Cattle production strategies to deliver protein with less land and lower environmental impact

Global land resources are over-exploited and natural habitats are declining, often driven by expanding livestock production. In Ireland, pastureland for grazing cattle and sheep account for circa 60% of terrestrial land use. The agriculture, forestry and other land use sector (AFOLU) is responsible for 44% of national greenhouse gas (GHG) emissions. A new Grassland Animal response Model (GLAM) was developed to relate livestock-cohort grass and feed requirements to farm-grassland system areas, enhancing environmental assessment of prospective AFOLU configurations. Although land conversion targets are often well-defined, they tend to lack a clear definition of where land sparing can occur. Through analyses of 10 scenarios of milk and beef production and management strategies, we found that displacing beef cows with dairy cows can increase national protein output while sparing up to 0.75 million ha (18%) of grassland (albeit with a minor increase in overseas land requirement for additional concentrate feed). Reducing slaughter age, increasing exports of male dairy calves and increasing grassland use efficiency on beef farms each achieved between 0.19 and 0.32 million ha of land sparing. Sexed semen to achieve more favourable male-female birth ratios had a minor impact. GHG emissions, ammonia emissions and nutrient leaching were only reduced substantially when overall cattle numbers declined, confirming the need for cattle reductions to achieve environmental objectives. Nonetheless, application of GLAM shows potential for improved grass and cattle management to spare good quality land suitable for productive forestry and wetland restoration. This change is urgently needed to generate scalable carbon dioxide removals from the land sector in Ireland, and globally.

Embryo mortality in Holstein x Limousine embryos

The objective of this study was to compare the late embryo mortality (LEM) rate (losses approximately between 32 and 53 days of gestation) and Pregnancy Specific Protein B (PSPB) and progesterone (P4) concentrations on day 32 post AI in Holstein cows bred with either Holstein or Limousine semen. A sample size of 1,082 cows per group diagnosed pregnant between 28- and 35-days post breeding was calculated. The study consisted of evaluating LEM (%) in a cohort of Holstein cows bred with Holstein semen (HO x HO) or Limousine semen (HO x LM), to compare pregnancy loss from 28-35 days post breeding to 50-57 days post breeding. A logistic regression model to compare embryo losses was developed considering as main explanatory variable the cohort (HO x HO embryo vs. HO x LM embryo), correcting by lactation number, breeding season, days to breeding and AI technician. HO x HO embryos had greater LEM (15.16%) than HO x LM embryos (9.79%). Cows bred in summertime had higher LEM (15.23%) than cows bred in no-summertime (9.88%). There were no differences among AI technicians. Within summertime there was no difference in LEM (%) between groups within each lactation number; however, within no-summertime, LEM (%) was higher in HO x HO than HO x LM within each lactation number. Pregnancy SPB optical densities were significantly greater in the HO x HO than in the HO x LM (P=0.023) group; however, the concentration of P4 was not different between groups (P > 0.05).

A Scoping Review of Non-Structural Airway Disease as a Cause of Poor Performance in Racehorses

The association between poor performance and respiratory disease in Thoroughbred racehorses that do not have a structural abnormality of the respiratory tract, is often based on anecdotal evidence. The objective of this scoping review was to examine the scientific evidence for such associations. Publications were selected based on a search of three databases (PubMed, Scopus, and CAB Direct), in English and without date restriction, followed by a screening process to exclude non-relevant papers, duplicates, and reviews. This process identified 996 publications of which 20 were analysed using the Quality in Prognosis Studies (QUIPS) tool. The results indicated that the evidence supporting the relationship between proposed diagnostic indicators and poor performance is variable. There is a need for better quality evidence. In particular, there are conflicting reports relating to the impact of equine asthma and EIPH on athletic performance. Furthermore, a lack of standardisation in the measurement of racehorse performance makes it difficult to compare findings from different studies. The industry would benefit from high-level guidance concerning the design of controlled performance studies in Thoroughbred racehorses to collect comprehensive data and facilitate targeted interventions.

