Modelling bodyweight to avoid anthelmintic underdosing of goats in resources-limited settings.

Improved management of livestock in resource-limited settings can provide a means towards improved human nutrition and livelihoods. However, gastrointestinal nematodes (GIN) are a significant production-limiting factor. Anthelmintics play a role in GIN management; however, few anthelmintic classes are available in many low-middle-income countries. Utilising a limited range of classes may increase selection for anthelmintic resistance; therefore, strategies to reduce other selective pressures are of heightened importance. Avoiding anthelmintic underdosing is one such strategy, but it can be challenging without access to accurate bodyweight measurement. Many previous studies have used thoracic girth as a practical proxy for bodyweight in goats; however, they have rarely considered the potential impact of natural variation on therapeutic doses. Here, the relationship between bodyweight and thoracic girth was modelled using data from 820 goats from three Malawian biomes in two seasons, with the specific aim of avoiding underestimation of bodyweight. The internally cross-validated linear regression (∛Weight ~ 0.053 + 0.040*Girth, R2 = 0.92, rounded up to the nearest 5 kg) was validated against data from an additional 352 Malawian goats (1.4% of goats allocated an underdose and 10.2% allocated a dose > 200% of bodyweight). The equation was further externally validated using an historical dataset of 150 goats from Assam, India (2.7% of goats were allocated to an underdose and 24.8% allocated to a > 200% of bodyweight). These results suggest that a more globally generalisable approach may be feasible, provided the accuracy of the estimate is considered alongside the therapeutic index of the pharmaceutical.

Students' Engagement in and Perceptions of Blended Learning in a Clinical Module in a Veterinary Degree Program.

Blended learning has received much interest in higher education as a way to increase learning efficiency and effectiveness. By combining face-to-face teaching with technology-enhanced learning through online resources, students can manage their own learning. Blended methods are of particular interest in professional degree programs such as veterinary medicine in which students need the flexibility to undertake intra- and extramural activities to develop the range of competencies required to achieve professional qualification. Yet how veterinary students engage with blended learning activities and whether they perceive the approach as beneficial is unclear. We evaluated blended learning through review of student feedback on a 4-week clinical module in a veterinary degree program. The module combined face-to-face sessions with online resources. Feedback was collected by means of a structured online questionnaire at the end of the module and log data collected as part of a routine teaching audit. The features of blended learning that support and detract from students' learning experience were explored using quantitative and qualitative methods. Students perceived a benefit from aspects of face-to-face teaching and technology-enhanced learning resources. Face-to-face teaching was appreciated for practical activities, whereas online resources were considered effective for facilitating module organization and allowing flexible access to learning materials. The blended approach was particularly appreciated for clinical skills in which students valued a combination of visual resources and practical activities. Although we identified several limitations with online resources that need to be addressed when constructing blended courses, blended learning shows potential to enhance student-led learning in clinical courses.

Assessing the performance of a Fasciola gigantica serum antibody ELISA to estimate prevalence in cattle in Cameroon.

BACKGROUND: Cattle rearing in Cameroon is both economically and culturally important, however parasitic diseases detrimentally impact cattle productivity. In sub-Saharan Africa bovine fasciolosis is generally attributed to F. gigantica, although understanding of Fasciola species present and local epidemiology in individual countries is patchy. Partly limited by the lack of representative surveys and understanding of diagnostic test perfromance in local cattle populations. The aims of this paper were to determine the Fasciola species infecting cattle, develop a species specific serum antibody ELISA, assess the performance of the ELISA and use it to assess the prevalence of F. gigantica exposure in two important cattle-rearing areas of Cameroon. RESULTS: A random sample of Fasciola parasites were collected and were all identified as F. gigantica (100%, CI:94.0-100%, n = 60) using RAPD-PCR analysis. A F. gigantica antibody ELISA was developed and initially a diagnostic cut-off was determined using a sample of known positive and negative cattle. The initial cut-off was used as starting point to estimate an optimal cut-off to estimate the best combination of sensitivity and specificity. This was achieved through sampling a naturally infected population with known infection status (cattle slaughtered at Bamenda abattoir, North West Region (n = 1112) and Ngaoundere abattoir, Vina Division, Adamawa Region (n = 776) in Cameroon). These cattle were tested and results analysed using a Bayesian non-gold standard method. The optimal cut-off was 23.5, which gave a sensitivity of 65.3% and a specificity of 65.2%. The prevalence of exposure to F. gigantica was higher in cattle in Ngaoundere (56.4% CI: 50.2-60.0%) than Bamenda (0.6% CI: 0.0-1.4%). CONCLUSION: Fasciola gigantica was identified as the predominant Fasciola species in Cameroon. Although the sensitivity and specificity F. gigantica antibody ELISA requires improvement, the test has shown to be a potentially useful tool in epidemiological studies. Highlighting the need for better understanding of the impact of F. gigantica infections on cattle production in Cameroon to improve cattle production in the pastoral systems of Central-West Africa. This paper also highlights that non-gold standard latent class methods are useful for assessing diagnostic test performance in naturally-infected animal populations in resource limited settings.

