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1.
A total of 1,355 random samples taken from bovine serums submitted for brucellosis testing in Victoria were submitted to the microscopic agglutination test for the presence of antibody to 12 serovars of Leptospira interrogans . The most common reaction obtained was to serovar hardjo , although the percentage of reactors varied from 24.8% in the metropolitan area to 56.3% in north-eastern Victoria (mean 40.6%). A total of 86.3% of farms from which 3 or more samples were taken had at least one reactor to serovar hardjo . The prevalence of antibody to other serovars was tarassovi (7.8% of reactors), ballum (3.7%), pomona (2.4%), autumnalis (1.8%) and bataviae (1.2%). Reactions to other serovars were observed in serums of less than 1% of cattle tested; serums from 50.8% of cattle did not react to any antigen.  相似文献   

2.
Four red deer calves (Cervus elaphus) died with severe nephritis apparently associated with infection by Leptospira interrogans serovar pomona. The sera of 12 in-contact red deer calves were examined for leptospiral agglutinins and nine showed titres to pomona consistent with recent infection. Two also showed titres of 1:100 to serovar hardjo. The urine of five of these in-contact calves was examined periodically over a period of nine months. All were initially leptospiruric, four being infected with pomona and one with hardjo. In four animals leptospiruria could only be detected for up to six months, but one animal infected with pomona was leptospiruric for at least eight months. The apparent source of infection was from infected cattle, and it is suggested that deer are unlikely to act as maintenance hosts for serovar pomona.  相似文献   

3.
Serological surveys of leptospiral antibodies in cattle were carried out in Macon and the surrounding counties of East Central Alabama. A total of 286 bovine serum samples were screened for the presence of antibodies against live antigens from twelve pathogenic leptospiral serotypes using a microscopic agglutination test. The most frequently encountered serotypes were Leptospira hardjo (47%), Leptospira wolffi (34%), Leptospira canicola (12%), Leptospira pomona (10%) and Leptospira ballum (10%). Leptospira autumnalis, Leptospira grippotyphosa, Leptospira icterohemorrhagiae, Leptospira pyrogenes and Leptospira tarassovi were observed in less than 5% of the samples.  相似文献   

4.
Washed red blood cells from normal cows were incubated as 10 and 20 per cent suspensions in media containing 0, 2.5 and 25 mM phosphate. The results showed that the rate of glycolysis was dependent on the inorganic phosphate concentration. In the absence of phosphate, the consumption of glucose and the production of 2,3-diphosphoglycerate, lactate and adenosine 5'-triphosphate (ATP) were decreased. Incubation without added phosphate also greatly increased the production of fructose-1,6-diphosphate, glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. Moderate hypophosphataemia was induced in two pre-ruminant calves. Washed red cells from the blood of these animals showed a depletion of ATP when compared with red cells from a control calf. The results indicate that phosphorus deficiency, leading to hypophosphataemia, may be a mechanism of post parturient and related syndromes of haemoglobinuria by decreasing red cell glycolysis and resultant ATP synthesis. Subnormal concentrations of ATP would predispose red cells to altered structure and function, a loss of normal deformability, and an increase in fragility and haemolysis with resultant haemoglobinuria.  相似文献   

5.
Clinical and serological evidence has indicated that human leptospirosis in Fiji is an important disease, and the prevalence of antibody is exceptionally high. A serological survey of the rural population showed that only 12% of the people studied did not have complement fixing (CF) leptospiral antibody. As the origin of this infection could not be explained by the known distribution of leptospiral infection in domestic and wild animals, a serological survey using the complement fixation test (CFT) was undertaken as the first stage of an epidemiological investigation into human and animal leptospirosis. Sera from domestic and wild animals were tested for CF antibody to 12 leptospiral serovars, namely: pomona, copenhageni, grippotyphosa, hardjo, ballum, tarassovi, canicola, australis, bratislava, autumnalis, pyrogenes and bataviae. Antibody was detected in 27.5% of 480 cattle, 17.1% of 70 sheep, 10.3% of 252 goats, 10.0% of 480 pigs, 57.0% of 100 dogs, 55.8% of 34 rats (Rattus rattus, R. frugivorus, R. exulans and R. norvegicus), 53.1% of 32 mongooses (Herpestes auropunctatus) and 40.0% of 10 mice (species unknown.) Cross-reactivity precluded the identification of infecting serogroups with the exception of pomona in pigs and icterohaemorrhagiae, ballum and australis in dogs. Infection of dogs with a serovar of the australis serogroup may explain the predominance of serological reactions to bratislava in man. The survey revealed a significant level of leptospiral antibody in the animal populations of Fiji and indicated that cattle, dogs, rats, mongooses and mice are probably the most important maintenance hosts. Consequently, further investigation will concentrate on the attempted isolation of leptospires from these species.  相似文献   

