Unveiling the Role of Endoplasmic Reticulum Stress Pathways in Canine Demodicosis.

Canine demodicosis is a prevalent skin disease caused by overpopulation of a commensal species of Demodex mite, yet its precise cause remains unknown. Research suggests that T-cell exhaustion, increased immunosuppressive cytokines, induction of regulatory T cells and increased expression of immune checkpoint inhibitors may contribute to its pathogenesis. This study aimed to gain a deeper understanding of the molecular changes occurring in canine demodicosis using mass spectrometry and pathway enrichment analysis. The results indicate that endoplasmic reticulum stress promotes canine demodicosis through regulation of three linked signalling pathways: eIF2, mTOR, and eIF4 and p70S6K. These pathways are involved in the modulation of Toll-like receptors, most notably TLR2, and have been shown to play a role in the pathogenesis of skin diseases in both dogs and humans. Moreover, these pathways are also implicated in the promotion of immunosuppressive M2 phenotype macrophages. Immunohistochemical analysis, utilising common markers of dendritic cells and macrophages, verified the presence of M2 macrophages in canine demodicosis. The proteomic analysis also identified immunological disease, organismal injury and abnormalities and inflammatory response as the most significant underlying diseases and disorders associated with canine demodicosis. This study demonstrates that Demodex mites, through ER stress, unfolded protein response and M2 macrophages contribute to an immunosuppressive microenvironment, thereby assisting in their proliferation.

Validating the female fertility estimated breeding value in Australian commercial dairy herds.

We conducted a retrospective cohort study to validate the efficacy of the Australian multitrait fertility estimated breeding value (EBV). We did this by determining its associations with phenotypic measures of reproductive performance (i.e., submission rate, first service conception rate, and early calving). Our secondary aim was to report the associations between these reproductive outcomes and management and climate-related factors hypothesized to affect fertility. Our study population included 38 pasture-based dairy herds from the northern Victorian irrigation region in Australia. We collected records for 86,974 cows with 219,156 lactations and 438,578 mating events from the date on which managers started herd recording until December 2016, comprising both fertility-related data such as insemination records, calving dates, and pregnancy test results, and systems-related data such as production, herd size, and calving pattern. We also collected hourly data from 2004 to 2017 from the closest available weather station to account for climate-related factors (i.e., temperature humidity index; THI). Multilevel Cox proportional hazard models were used to analyze time-to-event outcomes (days to first service, days to cow calving following the planned herd calving start date), and multilevel logistic regression models for binomial outcomes (conception to first service) in the Holstein-Friesian and Jersey breeds. A 1-unit increase in daughter fertility EBV was associated with a 5.4 and 8.2% increase in the daily hazard of calving in the Holstein-Friesian and Jersey breeds respectively. These are relative increases (i.e., a Holstein-Friesian herd with a 60% 6-wk in-calf rate would see an improvement to 63.2% with a 1-unit increase in herd fertility EBV). Similar results were obtained for submission and conception rate. Associations between 120-d milk yield and reproductive outcome were complicated by interactions with 120-d protein percentage and calving age, depending on the breed and outcome. In general, we found that the reproductive performance of high milk-yielding animals deteriorated faster with age than low milk-yielding animals, and high protein percentage exacerbated the differences between low and high milk-yielding animals. Climate-related factors were also associated with fertility, with a 1-unit increase in maximum THI decreasing first service conception rate by 1.2% for Holstein-Friesians but having no statistically significant association in the Jersey breed. However, THI had a negative association in both breeds on the daily hazard of calving. Our study validates the efficacy of the daughter fertility EBV for improving herd reproductive performance and identifies significant associations between 120-d milk and protein yields and THI on the fertility of Australian dairy cows.

Oregano Oil and Its Principal Component, Carvacrol, Inhibit HIV-1 Fusion into Target Cells.

Oregano essential oil has long been known for its health-promoting benefits. Here, we report its activity against viral replication. Oregano oil was found to specifically inhibit lentiviruses, such as human and simian immunodeficiency viruses (HIV and SIV), irrespective of virus tropism, but not hepatitis C virus, adenovirus 5 (ADV5), Zika virus, and influenza (H1N1) virus. Oregano oil's most abundant components, carvacrol and its isomer, thymol, were shown to block virus-target cell fusion while not perturbing other stages of the virus life cycle. We detected changes in virus particle density, suggesting that cholesterol depletion from the HIV-1 envelope membrane reduces virus entry. Furthermore, infection was rescued by adding exogenous cholesterol. The evolution of viral resistance to carvacrol supported this mechanism of action with the identification of mutations in the viral gp41 fusion protein that counteracted cholesterol depletion. In addition, resistance to carvacrol emerged later than typically observed for other clinically used drugs, strengthening its antiviral potential. Structure-activity relationship studies revealed key motifs of carvacrol and thymol required for HIV neutralization and identified previously unknown active analogs. Carvacrol was also shown to additively cooperate with antiretroviral therapy. In sum, oregano oil and improved carvacrol and thymol analogs could be considered to supplement current HIV therapeutics.IMPORTANCE Oregano essential oil has multiple benefits in traditional medicine, cosmetics, and food industries. Carvacrol and its analog, thymol, are well-described components of oregano oil. Here, we show that these compounds inhibit HIV-target cell fusion independently of viral tropism. Our results suggest that carvacrol and thymol alter the cholesterol content of the viral membrane, blocking HIV-1 entry into the target cell. Resistance to carvacrol has selected for viruses with mutations in the viral envelope glycoprotein, gp41. This protein is known for its interaction with cholesterol present in membrane lipid rafts. Together, these results demonstrate the potential of therapies targeting the viral envelope membrane, and oregano oil is a safe supplement to antiretrovirals, potentially delaying disease progression and resistance development.

