28 research outputs found
Pulmonary arterial pressures, arterial blood-gas tensions, and serum biochemistry of beef calves born and raised at high altitude
Includes bibliographical references (page 8).High-altitude exposure is physiologically challenging. This is particularly true for animals native to low-altitude environments, such as British breeds of cattle. The objective of this study was to document the effect of high altitude on select physiological parameters of healthy beef calves (Bos taurus) born and raised on a high-altitude ranch typical of the Rocky Mountain region. Pulmonary arterial pressures, arterial blood-gas tensions, serum biochemistry, and hematocrit were evaluated. The calves studied were a composite of British (50%-75%) and Continental (25-50%) breeds born on one ranch at an altitude of 2410 m. Calves were sampled at an altitude of 2410 m when 1 month old and again at an altitude of 2730 m when 3 and 6 months old. Between 3 and 6 months of age, calves had access to grazing from 2730 m to approximately 3500 m above sea level. On each occasion, 16 to 50 calves were sampled. Only calves that remained healthy throughout all three testing periods were included in the dataset. Calves with the highest pulmonary arterial pressures at 1 month of age tended to have the highest pressures at 6 months of age (r = 0.43, P = 0.16, n = 12). Respiratory alkalosis was greatest at 6 months of age (pH 7.48 ± 0.06). Mean alveolar-arterial oxygen pressure gradients were 11.7and 11.6 mmHg at 3 and 6 months of age, indicating poor transfer of oxygen from the alveoli into the pulmonary blood. Median values for blood lactate ranged from 1.4 to 3.4 mmol/L indicating substantial anaerobic respiration at all ages. Mean hematocrits were ≤ 35.7%, only slightly higher than values obtained from age-matched calves at sea level. These results suggest that the provision of oxygen to the peripheral tissues of beef calves may be compromised at altitudes over 2410 m. This may have implications for diseases of the cardiopulmonary system.Published with support from the Colorado State University Libraries Open Access Research and Scholarship Fund
Prevalence of internal parasites in beef cows in the United States: Results of the National Animal Health Monitoring System’s (NAHMS) beef study, 2007–2008
During the United States Department of Agriculture (USDA) National Animal Health Monitoring System’s (NAHMS) 2007–2008 beef study, 567 producers from 24 US States were offered the opportunity to collect fecal samples from weaned beef calves and have them evaluated for the presence of parasite eggs (Phase 1). Participating producers were provided with instructions and materials for sample collection. Up to 20 fresh fecal samples were collected from each of the 99 participating operations. Fresh fecal samples were submitted to one of 3 randomly assigned laboratories for evaluation. Upon arrival at the laboratories, all samples were processed for the enumeration of strongyle, Nematodirus, and Trichuris eggs using the modified Wisconsin technique. The presence or absence of coccidian oocysts and tapeworm eggs was also noted. In submissions where the strongyle eggs per gram exceeded 30, aliquots from 2 to 6 animals were pooled for DNA extraction. Extracted DNA was subjected to genus level polymerase chain reaction (PCR) identification for the presence of Ostertagia, Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. In this study, 85.6% of the samples had strongyle type, Nematodirus, and Trichuris eggs. Among the samples evaluated, 91% had Cooperia, 79% Ostertagia, 53% Haemonchus, 38% Oesophagostomum, 18% Nematodirus, 7% Trichuris, and 3% Trichostrongylus. The prevalence of coccidia and tapeworm eggs was 59.9% and 13.7%, respectively
Effectiveness of current anthelmintic treatment programs on reducing fecal egg counts in United States cow-calf operations
During the United States Department of Agriculture (USDA) National Animal Health Monitoring System’s (NAHMS) 2007–2008 beef study, producers from 24 states were offered the opportunity to evaluate their animals for internal parasites and for overall responses to treatment with anthelmintics. A lapse of 45 d was required between initial sampling and any previous treatments. Choice of anthelmintic (oral benzimidazoles, and both injectable and pour-on endectocides) was at the discretion of the producer so as not to alter the local control programs. Fresh fecal samples were collected from 20 animals, or from the entire group if less than 20, then randomly assigned to 1 of 3 participating laboratories for examination. Analyses consisted of double centrifugation flotation followed by enumeration of strongyle, Nematodirus, and Trichuris eggs (the presence of coccidian oocysts and tapeworm eggs was also noted). Where strongyle eggs per gram (epg) exceeded 30, aliquots from 2 to 6 animals were pooled for egg isolation and polymerase chain reaction (PCR) analysis for the presence of Ostertagia, Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. Results from 72 producers (19 States) indicated that fecal egg count reductions were , 90% in 1/3 of the operations. All operations exhibiting less than a 90% reduction had used pour-on macrocyclic lactones as the anthelmintic treatment. While some of these less than expected reductions could have been the result of improper drug application, PCR analyses of the parasite populations surviving treatment, coupled with follow-up studies at a limited number of sites, indicated that less than expected reductions were most likely due to anthelmintic resistance in Cooperia spp. and possibly Haemonchus spp
