Modeling the effects of steroid implant use on the environmental and economic sustainability of Brazilian beef production.

Brazilian beef systems contribute 14.9% of global beef production, therefore given climate change concerns, there is a clear need to reduce environmental impacts while maintaining economic viability. This study evaluated the hypothesis that steroid implant use in Brazilian beef cattle would reduce resource use, greenhouse gas (GHG) emissions and economic costs of production, thereby improving environmental and economic sustainability. A deterministic model based on beef cattle population demographics, nutrition and performance was used to quantify resource inputs and GHG emissions per 1.0 × 106 kg of hot carcass weight (HCW) beef. System boundaries extended from cropping input manufacture to cattle arriving at the slaughterhouse. Beef systems were modeled using herd population dynamics, feed and performance data sourced from producers in four Brazilian states, with additional data from global databases. Implants were used in calves, growing and finishing cattle at low (LI), medium (MI), and high (HI) levels of performance enhancement, compared to nonimplanted (NI) controls. Feed use results were used in combination with producer-derived input costs to assess the economic impacts of implant use, including production costs and returns on investment. Improved FCE, ADG, and carcass weights conferred by implant use reduced the number of cattle and the time taken to produce 1.0 × 106 kg HCW beef. Compared to NI controls, the quantities of feed, land, water and fossil fuels required to produce 1.0 × 106 kg HCW beef was reduced in implanted cattle, with reductions proportional to the performance-enhancing effect of the implant (HI > MI > LI). Implant use reduced GHG emissions per 1.0 × 106 kg HCW beef by 9.4% (LI), 12.6% (MI), or 15.8% (HI). Scaling up the MI effects to represent all eligible Brazilian cattle being implanted, revealed avoided GHG emissions equivalent to the annual exhaust emissions of 62.0 × 106 cars. Economic impacts of implant use reflected the environmental results, resulting in a greater margin for the producers within each system (cow-calf through to finishing). The 6.13% increase in kg of HCW beef produced generates a cost reduction of 3.76% and an increase in the return on invested capital of 4.14% on average. Implants offer the opportunity for Brazilian beef producers to demonstrate their dedication to improving environmental and economic sustainability through improved productivity, although care must be taken to avoid negative trade-offs.

A multi-country study to assess the effect of a treatment with moxidectin pour-on during the dry period on milk production in dairy cows.

A randomized clinical study was conducted in a total of 45 commercial dairy farms in France (14 farms), Germany (28 farms) and the UK (3 farms) to evaluate the effect of an anthelmintic treatment on milk yield in the subsequent lactation. A total of 1287 animals with suspected exposure to Ostertagia ostertagi were included in the study. Animals were treated during the dry period (7-77days before parturition) with moxidectin pour-on (Cydectin® 0.5% Pour-On, Zoetis; 638 animals) or left untreated (649 animals) according to a randomized block design. Animals were either heifers (n=296) or multiparous cows (n=991). The milk production was monitored at regular intervals after treatment up to 335days after lactation, and analysed using a general linear mixed model with the milk production as outcome variable and several random effects. The effect on milk yield after anthelmintic treatment over the whole subsequent lactation varied from no effect (-0.43kg/day; P=0.35) to an increase of milk yield with 2.35kg/day (P=0.01), depending on the study region and parity of the cows. Lactation curve analysis suggested that the treatment effect was mainly caused by a slower decay of the milk production in the treated animals compared to untreated animals. The present study highlights the beneficial effect of a topical treatment with moxidectin before parturition on milk yield in the subsequent lactation, as well as the importance of a careful evaluation of nematode exposure risk based on local grazing management practices to guide and target production-based anthelmintic treatment decisions.

Veterinary Students' Perspectives on Resilience and Resilience-Building Strategies.

In recent years, resilience has been lauded as a valuable, even necessary, facet of an effective veterinary practitioner. This study describes a mixed-methods research exploration of the impact of a self-care and mental well-being teaching intervention on the self-reported resilience of 105 first-year veterinary students enrolled at the School of Veterinary Medicine, University of Surrey, UK. Quantitative data were obtained through a questionnaire, the 10-item Connor-Davidson Resilience Scale (CD-RISC 10), which students completed before and after the teaching intervention. The median total score on the scale increased from 27 (IQR=25-30) to 29 (IQR=26-32) (p<.001), a medium effect size (r=-0.28). Student focus groups were held to allow qualitative data analysis of the students' perspectives on the teaching intervention and on the topic of resilience in general. The results of this study suggest that appropriate training in resilience-building strategies can help veterinary students build greater awareness of resilience, and potentially support their development of a more resilient approach in their personal and professional lives. In this study, veterinary students felt that resilience training was a valuable addition to the veterinary curriculum, and that resilience likely plays an important role in achieving a successful veterinary career. The study also suggested that veterinary students utilize a variety of different resilience-building strategies, including drawing on past experiences, seeking help from support networks, and developing an ability to change their perspectives.

