose vaccine (8.32 x 10(8) cells/dose); 9 heifers were given 2 doses of high-dose vaccine (8.32 x 10(9) cells/dose); and 1 steer and 1 heifer were maintained as nonvaccinated controls. Groups of vaccinated cattle were challenge-exposed with serovar hardjo type hardjo-bovis at 7 (n = 6), 11 (n = 6), or 15 (n = 6) weeks after completion of vaccination. All cattle were challenge-exposed by conjunctival instillation of 1 x 10(5) hardjo-bovis cells on 3 consecutive days. Both control and all vaccinated cattle became infected and shed serovar hardjo type hardjo-bovis in their urine. Leptospires were detected in 15 of 16 (94%) urine samples from control cattle and in 124 of 143 (87%) samples from vaccinated cattle. Leptospires were detected in kidneys of 17 of 18 vaccinated cattle and 2 of 2 control cattle and in the uterus or oviducts of 13 of 18 vaccinates and the 1 control heifer.  相似文献   

3.
Kidneys from 117 cattle from 110 Ontario farms were examined at slaughter for leptospires. Leptospira hardjo (hardjo-bovis A) was isolated from 11 kidneys and L. kennewicki from one. The isolations were all made (12/89, 13.5%) from beef cattle from feedlots, no isolates being obtained from dairy or beef cattle from extensive farms (0/28). Isolations were only made from cattle with antibody titers (greater than or equal to 20) against the serovars recovered. Isolation was more sensitive than immunofluorescence in identifying leptospira, particularly in animals with low antibody titers against L. hardjo. Leptospira were isolated from two kidneys with multiple gross lesions of focal nephritis, but there was no correlation between the presence of scanty kidney lesions and isolations of leptospira. Leptospira hardjo infection appears to be common in Ontario feedlot cattle.  相似文献   

4.
Mass screening ELISA methods were developed for testing cattle serum for antibodies against 14 common livestock diseases simultaneously. The absorbance values were transformed to a %ELISA (spectrophotometric antibody end point) by a computer interfaced with a microplate reader. A histogram indicating a cutoff point and a report for the veterinarian also was generated. The computer program produced a print-out of the antibody profile for each animal tested, the antibody concentration against each disease, and a histogram (antibody profile) showing the prevalence of each disease in the herd. Serum samples were obtained from 1,953 cattle, including 880 dairy cattle from 10 herds and 1,073 beef cattle from 20 herds. These samples were obtained from June 1988 through June 1989. The highest antibody prevalence was against bluetongue virus. Of the 1,953 cattle tested, 1,223 (63%) were seropositive for bluetongue virus, including 502 (57%) of the dairy cattle and 721 (67%) beef cattle. Other antibody prevalences, in descending order, were: rotavirus (44%), Pasteurella spp (25%), Leptospira spp and Haemophilus spp (22%), Mycoplasma spp (18%), parainfluenza virus (17%), Campylobacter spp (16%), Anaplasma marginale (15%), bovine leukosis virus (13%), Brucella spp (8%), Mycobacterium paratuberculosis (8%), bovine viral diarrhea virus (3%), and infectious bovine rhinotracheitis virus (3%). Major differences in antibody prevalence between dairy and beef cattle were that only 4% of the dairy cattle were seropositive for A marginale, compared with 25% of the beef cattle, and conversely, 29% of the dairy cattle were seropositive for bovine leukosis virus, compared with 1% of the beef cattle.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
This study was designed to investigate the presence of leptospiral antigens in kidney and liver of naturally infected cattle using an immunoperoxidase (IP) staining and Levaditi's staining methods. A total of 39 cattle suspected from leptospirosis were examined histologically and immunohistochemically for the presence of leptospiral antigens. The leptospiral antigens were detected in 16 out of 39 cases (seven kidneys, three livers, and six kidneys and livers) when IP staining method was used, whereas leptospiral antigens were detected in 6 out of 39 cases (four kidneys and two livers) when Levaditi's staining method was used. This study ascertained that IP staining was more sensitive method than Levaditi's staining method for demonstrating the presence of leptospirosis in cattle.  相似文献   

