Relationship of rumen gram-negative bacteria and free endotoxin to lactic acidosis in cattle.   总被引：1，自引：0，他引：1  

T G Nagaraja  E E Bartley  L R Fina  H D Anthony 《Journal of animal science》1978,47(6):1329-1337

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Effect of antibiotics in milk replacer on fecal shedding of Escherichia coli O157:H7 in calves     

Alali WQ  Sargeant JM  Nagaraja TG  DeBey BM 《Journal of animal science》2004,82(7):2148-2152

The objective of this study was to compare the concentration and duration of fecal shedding of Escherichia coli O157:H7 between calves fed milk replacer with or without antibiotic (oxytetracycline and neomycin) supplementation. Eighteen 1-wk-old Holstein calves were orally inoculated with a strain of E. coli O157:H7 (3.6 x 10(8) cfu/calf) made resistant to nalidixic acid (NA). Rectal samples were obtained three times weekly for 8 wk following oral inoculation. Fecal shedding of NA-resistant E. coli O157:H7 was quantified by direct plating or detected by selective enrichment procedure. Eight weeks after inoculation, calves were killed, necropsied, and tissues (tonsils, retropharyngeal and mesenteric lymph nodes, and Peyer's patches) and gut contents (rumen, omasum, abomasum, ileum, cecum, colon, and rectum) were sampled to quantify or detect NA-resistant E. coli O157:H7. The percentage of calves shedding NA-resistant E. coli O157:H7 in the feces in the antibiotic-fed group was higher (P < 0.001) early in the study period (d 6 and 10) compared with the control group fed no antibiotics. There was no difference between treatment and control groups in the concentration of E. coli O157 in feces that were positive at quantifiable concentrations. A comparison of the duration of fecal shedding between treated and untreated calves showed no significant difference between groups. At necropsy, E. coli O157:H7 was recovered from the rumen and omasum of one calf in the control group and from retropharyngeal lymph node and Peyer's patch of two calves in the antibiotic group. Supplementation of milk replacer with antibiotics may increase the probability of E. coli O157:H7 shedding in dairy calves, but the effect seems to be of low magnitude and short duration.  相似文献   

Susceptibility of broiler chicks to infection by avian pneumovirus of turkey origin     

Shin HJ  McComb B  Back A  Shaw DP  Halvorson DA  Nagaraja KV 《Avian diseases》2000,44(4):797-802

In this paper we present the results of studies on the infectivity of an isolate of avian pneumovirus (APV) from turkeys to broiler chickens. Two-week-old broiler chicks free of antibodies to APV were exposed either by oculonasal or oral route with a cell cultured APV of turkey origin. Chickens from both APV-inoculated groups exhibited clinical signs that included coughing, sneezing, nasal discharge, and watery eyes during 2-8 days postinoculation. Tissue samples from birds in the APV-inoculated group were positive for APV by polymerase chain reaction (PCR) up to 9 days postinoculation. Samples of blood from both oculonasally and orally infected chickens were positive for APV. Intestinal samples from chickens infected with APV orally were positive for the presence of APV on PCR up to 9 days postinoculation. APV was reisolated from samples taken from chickens in both groups inoculated orally and oculonasally. Sera from birds exposed by the oculonasal or by the oral route showed the presence of APV-specific antibodies.  相似文献   

Isolation of avian pneumovirus from an outbreak of respiratory illness in Minnesota turkeys.     

S M Goyal  S J Chiang  A M Dar  K V Nagaraja  D P Shaw  D A Halvorson  V Kapur 《Journal of veterinary diagnostic investigation》2000,12(2):166-168

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Managing scarce water resources in Asia: The nature of the problem and can remote sensing help?     

Wim G. M. Bastiaanssen  Nagaraja Rao Harshadeep 《Irrigation and Drainage Systems》2005,19(3-4):269-284

Water demands are outstripping supplies in many parts of Asia and causing conflicts, especially as rapidly urbanizing and industrializing areas compete with more traditional agriculture on alluvial plains near expanding metropolises. The environment is increasingly being seen as a legitimate and important user of water, often in competition with irrigation, domestic, industrial, hydropower and community uses of water. Any future scenario requires an improvement in water productivity, especially in agriculture. Surface and ground water supplies are not well regulated owing primarily to a weak knowledge base, analytical capacity in addition to a number of traditional institutional, governance, political and other factors. Water policy makers have, therefore, to work out strategies for integrated water and environmental management, which rely on a proper knowledge base of the basin hydrological and pollution conditions. Examples from various countries in Asia are elaborated in this paper to demonstrate how spatially distributed evapotranspiration data from remote sensing, in conjunction with other key data, can help to build the knowledge base for integrated basin scale water management. Remote sensing is not a solution, but it provides key data that is difficult to access by conventional data collection methods.  相似文献   

Electropherotypic analysis of rotaviruses isolated from turkeys     

S Y Kang  K V Nagaraja  J A Newman 《Avian diseases》1986,30(4):794-801

From 1980 to 1984, several flocks of turkeys in Minnesota exhibiting signs of clinical enteritis were examined for viruses. Electron microscopic (EM) examination of fecal specimens from 35 flocks revealed the presence of rotavirus particles. Rotaviruses were successfully isolated in cell cultures from only 24 of these positive fecal specimens. Double-stranded RNA (dsRNA) preparations made from these 24 cell-culture isolates and from the remaining 11 fecal samples that were rotavirus-positive on EM examination were analyzed by polyacrylamide gel electrophoresis for genetic differences in their genomes. The study revealed eight distinct electropherotypes among the rotavirus dsRNA preparations. Atypical dsRNA migration patterns were recognized only in preparations of dsRNA from fecal materials.  相似文献   

