RESUMO
The objective of this study was to investigate the pharmacokinetics and effect of nalbuphine administered intravenously to calves immediately prior to surgical castration. Ten healthy calves were randomly assigned to two treatments (n = 5): (i) 0.9% sodium chloride (CONT) placebo, (ii) nalbuphine hydrochloride (NAL) (0.4 mg/kg). Blood samples collected over 10 h postcastration were analyzed for nalbuphine and cortisol concentrations. Additionally, heart rate, respiratory rate, rectal temperature, and step count was compared between groups using a random-effects mixed model. Changes in behavior and attitude were assessed using a six-point ordinal scoring system and compared using chi-square analysis. Plasma NAL concentrations were only detectable for 3 h postadministration (T½ = 0.68 h; Range: 0.53-0.79 h). There was no effect of NAL treatment prior to castration on cortisol concentrations (P = 0.99), heart rate (P = 0.73), respiratory rate (P = 0.59), rectal temperature (P = 0.22), and step count (P = 0.08) but fewer calves showed signs of head shaking, kicking, and tail flicking in the NAL group compared with the CONT group (P = 0.036). Therefore, we conclude that a single intravenous injection of nalbuphine at 0.4 mg/kg reduced some pain-related behaviors but did not significantly eliminate the physiological signs of distress in calves after surgical castration.
Assuntos
Analgésicos Opioides/uso terapêutico , Doenças dos Bovinos/tratamento farmacológico , Nalbufina/uso terapêutico , Orquiectomia/veterinária , Dor Pós-Operatória/veterinária , Analgésicos Opioides/farmacocinética , Animais , Bovinos , Doenças dos Bovinos/sangue , Masculino , Nalbufina/farmacocinética , Orquiectomia/efeitos adversos , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/etiologiaRESUMO
Our objectives were to evaluate the prevalence of Escherichia coli O157:H7 in cattle fed diets supplemented with 20 or 40% dried distillers' grains (DG) (DDG) or wet DG (WDG) and assess whether removing DG from diets before slaughter affected fecal shedding of E. coli O157:H7. Eight hundred forty steers were allocated to 70 pens (12 steers/pen). Treatments were no DG (control), 20% DDG or WDG, and 40% DDG or WDG, and each was replicated in 14 pens. In phase 1, eight floor fecal samples were collected from each pen every 2 weeks for 12 weeks for isolation of E. coli O157:H7 and detection of high shedders. In phase 2, half of the pens with DG were transitioned to the no-DG control diet, and pen floor fecal samples were collected weekly from all pens for 4 weeks. During phase 1, prevalence of E. coli O157:H7 was 20.8% and 3.2% for high shedders. The form of DG had no significant effect on fecal E. coli O157:H7 shedding. The prevalence levels of E. coli O157:H7 and the numbers of high shedders were not different between diets with 0 or 20% DG; however, cattle fed 40% DG had a higher prevalence and more high shedders than cattle fed 0 or 20% DG (P ≤ 0.05). During phase 2, overall and high-shedder prevalence estimates were 3.3% and <0.1%, respectively, and there were no differences between those for different DG forms and inclusion levels or when DG was removed from diets. The form of DG had no impact on E. coli O157:H7; however, fecal shedding was associated with the DG inclusion level.
Assuntos
Ração Animal/microbiologia , Derrame de Bactérias/fisiologia , Bovinos/microbiologia , Escherichia coli O157/fisiologia , Fezes/microbiologia , Criação de Animais Domésticos , Animais , Bovinos/metabolismo , Bovinos/fisiologia , Doenças dos Bovinos/metabolismo , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/prevenção & controle , Dieta/veterinária , Grão Comestível/microbiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Infecções por Escherichia coli/veterinária , Escherichia coli O157/isolamento & purificação , MasculinoRESUMO
Feedlot cattle ( = 128; BW = 549 ± 60 kg) were used to evaluate the effects of ractopamine hydrochloride (RAC) on growth performance, physiological response to handling, and mobility during shipment for slaughter in a study utilizing a split-plot design with a 2 × 2 factorial arrangement of treatments: 1) diet (CON [no ß-adrenergic agonist] vs. RAC [400 mg·animal·d ractopamine hydrochloride for 28 d]) and 2) handling intensity (HI; low-stress handling [LSH; cattle moved at a walking pace with no electric prod use] vs. high-stress handling [HSH; cattle moved at a minimum of a trot and an electric prod applied while in the alley for posthandling restraint and during loading for shipment to the abattoir]). Cattle fed RAC tended to have greater ADG and G:F ( = 0.06), and had greater HCW and LM area ( = 0.04). The HI treatments were applied on the day after the 28-d growth performance period. Blood samples were collected before HI treatment (baseline), after HI treatments (POSTHAND), after transport to the abattoir (POSTTRANS), and during exsanguination at slaughter. A diet × HI interaction ( = 0.01) was observed in the change in cortisol from baseline to POSTTRANS, and there tended ( ≤ 0.07) to be diet × HI interactions for the change in epinephrine from baseline to POSTHAND and for the change in creatine kinase (CK) from baseline to POSTTRANS. Feeding RAC and HSH both increased the change from baseline to POSTHAND in norepinephrine and pH ( ≤ 0.05). The HSH cattle also had greater changes from baseline to POSTHAND in blood HCO, base excess, partial pressure of CO, lactate, cortisol, and glucose ( ≤ 0.01). Ractopamine and HSH both produced greater increases in CK concentrations from baseline to slaughter ( < 0.01). Mobility was not affected by RAC at the feedlot or following an average 6-h lairage ( ≥ 0.43). This study confirms RAC improves growth performance and suggests metabolic acidosis, a precursor to fatigued cattle syndrome, develops in cattle allowed to trot without the use of a lead rider regardless of RAC administration. Cattle fed RAC displayed altered hormonal responses to handling and transport stress, and the overall proportion of cattle with compromised mobility appears to increase later in the marketing channel. These findings warrant additional research aimed at better understanding the physiological response to stress and protect the welfare of cattle during shipment for slaughter.