6.
OBJECTIVE: To determine prevalence of papillomatous digital dermatitis (PDD) among culled adult dairy and beef cattle in the southeastern United States. ANIMALS: 815 cattle examined during 4 visits to a slaughterhouse. PROCEDURE: The left hind foot of each animal was examined for gross lesions of PDD. Breed and sex of the animals were recorded. Lesions were examined histologically for pathologic changes and bacteria, especially spirochetes. RESULTS: 22 of 76 (29%) dairy cattle and 29 of 739 (4%) beef cattle had gross lesions of PDD. Detection of lesions was not associated with sex of dairy cattle, but male beef cattle were more likely to have lesions of PDD than were female beef cattle. Histologically, acute and chronic lesions were seen; the most severe changes were localized to the stratum corneum. Spirochetes were seen in lesions from 31 of 51 (61%) cattle. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that PDD is common among culled adult cattle. Prevalence was higher in culled adult dairy cattle than in culled adult beef cattle.  相似文献   

7.
Peripheral blood mononuclear cells were obtained from 13 bovine leukosis virus infected cattle and inoculated subcutaneously into 29 recipient adult steers to determine (a) the number of mononuclear cells (equivalent amount of blood) necessary to cause infection and (b) factors influencing infectivity of mononuclear cells from bovine leukosis virus-infected animals. A total of 55 inoculations were made. Inoculation of 1 X 10(4), 2 X 10(4) and 5 X 10(4) mononuclear cells caused seroconversion in 12%, 57% and 62% of steers, respectively. No infections occurred with 1 X 10(3) or 2 X 10(3) mononuclear cells. Cattle infected for longer than 24 months and those animals greater than three years of age were more likely to cause infection with 1 to 5 X 10(4) mononuclear cells than were cattle infected for less than 24 months or animals less than three years of age. Lymphocytes from cattle with persistent lymphocytosis caused more infections when 1 X 10(4) or 2 X 10(4) mononuclear cells were inoculated, than did lymphocytes from nonpersistent lymphocytosis cattle; however, both groups were equally infectious when 5 X 10(4) mononuclear cells were inoculated. No differences were found in infectivity of experimentally vs naturally exposed animals.  相似文献   

8.
Leptospirosis is a zoonotic bacterial disease reported worldwide. In Uganda, seropositivity has been reported in both humans and domesticated animals, including cattle. However, it remains unknown whether cattle are shedding leptospires and thus acting as potential source for human leptospirosis. We conducted this cross‐sectional study in two cattle abattoirs in Kampala, Uganda between June and July 2017. Kidney and urine samples from 500 cattle sourced from across the country were analysed by real‐time PCR to establish the prevalence of Leptospira‐positive cattle and risk of exposure to abattoir workers. The species of infecting Leptospira was determined by amplification of secY gene and compared to reference sequences published in GenBank. Of 500 cattle tested, 36 (7.2%) had Leptospira DNA in their kidneys (carriers), 29 (5.8%) in their urine (shedders); with an overall prevalence (kidney and/or urine) of 8.8%. Leptospira borgpetersenii was confirmed as the infecting species in three cattle and Leptospira kirschneri in one animal. Male versus female cattle (OR = 3, p‐value 0.003), exotic versus local breeds (OR = 21.3, p‐value 0.002) or cattle from Western Uganda (OR = 4.4, p‐value 0.001) and from regions across the border (OR = 3.3, p‐value 0.032) versus from the central region were more likely to be Leptospira‐positive. The daily risk of exposure of abattoir workers to ≥1 (kidney and/or urine) positive carcass ranged from 27% (95% credibility interval 18.6–52.3) to 100% (95% CI 91.0–100.0), with halal butchers and pluck inspectors being at highest risk. In conclusion, cattle slaughtered at abattoirs in Uganda carry and shed pathogenic Leptospira species; and this may pose occupation‐related risk of exposure among workers in these abattoirs, with workers who handle larger numbers of animals being at higher risk.  相似文献   