International Spread of Multidrug-Resistant Rhodococcus equi

A multidrug-resistant clone of the animal and human pathogen Rhodococcus equi, MDR-RE 2287, has been circulating among equine farms in the United States since the 2000s. We report the detection of MDR-RE 2287 outside the United States. Our finding highlights the risk for MDR-RE spreading internationally with horse movements.

257 The Effect of the COVID-19 Pandemic on Mental Health Associated Trauma, Admissions and Fractures at a London Major Trauma Centre

Aim

Non-injury related factors have been extensively studied in major trauma and shown to have a significant impact on patient outcomes, with mental illness and associated medication use proven to have a negative effect on bone health and fracture healing. We report the epidemiological effect of COVID-19 pandemic on mental health associated Orthopaedic trauma, fractures, and admissions to our centre.

Method

We collated data retrospectively from the electronic records of Orthopaedic inpatients in an 8-week non-COVID and COVID period analysing demographic data, referral and admission numbers, orthopaedic injuries, surgery performed and patient co-morbidities including psychiatric history.

Results

here were 824 Orthopaedic referrals and 358 admissions (6/day) in the non-COVID period with 38/358 (10.6%) admissions having a psychiatric diagnosis and 30/358 (8.4%) also having a fracture. This was compared to 473 referrals and 195 admissions (3/day) in the COVID period with 73/195 (37.4%) admissions having a documented psychiatric diagnosis and 47/195 (24.1%) a fracture. 22/38 (57.9%) and 52/73 (71.2%) patients were known to mental health services, respectively.

Conclusions

Whilst total numbers utilising the Orthopaedic service decreased, the impact of the pandemic and lockdown disproportionately affected those with mental health problems, a group already at higher risk of poorer functional outcomes and non-union. The proportion of patients with both a fracture and a psychiatric diagnosis more than doubled and the number of patients presenting due to a traumatic suicide attempt almost tripled. It is imperative that adequate support is in place for vulnerable mental health patients, particularly as we are currently experiencing the “second wave” of COVID-19.

Elevated serum antibody responses to synthetic mycobacterial lipid antigens among UK farmers: an indication of exposure to environmental mycobacteria?

Background: mycobacterial cells contain complex mixtures of mycolic acid esters. These can be used as antigens recognised by antibodies in the serum of individuals with active tuberculosis, caused by Mycobacterium tuberculosis. In high burden populations, a significant number of false positives are observed; possibly these antigens are also recognised by antibodies generated by other mycobacterial infections, particularly ubiquitous 'environmental mycobacteria'. This suggests similar responses may be observed in a low burden TB population, particularly in groups regularly exposed to mycobacteria. Methods: ELISA using single synthetic trehalose mycolates corresponding to major classes in many mycobacteria was used to detect antibodies in serum of individuals with no known mycobacterial infection, comprising farmers, abattoir workers, and rural and urban populations. Results: serum from four Welsh or Scottish cohorts showed lower (with some antigens significantly lower) median responses than those reported for TB negatives from high-burden TB populations, and significantly lower responses than those with active TB. A small fraction, particularly older farmers, showed strong responses. A second study examined BCG vaccinated and non-vaccinated farmers and non-farmers. Farmers gave significantly higher median responses than non-farmers with three of five antigens, while there was no significant difference between vaccinated or non-vaccinated for either farmer or non-farmer groups. Conclusions: this initial study shows that serodiagnosis with mycobacterial lipid antigens can detect antibodies in a population sub-group that is significantly exposed to mycobacteria, in an assay that is not interfered with by vaccination. Given the links between mycobacterial exposure and a range of immune system diseases, further understanding such responses may provide a new opportunity for monitoring public health and directing treatment.