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Serosurvey for Influenza D Virus Exposure in Cattle, United States, 2014–2015 - Volume 25, Number 11—November 2019 - Emerging Infectious Diseases journal - CDC
Influenza D virus has been detected predominantly in cattle from several countries. In the United States, regional and state seropositive rates for influenza D have previously been reported, but little information exists to evaluate national seroprevalence. We performed a serosurveillance study with 1,992 bovine serum samples collected across the country in 2014 and 2015. We found a high overall seropositive rate of 77.5% nationally; regional rates varied from 47.7% to 84.6%. Samples from the Upper Midwest and Mountain West regions showed the highest seropositive rates. In addition, seropositive samples were found in 41 of the 42 states from which cattle originated, demonstrating that influenza D virus circulated widely in cattle during this period. The distribution of influenza D virus in cattle from the United States highlights the need for greater understanding about pathogenesis, epidemiology, and the implications for animal health
Prediction of overall survival for patients with metastatic castration-resistant prostate cancer : development of a prognostic model through a crowdsourced challenge with open clinical trial data
Background Improvements to prognostic models in metastatic castration-resistant prostate cancer have the potential to augment clinical trial design and guide treatment strategies. In partnership with Project Data Sphere, a not-for-profit initiative allowing data from cancer clinical trials to be shared broadly with researchers, we designed an open-data, crowdsourced, DREAM (Dialogue for Reverse Engineering Assessments and Methods) challenge to not only identify a better prognostic model for prediction of survival in patients with metastatic castration-resistant prostate cancer but also engage a community of international data scientists to study this disease. Methods Data from the comparator arms of four phase 3 clinical trials in first-line metastatic castration-resistant prostate cancer were obtained from Project Data Sphere, comprising 476 patients treated with docetaxel and prednisone from the ASCENT2 trial, 526 patients treated with docetaxel, prednisone, and placebo in the MAINSAIL trial, 598 patients treated with docetaxel, prednisone or prednisolone, and placebo in the VENICE trial, and 470 patients treated with docetaxel and placebo in the ENTHUSE 33 trial. Datasets consisting of more than 150 clinical variables were curated centrally, including demographics, laboratory values, medical history, lesion sites, and previous treatments. Data from ASCENT2, MAINSAIL, and VENICE were released publicly to be used as training data to predict the outcome of interest-namely, overall survival. Clinical data were also released for ENTHUSE 33, but data for outcome variables (overall survival and event status) were hidden from the challenge participants so that ENTHUSE 33 could be used for independent validation. Methods were evaluated using the integrated time-dependent area under the curve (iAUC). The reference model, based on eight clinical variables and a penalised Cox proportional-hazards model, was used to compare method performance. Further validation was done using data from a fifth trial-ENTHUSE M1-in which 266 patients with metastatic castration-resistant prostate cancer were treated with placebo alone. Findings 50 independent methods were developed to predict overall survival and were evaluated through the DREAM challenge. The top performer was based on an ensemble of penalised Cox regression models (ePCR), which uniquely identified predictive interaction effects with immune biomarkers and markers of hepatic and renal function. Overall, ePCR outperformed all other methods (iAUC 0.791; Bayes factor >5) and surpassed the reference model (iAUC 0.743; Bayes factor >20). Both the ePCR model and reference models stratified patients in the ENTHUSE 33 trial into high-risk and low-risk groups with significantly different overall survival (ePCR: hazard ratio 3.32, 95% CI 2.39-4.62, p Interpretation Novel prognostic factors were delineated, and the assessment of 50 methods developed by independent international teams establishes a benchmark for development of methods in the future. The results of this effort show that data-sharing, when combined with a crowdsourced challenge, is a robust and powerful framework to develop new prognostic models in advanced prostate cancer.Peer reviewe