6.
AIM: To obtain information on serum and liver vitamin B12 and urinary methylmalonic acid concentrations as diagnostic tests to predict a weight gain response to supplementation with vitamin B12 in young dairy cattle when grazing pasture of low cobalt content. Methodology. Forty dairy cattle (12 Friesian, 14 Friesian x Jersey and 14 Jersey) were allocated to two equal sized groups, treated and untreated, based on liveweight. At monthly intervals for 14 months, all animals were weighed, their serum and urine sampled, their liver biopsied and the pasture sampled from the paddocks they were grazing and going to graze. Serum and liver were assayed for vitamin B12 concentrations. For the first 5 months of the trial, urine was assayed for methylmalonic acid concentrations. Both washed and unwashed pasture samples were assayed for cobalt concentrations. RESULTS: No weight gain response occurred vitamin B12 supplementation in young growing cattle grazing pasture with a cobalt concentration of 0.04-0.06 mg/kg DM. For 5 months of the trial, liver vitamin B12 concentrations from untreated calves were in the range 75-220 nmol/kg and serum vitamin B12 concentrations were as low as 72 pmol/1. There was no associated growth response to supplementation. CONCLUSION: Further trials involving young cattle grazing pastures with cobalt concentrations less than 0.04 mg/kg DM are required to reliably determine liver and serum vitamin B12 concentrations at which growth responses to vitamin B12 or cobalt supplementation are likely under New Zealand pastoral grazing conditions.  相似文献   

7.
Although Se is essential for antioxidant and thyroid hormone function, factors influencing its requirement are not well understood. A survey and two experiments were conducted to determine the influence of cattle breed and age on selenoprotein activity and the effect of maternal Se supplementation on cow and calf selenoprotein activity and neonatal thyroid hormone production. In our survey, four cowherds of different ages representing three breeds were bled to determine the influence of breed and age on erythrocyte glutathione peroxidase activity (RBC GPX-1). All females were nonlactating, pregnant, and consumed total mixed diets (Holstein) or grazed pasture (Angus and Hereford). In our survey of beef breeds, yearlings had greater average RBC GPX-1 activity than mature cows. In Exp. 1, neonatal Holstein heifers (n = 8) were bled daily from 0 to 6 d of age to determine thyroid hormone profile. An injection of Se and vitamin E (BO-SE) was given after the initial bleeding. Thyroxine (T4) and triiodothyronine (T3) concentrations were greatest on d 0 and decreased (P < 0.05) continuously until d 5 postpartum (156.13 to 65.88 and 6.69 to 1.95 nmol/L, d 0 to 5 for T4 and T3, respectively). Reverse T3 concentrations were 3.1 nmol/L on d 0 and decreased (P < 0.05) to 0.52 nmol/ L by d 5. In Exp. 2, multiparous Hereford cows were drenched weekly with either a placebo containing 10 mL of double-deionized H2O (n = 14) or 20 mg of Se as sodium selenite (n = 13). After 2 mo of treatment, Se-drenched cows had greater (P < 0.01) plasma concentrations than control cows (84.92 vs. 67.08 ng/mL), and at parturition, they had plasma Se concentrations twofold greater than (P < 0.05) control cows (95.51 vs. 47.14 ng Se/mL). After 4 mo, cows receiving Se had greater (P < 0.05) RBC GPX-1 activity than controls; this trend continued until parturition. Colostrum Se concentration was twofold greater (P < 0.05) in Se-drenched cows than control cows (169.97 vs. 87.00 ng/mL). Calves born to cows drenched with Se had greater (P < 0.05) plasma Se concentration, RBC GPX-1, and plasma glutathione peroxidase activity on d 0 compared with calves born to control cows. By d 7, no differences in plasma glutathione peroxidase activity in calves were observed. Maternal Se supplementation did not influence calf thyroid hormone concentrations. Selenium provided by salt and forages is not adequate for cattle in Se-deficient states.  相似文献   