Gentamicin and bacterial culture (Nurmi culture) treatments either alone or in combination against experimental Salmonella hadar infection in turkey poults     

E Seuna  K V Nagaraja  B S Pomeroy 《Avian diseases》1985,29(3):617-629

The effect of three treatments on Salmonella hadar infection in turkey poults was examined. The three treatments were: (A) a single injection of gentamicin, (B) peroral treatment with anaerobic culture derived from cecal contents of an adult turkey (Nurmi culture), and (C) combination of treatments A and B. Nurmi culture was significantly more effective than gentamicin treatment. Nurmi culture along with gentamicin reduced the number of shedding birds, but a higher proportion of birds became carriers compared with the groups given Nurmi culture only. Gentamicin injection alone did not prevent the spreading of infection in larger groups raised on litter, but it did so in one experimental group raised on wire floor.  相似文献   

Effect of ionophore antibiotics on experimentally induced lactic acidosis in cattle   总被引：3，自引：0，他引：3  

T G Nagaraja  T B Avery  S J Galitzer  D L Harmon 《American journal of veterinary research》1985,46(12):2444-2452

Salinomycin, a new ionophore antibiotic, was tested and compared with lasalocid and monensin for preventing experimentally induced lactic acidosis. Five rumen-fistulated adult cattle were used in a 5 X 5 Latin square design, and the treatments were as follows: no treatment (control), 0.11 mg of salinomycin/kg of body weight (S1), 0.22 mg of salinomycin/kg (S2), 0.66 of lasalocid/kg, and 0.66 mg of monensin/kg. Acidosis was induced by intraruminal administration of a ground corn-corn starch mixture (50:50, 12.5 g/kg) once a day for up to 4 days. Antibiotics were administered along with grain-starch mixture. Rumen and blood samples were obtained before and at 6, 12, and 24 hours after each carbohydrate-antibiotic dosing to monitor acid-base status. Control and S1-treated cattle became ruminally acidotic within 54 hours, whereas cattle treated with S2, lasalocid, and monensin resisted acidosis for up to 78 hours after dosing. Cattle treated with S2, lasalocid, or monensin had higher rumen pH and lower L(+)- and D(-)-lactate concentrations than did control or S1-treated cattle. Rumen pH decrease to below 5.0 in S2-, lasalocid-, and monensin-treated cattle was not due to lactic acid, but to increased production of volatile fatty acids. Rumen propionate proportion increased initially in antibiotic-treated cattle, but after 48 hours, butyrate proportion increased significantly. Despite low rumen pH and high lactate concentration, lacticacidemia was not evident, and the systemic acid-base disturbance was mild in control cattle.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

A survey of cattle producers in the Boophilus microplus endemic area of Queensland to determine attitudes to the control of and vaccination against tick fever     

RE BOCK  GW BLIGHT†  TG KINGSTON  AJ de  VOS 《Australian veterinary journal》1995,72(3):88-92

SUMMARY: A survey by mail was used to determine the views of beef producers in the Boophilus microplus endemic area of Queensland on the control of and vaccination against tick fever. Data from 448 questionnaires were analysed, representing 2.7% of beef producers in the survey area. Producers considered buffalo fly ( Haematobia irritans exigua ) infestation as the most important problem whereas tick fever ranked sixth overall. Private veterinarians were regarded as the most important source of information on vaccines for cattle followed by a weekly rural newspaper. From the survey we estimate that about 33% of producers used the tick fever vaccine produced by the Tick Fever Research Centre of Queensland Department of Primary Industries but there were significant (P < 0.05) variations between regions and herds. Large herds (≥ 400 head) in south-east Queensland were the most likely to be vaccinated against tick fever. Of the producers who did not use the vaccine, over 70% replied that there was no need to vaccinate because of the low risk of the disease in their herds. In 52% of unvaccinated herds the treatment of animals with acaricide was considered the most important means of tick fever control and 61% of these herds comprised Bos indicus x Bos taurus or Bos indicus cattle.  相似文献   

Use of membrane proteins from Salmonella gallinarum for prevention of fowl typhoid infection in chickens   总被引：1，自引：0，他引：1  

K Bouzoubaa  K V Nagaraja  J A Newman  B S Pomeroy 《Avian diseases》1987,31(4):699-704

Outer membrane protein isolated from Salmonella gallinarum was examined at different concentrations with or without a mineral-oil adjuvant for its immunogenicity and protection against live challenge. A formalin-killed whole-cell bacterin of the same organism was used for comparison. The results suggested that membrane proteins from S. gallinarum give better protection than formalin-killed whole-cell bacterin. Addition of an oil adjuvant to the protein appeared to increase the efficiency of the vaccine. When protein was given to chickens at 400 micrograms/100 g of live body weight, it produced 100% protection against oral challenge with S. gallinarum.  相似文献