Microbial contamination in drinking water at public outdoor recreation facilities in New Zealand.

AIM: The aim of our study was to assess the presence and risk of waterborne pathogens in the drinking water of outdoor facilities in New Zealand and track potential sources of microbial contamination in water sources. METHODS AND RESULTS: A serial cross-sectional study with a risk-based sample collection strategy was conducted at 15 public campgrounds over two summer seasons (2011-2012 and 2012-2013). Drinking water supplied to these campgrounds was not compliant with national standards, based on Escherichia coli as an indicator organism, in more than half of the sampling occasions. Campylobacter contamination of drinking water at the campgrounds was likely to be of wild bird origin. Faecal samples from rails (pukeko and weka) were 35 times more likely to return a Campylobacter-positive result compared to passerines. Water treatment using ultraviolet (UV) irradiation or a combination of filtration and UV irradiation or chemicals was more likely to result in water that was compliant with the national standards than water from a tap without any treatment. The use of filters alone was not associated with the likelihood of compliance. CONCLUSIONS: Providing microbiologically safe drinking water at outdoor recreational facilities is imperative to avoid gastroenteritis outbreaks. This requires an in-depth understanding of potential sources of contamination in drinking water sources and the installation of adequate water treatment facilities. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study provides evidence that drinking water without treatment or filter-only treatment in public campgrounds is unlikely to comply with national standards for human consumption and extra water treatment measures such as UV irradiation or chemical treatment are needed.

Herd manager attitudes and intentions regarding the selection of high-fertility EBV sires in Australia.

Reproductive performance in dairy cattle has declined over the last 50 years as an unintended consequence of selection for high milk yield. Since the early 2000s, dairy geneticists have released successive versions of fertility estimated breeding values (EBV) to assist in reversing this trend. At the herd level, fertility EBV can help managers accelerate improvements in reproductive performance by acting as a second selection criteria when used in tandem with a breeding index. However, use of the fertility EBV in sire selection currently varies between herd managers. The aim of this study was to better understand the reasons why herd managers choose or do not choose to select high-fertility EBV sires, using the Theory of Planned Behavior (TPB) as a social research framework. Thirty-five Victorian dairy herd managers were recruited as part of a larger study investigating the daughter fertility Australian Breeding Value and interviewed using a series of questions examining TPB constructs. The interviews were recorded and transcribed using template analysis. A wide range of herd manager types were enrolled into the study, with representation from diverse systems. Out of the 35 herd managers, 27 included fertility in their list of high-priority breeding objectives. A wide variation in results was consistent with previous studies that have demonstrated marked heterogeneity in herd manager attitudes toward bull selection. Herd manager-perceived barriers to selection of sires with high daughter fertility EBV included a lack of high daughter fertility bulls with other desirable traits, a lack of trust in the fertility EBV or in the Australian EBV system, difficulty in interpreting international proofs, information overload, semen prices, low bull reliability, and difficulty in understanding bull catalogs. Not all herd managers found the process problematic, however, particularly if a breeding consultant was employed to select all or most of the sires. Herd manager-perceived barriers for choosing to select daughter fertility as a breeding objective include a lack of awareness of the EBV, a lack of interest in genetics in general, low confidence in the impact of genetic selection for fertility, and a feeling that fertility was not important for their production system. The results of this study suggest that animal geneticists and on-farm service providers need to work together to allow the opportunities arising from appropriate use of fertility EBV to be realized more broadly across the dairy industry.

Emerging and endemic zoonotic diseases: surveillance and diagnostics.

In this paper, the authors: (a) list methods used to diagnose zoonotic diseases in humans and animals; (b) identify between-species differences in diagnostic approaches, providing commentary on the benefits that might arise from simultaneous interpretation of data from human and animal health surveillance systems; and (c) reiterate the importance of using species-specific, validated diagnostic tests for surveillance and disease outbreak investigations. Emerging and endemic zoonotic diseases are likely to provide a continued threat to global health in the short- to medium-term future. A good deal of knowledge about the drivers of infectious disease emergence has been developed based on numerous examples from the recent past. Sharing of diagnostic resources across human and animal health sectors, sharing of human and animal health surveillance data, development of skills in the interpretation of that data and awareness of issues related to the validation and interpretation of diagnostic test data are necessary prerequisites for an effective endemic disease surveillance system. A good understanding of the epidemiological patterns of endemic disease will allow human and animal health professionals be able to more quickly detect the presence of emerging disease threats.