The feeding of heather (Calluna vulgaris) to Teladorsagia circumcincta infected lambs reduces parasitism but can detrimentally impact performance.

Gastrointestinal nematode (GIN) infections impact small ruminant health, welfare, and production across farming systems. Rising anthelmintic resistance and regulation of synthetic drug use in organic farming is driving research and development of sustainable alternatives for GIN control. One alternative is the feeding of plants that contain secondary metabolites (PSMs) e.g., proanthocyanidins (PA, syn. condensed tannins) that have shown anthelmintic potential. However, PSMs can potentially impair performance, arising from reduced palatability and thus intake, digestibility or even toxicity effects. In this study, we tested the trade-off between the antiparasitic and anti-nutritional effects of heather consumption by lambs. The impact of additional feeding of a nematophagous fungus (Duddingtonia flagrans) on larval development was also explored. Lambs infected with Teladorsagia circumcincta or uninfected controls, were offered ad libitum heather, or a control chopped hay for 22 days during the infection patent period. Eight days into the patent period, parasitised lambs were supplemented (or remained unsupplemented) with D. flagrans for a 5-day period. Performance and infection metrics were recorded, and polyphenol levels in the heather and control hay were measured to investigate their association with activity. The lambs consumed heather at approximately 20% of their dry matter intake, which was sufficient to exhibit significant anthelmintic effects via a reduction in total egg output (P = 0.007), compared to hay-fed lambs; the magnitude of the reduction over time in heather fed lambs was almost 10-fold compared to control lambs. Negative effects on production were shown, as heather-fed lambs weighed 6% less than hay-fed lambs (P < 0.001), even though dry matter intake (DMI) of heather increased over time. D. flagrans supplementation lowered larval recovery in the faeces of infected lambs by 31.8% (P = 0.003), although no interactions between feeding heather and D. flagrans were observed (P = 0.337). There was no significant correlation between PA, or other polyphenol subgroups in the diet and egg output, which suggests that any association between heather feeding and anthelmintic effect is not simply and directly attributable to the measured polyphenols. The level of heather intake in this study showed no antagonistic effects on D. flagrans, demonstrating the methods can be used in combination, but provide no additive effect on overall anthelmintic efficacies. In conclusion, heather feeding can assist to reduce egg outputs in infected sheep, but at 20% of DMI negative effects on lamb performance can be expected which may outweigh any antiparasitic benefits.

Development of a diagnostic tool: the wastewater collection network odour wheel.

The assessment of nuisance odour problems and the application of an effective odour management programme for the associated industrial activity may be achieved using a representative odour wheel and Odour Profile Analysis methodology. The odour wheel is a very useful tool for conducting odour quality control monitoring and developing a constructive dialogue regarding nuisance odours with the public. Previously, odours from wastewater treatment plant activities have been identified and described with a dedicated odour wheel. The oxidation state of the organic chemicals responsible for a given odour depends on multiple parameters specific to the individual wastewater collection networks (residence time of wastewater, topographic disposition and network slope, aeration and on line chemical treatment processes). This is especially important for odorous nitrogen, sulfur and volatile fatty acids. Trained sensory odour panels combined with chemical analyses have been used to study wastewater collection network odours and to adapt the wastewater odour wheel accordingly. The wastewater collection network odour wheel has been produced using the results of five sampling campaigns; eight out of the 11 odour families constituting the wastewater odour wheel have been identified and consequently validated for sewer networks. Different groups of odours have been perceived according to the presence or absence of wastewater effluents at the various sampling points.