Comparative efficacy of tulathromycin and tildipirosin for the treatment of experimental Mycoplasma bovis infection in calves.

The objective of this negative controlled, blinded, randomised, parallel group study was to compare the efficacy of two injectable macrolide antimicrobials, tulathromycin and tildipirosin, administered by single subcutaneous injection at dose rates of 2.5 and 4.0 mg kg-1 bodyweight, respectively, in the treatment of an experimentally induced Mycoplasma bovis infection in calves. A total of 238 M. bovis-negative calves were challenged on three consecutive days with M. bovis by endobronchial deposition. Post-challenge, a total of 126 animals fulfilled the inclusion criteria and were randomly allocated to three treatment groups: tulathromycin, tildipirosin and saline. Clinical observations for signs of respiratory disease and injection site assessments were conducted daily for 14 days post-treatment. The animals were then killed, the lungs were examined for evidence of lesions, and samples collected for bacterial isolation. Calves treated with tulathromycin had a lower percentage of lung with lesions (P = 0.0079), lower mortality (P = 0.0477), fewer days with depressed demeanour (P = 0.0486) and higher body weight (P = 0.0112) than calves administered tildipirosin.

Anthelmintic resistance to ivermectin and moxidectin in gastrointestinal nematodes of cattle in Europe.

Anthelmintic resistance has been increasingly reported in cattle worldwide over the last decade, although reports from Europe are more limited. The objective of the present study was to evaluate the efficacy of injectable formulations of ivermectin and moxidectin at 0.2 mg per kg bodyweight against naturally acquired gastro-intestinal nematodes in cattle. A total of 753 animals on 40 farms were enrolled in Germany (12 farms), the UK (10 farms), Italy (10 farms), and France (8 farms). Animals were selected based on pre-treatment faecal egg counts and were allocated to one of the two treatment groups. Each treatment group consisted of between 7 and 10 animals. A post-treatment faecal egg count was performed 14 days (±2 days) after treatment. The observed percentage reduction was calculated for each treatment group based on the arithmetic mean faecal egg count before and after treatment. The resistance status was evaluated based on the reduction in arithmetic mean faecal egg count and both the lower and upper 95% confidence limits. A decreased efficacy was observed in half or more of the farms in Germany, France and the UK. For moxidectin, resistance was confirmed on 3 farms in France, and on 1 farm in Germany and the UK. For ivermectin, resistance was confirmed on 3 farms in the UK, and on 1 farm in Germany and France. The remaining farms with decreased efficacy were classified as having an inconclusive resistance status based on the available data. After treatment Cooperia spp. larvae were most frequently identified, though Ostertagia ostertagi was also found, in particular within the UK and Germany. The present study reports lower than expected efficacy for ivermectin and moxidectin (based on the reduction in egg excretion after treatment) on European cattle farms, with confirmed anthelmintic resistance on 12.5% of the farms.

The Life of Meaning: A Model of the Positive Contributions to Well-Being from Veterinary Work.

We present a veterinary model of work-derived well-being, and argue that educators should not only present a (potentially self-fulfilling) stress management model of future wellness, but also balance this with a positive psychology-based approach depicting a veterinary career as a richly generative source of satisfaction and fulfillment. A review of known sources of satisfaction for veterinarians finds them to be based mostly in meaningful purpose, relationships, and personal growth. This positions veterinary well-being within the tradition of eudaimonia, an ancient concept of achieving one's best possible self, and a term increasingly employed to describe well-being derived from living a life that is engaging, meaningful, and deeply fulfilling. The theory of eudaimonia for workplace well-being should inform development of personal resources that foster resilience in undergraduate and graduate veterinarians.

Further validation of the Warwick-Edinburgh Mental Well-being Scale (WEMWBS) in the UK veterinary profession: Rasch analysis.