Après avoir répertorié les méthodes utilisées pour diagnostiquer les maladies zoonotiques chez l'homme comme chez les animaux, les auteurs définissent les différentes approches diagnostiques suivant les espèces considérées et commentent les avantages qui pourraient découler d'une interprétation simultanée des données par les systèmes de surveillance en santé animale et en santé publique ; il réitèrent ensuite l'importance de recourir à des tests diagnostiques validés et spécifiques de l'espèce considérée dans le cadre de la surveillance et des enquêtes suite à l'apparition d'un foyer. Les maladies zoonotiques émergentes et endémiques représentent potentiellement une menace continue pour la santé mondiale à court et à moyen terme. Les facteurs favorisant l'émergence des maladies infectieuses sont désormais beaucoup mieux connus grâce aux enseignements tirés de nombreux exemples récents. Le partage des ressources diagnostiques entre les secteurs de la santé humaine et animale, les échanges des données de la surveillance sanitaire réunies par les deux secteurs, le renforcement des compétences en matière d'interprétation des données et la sensibilisation aux problématiques de la validation et de l'interprétation des données générées par les tests de diagnostic sont des conditions préalables à la mise en place d'un système efficace de surveillance des maladies endémiques. Une bonne compréhension des profils épidémiologiques des maladies endémiques permettra aux professionnels de la santé humaine et animale de détecter plus rapidement la présence de menaces émergentes.

Los autores proceden aquí a: a) relacionar los métodos empleados para diagnosticar enfermedades zoonóticas en personas y animales; b) señalar las diferencias que existen entre los distintos planteamientos de diagnóstico según la especie de que se trate, comentando asimismo las ventajas que podrían derivarse de la interpretación simultánea de los datos de los sistemas de vigilancia sanitaria y de los de vigilancia zoosanitaria; y c) reiterar la importancia que reviste el uso de pruebas de diagnóstico no solo validadas, sino también adaptadas específicamente a cada especie, para las labores de vigilancia y estudio de brotes. Lo más probable es que a corto y medio plazo las enfermedades zoonóticas, ya sean emergentes o endémicas, sigan constituyendo una amenaza para la salud mundial. Gracias a numerosos ejemplos del pasado reciente se ha ido constituyendo un buen conocimiento de los factores que propician la aparición de enfermedades infecciosas. Para disponer de un eficaz sistema de vigilancia de enfermedades endémicas hay una serie de requisitos previos indispensables: utilización compartida de los recursos de diagnóstico entre los sectores de la salud humana y la sanidad animal; intercambio de los datos de vigilancia sanitaria y de vigilancia zoosanitaria; adquisición de competencias para interpretar esos datos; y buen conocimiento de las cuestiones ligadas a la validación de pruebas de diagnóstico y a la interpretación de los datos que arrojan. Si los profesionales de la salud humana y la sanidad animal conocen debidamente los patrones epidemiológicos de las enfermedades endémicas, estarán en condiciones de detectar con más celeridad la presencia de enfermedades emergentes que constituyan una amenaza.

Diagnostic test validation studies when there is a perfect reference standard.

Before tools became available to consider diagnostic test validation studies where a 'gold-standard' is not available, new diagnostic tests were compared to a reference standard assumed to be highly accurate if not perfect. This paper reviews such 'traditional' situations with examples and methods of study design and analysis. Three situations are described, two where a perfect reference is available for either positive or negative animals, and one where the reference is perfect for both. Thus, here the authors review circumstances to be considered when validating a diagnostic test with a credible reference standard. An appropriate study design requires an unbiased selection of animals from the population to which a new test will be applied. Examples for calculating sample size and data analysis are provided. Finally, the authors discuss situations where it may be appropriate to include influential variables ('covariates') in a diagnostic test validation study..

Avant la mise au point d'outils permettant de concevoir des études de validation pour des tests candidats en l'absence d'un étalon de référence à l'exactitude parfaite (référence absolue ou gold standard), les tests à valider étaient comparés à un étalon de référence censé présenter un niveau élevé d'exactitude, à défaut d'être parfait. Les auteurs décrivent ces situations « classiques ¼ en donnant quelques exemples et en précisant les méthodes employées pour la conception et l'analyse de ces études. Ils décrivent trois situations : dans deux d'entre elles, un étalon de référence parfait existe, soit pour les animaux positifs, soit pour les animaux négatifs ; dans la troisième situation, l'étalon de référence est parfait pour les deux catégories. Ainsi, les circonstances prises en compte ici sont celles de la validation d'un test diagnostique au moyen d'un réactif de référence crédible. Une conception d'étude appropriée passe par une sélection non biaisée des individus composant l'échantillon au sein de la population animale à laquelle sera appliqué le test. Les auteurs donnent quelques exemples de calcul de la taille de l'échantillon et d'analyse des données. Enfin, ils examinent les situations où il peut être opportun d'inclure des variables influentes (« covariance ¼) dans l'étude de validation d'un test diagnostique.