The effect of the COVID-19 pandemic on mental health associated trauma, admissions and fractures at a London major trauma centre

INTRODUCTION

Non-injury-related factors have been extensively studied in major trauma and have been shown to have a significant impact on patient outcomes. Mental illness and associated medication use has been proven to have a negative effect on bone health and fracture healing.

MATERIALS AND METHODS

We collated data retrospectively from the records of orthopaedic inpatients in a non-COVID and COVID period. We analysed demographic data, referral and admission numbers, orthopaedic injuries, surgery performed and patient comorbidities, including psychiatric history.

RESULTS

There were 824 orthopaedic referrals and 358 admissions (six/day) in the non-COVID period, with 38/358 (10.6%) admissions having a psychiatric diagnosis and 30/358 (8.4%) also having a fracture. This was compared with 473 referrals and 195 admissions (three/day) in the COVID period, with 73/195 (37.4%) admissions having a documented psychiatric diagnosis and 47/195 (24.1%) having a fracture.

DISCUSSION

There was a reduction in the number of admissions and referrals during the pandemic, but a simultaneous three-fold rise in admissions with a psychiatric diagnosis. The proportion of patients with both a fracture and a psychiatric diagnosis more than doubled and the number of patients presenting due to a traumatic suicide attempt almost tripled.

CONCLUSION

While total numbers using the orthopaedic service decreased, the impact of the pandemic and lockdown disproportionately affects those with mental health problems, a group already at higher risk of poorer functional outcomes and non-union. It is imperative that adequate support is in place for patients with vulnerable mental health during these periods, particularly as we look towards a potential 'second wave' of COVID-19.

59 Incubation of frozen/thawed bovine embryos

High-quality, properly developed bovine embryos are crucial to the embryo transfer industry and enable cryopreservation; however, ∼30% of invivo embryos do not develop to the appropriate stage and are discarded. Currently, frozen/thawed embryos are transferred directly into a recipient, and the quality of embryos post-thaw is seldom evaluated. The objective of this experiment was to evaluate frozen/thawed bovine embryos immediately post-thaw, and again after incubation in different environments. Frozen/thawed bovine embryos (n=30/treatment) processed for direct transfer were thawed (30°C water; 30s) and graded and staged in holding medium. Embryos were then placed into either holding medium, phosphate-buffered saline supplemented with 15% fetal bovine serum (v/v) and antibiotic/antimycotic (2μL mL−1) (PBS+FBS), or a commercially available invitro culture (IVC) medium for ∼18h. Embryos in holding medium and PBS+FBS were loaded into 0.25-mL straws with the appropriate medium, and the straws were sealed and submerged in 38.5°C water. The IVC embryos were placed individually into 25-μL culture drops on tissue-coated 60-mm plastic Petri dishes overlaid with mineral oil and incubated (18h) at 38.5°C in 5% CO2 and air at 100% humidity. Embryos were then collected, regraded, and staged, and comparisons among groups were analysed via the Kruskal–Wallis H-test. Quality score of all embryos decreased by at least one-third post-thaw; however, the developmental stage was unaffected by the freeze/thaw cycle. Following incubation, all embryos suffered a significant (P<0.05) decrease in embryo quality but the IVC group demonstrated less (P<0.05) of a decline in resulting quality (Table 1). The IVC group demonstrated significant development (P<0.05) during incubation compared to the Holding and PBS+FBS groups (Table 1) indicating that on average, viability was maintained during IVC. Regardless of group, the zona pellucida was damaged during the freeze/thaw process in 31.1% of embryos. These data illuminated embryo damage after cryopreservation, and demonstrated that short-term invitro incubation of frozen/thawed embryos (IVC) facilitated continued development and may be a practical mechanism to salvage poor quality or developmentally suppressed embryos. Future research will focus on salvaging fresh embryos that are classified as degenerate and may prove useful in the bovine embryo industry, and for cattle producers alike, by ultimately increasing the number of transferable embryos that would otherwise be discarded. Table 1. Descriptive statistics (mean±s.e.m.) of bovine embryos pre-freeze and post-thaw and incubation Item Media Pre-freeze Post-thaw Post-incubation Grade Holding 1.4±0.1 1.7±0.1a 3.3±0.1b,x PBS+FBS 1.2±0.1 1.6±0.1a 3.1±0.1b,x IVC1 1.2±0.1 1.6±0.1a 2.5±0.2b,y Stage Holding 4.0±0.1 4.0±0.1 3.9±0.1x PBS+FBS 4.7±0.2 4.4±0.2 4.5±0.2y IVC 4.3±0.1 4.3±0.1a 5.8±0.2b,z a,b, x–zDifferent superscripts within row (a, b) and column (x, y, z) indicate a significant difference (P<0.05, Kruskal-Wallis H-test). 1Invitro culture medium.