Assuntos
Agonistas Adrenérgicos beta/farmacologia , Bovinos/fisiologia , Manobra Psicológica , Fenetilaminas/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Matadouros , Ração Animal , Animais , Composição Corporal/efeitos dos fármacos , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Feminino , Masculino , Meios de Transporte , Aumento de Peso/efeitos dos fármacosRESUMO
The efficacy of a single dose of tulathromycin, a novel triamilide antimicrobial of the macrolide class, given at 2.5 mg/kg or 5 mg/kg bodyweight, or three daily doses of ceftiofur, given at 3 mg/kg bodyweight, was evaluated in pigs with respiratory disease induced experimentally with Actinobacillus pleuropneumoniae. On day 0, 100 pigs with clinical signs of respiratory disease were randomly assigned to groups of 25 pigs, which were treated with either saline, one of the doses of tulathromycin, or ceftiofur. The pigs' rectal temperatures and clinical scores for respiratory signs and general attitude were recorded daily until day 10. Animals withdrawn from the study for welfare reasons were recorded. On day 10, the animals remaining in the study were weighed, euthanased and examined postmortem. Three of the animals treated with saline and one of those treated with 2.5 mg/kg tulathromycin were withdrawn from the study, but none of those treated with 5 mg/kg tulathromycin or ceftiofur were withdrawn. The least squares mean bodyweight gains of the pigs treated with the antimicrobial agents were significantly (P<0.05) higher than that of the saline-treated group, and the least squares mean percentages of the total lung involvement and incidence of respiratory disease associated with A. pleuropneumoniae were significantly (P<0.05) lower, but there were no significant differences between the three groups of pigs treated with the antimicrobial agents.
Assuntos
Infecções por Actinobacillus/veterinária , Actinobacillus pleuropneumoniae/efeitos dos fármacos , Anti-Infecciosos/uso terapêutico , Dissacarídeos/uso terapêutico , Compostos Heterocíclicos/uso terapêutico , Doenças dos Suínos/tratamento farmacológico , Infecções por Actinobacillus/tratamento farmacológico , Infecções por Actinobacillus/microbiologia , Animais , Cefalosporinas/uso terapêutico , Modelos Lineares , Pulmão/microbiologia , Pulmão/patologia , Masculino , Suínos , Doenças dos Suínos/microbiologia , Resultado do TratamentoRESUMO
The National Animal Disease Laboratory (NADL) vaccine strain of bovine viral diarrhea virus (BVDV) genes for gp48 and p80 were expressed in Escherichia coli. The BVDV-NADL gene for gp62 was integrated into a baculovirus genome for expression in Spodoptera frugiperda (Sf-9) insect ovarian cells. The antigenicity of baculovirus expressed BVDV protein was detected by anti-BVDV specific antibodies in an enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescent assay (IFA) and radio-immunoprecipitation (RIP). The recombinant proteins isolated from bacteria showed antigenic properties when analyzed by ELISA and immunoblotting using BVDV antibodies. The recombinant proteins were then used in ELISA or IFA to detect BVDV infection by testing 54 independent bovine serum samples. The baculovirus-expressed BVDV protein was used as an ELISA and IFA antigen, and the bacteria-expressed proteins were used as ELISA antigens. BVDV-NADL-infected Madin-Darby bovine kidney (MDBK) cell monolayers served as a control antigen. Statistical analysis showed a high degree of correlation between the reactivity of recombinants and natural antigens in ELISA using bovine sera. The results of ELISA or IFA proved there is a high degree of correlation with the virus neutralization. In the comparative ELISA assays, the insect-cell-mediated expression revealed greater specificity and sensitivity than the bacterial expression or the natural BVDV antigens produced by cell cultures.
Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/biossíntese , Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Pestivirus/genética , Proteínas Virais/biossíntese , Animais , Anticorpos Monoclonais , Doença das Mucosas por Vírus da Diarreia Viral Bovina/imunologia , Bovinos , Clonagem Molecular , Ensaio de Imunoadsorção Enzimática , Escherichia coli , Técnica Indireta de Fluorescência para Anticorpo , Genes Virais , Testes de Neutralização , Radioimunoensaio , Proteínas Recombinantes/biossíntese , Spodoptera , TransfecçãoRESUMO
Bovine viral diarrhea virus (BVDV) is a primary pathogen responsible for bovine enteric, respiratory and reproductive failure. A genetic region is encoding the p80 (NS3) of BVDV as the most conserved protein among Pestiviruses. BVDV infection in cattle induces NS3 specific lymphocyte proliferation and humoral responses. To generate a DNA vaccine against BVDV, the gene for BVDV-NADL NS3 was cloned into an eukaryotic expression vector of Semiliki Forest virus (pSFV-1). Quadriceps muscles of BALB/c mice were injected with recombinant DNA generated statistically significant cytotoxic T-lymphocyte activity (CTL) and cell mediated immune (CMI) responses against cytopathic and noncytopathic BVDV. Whereas, the BVDV-NS3 did not generate neutralizing antibodies against BVDVin mice. pSFV-1-NS3 DNA was subjected to in vitro transcription into mRNA. The mRNA was transfected into baby hamster kidney cells (BHK-21) and Madin-Darby bovine kidney cells (MDBK). The recombinant cells were used in the detection of DNA antigen responses by immunological assays. This report establishes the ability of BVDV-NS3 DNA inoculation to induce a strong cellular immune responses in mice.
Assuntos
Anticorpos Antivirais/biossíntese , DNA Complementar/imunologia , Peptídeo Hidrolases , RNA Helicases , Vírus da Floresta de Semliki , Vacinas de DNA/imunologia , Proteínas não Estruturais Virais/genética , Vacinas Virais/imunologia , Animais , Formação de Anticorpos , Doença das Mucosas por Vírus da Diarreia Viral Bovina/prevenção & controle , Bovinos , Linhagem Celular , Cricetinae , Vetores Genéticos , Camundongos , Camundongos Endogâmicos BALB C , Linfócitos T Citotóxicos/imunologia , TransfecçãoRESUMO
A rapid serological test for tuberculosis (TB) infection was designed using antigens specific to Mycobacterium tuberculosis. Tuberculosis infection, TB vaccination and exposure to environmental Mycobacteria cannot be distinguished using skin tests based on tuberculin protein derivatives. The standard diagnostic techniques such as skin tests, X-rays and DNA techniques are time consuming, expensive, and not practical for screening large populations. We used the 38, 63, 64, 14, 59-kDa antigens of M. tuberculosis to develop a rapid immunochromatographic test kit. This study evaluates the diagnostic potential of the rapid test kit using TB positive and TB negative serum samples from various hospitals in India. The samples were obtained from patients infected with or exposed to bacteria and viral pathogens. The results demonstrated that the combination of antigens improved the diagnostic specificity and sensitivity. The specificity of the test was 99.42% with sensitivity of 98.52% (n = 241). In case of multiple infections, the specificity was 93.15% with a low sensitivity of 73.52% n = 141). The test kit may offer an improved alternative to purified protein derivative (PPD). This rapid TB test kit may be a useful tool for first-line testing of suspected cases, epidemiological studies and in designing a quality health system to reduce health hazards in resource-poor countries.
Assuntos
Anticorpos Antibacterianos/sangue , Antígenos de Bactérias , Mycobacterium tuberculosis/imunologia , Testes Sorológicos/métodos , Tuberculose/diagnóstico , Antígenos de Bactérias/imunologia , Cromatografia/métodos , Humanos , Programas de Rastreamento , Mycobacterium tuberculosis/isolamento & purificação , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade , Fatores de Tempo , Tuberculose/sangue , Tuberculose/imunologiaRESUMO
In a 172-d finishing trial (Exp. 1), 210 recently weaned crossbred heifers were allotted to six growth promotant treatment groups, involving implanting initially with Synovex-C (C) or H (H) followed by reimplanting with Finaplix-H (F) or H and F. Melengestrol acetate (MGA) was provided in the diet to four of the treatment groups. Heifers fed MGA and administered only F as the terminal implant had the greatest (P = .01) number of mature ovaries with follicles but also had lower (P = .01) gain/DMI. In a 182-d finishing study (Exp. 2), 270 recently weaned crossbred heifers were allotted to the following six implant (d 0)/ reimplant (d 70) groups using no implant (N), Ralgro (R) or H: N/R, R/H, R/R, N/R, H/H and R/R for Treatments 1 through 6, respectively. On d 70, all heifers were implanted with F. Heifers were fed MGA from d 70 to 182 (Treatments 1, 2, and 3) or for the entire trial (Treatments 4, 5, and 6). Implanting on d 0 increased (P < .05) overall ADG. Differences (P > .05) in performance were not found between MGA treatment groups. Using an H implant/reimplant regimen decreased (P = .01) ovarian and(or) follicular development when compared with an R implant/reimplant regimen. In a 126-d finishing trial (Exp. 3), 360 crossbred yearling heifers were used to evaluate F and estrogen (Implus-H) implants when used in combination with an MGA feeding program. Heifers receiving only F in combination with MGA had greater (P < .05) ADG, whereas all heifers fed MGA had greater (P < .05) gain/DMI than heifers not fed MGA. These data suggest that feeding MGA was not beneficial for young heifers, particularly if they are provided an initial estrogenic implant followed by a second implant. In older (yearling) heifers, increased gains and gain/DMI were obtained by feeding MGA and implanting initially or 56 d later with F.