8.
Subsequent to a cross-sectional serological survey of Manawatu dairy farm workers, a case-control study was carried out to investigate the correlation between titres to leptospiral serovars in workers and those in cattle in their herds. A total of 52 herds was investigated, 25 of which were high risk where milkers had titres of 1:96 or greater, and 27 were case-controls where milkers had no detectable agglutinin titres at a minimum serum dilution of 1:24. The serological prevalence of titres to hardjo in cattle on high risk farms (76.5%) was significantly higher (P<0.05) than on the case-control farms (60.0%). The geometric mean titres of seropositive cattle on high risk farms were also significantly higher (P<0.01) than in the cattle from the case-control farms, especially in the younger cohorts. These findings suggest that there was active endemic hardjo infection in the two- to three-year-old cattle on the high risk farms. Titres to pomona were demonstrated in only 5.2% of the cattle from both types of farm. Workers with titres to pomona tended to be from farms on which stock, especially calves, were bought-in and pigs were kept. Conventional measures for protecting milkers from contact with infected urine appeared to be ineffective and it is concluded that prevention of leptospirosis in dairy farm workers can only be achieved by elimination of infection in the herd by vaccination of cattle.  相似文献   

9.
The chemical form and site of administration of vitamin E were assessed in cattle by measuring area under the time curve alpha-tocopherol levels in plasma and red blood cells (RBC). In Exp. 1, four groups of Holstein calves, 4 to 6 d old, received daily one of the following forms equivalent to 228 mg of alpha-tocopherol: D-alpha-tocopheryl acetate (DTA); DL-alpha-tocopheryl acetate (DLTA); D-alpha-tocopheryl polyethylene glycol 1,000 succinate (TPGS); and an experimental blend (EB) containing DTA and TPGS. A control group received no supplement. Temporal alpha-tocopherol responses were determined in blood samples collected for 35 d. Relative to controls whose plasma and RBC alpha-tocopherol levels remained unchanged, all supplementation increased (P less than .05) alpha-tocopherol levels in plasma and RBC in calves; the highest levels occurred in those that received either DTA or EB. In a second experiment, five Hereford steers with ruminal and duodenal cannulas were used in a crossover design to determine whether site of vitamin E administration affected plasma alpha-tocopherol levels. A single dose of 810 mg of DTA was placed daily into the rumen, and the same amount divided into five equal doses was given (into the duodenum) during a 12-h period. Plasma alpha-tocopherol levels were higher (P less than .05) when steers were ruminally dosed than when they were dosed duodenally. The results suggest that the alpha-tocopherol concentration of plasma and red blood cells in cattle depends on both the chemical form and on the site of administration.  相似文献   

10.
The course of haemolytic anaemia, caused by immune antibody, was characterised in greater detail with reference to eight heads of young cattle examined for plasma haemoglobin, bilirubin, inorganic phosphorus, and calcium in serum. Inorganic serum phosphorous values were found to decline strongly immediately after the onset of iso-immune serum transmission. Severe haemolysis developed, but only moderate haemoglobinaemia and no haemoglobinuria at all occurred. Bilirubin was increased over a long time, which seemed to support the assumption of gradual erythrocyte decomposition. The usefulness of inorganic serum phosphorus determination as an approach in support of early diagnosis of aggravating haemolysis is confirmed and recommended for metabolic monitoring of cattle herds.  相似文献   

11.
The significance of leptospiral titres associated with bovine abortion   总被引：1，自引：0，他引：1  
To investigate relationships between serological titres to 2 serovars, pomona (L. pomona) and hardjo (L. hardjo), of Leptospira interrogans and abortions, log linear and logit models were fitted to herd and individual cow data from cattle serologically negative for brucellosis. Serological titres to both serovars were significantly related to abortions in individual cows, with L. pomona having a stronger relationship than L. hardjo. L. hardjo was not significant when herd data were analysed. Differences between dairy and beef cattle in the serological titres found to both L. pomona and L. hardjo were detected when data sets of all cattle or cattle with no history of abortion were analysed. The beef/dairy differences may be due to different management practices and/or to different geographical distributions of both serovars and populations of beef and dairy cattle. If there are no cattle in a herd with a reciprocal titre of 3000 or greater for L. pomona, it is unlikely that L. pomona is associated with the abortion problem. There was no specific L. hardjo titre which separated high and low probabilities that the serum came from a cow or herd with an abortion history.  相似文献   