Key traits for ruminant livestock across diverse production systems in the context of climate change: perspectives from a global platform of research farms

Ruminant livestock are raised under diverse cultural and environmental production systems around the globe. Ruminant livestock can play a critical role in food security by supplying high-quality, nutrient-dense food with little or no competition for arable land while simultaneously improving soil health through vital returns of organic matter. However, in the context of climate change and limited land resources, the role of ruminant-based systems is uncertain because of their reputed low efficiency of feed conversion (kilogram of feed required per kilogram of product) and the production of methane as a by-product of enteric fermentation. A growing human population will demand more animal protein, which will put greater pressure on the Earth's planetary boundaries and contribute further to climate change. Therefore, livestock production globally faces the dual challenges of mitigating emissions and adapting to a changing climate. This requires research-led animal and plant breeding and feeding strategies to optimise ruminant systems. This study collated information from a global network of research farms reflecting a variety of ruminant production systems in diverse regions of the globe. Using this information, key changes in the genetic and nutritional approaches relevant to each system were drawn that, if implemented, would help shape more sustainable future ruminant livestock systems.

72 Evaluation of digital images of bovine embryos

Bovine embryo transfer is an assisted reproductive technology that enables cattle producers to reach their reproductive, genetic, and financial goals. Proper evaluation of embryo quality and developmental stage is key to the success of the embryo transfer industry and is often acquired “on the job” as there are few embryo evaluation training opportunities. The goals of this project were to develop a bank of digital images of invivo-produced bovine embryos, and to evaluate interrater reliability and variation of grade and stage scores and the assessment of the integrity of the zona pellucida (ZP) using an online platform. Frozen/thawed bovine embryos (Day 7) were placed in a commercially available holding medium, and images were captured using a high-resolution camera (112× magnification). Survey participants (n=89) responded to questions on demographic and embryo evaluation experience and assigned grades and stages and evaluated the integrity of the ZP in 58 embryo images (the IETS embryo evaluation rubric was provided). The variation among raters within and between demographic categories was analysed using the “kappaetc” package with weights for ordinal variables (grade and stage) in Stata version 14.2 (StataCorp). The Kruskal–Wallis test was used to assess whether variation [measured as interquartile range (IQR)] in grade and stage ratings within individual were significantly different (P=0.05) by demographic factors. Overall, interrater reliability (measured by Cohen’s Kappa, κ) for stage was moderate (κ=0.57), whereas identification of grade and the ZP was substantial (κ=0.69 and 0.73, respectively). Interrater reliability for grade was significantly lower among those with ≤2 years (n=17) of experience (κ=0.44) compared with those having 3–9 years (n=29; κ=0.57) and ≥10 years (n=43; κ=0.64). Similarly, interrater agreement for stage was significantly lower for those with ≤2 years of experience (κ=0.58) compared with those having 3–9 years (κ=0.68) and ≥10 years (κ=0.75). Interrater agreement for stage was higher for those who did not use the IETS rubric compared with those who did (κ=0.73 vs. κ=0.63, respectively), and the variability was highest for Stage 6 and lowest for Stage 4 embryos. No demographic variables were significantly associated with interrater reliability for the integrity of the ZP. The variability of stage ratings (IQR) within individual significantly increased with more years of experience, with greatest IQR among those with ≥10 years of experience. The IQR within individual for grade decreased with increasing length of time rating, with the lowest IQR for the longest duration spent on rating the embryos. Overall, there was a moderate to substantial interrater agreement in embryo evaluation, which increased with experience. Further, evaluation of bovine embryo digital images may be a useful training tool instead of or in conjunction with a “hands-on” experience. Future surveys will involve multiple images of the same embryo and video to enhance the evaluation process and increase interrater reliability.