9.
Nine cases affected with disseminated mucormycosis (1.3% of all autopsy cases and 20.0% of systemic mycosis) were found among bovine systemic mycosis examined from 1975 to 1985. The disseminated lesions were found in the lungs (3 cattle), heart (2 cattle), liver (2 cattle), spleen (1 beef cattle), kidneys (1 cattle), central nervous system (1 cattle) and lymph node (1 cattle). Histological examination revealed granulomatous lesions, necrotic foci including infarcts, and thromboangiitis with the hyphae of a member of the Zygomycetes and neutrophil reaction. Granulomatous lesions with asteroid bodies were found in the liver. Metastatic foci were established from the primary lesions found in the alimentary organ (4 from the forestomach or abomasum and 1 from the tongue). One case resulted from uterine mucormycosis, and no primary lesion was found in the other 3 cattle. Complicated infection with respiratory aspergillosis occurred in 4 cases with alimentary mucormycosis. All of the 9 cattle had predisposing disorders. Six cattle had been manifested with prolonged debilitating conditions. Anemia was present in 4, leukopenia in 2 and lymphopenia in 1 cattle.  相似文献   

10.
Kidneys from cattle at slaughter were examined for the presence of leptospires. Of 218 (8.3%) kidneys leptospires were isolated from 18; all were identified as Leptospira interrogans serovar hardjo. None of the leptospire-infected kidneys had histopathological lesions indicative of leptospirosis and leptospires were demonstrated in only 2 by immunogold silver staining. Leptospires infected kidneys remained viable for at least 21 days when stored at 4 degrees but became non-viable within 14 days when stored frozen at -15 degrees.  相似文献   

11.
Fifty-three American cattle were inoculated with malignant catarrhal fever virus isolated from a wildebeest in Kenya. Three animals showed the mild form of the disease and recovered, and 47 showed the severe form of the disease. The other three did not react. Of the 47 cattle, 28 died, 16 were killed for the collection of specimens and three recovered. The incubation period for the 47 cattle ranged from 16 to 29 days and the course of the fatal disease for 28 cattle averaged three to 23 days. Virus titration of specimens from nine infected steers yielded a mean titer of 10(4)/TCID50 per gm for lymph nodes, 10(3) TCID50 per mL for buffy coats and 10(2.3) TCID50 per gm for spleens. Smaller amounts of virus were found in the liver, kidneys, adrenals and thyroids. Malignant catarrhal fever virus was also found in nasal secretions and saliva of viremic cattle. Viral infectivity was shown in bovine buffy coat cells stored at 4 degrees C for two days but was immediately destroyed upon freezing even when glycerine or dimethylsulfoxide was added. Viral particles were not found in infected animal tissues by electron microscopy. The disease was successfully transmitted in steers by intratracheal intubation and by aerosol inhalation but not by contact.  相似文献   

12.
Resistance to renal leptospirosis was demonstrated in cattle vaccinated with Leptospira interrogans serotype pomona bacterin. Fewer vaccinated cattle given challenge inoculum of virulent serotype pomona leptospires 12 months after vaccination had kidneys with gross focal lesions in the cortex than did nonvaccinated controls. Histopathologic changes characteristically associated with renal leptospirosis occurred less frequently and renal tissue damage was less severe in vaccinated cattle than in nonvaccinated controls. The isolation of serotype pomona from only 1 of 29 vaccinated cattle, compared to 7 isolations from 11 nonvaccinated cattle, at 26 days after challenge inoculum was given, indicated that mild renal infection occurred only infrequently in vaccinated cattle. It appeared that challenge inoculation of vaccinated cattle with virulent serotype pomona leptospires stimulated an accelerated secondary immune response in which immunity limited the multiplication of leptospires in the kidney.  相似文献   