Assuntos
Criação de Animais Domésticos/métodos , Bovinos/crescimento & desenvolvimento , Estradiol/análogos & derivados , Estradiol/farmacologia , Acetato de Melengestrol/farmacologia , Congêneres da Progesterona/farmacologia , Progesterona/farmacologia , Testosterona/farmacologia , Ração Animal , Animais , Preparações de Ação Retardada , Combinação de Medicamentos , Ingestão de Energia , Estradiol/administração & dosagem , Feminino , Acetato de Melengestrol/administração & dosagem , Ovário/efeitos dos fármacos , Progesterona/administração & dosagem , Congêneres da Progesterona/administração & dosagem , Testosterona/administração & dosagem , Vacinação/veterinária , Aumento de Peso/efeitos dos fármacosRESUMO
The relationship between serum-neutralizing antibody against Fusobacterium necrophorum leukotoxin and hepatic abscesses was investigated in cattle fed diets supplemented with or without tylosin. Sixteen cattle (eight each in tylosin and in control groups) were inoculated intraportally with F. necrophorum. Ultrasonographic scanning showed that all control animals developed hepatic abscesses after inoculation. In the tylosin group, two animals were free of abscess by d 7 and one was free by d 14. Leukotoxin-neutralizing antibody titers were low on d 0, but increased (P < .05) markedly after intraportal inoculation in both groups. In a second study, blood was collected at the time of slaughter from 141 feedlot cattle (36 fed diets with tylosin and 105 fed diets without tylosin), and livers were examined for presence or severity of hepatic abscesses at slaughter. The incidences of hepatic abscesses were 32% in the control group and 6% in the tylosin group. Antibody was detected in all animals; however, antibody titers were greater (P < .05) in cattle with abscessed liver than those without, and greater (P < .01) in the nontylosin than in the tylosin group. Abscess score and antibody titer were correlated (r = .34; P < .0001). We conclude that F. necrophorum leukotoxin is highly antigenic and that anti-leukotoxin antibody titer is related to the severity of hepatic abscesses.
Assuntos
Doenças dos Bovinos/imunologia , Exotoxinas/imunologia , Infecções por Fusobacterium/veterinária , Fusobacterium necrophorum/imunologia , Abscesso Hepático/veterinária , Animais , Anticorpos Antibacterianos/sangue , Toxinas Bacterianas/imunologia , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Feminino , Infecções por Fusobacterium/tratamento farmacológico , Infecções por Fusobacterium/imunologia , Fígado/diagnóstico por imagem , Fígado/patologia , Abscesso Hepático/tratamento farmacológico , Abscesso Hepático/imunologia , Masculino , Distribuição Aleatória , Tilosina/uso terapêutico , UltrassonografiaRESUMO
The efficacy and the optimum dose of Fusobacterium necrophorum crude leukotoxoid vaccine required to immunize and protect steers against experimentally induced liver abscesses were evaluated. The vaccine consisted of cell-free culture supernatant of a high leukotoxin-producing strain of F. necrophorum, inactivated with formalin and homogenized with an adjuvant. Twenty-five steers were assigned randomly to the following five treatment groups: control; three doses (1.0, 2.0, and 5.0 mL) of the culture supernatant; and 2.25 mL of the concentrated supernatant (equivalent to 5 mL of the original supernatant). Vaccine was injected subcutaneously on d 0 and 21. Blood samples were collected weekly to monitor antileukotoxin antibody titers. Three weeks after the second vaccination (d 42), all steers were injected intraportally with F. necrophorum culture to induce liver abscesses. Three weeks later (d 63), steers were euthanatized and necropsied; livers were examined and protection assessed. Antileukotoxin antibody titers in the control steers generally did not differ from the baseline (wk 0) titers. The titers in the vaccinated groups increased, more so after the second injection, and the increase was generally dose-dependent. Necropsy examination revealed that all steers in the control group had abscesses in the liver. In the vaccinated groups, two of five steers in the 1.0-mL group and one each in the 2.0-, 5.0-, and 2.25-mL (concentrated) groups had liver abscesses. Antileukotoxin antibody titers were higher (P < .05) in steers that did not develop abscesses than in steers that developed abscesses. The difference suggested a protective effect of antileukotoxin antibodies against experimentally induced liver abscesses.