Antes de que apareciesen herramientas que permiten juzgar los estudios de validación de pruebas de diagnóstico en ausencia de un modelo o patrón de calibración, las nuevas pruebas de diagnóstico eran comparadas con un patrón de referencia considerado muy exacto, cuando no perfecto. Los autores se refieren aquí a este tipo de situaciones "clásicas", exponiendo ejemplos y métodos de diseño de estudios y análisis de los datos obtenidos. Los autores describen tres tipos de situación: cuando se dispone de una referencia perfecta para animales positivos; cuando se dispone de una referencia perfecta para animales negativos; y cuando la referencia es perfecta para ambos casos. Para cada tipo de situación examinan los aspectos que hay que tener en cuenta al validar una prueba de diagnóstico con un patrón de referencia fiable. El diseño adecuado de un estudio exige una selección no sesgada de los animales a partir de una población a la que vaya a aplicarse la nueva prueba. Los autores ofrecen ejemplos del modo de calcular el tamaño muestral y analizar los datos de un estudio. Por último, examinan situaciones en las que pueda ser conveniente incluir en el estudio de validación uno o más factores que puedan influir (covariables).

Bayesian latent class analysis when the reference test is imperfect.

Latent class analysis (LCA) has allowed epidemiologists to overcome the practical constraints faced by traditional diagnostic test evaluation methods, which require both a gold standard diagnostic test and ample numbers of appropriate reference samples. Over the past four decades, LCA methods have expanded to allow epidemiologists to evaluate diagnostic tests and estimate true prevalence using imperfect tests over a variety of complex data structures and scenarios, including during the emergence of novel infectious diseases. The objective of this review is to provide an overview of recent developments in LCA methods, as well as a practical guide to applying Bayesian LCA (BLCA) to the evaluation of diagnostic tests. Before conducting a BLCA, the suitability of BLCA for the pathogen of interest, the availability of appropriate samples, the number of diagnostic tests, and the structure of the data should be carefully considered. While formulating the model, the model's structure and specification of informative priors will affect the likelihood that useful inferences can be drawn. With the growing need for advanced analytical methods to evaluate diagnostic tests for newly emerging diseases, LCA is a promising field of research for both the veterinary and medical disciplines.

L'analyse à classes latentes a permis aux épidémiologistes de surmonter les problèmes concrets posés par les méthodes traditionnelles d'évaluation des essais de diagnostic, qui nécessitent à la fois un test de référence absolue (étalon ou gold standard) et un grand nombre d'échantillons de référence aux caractéristiques appropriées. Au cours des quatre dernières décennies, les méthodes d'analyse à classes latentes ont acquis de l'ampleur et permettent aux épidémiologistes d'évaluer les essais diagnostiques et d'estimer les taux de prévalence réelle tout en recourant à des tests supposés imparfaits, grâce à l'utilisation de données et de scénarios divers et complexes, y compris dans les situations d'émergence de nouvelles maladies infectieuses. Les auteurs font un tour d'horizon des dernières évolutions dans ce domaine et donnent des orientations pratiques concernant la manière d'utiliser l'analyse bayésienne à classes latentes pour évaluer les performances d'un test de diagnostic. Avant de conduire une telle analyse, il convient de déterminer avec soin si elle est adaptée à l'agent pathogène considéré et si les échantillons disponibles sont appropriés et en nombre suffisant ; il convient également de prendre en compte le nombre de tests de diagnostic à évaluer et la structure des données utilisées. Lors de la conception du modèle, sa structure et la définition préalable des données informatives vont affecter la probabilité que le modèle génère des inférences utiles. Face à la nécessité croissante de disposer de méthodes analytiques sophistiquées pour évaluer les tests de diagnostic utilisés pour les maladies émergentes nouvelles, les analyses à classes latentes offrent des perspectives prometteuses pour la recherche, aussi bien dans le domaine de la santé vétérinaire que de la médecine humaine.

El análisis de clases latentes ha servido a los epidemiólogos para superar las limitaciones prácticas que imponen los métodos tradicionales de evaluación de pruebas de diagnóstico, que requieren a la vez una prueba de diagnóstico que sirva de patrón de referencia perfecto y un gran número de muestras de referencia adecuadas. En los últimos cuatro decenios, los métodos de análisis de clases latentes se han ido ampliando hasta permitir a los epidemiólogos evaluar pruebas de diagnóstico y calcular la prevalencia real empleando pruebas imperfectas ante muy diversas estructuras de datos y situaciones complejas, incluida la aparición de nuevas enfermedades infecciosas. Los autores, tras presentar a grandes líneas los últimos adelantos en cuanto a métodos de análisis de clases latentes, ofrecen indicaciones prácticas para aplicar el análisis bayesiano de clases latentes a la evaluación de pruebas de diagnóstico. Antes de proceder a un análisis bayesiano de este tipo conviene estudiar con detenimiento la idoneidad del método para el patógeno en cuestión, la disponibilidad de muestras apropiadas, el número de pruebas de diagnóstico y la estructura de los datos. A la hora de formular el modelo, la estructura del propio modelo y la especificación de los elementos informativos previos influirán en la probabilidad de poder extraer conclusiones provechosas. Ante la creciente necesidad de disponer de métodos analíticos avanzados con los que evaluar pruebas de diagnóstico de nuevas enfermedades emergentes, el análisis de clases latentes abre un promisorio campo de investigación para las disciplinas veterinarias y médicas.

Pet health insurance reduces the likelihood of pre-surgical euthanasia of dogs with gastric dilatation-volvulus in the emergency room of an Australian referral hospital.