13.
During a 19-month period, the agar gel immunodiffusion (AGID) test was used as an aid in differential diagnosis of paratuberculosis in 51 cattle with a history of chronic weight loss and/or chronic diarrhea. Thirty-three cattle were AGID test-positive for paratuberculosis. Twenty-eight cattle (87.5%) yielded Mycobacterium paratuberculosis from bacterial culture of feces. Four cattle were confirmed as having paratuberculosis on necropsy. One had a negative fecal culture but was lost to follow-up. Thus, 32 of the 33 AGID test-positive cattle (96.9%) were confirmed as paratuberculous by culture or necropsy. Of the 18 cattle that were AGID test-negative, 17 (94%) also were culture-negative after 12 to 20 weeks' incubation of the culture tubes. Direct fecal smears from 29 confirmed paratuberculous cattle were examined. Twenty-three (79.3%) had smears positive for M paratuberculosis. Fifteen culture-negative cattle were examined by direct smear; the results were negative for all.  相似文献   

14.
Bovine coronavirus (BCoV) is an important cause of diarrhoea in calves, winter dysentery in adult cattle and respiratory tract disease in feedlot cattle. Serum, faecal and nasal swab samples were collected from a total of 96 cattle with clinical signs in 29 barns of 23 villages in Northwestern Turkey. The cattle were subdivided into 3 distinct age groups (0-30 days old, 4-12 months old and 2-7 years old). An indirect antigen-capture ELISA and an antibody-detection ELISA as well as geometric mean BCoV antibody titres were used to detect BoCV shed in the faeces and in the nasal secretions, respectively. Relationships between BCoV shedding and age group, seroconversion and clinical signs in cattle were also analysed. The rate of faecal shedding of BoCV was 37.1% (13/35) in 0-30 days old calves, 25.6% (10/39) in 4-12 months old feedlot cattle and 18.2% (4/22) in 2-7 years old cows. The overall rate of BCoV faecal shedding was 28.1% (27/96) in the cattle examined. Only one animal in the 4-12 months old age group was found to shed BoCV nasally. The analysis showed that there was a significant difference (P < 0.0001) with respect to faecal shedding between the clinical signs and the age groups. BCoV antibody titre in 50% of all cattle was < or =100 as detected by ELISA while 27.1% of the cattle had high titres ranging between 1,600 and 25,600. The seroconversion rate was 7.3% (7/96) in animals shedding BoCV in the faeces and 42.7% (41/96) in cattle negative for faecal shedding as detected by ELISA, and 20.8% of cattle with no seroconversion shed BCoV in the faeces. There was no statistically significant association between seroconversion and nasal or faecal BCoV shedding. These findings confirm the presence of BCoV infections in Turkey. Further studies are needed to isolate BCoV strains in Turkey and to investigate their antigenic and genetic properties.  相似文献   

15.
研究了日粮中C3和C4饲料组成不同时,牛不同组织中δ13C值的变化规律。18头12~14月龄的青年牛随机分为6组,分别饲喂C4植物含量为52.0%,61.6%,71.2%,80.8%,90.4%,100.0%的饲料,其他日粮成分为C3植物,132 d后屠宰。利用同位素比值质谱仪测定了牛尾毛、脱脂牛肉、粗脂肪、各种饲料的δ13C值。结果表明,牛组织中碳同位素组成主要受饲料的影响,随着时间的延长,饲喂同一种饲料的牛个体间碳同位素组成差异减小;牛尾毛、脱脂肌肉、粗脂肪中的δ13C值随着C4植物含量在牛饲料中的比例增大而升高,并且均与C4植物含量呈极显著的相关性(P<0.01);牛尾毛、脱脂肌肉、粗脂肪中的δ13C值依次递减,三者之间相关性达到极显著水平(P<0.01)。用牛组织中的δ13C值可以预测日粮中C4植物所占的比例,牛尾毛、脱脂肌肉、粗脂肪均可作为牛肉溯源的材料。  相似文献   