Assuntos
Vacinas Bacterianas/farmacologia , Doenças dos Bovinos/etiologia , Doenças dos Bovinos/prevenção & controle , Exotoxinas/farmacologia , Fusobacterium necrophorum/fisiologia , Imunossupressores/farmacologia , Abscesso Hepático/veterinária , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Anticorpos Antibacterianos/metabolismo , Vacinas Bacterianas/imunologia , Bovinos , Doenças dos Bovinos/microbiologia , Suscetibilidade a Doenças , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Exotoxinas/imunologia , Fusobacterium necrophorum/imunologia , Fusobacterium necrophorum/isolamento & purificação , Imunização/métodos , Imunização/veterinária , Imunossupressores/imunologia , Fígado/microbiologia , Fígado/patologia , Abscesso Hepático/etiologia , Abscesso Hepático/prevenção & controle , MasculinoRESUMO
Hepatic abscesses were induced experimentally in 5 steers by inoculating Fusobacterium necrophorum via ultrasonography-guided, percutaneous catheterization of the portal vein. Hepatic ultrasonography was performed to determine the onset and progression of abscessation. Blood samples were collected before and after inoculation for performing leukocyte counts and hepatic function tests. Ultrasonographic evidence of liver abscesses was observed as early as 3 days after inoculation. Abscesses appeared as hyperechoic centers (cellular debris and pus) surrounded by hypoechoic or anechoic areas (fluid). Increases in rectal temperature, leukocyte counts, fibrinogen, globulin, bilirubin, gamma-glutamyltransferase, and sorbitol dehydrogenase concentrations were detected. Hepatic dysfunction was evidenced by decrease in serum albumin concentration and low sulfobromophthalein clearance. The ultrasonographic diagnosis of abscesses correlated well with necropsy findings.
Assuntos
Doenças dos Bovinos/diagnóstico por imagem , Infecções por Fusobacterium/veterinária , Abscesso Hepático/veterinária , Fosfatase Alcalina/sangue , Animais , Aspartato Aminotransferases/sangue , Bilirrubina/sangue , Bovinos , Doenças dos Bovinos/sangue , Fibrinogênio/análise , Infecções por Fusobacterium/sangue , Infecções por Fusobacterium/diagnóstico por imagem , L-Iditol 2-Desidrogenase/sangue , Contagem de Leucócitos/veterinária , Abscesso Hepático/sangue , Abscesso Hepático/diagnóstico por imagem , Masculino , Albumina Sérica/análise , Soroglobulinas/análise , Sulfobromoftaleína/farmacocinética , Ultrassonografia , gama-Glutamiltransferase/sangueRESUMO
Five strains of Actinobacillus pleuropneumoniae serotype 1 were used to intranasally infect 5 groups of pigs. Using each bacterial strain, infected pigs (termed seeder pigs) were commingled for 48 hours with 5 groups of noninfected test pigs, then were removed. Seeder and test pigs were maintained in isolation and were observed for 14 days. Seeder pigs had mortality that was threefold greater than that of test pigs (24% vs 8%). Rectal temperature in excess of 40.3 C was achieved for 84% of test pigs and 88% of seeder pigs. Neither of these 2 variables was statistically different between the 2 groups of pigs. Clinical impression scores > or = 2 (on a 0 to 3 scale) were three-fold (64% vs 20%) greater for seeder than for test pigs (P < 0.05). The total number of bacterial isolations or nonrecoverable isolates was tabulated for test and seeder pigs' lungs at necropsy, irrespective of the amount of lesions. The number of A pleuropneumoniae isolations was not statistically different between test and seeder pig populations. Recovery of Pasteurella multocida or other bacteria was greater from the seeder pigs (P < 0.05), whereas the number of non-recoverable isolates was greater from test pigs than from seeder pigs (P < 0.05). Assessment of lung lesions at necropsy by either visual estimation or on a weight basis were in agreement.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Infecções por Actinobacillus/veterinária , Actinobacillus pleuropneumoniae , Modelos Animais de Doenças , Doenças dos Suínos/microbiologia , Doenças dos Suínos/transmissão , Infecções por Actinobacillus/patologia , Infecções por Actinobacillus/transmissão , Animais , Organismos Livres de Patógenos Específicos , Suínos , Doenças dos Suínos/patologiaRESUMO
OBJECTIVE: To determine the resistance and susceptibility to antimicrobial compounds of Fusobacterium necrophorum isolates from bovine hepatic abscesses. PROCEDURE: 37 isolates of F necrophorum (21 subsp necrophorum and 16 subsp funduliforme) isolated from bovine hepatic abscesses were obtained from cultures grown and maintained in anaerobic brain heart infusion broth. A broth dilution method was used as an initial screening to determine general susceptibility to 31 antimicrobial compounds. The minimal inhibitory concentrations (MIC) of 19 of the antimicrobial compounds that inhibited growth in the initial test were determined by use of the broth microdilution method. RESULTS: Fusobacterium necrophorum isolates were generally susceptible to penicillins, tetracyclines (chlortetracycline and oxytetracycline), lincosamides (clindamycin and lincomycin), and macrolides (tylosin and erythromycin), and were resistant to aminoglycosides (kanamycin, neomycin, gentamicin, and streptomycin), ionophores (except narasin), and peptides (avoparcin, polymyxin, and thiopeptin). The 5 antimicrobials (bacitracin, chlortetracycline, oxytetracycline, tylosin, and virginiamycin) that have FDA approval for prevention of liver abscesses in feedlot cattle were inhibitory to F necrophorum. Differences in antimicrobial susceptibility patterns were observed between the 2 subspecies only for clindamycin and lincomycin. The MIC of F necrophorum isolates from antibiotic-fed cattle were similar to those for isolates from nonantibiotic-fed cattle. CONCLUSIONS: The MIC of FDA-approved antibiotics were not reflective of the efficacy of antibiotics in preventing liver abscesses in feedlot cattle. Also, continuous feeding of tylosin did not appear to select resistant F necrophorum.