AIMS: To determine the association between the presence of pet health insurance and the risk of euthanasia at the time of diagnosis for dogs with gastric dilatation-volvulus (GDV). METHODS: Insurance status at the time of GDV diagnosis was sought for a cohort of 147 non-referred, confirmed cases of GDV that presented to the emergency department of a university-based veterinary hospital in Australia between 2008 and 2017. Insurance status was obtained from the medical record (n=18) or after contacting the owners by phone using a standardised questionnaire (n=129). Animal, clinical and outcome data was retrospectively compiled in a research database. The primary outcome measure was whether or not the dog was euthanised before surgery. The Mantel-Haenszel procedure was used to quantify the association between the presence of pet health insurance and the risk of euthanasia at the time of diagnosis for dogs with GDV, adjusting for the confounding effect of age at the time of presentation using Bayesian methods. RESULTS: Of the 69 dogs for which insurance information could be obtained, 10 (14%) cases were insured at the time of the GDV event and 59 (86%) cases were not. The majority of non-insured dogs (37/59; 63 (95% CI=50-74)%) were euthanised before surgery, while none (0 (95% CI=0-28)%) of the insured dogs were euthanised at that time (p<0.001). Of the 32 insured and non-insured dogs that underwent surgery, four dogs (13 (95% CI=5-28)%) did not survive to hospital discharge. Three dogs (9%) were euthanised during or after surgery and one dog (3%) experienced cardiopulmonary arrest during treatment. The majority of dogs for which insurance status was known did not survive to hospital discharge (41/69; 59%), and 90 (95% CI=7-96)% of deaths were caused by euthanasia prior to surgery. Uninsured dogs were 5.0 (95% credible interval=1.8-26) times more likely to undergo presurgical euthanasia compared with insured dogs. CONCLUSIONS: Euthanasia prior to treatment was most common cause of death in non-referred dogs with GDV; such euthanasia was entirely absent in the cohort of dogs that were insured. CLINICAL RELEVANCE: Financial considerations significantly contribute to mortality of dogs with GDV presented to an emergency room. Financial instruments to reduce the out-of-pocket expense for pet owners confronted with unexpected veterinary expenses have potential to reduce pet mortality.

A case-control study to identify risk factors for adult-onset idiopathic megaoesophagus in Australian dogs, 2017-2018.

BACKGROUND: Epidemiological investigations were carried out following detection of an outbreak of megaoesophagus in Victorian Police working dogs in early 2018 and an increase in the number of canine megaoesophagus cases reported by companion animal veterinarians in Eastern Australia starting in late 2017. VetCompass Australia data were used to quantify the incidence of canine megaoesophagus for the period January 2012 to February 2018 and a matched case-control study carried out to identify individual animal risk factors for canine megaoesophagus in 2017-2018. RESULTS: There was a 7-fold increase in the incidence rate of canine megaoesophagus from 2014 (0.11 [95% CI 0.02 to 0.58] cases per 100,000 dogs per day) to 2018 (0.82 [95% CI 0.19 to 4.2] cases per 100,000 dogs per day). Since 2013, the incidence of megaoesophagus in Australia has shown a seasonal pattern, with greater numbers of cases diagnosed during the warmer months of the year. In the case-control study, use of Mars Petcare Advance Dermocare as a source of food was 325 (95% CI 64 to 1644) times greater for cases, compared with controls. CONCLUSIONS: Our analyses provide evidence that the feeding of Advance Dermocare was responsible for the majority of cases in the outbreak of megaoesophagus in Eastern Australia in 2017-2018. The increase in the incidence rate of megaoesophagus in Australia since 2014-2015 warrants further investigation.

Assessment of knowledge, attitude, and practice on livestock traceability among cattle farmers and cattle traders in peninsular Malaysia and its impact on disease control.

The ability to trace the movement of animals and their related products is key to success in animal disease control. To ensure that a traceability system is optimized, livestock farmers and traders must have good appreciation and understanding about animal tracing. The present study examined the traceability of cattle in Malaysia vis-à-vis the domains of knowledge, attitude, and practice among cattle farmers and traders. A total of 543 farmers and traders in Peninsular Malaysia were interviewed. The results revealed that over 60% of the respondents had satisfactory knowledge and attitude about cattle movement and traceability. A lower proportion of the respondents (49%) were involved in appropriate practice that facilitated traceability of cattle. We found that the type of husbandry system and stakeholders' participation in livestock management-specific short courses were positively associated with satisfactory knowledge, attitude, and practice. A structured education and training program should be formulated to improve these domains so that the benefit of traceability becomes clear, paving the way to a successful traceability program.

Associations between immune competence, stress responsiveness, and production in Holstein-Friesian and Holstein-Friesian × Jersey heifers reared in a pasture-based production system in Australia.