12 Artificial insemination and embryo transfer results in ewes during a long daylength period

Sheep are polyestrous, short-day breeders (∼11h of daylength), and exhibit oestrus approximately every 16–17 days during the breeding season, usually in late September to late December in the Northern Hemisphere. Progressive sheep producers often use assisted reproductive techniques such as laparoscopic AI and ovarian hyper-stimulation, embryo collection, and embryo transfer (ET) to increase genetic gain, and strive to have early December lambs to target specific show markets, which dictates AI or ET during the late summer. This field trial compared pregnancy rates following AI or ET in July and August (∼14h of daylength) in southwest Virginia (36–38′12″ N). Ewes (AI, n=83; ET recipients, n=33) were synchronized using a modified Ovsynch protocol involving intravaginal progesterone implants for 14 days, prostaglandin F2α (intramuscular) 48h before expected oestrus, and PG600 (IM) and gonadotrophin-releasing hormone (intramuscular) 52 to 54h and 16h before AI, respectively. Ewes were subjected to AI (frozen/thawed semen) regardless of whether they displayed signs of oestrus, and ewes selected as embryo recipients were subjected to a similar protocol but instead received 1 or 2 embryos (based upon the number of viable embryos produced per embryo donor) 6 days following the AI of the embryo donors. Ovarian hyper-stimulation of the embryo donors (n=13) was enabled by twice-daily FSH injections [totalling 350–455IU of Folltropin V (10–13mL)] for the 4 days before AI. Six days following AI, embryos were recovered surgically from the embryo donors (n=13) and yielded an average (±s.e.m.) of 6.6±1.2 total ova, 4.7±1.1 transferable quality embryos, and 1.9±0.8 unfertilized ova per collection. Pregnancy was detected using transrectal ultrasonography at ∼30 days of gestation and the pregnancy rates were analysed using Chi-squared. There was a tendency (P=0.092) for more pregnancies to be established following ET (22/33; 66%) compared with AI (41/83; 49%). There was no statistical relationship between AI ewes or ET recipient ewes that became pregnant relative to whether they displayed signs of oestrus or not. Embryo transfer was a more successful approach to produce pregnancies in ewes compared with AI during long daylength periods in this field trial. Further, ova from hyper-stimulated embryo donor ewes experienced a very high fertilization rate. Future studies will evaluate the ova capability directly via laparoscopic aspiration of ovarian follicles and IVF and evaluation of hyper- and non-hyper-stimulated follicular waves (using transrectal ultrasonography) and endocrine dynamics during different long and short daylength periods. Extending the opportunity to generate embryos and offspring regardless of daylength will assist aggressive sheep producers in reaching their reproductive, financial, and genetic goals.

Dairy cow trade-off preference for 2 different lying qualities: Lying surface and lying space