16.
Objective: To investigate the presence of Salmonella Dublin in Queensland cattle.
Design: An epidemiological study using diagnostic laboratory information and farm records.
Procedure: Outbreaks of gastroenteritis or pneumonia in calves, and abortions and enteritis in cows were routinely investigated for the presence of salmonellae. Where S Dublin was isolated, attempts were made to gather further epidemiological information.
Results: Prior to 1983 only two outbreaks of S Dublin have been recorded in Queensland dairy cattle. In 1983 S Dublin abortions were diagnosed in dairy heifers introduced from southern Australia to south-east Queensland. Sampling indicated that at least 10% of the 500 introduced heifers were faecal excretors of S Dublin. On 3 of the 7 farms from which S Dublin was recorded, infection spread to other cattle that were in contact. From February 1985 to February 1996, 29 outbreaks of S Dublin in cattle occurred on 29 farms (28 in south east Queensland and 1 in north Queensland). Calves were primarily affected. Continuing outbreaks were confirmed on only 4 of these 29 farms. On 15 farms S Dublin infections were associated with the purchase of infected calves or cows, while another farm adjoined 2 previously infected farms. No source of S Dublin was evident for the other 13 farms, where histories were often inadequate.
Conclusion: There has been a marked increase in S Dublin outbreaks in Queensland dairy cattle since 1983. Introduction of S Dublin carrier and aborting dairy heifers from southern Australia, where S Dublin is not uncommon, was associated with the initial outbreaks.  相似文献   

17.
As cattle mature, the dietary protein requirement, as a percentage of the diet, decreases. Thus, decreasing the dietary CP concentration during the latter part of the finishing period might decrease feed costs and N losses to the environment. Three hundred eighteen medium-framed crossbred steers (315 +/- 5 kg) fed 90% (DM basis) concentrate, steam-flaked, corn-based diets were used to evaluate the effect of phase-feeding of CP on performance and carcass characteristics, serum urea N concentrations, and manure characteristics. Steers were blocked by BW and assigned randomly to 36 feedlot pens (8 to 10 steers per pen). After a 21-d step-up period, the following dietary treatments (DM basis) were assigned randomly to pens within a weight block: 1) 11.5% CP diet fed throughout; 2) 13% CP diet fed throughout; 3) switched from an 11.5 to a 10% CP diet when approximately 56 d remained in the feeding period; 4) switched from a 13 to an 11.5% CP diet when 56 d remained; 5) switched from a 13 to a 10% CP diet when 56 d remained; and 6) switched from a 13 to an 11.5% CP diet when 28 d remained. Blocks of cattle were slaughtered when approximately 60% of the cattle within the weight block were visually estimated to grade USDA Choice (average days on feed = 182). Nitrogen volatilization losses were estimated by the change in the N:P ratio of the diet and pen surface manure. Cattle switched from 13 to 10% CP diets with 56 d remaining on feed or from 13 to 11.5% CP with only 28 d remaining on feed had lower (P < 0.05) ADG, DMI, and G:F than steers fed a 13% CP diet throughout. Steers on the phase-feeding regimens had lower (P = 0.05) ADG and DMI during the last 56 d on feed than steers fed 13.0% CP diet throughout. Carcass characteristics were not affected by dietary regimen. Performance by cattle fed a constant 11.5% CP diet did not differ from those fed a 13% CP diet. Serum urea N concentrations increased (P < 0.05) with increasing dietary CP concentrations. Phase-feeding decreased estimated N excretion by 1.5 to 3.8 kg/steer and nitrogen volatilization losses by 3 to 5 kg/steer. The results suggest that modest changes in dietary CP concentration in the latter portion of the feeding period may have relatively small effects on overall beef cattle performance, but that decreasing dietary CP to 10% of DM would adversely affect performance of cattle fed high-concentrate, steam-flaked, corn-based diets.  相似文献   