The objectives of this study were to assess antibody and cellular immune responses in first-lactation dairy heifers reared under a pasture-based production system and to investigate associations between immune competence and stress responsiveness, health, and productivity. A commercial vaccine was used to induce antibody and cellular immune responses and, based on measured responses, animals were classified as above average, average, and below average for each trait independently and in combination (overall immune competence). Overall immune competence phenotypic rankings were generated by combining standardized residual values for antibody and cellular responses measured in individual heifers. Cortisol responses to handling and yarding were used to assess stress responsiveness, worm egg counts were used to assess internal parasite burden, somatic cell counts to assess udder health and estimates of total daily milk volume, and milk fat and milk protein contents to assess productivity. A total of 393 Holstein-Friesian and Holstein-Friesian × Jersey crossbred heifers from 2 herds practicing seasonal calving in a pasture-fed production system were enrolled in the study. The immune competence phenotypes of individual heifers were assessed before their first mating and their subsequent performance during their first lactation was monitored. Animals with below-average antibody and cellular immune competence had higher serum cortisol concentrations compared with their counterparts following handling, suggesting they had a reduced ability to cope with management-induced stress. Furthermore, a significant negative (favorable) correlation was observed between antibody responses and stress responsiveness. Similarly, correlations between antibody responses and internal parasite burden were significant and negative (favorable). No correlations were observed between overall immune competence and milk yield, milk fat, and milk protein content.

Scrotal circumference, bodyweight and semen characteristics in growing dairy-breed natural-service bulls in Tasmania, Australia.

AIMS: To provide herd managers with a set of decision rules allowing them to predict the likelihood that a juvenile bull is ready for Bull Breeding Soundness Evaluation (BBSE), or breeding, if bodyweight and scrotal circumference are known. METHODS: This was a longitudinal study following two groups of young pasture-fed Holstein and Jersey bulls from northwest Tasmania, Australia. Individual scrotal circumference, bodyweight and semen characteristics were recorded at 6-8 weekly intervals, from 6-18 months of age. Classification and regression tree analyses were used to predict the probability that a bull had ≥70% normal sperm morphology based on scrotal circumference and bodyweight measurements. RESULTS: Overall 1,661 scrotal circumference and bodyweight measurements were obtained, and 518 semen samples from 356 bulls were assessed for sperm morphology, from 16 examination sessions that took place between 29 May 2015 and 17 August 2016. Classification and regression tree analyses generated a decision tree for Holstein bulls with four node endpoints, and for Jersey bulls with three node endpoints. Diagnostic test performance showed that for Holstein bulls, using the node endpoints of scrotal circumference ≥27 cm and bodyweight ≥349 kg, 98% had ≥70% normal sperm (positive likelihood ratio 10.4; 95% CI = 2.7-41), and using the node endpoints of scrotal circumference ≥27 cm and bodyweight between 282-349 kg, 89% had ≥70% normal sperm (positive likelihood ratio 1.6; 95% CI = 0.9-2.6). For Jersey bulls, using the node endpoints of bodyweight ≥259 kg and scrotal circumference ≥29 cm, 88% had ≥70% normal sperm (positive likelihood ratio 3.4; 95% CI = 1.6-7.0). CONCLUSIONS: This study provides a set of relatively simple decision rules based on bodyweight and scrotal circumference measurements that allows herd managers to assess the likelihood that juvenile bulls are ready for BBSE or breeding. ABBREVIATIONS: BBSE: Bull breeding soundness evaluation; BRT: Boosted regression tree.

Potent suppression of HIV-1 cell attachment by Kudzu root extract.

There is a constant need to improve antiretrovirals against HIV since therapy is limited by cost, side effects and the emergence of drug resistance. Kudzu is a climbing vine from which the root extract (Pueraria lobata), rich in isoflavones and saponins, has long been used in traditional Chinese medicine for a variety of purposes, from weight loss to alcoholism prevention. Here we show that Kudzu root extract significantly inhibits HIV-1 entry into cell lines, primary human CD4+T lymphocytes and macrophages, without cell-associated toxicity. Specifically, Kudzu inhibits the initial attachment of the viral particle to the cell surface, a mechanism that depends on the envelope glycoprotein gp120 but is independent from the HIV-1 cell receptor CD4 and co-receptors CXCR4/CCR5. This activity seems selective to lentiviruses since Kudzu inhibits HIV-2 and simian immunodeficiency virus, but does not interfere with Hepatitis C, Influenza, Zika Brazil and adenovirus infection. Importantly, depending on the dose, Kudzu can act synergistically or additively with the current antiretroviral cocktails against HIV-1 and can block   viruses resistant to the fusion inhibitor Enfuvirtide. Together our results highlight Kudzu's root extract value as a supplement to current antiretroviral therapy against HIV.

Evaluating vaccination strategies to control foot-and-mouth disease: a country comparison study.

Vaccination is increasingly being recognised as a potential tool to supplement 'stamping out' for controlling foot-and-mouth disease (FMD) outbreaks in non-endemic countries. Infectious disease simulation models provide the opportunity to determine how vaccination might be used in the face of an FMD outbreak. Previously, consistent relative benefits of specific vaccination strategies across different FMD simulation modelling platforms have been demonstrated, using a UK FMD outbreak scenario. We extended this work to assess the relative effectiveness of selected vaccination strategies in five countries: Australia, New Zealand, the USA, the UK and Canada. A comparable, but not identical, FMD outbreak scenario was developed for each country with initial seeding of Pan Asia type O FMD virus into an area with a relatively high density of livestock farms. A series of vaccination strategies (in addition to stamping out (SO)) were selected to evaluate key areas of interest from a disease response perspective, including timing of vaccination, species considerations (e.g. vaccination of only those farms with cattle), risk area vaccination and resources available for vaccination. The study found that vaccination used with SO was effective in reducing epidemic size and duration in a severe outbreak situation. Early vaccination and unconstrained resources for vaccination consistently outperformed other strategies. Vaccination of only those farms with cattle produced comparable results, with some countries demonstrating that this could be as effective as all species vaccination. Restriction of vaccination to higher risk areas was less effective than other strategies. This study demonstrates consistency in the relative effectiveness of selected vaccination strategies under different outbreak start up conditions conditional on the assumption that each of the simulation models provide a realistic estimation of FMD virus spread. Preferred outbreak management approaches must however balance the principles identified in this study, working to clearly defined outbreak management objectives, while having a good understanding of logistic requirements and the socio-economic implications of different control measures.