PURPOSE: To examine the psychometric properties of the 14-item Warwick-Edinburgh Mental Well-being Scale (WEMWBS) in the UK veterinary profession by the application of Rasch analysis, and to assess the external construct validity of the derived interval scale measurements. METHODS: Data sets were derived from two independent cross-sectional surveys of the veterinary profession (n = 8,829 and n = 1,796). Rasch analysis (n = 500) included response option thresholds ordering, tests of fit, differential item functioning, targeting, response dependency, and person separation index (PSI). Unidimensionality was evaluated by principal component analysis of residuals. The findings were validated across further subsamples from both data sets. The external construct validity of the Rasch-fitting item set was evaluated by associations with other measures of psychological health or psychosocial work characteristics. RESULTS: Data for the original 14 items deviated significantly from Rasch model expectations (chi-square = 558.2, df = 112, P = <0.001, PSI = 0.918). A unidimensional 7-item scale (Short WEMWBS, SWEMWBS) with acceptable fit to the model (chi-square = 58.8, df = 56, P = 0.104, PSI = 0.832) was derived by sequential removal of the most misfitting items. The external construct validity of SWEMWBS was supported. CONCLUSIONS: SWEMWBS has robust interval-level measurement properties which support its suitability as an indicator of population mental health and well-being in this occupational group with elevated suicide risk.

The role of combination anthelmintic formulations in the sustainable control of sheep nematodes.

Combinations of anthelmintics with a similar spectrum of activity and different mechanisms of action and resistance are widely available in several regions of the world for the control of sheep nematodes. There are two main justifications for the use of such combinations: (1) to enable the effective control of nematodes in the presence of single or multiple drug resistance, and (2) to slow the development of resistance to the component anthelmintic classes. Computer model simulations of sheep nematode populations indicate that the ability of combinations to slow the development of resistance is maximised if certain prerequisite criteria are met, the most important of which appear to concern the opportunity for survival of susceptible nematodes in refugia and the pre-existing levels of resistance to each of the anthelmintics in the combination. Combinations slow the development of a resistant parasite population by reducing the number of resistant genotypes which survive treatment, because multiple alleles conferring resistance to all the component anthelmintic classes must be present in the same parasite for survival. Individuals carrying multiple resistance alleles are rarer than those carrying single resistance alleles. This enhanced efficacy leads to greater dilution of resistant genotypes by the unselected parasites in refugia, thus reducing the proportion of resistant parasites available to reproduce with other resistant adults that have survived treatment. Concerns over the use of anthelmintic combinations include the potential to select for resistance to multiple anthelmintic classes concurrently if there are insufficient parasites in refugia; the potential for shared mechanisms of resistance between chemical classes; and the pre-existing frequency of resistance alleles may be too high on some farms to warrant the introduction of certain combinations. In conclusion, anthelmintic combinations can play an important role in resistance management. However, they are not a panacea and should always be used in accordance with contemporary principles for sustainable anthelmintic use.

Validation of the Warwick-Edinburgh Mental Well-being Scale (WEMWBS) as an overall indicator of population mental health and well-being in the UK veterinary profession.

The Warwick-Edinburgh Mental Well-being Scale (WEMWBS) was evaluated as an indicator of mental health and well-being within the veterinary profession in a cross-sectional study among a representative sample of 3200 veterinary surgeons practising in the UK. The WEMWBS mean score for the sample was 48.85 (95% confidence interval 48.43-49.28). The score showed a negative correlation with anxiety and depressive symptoms and a positive correlation with favourable psychosocial working conditions. A 1 unit increase in score was associated with reduced odds of reporting having experienced suicidal thoughts in the previous 12 months, and reduced odds of reporting depressive or anxiety symptoms of clinical significance. The results support the validity of the scale as an overall indicator of population mental health and well-being for this occupational group.

Neutralising antibody responses in cattle and sheep following booster vaccination with two commercial inactivated bluetongue virus serotype 8 vaccines.

Cattle and sheep that had received a primary course of vaccination with an inactivated bluetongue virus serotype 8 (BTV-8) vaccine were booster vaccinated 6 or 12 months later with the homologous vaccine or an alternative inactivated BTV-8 vaccine and neutralising antibody responses were determined. Antibody titres to the alternative vaccine were significantly higher than to the homologous vaccine (P=0.013) in cattle. There was no significant difference between the antibody responses to alternative and homologous vaccines in sheep. These data indicate that cattle and sheep primed with one inactivated BTV-8 vaccine may be effectively boosted with an alternative commercial inactivated BTV-8 vaccine.