Lying down is an important behavior for cows, contributing to their health and welfare. With dairy cows being housed for increasingly longer periods, if not year-round, it is important to ensure that dairy cow lying comfort is not compromised when they are housed. The aim of this study was to assess cow preference for 2 different qualities of lying area that appear to be important to cows-surface type and an open lying space-to better understand how to optimize lying comfort for cows when housed. Twenty-four Holstein dairy cows were used during the study, which took place in Scotland from July to November 2018. The study consisted of 6 experimental periods, each lasting a total of 21 d. Cows were tested 4 at a time and individually housed in their own test pen. Each pen had 3 lying surfaces: sand, mattress, and straw (2.4 m × 2.4 m each) with a freestall in the middle of each, which could be removed. Cows were given access to one surface at a time (training period) with a freestall for 2 d, and then given a choice of all 3 surfaces for 2 d. When given the choice with freestalls in position, cows spent, on average, the largest amount of their lying time on straw (46.6 ± 7.8%) followed by mattress (44.3 ± 12.4%). Freestalls were then removed and the training and choice phase was repeated on the following day, with cows, on average, spending the most time lying on straw (64.4 ± 7.2%). Finally, a freestall was refitted onto each cow's most preferred surface and the cows were given a choice between lying on their most preferred surface with a freestall (P1 + freestall) or on their second or third preferred surface without a freestall (P2 + open and P3 + open, respectively) for 3 d. During this final trade-off stage, of the 19 cows for which data were available, 14 cows chose to give up the opportunity to lie down on their most preferred surface to have more space on P2 + open and P3 + open, 3 cows chose to lie down on P1 + freestall, and 2 cows made no clear choice. Overall, cows spent the largest amount of their total lying time on their second most preferred surface as an open lying space (65.7 ± 6.9%) compared with their preferred surface with a freestall (20.5 ± 5.9%) and their third preferred surface as an open lying space (13.8 ± 3.7%). The results indicate that when lying down, these dairy cows value an open lying space more than the lying surface.

Does the Use of Different Indicators to Benchmark Antimicrobial Use Affect Farm Ranking?

The need to reduce antimicrobial use (AMU) in livestock production has led to the establishment of national AMU data collection systems in several countries. However, there is currently no consensus on which AMU indicator should be used and many of the systems have defined their own indicators. This study sought to explore the effect of using different internationally recognized indicators on AMU data collected from Irish pig farms and to determine if they influenced the ranking of farms in a benchmarking system. AMU data for 2016 was collected from 67 pig farms (c. 35% of Irish pig production). Benchmarks were defined using seven AMU indicators: two based on weight of active ingredient; four based on the defined daily doses (DDD) used by the European Medicines Agency and the national monitoring systems of Denmark and the Netherlands; and one based on the treatment incidence (TI200) used in several published studies. An arbitrary “action zone,” characterized by farms above an acceptable level of AMU, was set to the upper quartile (i.e., the top 25% of users, n = 17). Each pair of indicators was compared by calculating the Spearman rank correlation and assessing if farms above the threshold for one indicator were also above it for the comparison indicator. The action zone was broadly conserved across all indicators; even when using weight-based indicators. The lowest correlation between indicators was 0.94. Fifteen farms were above the action threshold for at least 6 of the 7 indicators while 10 farms were above the threshold for all indicators. However, there were important differences noted for individual farms between most pairs of indicators. The biggest discrepancies were seen when comparing the TI200 to the weight-based indicators and the TI200 to the DDDA_NED (as used by Dutch AMU monitoring system). Indicators using the same numerator were the most similar. All indicators used in this study identified the majority of high users. However, the discrepancies noted highlight the fact that different methods of measuring AMU can affect a benchmarking system. Therefore, careful consideration should be given to the limitations of any indicator chosen for use in an AMU monitoring system.

Quantification, description and international comparison of antimicrobial use on Irish pig farms

Background

There is concern that the use of antimicrobials in livestock production has a role in the emergence and dissemination of antimicrobial resistance in animals and humans. Consequently, there are increasing efforts to reduce antimicrobial use (AMU) in agriculture. As the largest consumer of veterinary antimicrobials in several countries, the pig sector is a particular focus of these efforts. Data on AMU in pig production in Ireland are lacking. This study aimed to quantify AMU on Irish pig farms, to identify the major patterns of use employed and to compare the results obtained to those from other published reports and studies.