12.
Buffalo serum caused lysis of unsensitized red blood cells (RBC) of sheep, goat, rabbit and guineapig. There was minimal lysis of cattle RBC, and homologous RBC were resistant. Lysis of sheep and goat RBC was the result of natural antibodies as adsorption with respective RBC and addition of 8 mmol ethylene glycolbistetraacetate (EGTA) in diluent completely abrogated the haemolytic activity. The lysis of guinea-pig and rabbit RBC was only partially decreased by these treatments, indicating the presence of alternate complement pathway (ACP) activity in buffalo serum. The guinea-pig RBC were the most sensitive to lysis, and 50% CH titre units above 40 ml−1 of serum were obtained. The haemolytic activity of buffalo C for unsensitized guinea-pig RBC was reduced from 47 CH50 units to an undetectable level by heating at 50°C for 20 min and at 56°C for 4 min. Similarly, treatment with zymosan also inhibited this haemolytic activity. Maximum activation of buffalo ACP occurred in the presence of 4 mmol Mg2+ in the diluent.

Using standardized conditions, ACP activity was determined in sera of 98 healthy buffaloes of different age groups from 1 month to 12 years. Even young calves less then three months of age showed considerable ACP activity (45.60±1.21 CH50 units ml−1) which increased with age. The peak mean values of 79.79±1.45 CH50 units was recorded in 2 to 4-year-old animals. However, in all the 11 animals above 4 years of age, the haemolytic activity was greatly reduced and was even less than that in 1 to 3-month-old buffalo calves. Haemolytic activity did not vary between the sexes.  相似文献   


13.
Serum samples obtained from 1.537 cattle in the 14 local government areas (LGAs) of Plateau State of Nigeria were screened for the presence of leptospiral antibodies using 13 serovars in a modified microscopic agglutination test (MAT). Two hundred and twenty-two (14.4 p.100) of the cattle tested had leptospiral antibody titres of 1:100 or higher to one or more of the test antigens. The prevalence rates of antibodies to individual serovars were: hardjo (35.6 p.100), pomona (11.7 p.100), pyrogenes (11.7 p.100), canicola (9.5 p.100), grippotyphosa (7.7 p.100), bratislava (5.9 p.100), icterohaemorrhagiae (5.9 p.100), ballum (4.5 p.100), autumnalis (3.6 p.100), bataviae (2.3 p.100) and tarassovi (1.8 p.100). The serological prevalence of bovine leptospirosis in the various local government areas of Plateau State of Nigeria differed significantly (P less than 0.05; X2).  相似文献   

14.
The serological responses of calves at two different ages to a commercial hardjo/pomona vaccine were examined. Microscopic agglutination test (MAT) titres of a group of ten three-month-old calves and three groups of 11,12 and 12 six-month-old calves were monitored over a period of 28 weeks. The calves vaccinated at three months of age had a poorer serological response rate to vaccination (30% responded to pomona and 40% responded to hardjo) compared with those vaccinated at six months of age (91-100% responded to pomona and 83-91% responded to hardjo). Those three-month-old calves which did respond also produced a lower level of-antibody than six-month-old calves. It was concluded that in order to achieve adequate protection using commercially available leptospiral bacterins at the recommended dose, vaccination should not be undertaken routinely with animals less than six months of age. Where circumstances arise in which earlier vaccination is necessary, repeat vaccination for continued protection at six months or older is suggested.  相似文献   

15.
Cattle were vaccinated against leptospirosis with 3 bacterin preparations: (a) trivalent (serotypes grippotyphosa, pomona, and hardjo) whole cell bacterin; (b) bivalent pomona and hardjo whole cell bacterin; and (c) pentavalent (canicola, grippotyphosa, icterohaemorrhagiae, pomona, and hardjo) cell wall bacterin. Microscopic agglutinating antibody responses in cattle given the last-named bacterin were higher than those in cattle vaccinated with the 2 whole cell bacterins (trivalent and bivalent). However, microscopic agglutinating antibody responses occurred in all vaccinated cattle after they were given a challenge inoculation of serotype hardjo. Leptospires were isolated from 2 of 4 challenge controls (i.e., not given any bacterin), but none of the 15 vaccinated cattle given any one of the bacterins and then challenge inoculated with hardjo became culturally positive. It was concluded that the 3 multivalent bacterins were protective against experimental challenge inoculation of hardjo.  相似文献   