Optical mapping compendium of structural variants across global cattle breeds.

Structural variants (SV) have been linked to important bovine disease phenotypes, but due to the difficulty of their accurate detection with standard sequencing approaches, their role in shaping important traits across cattle breeds is largely unexplored. Optical mapping is an alternative approach for mapping SVs that has been shown to have higher sensitivity than DNA sequencing approaches. The aim of this project was to use optical mapping to develop a high-quality database of structural variation across cattle breeds from different geographical regions, to enable further study of SVs in cattle. To do this we generated 100X Bionano optical mapping data for 18 cattle of nine different ancestries, three continents and both cattle sub-species. In total we identified 13,457 SVs, of which 1,200 putatively overlap coding regions. This resource provides a high-quality set of optical mapping-based SV calls that can be used across studies, from validating DNA sequencing-based SV calls to prioritising candidate functional variants in genetic association studies and expanding our understanding of the role of SVs in cattle evolution.

Molecular epidemiology of Mycobacterium bovis in Cameroon.

We describe the largest molecular epidemiological study of Bovine Tuberculosis (bTB) in a sub-Saharan African country with higher spatial resolution providing new insights into bTB. Four hundred and ninety-nine samples were collected for culture from 201 and 179 cattle with and without bTB-like lesions respectively out of 2,346 cattle slaughtered at Bamenda, Ngaoundere, Garoua and Maroua abattoirs between 2012-2013. Two hundred and fifty-five M. bovis were isolated, identified and genotyped using deletion analysis, Hain® Genotype MTBC, spoligotyping and MIRU-VNTR. African 1 was the dominant M. bovis clonal complex, with 97 unique genotypes including 19 novel spoligotypes representing the highest M. bovis genetic diversity observed in Africa to date. SB0944 and SB0953 dominated (63%) the observed spoligotypes. A third of animals with multiple lesions had multiple strain infections. Higher diversity but little evidence of recent transmission of M. bovis was more common in Adamawa compared to the North-West Region. The Adamawa was characterised by a high frequency of singletons possibly due to constant additions from an active livestock movement network compared to the North-West Region where a local expansion was more evident. The latter combined with population-based inferences suggest an unstable and stable bTB-endemic status in the North-West and Adamawa Regions respectively.

ArI/ArII laser induced fluorescence system for measurement of neutral and ion dynamics in a large scale helicon plasma.

In order to investigate the role of both neutral and ion dynamics in large-scale helicon discharges, a laser induced fluorescence (LIF) system capable of measuring both ArI and ArII fluorescence using a single tunable laser is being developed. The system is based on a >250 mW solid state laser. For ArI measurements, the laser pumps the metastable (2P03/2)4s level to the (2P01/2)4p level using 696.7352 nm light, and fluorescence radiation from decay to the (2P01/2)4s level at 772.6333 nm is observed. For ArII, currently in development, the metastable (3P)3d 4F7/2 level will be pumped to the (3P)4p 4D07/2 level using 688.8511 nm, and decay fluorescence to the (3P)4s 4P5/2 level at 434.9285 nm measured. Here all wavelengths are in a vacuum.

Abattoir-based estimates of mycobacterial infections in Cameroon.