Early-life events associated with first-lactation performance in pasture-based dairy herds.

This was a prospective cohort study to determine how events from birth until first calving affect performance during the first lactation in pasture-based dairy herds in Victoria, Australia. Events during the preweaning (0-84 d), prepubertal (85-473 d), and postpubertal (474-804 d) periods were recorded in 6 herds, and their association with first-lactation 100-d and 250-d total milk, fat, and protein yields was quantified. Predictors of first-lactation performance included passive transfer status as a calf; season of birth; age of dam; the presence or absence of dystocia at the time of the heifer's birth; the presence or absence of preweaning diarrhea; preweaning, prepubertal, and postpubertal average daily weight gain; age at first calving; the presence or absence of periparturient disease at first calving; sex of the first-born calf; the presence or absence of a stillborn calf at the first calving; and requirement of assistance at the first calving. Lactation performance was quantified using cumulative 100-d and 250-d milk, fat, and protein yields estimated from herd recording. A multivariable linear regression model was developed for each outcome: cumulative 100-d milk, fat, and protein yield and cumulative 250-d milk, fat, and protein yield. Heifers that experienced dystocia at the time of their birth produced 7.6 kg [95% confidence interval (CI): 1.8-13.3] less fat and 4.8 kg (95% CI: 0.6-8.9) less protein at 100 d in milk in the first lactation compared with heifers that were delivered without dystocia. Heifers born in the summer and autumn produced 20 L (95% CI: 0.8-40) more milk and 20 kg (95% CI: 5.9-33) more protein at 250 d in milk in the first lactation compared with heifers born in the spring. For 100 g/d increases in prepubertal average daily gain, heifers produced an additional 182 L (95% CI: 149-216) of milk, 4.1 kg (95% CI: 2.8-5.5) of fat, and 4.0 kg (95% CI 3.1-5.0) of protein at 100 d in milk and an additional 345 L (95% CI 264-425) of milk, 6.1 kg (95% CI 3.2-9.0) of fat, and 7.5 kg (95% CI 5.3-9.7) of protein at 250 d in milk. Postpubertal average daily gain was positively associated with 100-d milk yield and 250-d milk yield and protein production. We conclude that of all the growth periods assessed in this study, events that occurred during the prepubertal period (85-473 d of age) had the greatest effect on first-lactation performance.

Variability in measurement of Pithomyces chartarum spore counts.

AIMS To examine the agreement between spore counts of Pithomyces chartarum measured in a single aliquot of wash water with counts from multiple aliquots from the same 60 g pasture sample, and between spore counts measured in an individual 60 g pasture sample with counts from three 60 g pasture samples selected from the same 200 g paddock sample. MATERIALS AND METHODS Four Waikato dairy farms were visited once weekly from early January to late May 2013. One paddock, with 40 sampling sites, was selected per farm. At each visit, ∼200 g of pasture was collected per site. Spore counting was undertaken using a standard method, except that three separate 60 g pasture samples per 200 g paddock sample was counted; and for each 60 g pasture sample, spores were counted in 10 aliquots of wash water. The relationship between the results of a single aliquot and 6-10 aliquots of wash water from the same 60 g grass sample were assessed by calculating 95% prediction intervals. Limits of agreement analysis was used to assess the agreement between counts from one, two or three aliquots per 60 g pasture sample compared with 10 aliquots, and between counts from one and three 60 g pasture samples from the same 200 g paddock sample. RESULTS Comparing spore counts from individual aliquots with multiple aliquots resulted in large prediction intervals and 95% limits of agreement, which increased with increasing spore count. For an individual aliquot count of 2 spores, the 95% prediction interval for the count from 10 aliquots was 3-49 spores, and for an individual count of 10 spores the 95% prediction interval was 28-222 spores. Increasing the number of aliquots counted improved agreement. For a total count of 10 spores measured in 10 aliquots, the 95% limits of agreement, based on a single aliquot, were 2-50 spores, and for three aliquots were 5-20 spores. The agreement in spore counts measured in one compared with three 60 g pasture samples was moderate and also decreased with increasing spore count; the 95% limits of agreement were 4-14.5 for a mean spore count of 10. CONCLUSIONS AND CLINICAL RELEVANCE Measuring the spore counts of three aliquots of wash water per 60 g grass sample improved repeatability, and should be used as the standard technique, particularly when determining whether to start or finish facial eczema control programmes.

Characterisation by multilocus sequence and porA and flaA typing of Campylobacter jejuni isolated from samples of dog faeces collected in one city in New Zealand.