18.
Serum samples from 145 dairy and 65 beef cattle with reproductive disorders and 54 normally calving dairy cattle (controls) in Japan were tested for presence of Neospora caninum antibodies by use of an indirect fluorescent antibody test (IFAT, titer 1:200). Overall, seroprevalence of N. caninum was significantly higher (P < 0.001) in dairy cattle (20.0%, 29/145) than in beef cattle (1.5%, 1/65). In cattle which aborted, seroprevalence of N. caninum was significantly higher (P = 0.041) in dairy cattle (26.1%, 23/88, compared with controls (3.7%, 2/54)) than in beef cattle (5.0%, 1/20), indicating that neosporosis might be a more common problem in dairy cattle than in beef cattle in Japan. Seropositive cattle were 9.2 times more likely to abort compared to seronegative cows. Abortions associated with N. caninum seropositivity in this study were most frequently observed in the second trimester, and the mean gestational age of the fetuses aborted from seropositive dams was 5.7 months. In conclusions, N. caninum seems to be causing serious economic losses in the dairy industry in Japan. This is the first report on an objective comparison of seroprevalence of dairy and beef cattle with reproductive disorders in Asia.  相似文献   

19.
Blood samples were obtained from sentinel beef cattle at monthly intervals, and the sera were tested for antibodies, using a bluetongue virus (BTV) immunodiffusion test (IDT) and virus-neutralization test (VNT), for 5 BTV serotypes (2, 10, 11, 13, and 17) and 2 epizootic hemorrhagic disease virus (EHDV) serotypes (1 and 2). The cattle tested were transported from Tennessee to Texas in 1984 and 1985. All cattle were seronegative by the BTV IDT at the initial bleeding in Texas in 1984 and 1985. In 1984, 16 of 40 (40%) cattle seroconverted as assessed by results of the BTV IDT. In the 16 seropositive cattle in 1984, neutralizing antibodies were detected to BTV serotypes 10 (n = 7), 11 (n = 3), and 17 (n = 11), and EHDV serotypes 1 (n = 1) and 2 (n = 7). In 1984, no cattle seroconverted to BTV-2 or BTV-13. In 1985, 10 of 36 (27.8%) cattle seroconverted as assessed by results of the IDT. Of the 10 seropositive cattle in 1985, neutralizing antibodies were detected to BTV serotypes 10 (n = 10), 11 (n = 10), 13 (n = 7), and 17 (n = 5), and EHDV serotypes 1 (n = 1) and 2 (n = 7). In 1985, no cattle seroconverted to BTV-2. Clinical diseases attributable to BTV or EHDV was not detected in these cattle in 1984 or 1985.  相似文献   

20.
Cattle allowed to graze pastures variously treated with anaerobically digested sludge (ADS) for up to 8 years, contained higher concentrations of heavy metals and organic compounds in some tissues than did cattle not exposed to ADS. Chemical analyses were made on heart, diaphragm, liver, kidney, brain, and bone to determine the amount of Zn, Cu, Cd, Cr, Ni, Pb, Fe, and Hg. Determinations for organic compounds (polychlorinated-biphenyls, dieldrin, and heptachlor/epoxide) were made on visceral fat. Cadmium was the only metal to accumulate consistently in increased amounts. Amounts of Cd accumulated in kidneys and livers were higher in cattle exposed to ADS than in cattle not exposed to ADS. Although the amounts were higher in cattle exposed to ADS, none of the cattle had detectable evidence of disease or pathologic conditions. The mean amount of Cd in kidneys of cattle exposed to ADS was 44 vs 9 mg/kg dry weight. Amounts of other heavy metals in the body tissues were generally not unusual and were similar in both groups of cattle. Polychlorinated-biphenyl concentrations were higher in the visceral fat of cattle exposed to ADS. All cattle in both herds remained healthy, and pathologic changes that could be attributed to association with ADS were not detected. Seemingly, ADS can be used safely to produce cattle forage without endangering the health of cattle.  相似文献   

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