Mycobacteria cause major diseases including human tuberculosis, bovine tuberculosis and Johne's disease. In livestock, the dominant species is M. bovis causing bovine tuberculosis (bTB), a disease of global zoonotic importance. In this study, we estimated the prevalence of Mycobacteria in slaughter cattle in Cameroon. A total of 2,346 cattle were examined in a cross-sectional study at four abattoirs in Cameroon. Up to three lesions per animal were collected for further study and a retropharyngeal lymph node was collected from a random sample of non-lesioned animals. Samples were cultured on Lowenstein Jensen media and the BACTEC MGIT 960 system, and identified using the Hain® Genotype kits. A total of 207/2,346 cattle were identified with bTB-like lesions, representing 4.0% (45/1,129), 11.3% (106/935), 23.8% (38/160) and 14.8% (18/122) of the cattle in the Bamenda, Ngaoundere, Garoua and Maroua abattoirs respectively. The minimum estimated prevalence of M. bovis was 2.8% (1.9-3.9), 7.7% (6.1-9.6), 21.3% (15.2-28.4) and 13.1% (7.7-20.4) in the four abattoirs respectively. One M. tuberculosis and three M. bovis strains were recovered from non-lesioned animals. The high prevalence of M. bovis is of public health concern and limits the potential control options in this setting without a viable vaccine as an alternative.

Utilization of coronary angiography and revascularization after acute myocardial infarction in men and women risk stratified by the American College of Cardiology/American Heart Association guidelines.

OBJECTIVES: We sought to determine whether men and women are equally likely to receive coronary angiography and revascularization after acute myocardial infarction (AMI) when they are risk stratified according to American College of Cardiology/American Heart Association (ACC/AHA) practice guidelines for post-MI care. BACKGROUND: Several previous studies have suggested that women may undergo angiography and revascularization procedures less frequently than men. METHODS: In 439 consecutive patients admitted to a public hospital with AMI, rates of coronary angiography and revascularization were compared in men and women categorized, according to ACC/AHA practice guidelines, as having strong (class I or IIa) or weaker (class IIb) indications for angiography. RESULTS: Women were older and more likely to be diabetic or hypertensive, but men and women were equally likely to meet class I/IIa criteria for post-MI angiography (both 51%). Angiography rates were nearly identical in men and women overall (63% vs. 64%), as well as in patients in class I/IIa (80% vs. 82%) and class IIb (46% vs. 46%) (all p > 0.80, with >80% power to detect important differences); the only multivariate predictors of post-MI angiography were age and ACC/AHA class. Significant coronary artery disease was equally prevalent in men and women undergoing angiography, and men and women were equally likely to undergo revascularization, whether they were in class I/IIa (both 55%, p = 0.90) or class IIb (59% vs. 58%, p = 0.88). No significant differences in mortality were noted between men and women. CONCLUSIONS: Despite being older and having more risk factors than men, women were equally likely to undergo coronary angiography and revascularization procedures after AMI, and they had in-hospital clinical outcomes that were at least as favorable.

SPECT imaging of fluorine-18.

UNLABELLED: The objective of this work was to determine the potential clinical usefulness of SPECT to image 511-keV annihilation photons. METHODS: A triple-headed gamma camera equipped with ultra-high-energy collimators was used to image 18F. Sensitivity measurements were carried out and the FWHM and FWTM were determined in air and for a unit-density scattering medium. Additionally, tomographic phantom studies were acquired to evaluate image quality. RESULTS: The sensitivities of the three cameras were, for all practical purposes, identical. At a source-to-collimator distance of 100 mm, the FWHM and FWTM were 13 and 29 mm, respectively. A tomographic phantom study demonstrated that spheres with a diameter of 20 mm were well resolved when filled with 18F activity and placed inside a water-filled phantom. CONCLUSION: The triple-headed SPECT camera in this investigation is a practical means of acquiring tomographic 18F images. The reconstructed slices were of sufficient quality to be of value in some clinical studies.

Conservative management of postoperative chylothorax using somatostatin.

Chylothorax is a rare but serious postoperative complication of thoracic surgical procedures. We report the case of a 77-year-old man who underwent a coronary artery bypass procedure using a left internal mammary artery pedicle graft. A permanent pacemaker was required postoperatively. A persistent postoperative chylothorax developed necessitating continuous drainage and conservative management. Somatostatin was instituted when after 1 week this management failed to resolve the chylothorax. This led to rapid cessation of chyle production. Enteral feeding was reinstituted without complication and surgical intervention was avoided.

Postpneumonectomy syndrome after left pneumonectomy.