Psychosocial working conditions and work-related stressors among UK veterinary surgeons.

BACKGROUND: Anecdotally, veterinary surgeons report high levels of work-related stress. AIMS: To investigate psychosocial working conditions, self-reported causes of work-related stress and satisfaction among a representative sample of vets practising in the UK. METHODS: A cross-sectional study using a questionnaire mailed to a stratified random sample of 3200 vets. The Health & Safety Executive Management Standards Indicator Tool and a series of bespoke questions were embedded in a 120 item questionnaire, which also assessed anxiety and depressive symptoms, alcohol consumption, suicidal ideation, positive mental well-being and work-home interaction. RESULTS: A total of 1796 useable questionnaires were returned (response rate 56%). Number of hours worked and making professional mistakes were the main reported contributors to stress. Good clinical outcomes and relationships with colleagues were the greatest sources of satisfaction. Anxiety and depressive symptoms are associated with less favourable working conditions. CONCLUSIONS: Compared to the general population, the sample reported higher risk of work-related stress for demands and managerial support but lower risk for relationships and change. The results could be used to inform the development of targeted interventions.

Alcohol consumption among veterinary surgeons in the UK.

BACKGROUND: Alcohol consumption can have both medical and occupational implications and may affect fitness to practise among veterinary surgeons (vets). AIMS: To investigate alcohol consumption and the prevalence and associations of 'at-risk' drinking among vets in the UK. METHODS: Alcohol consumption was measured using the Alcohol Use Disorders Identification Test alcohol consumption questions (AUDIT-C) embedded in a questionnaire which included measures of mental health and psychosocial working conditions, administered to a representative sample of 1796 vets. Scores of >or=4 for women and >or=5 for men were used as an indicator of 'at-risk' drinking. RESULTS: The response rate was 56%. Five per cent of respondents were non-drinkers, 32% low-risk drinkers and 63% at-risk drinkers. The estimated odds of at-risk drinking was not significantly different for men and women. A 1-year increase in age was associated with a 2% reduction in the odds of at-risk drinking (OR 0.98, 95% CI: 0.97-0.99, P < 0.01). There was no significant difference across hours worked or on call in a typical week. Lower psychological demands at work were associated with reduced odds of at-risk drinking (OR 0.75, 95% CI: 0.63-0.90, P < 0.01). CONCLUSIONS: It is estimated that vets drink more frequently than the general population, but consume less on a typical drinking day and have a prevalence of daily and weekly binge drinking that is similar to the general population. The level of alcohol consumption does not appear to be a negative influence on mental health within the profession as a whole.

A cross-sectional study of mental health and well-being and their associations in the UK veterinary profession.

BACKGROUND: Veterinary surgeons are at elevated risk of suicide, with a proportional mortality ratio around four times that of the general population and approximately twice that of other healthcare professions. There has been much speculation regarding possible mechanisms underlying increased suicide risk in the profession but little empirical research. We aimed to assess the contribution of mental health and well-being to the elevated risk, through a postal questionnaire survey of a large stratified random sample of veterinary surgeons practising within the UK. METHODS: A questionnaire was mailed twice to 3,200 veterinary surgeons. Anxiety and depressive symptoms, alcohol consumption, suicidal ideation, positive mental well-being, perceptions of psychosocial work characteristics, and work-home interaction were assessed using valid and reliable existing instruments and a series of bespoke questions previously developed through informal focus groups. RESULTS: Evaluable questionnaires were returned by 1,796 participants, a response rate of 56.1%. The demographic and occupational profile of respondents was representative of the UK veterinary profession. The prevalence of 'caseness' (i.e. HADS subscale score >/=8) for anxiety, depression, and co-morbid anxiety and depression was 26.3, 5.8 and 4.5%. 5.4% of respondents were non-drinkers, 32.0% low-risk drinkers, and 62.6% 'at-risk' drinkers (i.e. AUDIT-C score >/=4 for women, >/=5 for men). The 12-month prevalence of suicidal thoughts was 21.3%. CONCLUSIONS: Compared to the general population, the sample reported high levels of anxiety and depressive symptoms; higher 12-month prevalence of suicidal thoughts; less favourable psychosocial work characteristics, especially in regard to demands and managerial support; lower levels of positive mental well-being; and higher levels of negative work-home interaction. The levels of psychological distress reported suggest ready access to and knowledge of lethal means is probably not operating in isolation to increase suicide risk within the profession.