Prevalence of internal parasites in beef cows in the United States: Results of the National Animal Health Monitoring System’s (NAHMS) beef study, 2007–2008
During the United States Department of Agriculture (USDA) National Animal Health Monitoring System’s (NAHMS) 2007–2008 beef study, 567 producers from 24 US States were offered the opportunity to collect fecal samples from weaned beef calves and have them evaluated for the presence of parasite eggs (Phase 1). Participating producers were provided with instructions and materials for sample collection. Up to 20 fresh fecal samples were collected from each of the 99 participating operations. Fresh fecal samples were submitted to one of 3 randomly assigned laboratories for evaluation. Upon arrival at the laboratories, all samples were processed for the enumeration of strongyle, Nematodirus, and Trichuris eggs using the modified Wisconsin technique. The presence or absence of coccidian oocysts and tapeworm eggs was also noted. In submissions where the strongyle eggs per gram exceeded 30, aliquots from 2 to 6 animals were pooled for DNA extraction. Extracted DNA was subjected to genus level polymerase chain reaction (PCR) identification for the presence of Ostertagia, Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. In this study, 85.6% of the samples had strongyle type, Nematodirus, and Trichuris eggs. Among the samples evaluated, 91% had Cooperia, 79% Ostertagia, 53% Haemonchus, 38% Oesophagostomum, 18% Nematodirus, 7% Trichuris, and 3% Trichostrongylus. The prevalence of coccidia and tapeworm eggs was 59.9% and 13.7%, respectively
Effectiveness of current anthelmintic treatment programs on reducing fecal egg counts in United States cow-calf operations
During the United States Department of Agriculture (USDA) National Animal Health Monitoring System’s (NAHMS) 2007–2008 beef study, producers from 24 states were offered the opportunity to evaluate their animals for internal parasites and for overall responses to treatment with anthelmintics. A lapse of 45 d was required between initial sampling and any previous treatments. Choice of anthelmintic (oral benzimidazoles, and both injectable and pour-on endectocides) was at the discretion of the producer so as not to alter the local control programs. Fresh fecal samples were collected from 20 animals, or from the entire group if less than 20, then randomly assigned to 1 of 3 participating laboratories for examination. Analyses consisted of double centrifugation flotation followed by enumeration of strongyle, Nematodirus, and Trichuris eggs (the presence of coccidian oocysts and tapeworm eggs was also noted). Where strongyle eggs per gram (epg) exceeded 30, aliquots from 2 to 6 animals were pooled for egg isolation and polymerase chain reaction (PCR) analysis for the presence of Ostertagia, Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. Results from 72 producers (19 States) indicated that fecal egg count reductions were , 90% in 1/3 of the operations. All operations exhibiting less than a 90% reduction had used pour-on macrocyclic lactones as the anthelmintic treatment. While some of these less than expected reductions could have been the result of improper drug application, PCR analyses of the parasite populations surviving treatment, coupled with follow-up studies at a limited number of sites, indicated that less than expected reductions were most likely due to anthelmintic resistance in Cooperia spp. and possibly Haemonchus spp
Effect of Antimicrobial Dosage Regimen on Salmonella and Escherichia coli Isolates from Feeder Swineâ–ż
A body of evidence exists that suggests that antimicrobial use in food animals leads to resistance in both pathogenic and commensal bacteria. This study focused on the impact of three different antimicrobial regimes (low-level continuous, pulse, and no antimicrobial) for two antimicrobials (chlortetracycline and tylosin) on the presence of Salmonella spp. and on the prevalence of antimicrobial resistance of both Salmonella spp. and nonspecific Escherichia coli in fecal samples from feeder swine. The prevalence of fecal samples positive for Salmonella spp. significantly decreased between the samples taken at feeder placement compared to samples taken when the animals were close to market weight. Differences in resistance of Salmonella spp. did not appear to be influenced by dosing treatment including the control. Analysis of antimicrobial resistance examining both susceptibility and resistance, as well as MIC outcomes, demonstrated that only resistance to cephalothin increased in E. coli under the pulse chlortetracycline treatment. These results suggest that the dosing regimes examined in this study did not lead to an increase in either the prevalence of Salmonella spp. or the prevalence of antimicrobial resistance in isolates of Salmonella spp. or E. coli