Postpneumonectomy syndrome, a late complication of pneumonectomy, is secondary to shift of the mediastinum and remaining lung toward the pneumonectomy side, leading to tracheobronchial compression between the vertebral body and the aorta or pulmonary artery. Obstructive airway symptoms are usually due to tracheobronchial tree compression, however, secondary airway malacia may develop. We report herein a case of postpneumonectomy syndrome with secondary bronchomalacia after left pneumonectomy in a patient with normal mediastinal vascular anatomy.

Cardiac endothelin release and infarct size, myocardial blood flow, and ventricular function in canine infarction and reperfusion.

BACKGROUND: The potent vasoconstrictor endothelin-1 (ET) may play an important pathophysiologic role in acute myocardial infarction, but its precise effects are incompletely understood. The purpose of this study was to evaluate the interrelationships between cardiac ET-1 release and infarct size, myocardial blood flow, and ventricular function. METHODS: Fifteen closed chest dogs underwent 3 hours of coronary artery occlusion followed by 3 hours of reperfusion. Coronary sinus and aortic ET-1 levels during occlusion and after reperfusion were determined by radioimmunoassay. Left ventricular function and regional myocardial blood flow were measured by echocardiography and colored microspheres, respectively. Myocardial infarct size was determined by postmortem staining with blue dye and triphenyl tetrazolium chloride. RESULTS: Coronary occlusion and reperfusion produced significant elevations of coronary sinus ET-1 (p < 0.05) and cardiac ET-1 release (p < 0.05), and a trend toward an increase in aortic ET-1 (p = 0.08). A trend toward more ET-1 release was observed in dogs with larger infarcts (p = 0.06), and in dogs with substantial no-reflow in the reperfused territory (p = 0.05). Endothelin-1 release also was associated with increased contractility in nonischemic myocardial segments (p = 0.002), and ET-1 correlated with increased global left ventricular function (p < 0.02). CONCLUSIONS: In this canine model of coronary occlusion and reperfusion, greater increases in cardiac ET-1 release were observed in dogs with larger infarcts, and increased ET-1 release was associated with the no-reflow phenomenon in the reperfused territory. These data suggest that ET-1 release may have adverse consequences in acute myocardial infarction, including a reduction of myocardial blood flow in the reperfused zone after reperfusion and increased contractility in nonischemic myocardium.

New developments in percutaneous coronary intervention.

The field of percutaneous coronary intervention continues to progress at a tremendous rate. Advances in techniques, in device technology, and in adjunctive therapy have increased significantly the number of patients who may benefit from angioplasty and have increased the early and long-term success rates of these procedures. Future progress in radiation therapy, IIb/IIIa inhibitors, stent design, and other novel approaches undoubtedly will offer further improvements in the capability of coronary interventions to help patients live longer and feel better.

The effect of preparation procedures on original canal shape and on apical foramen shape.

With the use of clear casting resin, simulated curved canals were created so that canal preparation procedures could be directly visualized and compared. Regardless of the type of enlarging instrument or the technique used, undesirable characteristics were produced in all preparations that would make canal filling difficult. To modify the typical preparations, alteration of the enlarging flutes, use of rasping rather than rotation of the instruments, and a flaring technique are recommended.

Effects of ewe breed and management system on efficiency of lamb production: III. Meat characteristics.

Effects of management system, ewe breed, sex, and legume grazing on cooking and sensory characteristics and shear force of lamb meat were estimated from data collected on animals produced in three management systems. System 1 lambs were born in late fall and fed to slaughter on a concentrate diet. System 2 lambs were born in January and February and grazed pure stands of alfalfa or ladino clover after weaning. System 3 lambs were born in March and April and remained with their dams on native bluegrass-white clover pasture throughout the grazing season. Lambs were progeny of either 1/2-Suffolk, 1/2-Rambouillet ewes or 1/2-Suffolk, 1/4-Finnsheep, 1/4-Rambouillet or Dorset ewes and were sired by Suffolk rams. Lambs were slaughtered at 50 (females) to 55 kg (males). One-half of the males in System 1 were left intact; all males in Systems 2 and 3 were castrated. Mean age at slaughter was 156, 204, and 234 d for lambs in Systems 1, 2, and 3, respectively. Cooked weight of loin chops averaged 68.5% of uncooked weight and did not differ among systems. Shear force was greatest for System 1 lambs and least for System 3 lambs in yr 1, but systems did not differ in shear performance in yr 2. System differences in tenderness favored System 3 lambs. Although mean flavor intensity was least for System 2 lambs, the frequency of high-intensity, potentially objectionable flavors was highest for these lambs and especially for those grazing alfalfa. In general, however, sensory characteristics did not differ greatly among production systems, and correlation analysis revealed little potential to use carcass traits to predict meat characteristics.