Assuntos
Antibacterianos/farmacologia , Doenças dos Bovinos , Infecções por Fusobacterium/veterinária , Fusobacterium necrophorum , Abscesso Hepático/veterinária , Animais , Bovinos , Clindamicina/farmacologia , Infecções por Fusobacterium/microbiologia , Fusobacterium necrophorum/efeitos dos fármacos , Fusobacterium necrophorum/isolamento & purificação , Lincomicina/farmacologia , Abscesso Hepático/microbiologia , Macrolídeos , Testes de Sensibilidade Microbiana , Penicilinas/farmacologia , Tetraciclinas/farmacologiaRESUMO
Twenty-eight abscessed livers were collected from feedlot cattle at an abattoir; specimens were obtained from 49 abscesses for bacteriologic culture and for histologic examination. Cultural procedures included techniques to enumerate and isolate facultative and obligate anaerobic bacteria. Anaerobic bacteria were isolated from all 49 abscesses, whereas facultative bacteria were isolated from only 22. Mean bacterial counts for anaerobic and facultative bacteria were 3 X 10(8) and 8 X 10(8) bacteria/g of purulent material, respectively. Fusobacterium necrophorum, the only anaerobe isolated, was detected in 100% of the abscesses. Fusobacterium necrophorum biotype A was isolated from 57% of the abscesses (in pure culture from 75%), and F necrophorum biotype B was isolated from 47% of the abscesses (from 96% with mixed infections). Corynebacterium pyogenes was the predominant facultative bacterium isolated. Histologic changes in abscesses were qualitatively similar; abscesses were pyogranulomatous, with a necrotic center surrounded by zones of inflammatory tissue. However, the severity of lesions varied, depending on the F necrophorum biotype involved. Portal triad fibrosis and bile-duct proliferation were most severe in biotype A and mixed biotype B infections and less severe in abscesses from which biotype B was isolated in pure culture.
Assuntos
Doenças dos Bovinos/microbiologia , Infecções por Fusobacterium/veterinária , Abscesso Hepático/veterinária , Animais , Bovinos , Doenças dos Bovinos/patologia , Infecções por Fusobacterium/patologia , Fusobacterium necrophorum/isolamento & purificação , Abscesso Hepático/microbiologia , Abscesso Hepático/patologiaRESUMO
OBJECTIVE: To determine the effective dosage of tilmicosin phosphate when fed to pigs for the control of pneumonia attributable to Actinobacillus pleuropneumoniae. DESIGN: Randomized complete block design, with initial weight as the blocking factor. ANIMALS: Seeder pigs were used to infect clinically normal male and female pigs weighing between 13.6 and 36.3 kg at each of 4 trials. PROCEDURE: Five doses of tilmicosin phosphate (0, 100, 200, 300, and 400 micrograms/g) were fed to pigs for 21 days. Pigs received experimental feeds 7 days before the seeder pigs were placed into pens. Feeding continued for an additional 14 days, with seeder pigs removed 3 to 8 days after placement. All pigs were euthanatized and necropsied, with lung bacterial flora and percentages of pneumonic involvement determined. RESULTS: Improvement in clinical impression score, daily rectal temperature, and weight gain were seen for all doses of tilmicosin, compared with controls. For the same variables, tilmicosin administered at 200 to 400 micrograms/g resulted in improvements over the 100 micrograms/g dose. CONCLUSIONS: Data indicate that tilmicosin phosphate fed to pigs at 200 to 400 micrograms/g is effective in controlling and preventing A pleuropneumoniae-induced pneumonia, when administered in feed for 21 days.