16.
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   

17.
An investigation was undertaken to ascertain the possibility of a relationship between calcium, inorganic phosphorus, magnesium, 1,25-dihydroxyvitamin D [1,25(OH)2D], and insulin-like growth factor-1 (IGF-1) concentrations in blood plasma and occurrence of congenital joint laxity and dwarfism (CJLD) in young cattle. Pregnant cows were fed hay (30 cows) or grass silage (122 cows) during winter months (October 15 to calving in March). Blood samples were taken from cows on seven occasions during the experiment and 48 hours after calving, and from calves at birth, and at seven, 14 and 56 days old. Five per cent of calves born (six of 122) to cows fed grass silage and none born to cows fed hay were affected by CJLD. The diet and health status of calves were not significantly (P greater than 0.05) associated with the plasma concentration of 1,25(OH)2D. The plasma calcium concentration declined with age of the calves (P less than 0.05) but was not affected by the occurrence of CJLD. Plasma phosphorus and magnesium concentrations in calves born to cows fed silage were higher (P less than 0.05) than in those born to cows fed hay. At birth and seven days old, plasma phosphorus concentrations were higher (P less than 0.05) in CJLD-affected calves than in healthy calves but the plasma concentration of IGF-1 was not different (P greater than 0.05). It was concluded that the high plasma phosphorus concentrations in CJLD-affected calves and their dams could be related to the aetiology of the CJLD condition in calves.  相似文献   

18.
Peritoneal fluid from 10 healthy young male Holstein calves was analyzed three times (2 to 3 days, 12 to 15 days and 27 to 30 days) during the first month of life. A new technique for collection of peritoneal fluid from calves positioned in left lateral recumbency was developed. The technique was found to be reliable and without noticeable complications. Mean peritoneal fluid nucleated cell counts, red blood cell counts, and absolute counts for mononuclear cells, lymphocytes and eosinophils did not change significantly (P 相似文献   

19.
Three red deer calves (Cervus elaphus) died with a haemolytic disease associated with infection by Leptospira interrogans serovar pomona. Infection within the herd was more prevalent than disease. Sera from 16 herd mates were tested by the microscopic agglutination test (MAT) and 12 had leptospiral titres, the majority to serovar pomona. A few calves had titres to balcunica and hardjo. Urine was obtained for culture from six of these calves and serovar pomona was isolated from five with titres to pomona, and hardjo from one with a titre to hardjo but not pomona. A fourth calf died with severe nephritis but a diagnosis of leptospirosis was not confirmed in this case.  相似文献   

20.
Investigations were carried out in 1975, 1976 and 1977 in 16 dairy herds where leptospiral abortions were suspected and in five other herds where clinical disease was not present. Both Leptospira interrogans serovars pomona and hardjo were isolated from cattle in herds with leptospirosis, but only pomona was recovered from those that had aborted. There was no evidence that hardjo caused clinical disease in dairy cattle in the Waikato district. It was found that 73% of the cows that aborted and 19% of other animals in the same herds had microscopic agglutination test titres to pomona of 1:2,000 or greater. By contrast, only 2% of cattle in herds without clinical evidence of leptospirosis had such titres. One cow retained a titre of 1:2,000 or greater to pomona for 7 months; titres of this order had a shorter duration in other cows. Leptospiruria occurred in 50% of cows that had aborted and in 9% of in-contact cows in the same herds. Only 0.7% of cows had leptospiruria in the herds with no clinical disease. Ten of 35 cows shedding pomona still had leptospiruria one month later. It was concluded that clinical leptospirosis should be diagnosed by testing a sample of the herd, rather than just individual cows, because of the variability and persistence of leptospiruria and serological titres in cows with and without clinical signs. Although hardjo is common in cattle in the Waikato district, it was not found to cause abortion in cattle.  相似文献   

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