Effects of ewe breed and management system on efficiency of lamb production: II. Lamb growth, survival and carcass characteristics.

Lamb growth, survival and carcass characteristics were compared for progeny of either 1/2-Suffolk, 1/2-Rambouillet (Western) ewes or 1/2-Suffolk, 1/4-Rambouillet, 1/4-Finnsheep (1/4-Finn) ewes produced over 3 yr in three different management systems. System 1 lambs were born in late fall and fed to slaughter on a concentrate diet. System 2 lambs were born in January and February and grazed pure stands of alfalfa or ladino clover after weaning. System 3 lambs were born in March and April and remained with their dams on native bluegrass-white clover pasture throughout the grazing season. Lambs were slaughtered as males reached 55 kg and as females reached 50 kg. One-half of the males in System 1 were left intact; all males in Systems 2 and 3 were castrated. Lamb survival did not differ among systems. Lambs from yearling 1/4-Finn ewes had higher survival rates than lambs from yearling Western ewes, but at older ewe ages, progeny of the ewe groups did not differ in survival. Lambs in System 1 grew fastest (mean lifetime gains of 310 +/- 4 g/d) and were youngest at slaughter (156 +/- 3 d), and lambs in System 3 were oldest at slaughter (234 +/- 2 d). System 2 lambs differed considerably among years in growth rate and slaughter age (mean slaughter ages of 191, 230 and 193 d across years), primarily in response to differences in rainfall. Lifetime gains and slaughter ages of lambs did not differ between ewe breeds. Ram lambs grew 15% faster than wethers and were leaner. Differences among systems in carcass traits were small. System 1 lambs tended to be fattest and System 2 lambs leanest. Progeny of 1/4-Finn ewes had higher subjective scores for carcass fatness (e.g., feathering, flank fatness) and conformation but did not differ from progeny of Western ewes in objective measures of fatness (e.g., backfat, yield grade).

Forage systems for beef production from conception to slaughter: III. Finishing systems.

Fall-weaned Angus calves grazed or were fed different forages during winter followed by 1) N-fertilized tall fescue (Festuca arundinacea Schreb.) grazed alone, 2) bluegrass (Poa pratensis L.)-white clover (Trifolium repens L.) sequence grazed with tall fescue-red clover (Trifolium pratense L.), or 3) bluegrass-white clover sequence grazed with alfalfa (Medicago sativa L.)-orchardgrass (Dactylis glomerata L.). Heifers were supplemented with grain at 1% of BW from April until slaughter in July. One-half of steers were supplemented with grain at 1% of BW from July until slaughter in October. Remaining steers were fed no grain but were finished on corn silage supplemented with .9 kg of soybean meal per steer daily, from October until slaughter in late January. Including alfalfa-orchardgrass in systems during the finishing phase resulted in higher daily and total gains during the grazing period, and carcasses had more marbling and higher USDA quality grades at slaughter compared with carcasses of cattle on systems using fescue-red clover. Correlation of final weight with carcass characteristics was low (r < .5). Performance and carcass characteristics were influenced as much or more by forage consumed during the previous wintering phase as by forage fed during the finishing phase. Wintering cattle on stockpiled fescue-alfalfa or alfalfa-orchardgrass hay generally resulted in higher BW at slaughter and more desirable carcass characteristics than systems using tall fescue alone or in combination with red clover. This was particularly notable in steers that grazed without grain until October and were finished on corn silage plus supplement. Final BW and carcass characteristics in all cattle were improved by full season grazing followed by feeding corn silage, compared with cattle finished with grain on pasture.