Assuntos
Infecções por Actinobacillus/veterinária , Actinobacillus pleuropneumoniae , Antibacterianos/uso terapêutico , Macrolídeos , Pneumonia Bacteriana/veterinária , Doenças dos Suínos/prevenção & controle , Tilosina/análogos & derivados , Infecções por Actinobacillus/prevenção & controle , Ração Animal , Animais , Antibacterianos/administração & dosagem , Temperatura Corporal/fisiologia , Relação Dose-Resposta a Droga , Feminino , Alimentos Fortificados , Masculino , Pneumonia Bacteriana/prevenção & controle , Suínos , Tilosina/administração & dosagem , Tilosina/uso terapêutico , Aumento de Peso/fisiologiaRESUMO
OBJECTIVE: To determine the efficacy of leukotoxin-based Fusobacterium necrophorum vaccines and dietary tylosin in providing protection against experimentally induced hepatic abscesses in steers. DESIGN: 30 steers assigned randomly to 6 treatment groups of 5 steers each: 1, phosphate-buffered saline solution (PBSS; control); 2, PBSS control, fed tylosin (100 mg/steer) daily; 3, inactivated whole-cell culture with oil emulsion adjuvant; 4, culture supernatant (crude toxoid) with oil emulsion adjuvant; 5, semipurified leukotoxoid with oil emulsion adjuvant; and 6, semipurified leukotoxoid with saponin adjuvant. PROCEDURE: Steers were inoculated SC with emulsified antigen or PBSS on days 0 and 21. Blood samples were collected at weekly intervals to monitor serum antileukotoxin antibody titer. On day 42, all steers were challenge exposed intraportally with F necrophorum culture. Three weeks later (day 63), steers were euthanatized and necropsied to examine liver and assess protection. RESULTS: Antileukotoxin antibody titers of all vaccinated groups markedly increased from baseline values, and mean titers of vaccinated groups were higher than those of the control and tylosin-treated groups. Steers vaccinated with culture supernatant with oil emulsion adjuvant or semipurified leukotoxoid with saponin adjuvant had the highest mean antibody titers. All 5 steers in the control group developed liver abscesses. Tylosin feeding did not protect steers challenge exposed with F necrophorum intraportally. CONCLUSIONS: Culture supernatant was more protective than whole-cell culture or semipurified leukotoxin against experimentally induced hepatic abscesses. Partial purification of leukotoxin appeared to reduce its protective immunity.
Assuntos
Abscesso/veterinária , Anticorpos Antibacterianos/sangue , Vacinas Bacterianas , Doenças dos Bovinos , Infecções por Fusobacterium/veterinária , Fusobacterium necrophorum , Hepatopatias/veterinária , Testes de Função Hepática , Abscesso/imunologia , Abscesso/prevenção & controle , Adjuvantes Imunológicos , Ração Animal , Animais , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Formação de Anticorpos , Toxinas Bacterianas/imunologia , Bovinos , Exotoxinas/imunologia , Infecções por Fusobacterium/imunologia , Infecções por Fusobacterium/prevenção & controle , Fígado/efeitos dos fármacos , Fígado/patologia , Hepatopatias/imunologia , Hepatopatias/prevenção & controle , Masculino , Testes de Neutralização , Orquiectomia , Tilosina/administração & dosagem , Tilosina/uso terapêutico , Vacinação/veterináriaRESUMO
Anaerobic and aerobic cultures of facial and mandibular abscesses were made from 12 blue duiker (Cephalophus monticola fusicolor) housed at the Deer and Duiker Research Facility of the Pennsylvania State University (USA). Increases in concentrations of total protein and serum globulin occurred in all cases. Actinomyces pyogenes was isolated from nine animals. Fusobacterium necrophorum was present in eight and Bacteroides sp. was found in seven animals; other genera of isolated bacteria included: Streptococcus (from two animals), Lactobacillus (one), Staphylococcus (one) and Actinomyces (two). Eight (67%) of affected animals were less than or equal to 2 yr of age. Facial soft tissues and mandibles were the tissues most often affected. Tissues within the oral cavity were not affected at the time of presentation. A common finding, not reported in other host species with necrobacillosis, was the presence of nondestructive mandibular proliferation.
Assuntos
Abscesso/veterinária , Actinomicose/veterinária , Antílopes/microbiologia , Artiodáctilos/microbiologia , Dermatoses Faciais/veterinária , Infecções por Fusobacterium/veterinária , Doenças Mandibulares/veterinária , Abscesso/sangue , Abscesso/microbiologia , Actinomicose/sangue , Actinomicose/patologia , Animais , Dermatoses Faciais/sangue , Dermatoses Faciais/microbiologia , Feminino , Infecções por Fusobacterium/sangue , Infecções por Fusobacterium/patologia , Fusobacterium necrophorum/isolamento & purificação , Masculino , Doenças Mandibulares/microbiologiaRESUMO
Health programs based solely on vaccination and treatment regimens are often short-lived and unrewarding. The basis of any successful ongoing health program is a working health management system. The key to the success of the system is a functioning record system that generates information meaningful to management. The basic information generated should include morbidity and mortality data categorized by cause, the number of repeat treatments, and the number of chronic animals or railers. Goals should be set for each major category so that a database can be established for a feedlot operation to assess problems and progress. The most common reason for expectations not being achieved is factors that are largely beyond the control of the feed yard. Although attempts to address these factors should be periodically reviewed, attention to the health program and potential modifications are among the factors that we can control and modify as appropriate. BRD is the most important economic disease in the feedlot. Prearrival management is extremely important in assessing the risk category of incoming calves and in applying a preventive health strategy. Good husbandry, proper nutrition, proper pen maintenance, and selective immunization help to ensure that the cattle adapt quickly to the feed yard environment. Careful observation, timely effective therapy, and excellent hospital management increase the opportunity to produce cost-competitive, safe, and wholesome beef in a humane fashion with limited effects of the environment.