AIMS: To investigate the prevalence of Campylobacter spp. and C. jejuni in dog faecal material collected from dog walkways in the city of Palmerston North, New Zealand, and to characterise the C. jejuni isolates by multilocus sequence typing (MLST) and porA and flaA antigen gene typing. METHODS: A total of 355 fresh samples of dogs faeces were collected from bins provided for the disposal of dog faeces in 10 walkways in Palmerston North, New Zealand, between August 2008-July 2009. Presumptive Campylobacter colonies, cultured on modified charcoal cefoperazone deoxycholate plates, were screened for genus Campylobacter and C. jejuni by PCR. The C. jejuni isolates were subsequently characterised by MLST and porA and flaA typing, and C. jejuni sequence types (ST) were assigned. RESULTS: Of the 355 samples collected, 72 (20 (95% CI=16-25)%) were positive for Campylobacter spp. and 22 (6 (95% CI=4-9)%) were positive for C. jejuni. Of the 22 C. jejuni isolates, 19 were fully typed by MLST. Ten isolates were assigned to the clonal complex ST-45 and three to ST-52. The allelic combinations of ST-45/flaA 21/porA 44 (n=3), ST-45/flaA 22/porA 53 (n=3) and ST-52/ flaA 57/porA 905 (n=3) were most frequent. CONCLUSIONS: The successful isolation of C. jejuni from canine faecal samples collected from faecal bins provides evidence that Campylobacter spp. may survive outside the host for at least several hours despite requiring fastidious growth conditions in culture. The results show that dogs carry C. jejuni genotypes (ST-45, ST-50, ST-52 and ST-696) that have been reported in human clinical cases. CLINICAL RELEVANCE: Although these results do not provide any evidence either for the direction of infection or for dogs being a potential risk factor for human campylobacteriosis, dog owners are advised to practice good hygiene with respect to their pets to reduce potential exposure to infection.

Periparturient characteristics of mares and their foals on a New Zealand Thoroughbred stud farm.

AIMS: To describe selected periparturient variables in a sample of Thoroughbred mares and their foals on a commercial stud farm in New Zealand. METHODS: Data were collected for 969 foaling records, from 592 mares, by foaling attendants from one Thoroughbred stud farm in the Waikato region of New Zealand for the breeding seasons 2008-2013, inclusive, and collated retrospectively. The associations between mare- and foal-level variables and gestation length, time of birth (expressed as the number of hours after midday), fetal membrane retention time, time for the foal to stand and suckle after birth, and foal mortality were quantified using linear and logistic regression models. RESULTS: Mean gestation length for mares in this study was 350 (min 296, max 429) days, and was shorter for filly foals (348 (min 296, max 429) days) compared with colt foals (350 (min 310, max 404) days) (p=0.001). Overall, 517/968 (53%) foalings occurred between 19:00 and 01:00 and 212/968 (22%) foalings occurred during daylight. Overall, 815/855 (95%) expelled their fetal membranes within 4 hours of parturition. The mean interval from birth to standing and to suckling was shorter (p<0.001) for filly foals than colts by 13 (95% CI=9-17) and 17 (95% CI=8-26) minutes, respectively. Dystocia was reported for 81/968 (8.4%) foalings with relative fetal oversize being the most common cause (36/81 (44%) cases). Perinatal foal death was recorded for 26/966 (2.7%) foalings. The odds of foal mortality decreased with increasing length of gestation (p=0.027), and were greater for colt than filly foals (p=0.042) and when dystocia was reported (p<0.001). CONCLUSIONS: Gestation length was influenced by the sex of the foal, as was the time taken for the foal to stand and suckle after birth. One fifth of mares foaled during daylight hours. The majority of mares in this study population expelled their fetal membranes within 4 hours of foaling. CLINICAL RELEVANCE: Accurate measures for periparturient behaviour can be important in the management of mares and newborn foals. Clinically relevant differences appear to exist between mares and foals in New Zealand and those in the Northern Hemisphere for some key parameters, likely as a result of differences in management and environment. The results of this study suggest that mares should be considered to have retained their membranes if not passed within 4 hours of parturition.

A case-control study to identify risk factors for acute salmonellosis in New Zealand dairy herds, 2011-2012.

In late 2011 the New Zealand Ministry for Primary Industries reported an increase in confirmed laboratory diagnoses of salmonellosis in dairy herds. To identify risk factors for herd-level outbreaks of salmonellosis we conducted a case-control study of New Zealand dairy herds in 2011-2012. In a multivariable analysis, use of continuous feed troughs [adjusted odds ratio (aOR) 6·2, 95% confidence interval (CI) 2·0-20], use of pelletized magnesium supplements (aOR 10, 95% CI 3·3-33) and use of palm kernel meal as a supplementary feed (aOR 8·7, 95% CI 2·5-30) were positively associated with a herd-level outbreak of salmonellosis between 1 July 2011 and 31 January 2012. We conclude that supplementary feeds used on dairy farms (regardless of type) need to be stored and handled appropriately to reduce the likelihood of bacterial contamination, particularly from birds and rodents. Magnesium supplementation in the pelletized form played a role in triggering outbreaks of acute salmonellosis in New Zealand dairy herds in 2011-2012.