Assuntos
Criação de Animais Domésticos/métodos , Doenças dos Bovinos/epidemiologia , Criação de Animais Domésticos/normas , Criação de Animais Domésticos/estatística & dados numéricos , Animais , Bovinos , Doenças dos Bovinos/terapia , Doenças do Sistema Nervoso Central/epidemiologia , Doenças do Sistema Nervoso Central/terapia , Doenças do Sistema Nervoso Central/veterinária , Doenças do Sistema Digestório/epidemiologia , Doenças do Sistema Digestório/terapia , Doenças do Sistema Digestório/veterinária , Doenças Urogenitais Femininas/epidemiologia , Doenças Urogenitais Femininas/terapia , Doenças Urogenitais Femininas/veterinária , Doenças Urogenitais Masculinas , Doenças Musculoesqueléticas/epidemiologia , Doenças Musculoesqueléticas/terapia , Doenças Musculoesqueléticas/veterinária , Doenças Respiratórias/epidemiologia , Doenças Respiratórias/terapia , Doenças Respiratórias/veterinária , Estresse Fisiológico/prevenção & controle , Estresse Fisiológico/veterináriaRESUMO
The serum antileukotoxin antibody response and protection against subsequent experimental challenge with Fusobacterium necrophorum were investigated in 30 steers vaccinated with crude F. necrophorum leukotoxoid. Culture supernatant of F. necrophorum, strain 25, containing leukotoxoid was concentrated. The steers were assigned randomly to six groups (n = 5): PBS control with Stimulon adjuvant; vaccinated with concentrated supernatant diluted to provide 2.5, 5.0, 10.0, or 20.0 ml with the water-soluble Stimulon adjuvant; and 5.0 ml with the Ribi oil-emulsion adjuvant. The steers were injected subcutaneously on days 0 and 21. Blood samples were collected at weekly intervals to monitor serum antileukotoxin antibody titres. On day 42, all the steers were challenged intraportally with F. necrophorum culture. Three weeks later (day 63), the steers were killed and necropsied for examination of their livers and assessment of protection. Steers vaccinated with crude leukotoxoid tended to have higher antileukotoxin titres than the controls, but the difference was not significant. Also, the antibody titre did not appear to be dose-dependent. In the control group, 3 out of 5 steers developed liver abscesses. The incidence of liver abscesses in steers vaccinated with Stimulon adjuvant was not dose related; however, only 8 of the 25 vaccinated steers developed abscesses. None of the steers vaccinated with the 5.0 ml dose with Ribi had any abscesses. Evidence for a relationship between antileukotoxin antibody and protection was shown by the lower titre in those steers that developed abscesses compared to those that did not. It was concluded that antileukotoxin antibody titres probably provided some degree of protection against experimentally induced liver abscesses, but further dose-titration studies using Ribi or possibly another more effective adjuvant will be needed to confirm this.
Assuntos
Anticorpos Antibacterianos/biossíntese , Doenças dos Bovinos/prevenção & controle , Exotoxinas/imunologia , Infecções por Fusobacterium/veterinária , Fusobacterium necrophorum/imunologia , Abscesso Hepático/veterinária , Adjuvantes Imunológicos , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Vacinas Bacterianas , Bovinos , Esqueleto da Parede Celular/imunologia , Fatores Corda/imunologia , Relação Dose-Resposta Imunológica , Infecções por Fusobacterium/prevenção & controle , Lipídeo A/análogos & derivados , Lipídeo A/imunologia , Abscesso Hepático/prevenção & controle , Masculino , Distribuição Aleatória , Toxoides/imunologia , Vacinação/veterinária , Proteínas Virais/imunologiaRESUMO
Electronic feeding stations (EFS) were developed to automate data collection of individual animals housed in a group environment. In order for scientists to use EFS, such as feed intake recording equipment (FIRE), in research, data recorded electronically cannot differ from data recorded on calibrated scales. The objectives of 2 studies were to determine if data recorded by 2 FIRE stations (FIRE1 and FIRE2) were different from the same data recorded by calibrated scales and determine differences between the 2 independent FIRE stations. Body weight of pigs recorded by the platform scales of both FIRE stations did not differ (P > 0.6) from calibrated scales during a 21-d comparison (study 1). The weight of calibrated check weights recorded by the platform scale of FIRE1 tended to be less (P = 0.1) than the weight of check weights during a 126-d comparison (study 2). Feed disappearance recorded by FIRE1 was greater (P < 0.01) than recorded by calibrated scales during study 2. Feed dispensed to the FIRE trough and compared with calibrated scales did not differ (P ≥ 0.17) for either FIRE station during study 2. There were no differences (P ≥ 0.15) between FIRE1 and FIRE2 for any measured variables. The FIRE stations were not recalibrated during study 1. The platform scale of FIRE2 was recalibrated during study 2 when the percentage error between calibrated check weights and the weight recorded by FIRE exceeded 2.5%. The trough scales of FIRE1 and FIRE2 were recalibrated during study 2 when the percentage error between true weight of dispensed feed and the average recorded FIRE weight exceeded 4%. Establishing more stringent criteria for recalibration may have reduced differences among weights recorded by calibrated scales and weights recorded by FIRE. These data suggest that FIRE stations can be used in research; however, adequate verification procedures and recalibration criteria must be followed to ensure accuracy of data.