Results

Antimicrobial use data for 2016 was collected from 67 Irish pig farms which represented c. 35% of national production. The combined sample population consumed 14.5 t of antimicrobial by weight of active ingredient suggesting that the pig sector accounted for approximately 40% of veterinary AMU in Ireland in 2016. At farm level, median AMU measured in milligram per population correction unit (mg/PCU) was 93.9 (range: 1.0–1196.0). When measured in terms of treatment incidence (TI200), median AMU was 15.4 (range: 0.2–169.2). Oral treatments accounted for 97.5% of all AMU by weight of active ingredient and were primarily administered via medicated feed to pigs in the post weaning stages of production. AMU in Irish pig production in 2016 was higher than results obtained from the national reports of Sweden, Denmark, the Netherlands and France but lower than the United Kingdom.

Conclusions

Pig production in Ireland is an important consumer of veterinary antimicrobials. The quantities and patterns of AMU on Irish pig farms are comparable to pig production in other European countries but higher than some countries with more advanced AMU reduction strategies. This AMU is characterised by a high proportion of prophylactic use and is primarily administered to pigs post weaning via medicated feed. Further studies to better understand the reasons for AMU on Irish pig farms and strategies to improve health among weaner pigs will be of benefit in the effort to reduce AMU.

Mechanisms and impacts of an incentive-based conservation program with evidence from a randomized control trial

Conservation science needs more high-quality impact evaluations, especially ones that explore mechanisms of success or failure. Randomized control trials (RCTs) provide particularly robust evidence of the effectiveness of interventions (although they have been criticized as reductionist and unable to provide insights into mechanisms), but there have been few such experiments investigating conservation at the landscape scale. We explored the impact of Watershared, an incentive-based conservation program in the Bolivian Andes, with one of the few RCTs of landscape-scale conservation in existence. There is strong interest in such incentive-based conservation approaches as some argue they can avoid negative social impacts sometimes associated with protected areas. We focused on social and environmental outcomes based on responses from a household survey in 129 communities randomly allocated to control or treatment (conducted both at the baseline in 2010 and repeated in 2015-2016). We controlled for incomplete program uptake by combining standard RCT analysis with matching methods and investigated mechanisms by exploring intermediate and ultimate outcomes according to the underlying theory of change. Previous analyses, focused on single biophysical outcomes, showed that over its first 5 years Watershared did not slow deforestation or improve water quality at the landscape scale. We found that Watershared influenced some outcomes measured using the survey, but the effects were complex, and some were unexpected. We thus demonstrated how RCTs can provide insights into the pathways of impact, as well as whether an intervention has impact. This paper, one of the first registered reports in conservation science, demonstrates how preregistration can help make complex research designs more transparent, avoid cherry picking, and reduce publication bias.

Controlling spin current polarization through non-collinear antiferromagnetism

The interconversion of charge and spin currents via spin-Hall effect is essential for spintronics. Energy-efficient and deterministic switching of magnetization can be achieved when spin polarizations of these spin currents are collinear with the magnetization. However, symmetry conditions generally restrict spin polarizations to be orthogonal to both the charge and spin flows. Spin polarizations can deviate from such direction in nonmagnetic materials only when the crystalline symmetry is reduced. Here, we show control of the spin polarization direction by using a non-collinear antiferromagnet Mn₃GaN, in which the triangular spin structure creates a low magnetic symmetry while maintaining a high crystalline symmetry. We demonstrate that epitaxial Mn₃GaN/permalloy heterostructures can generate unconventional spin-orbit torques at room temperature corresponding to out-of-plane and Dresselhaus-like spin polarizations which are forbidden in any sample with two-fold rotational symmetry. Our results demonstrate an approach based on spin-structure design for controlling spin-orbit torque, enabling high-efficient antiferromagnetic spintronics.

In the typical spin-hall effect, spin-current, charge current, and spin polarisation are all mutually perpendicular, a feature enforced by symmetry. Here, using an anti-ferromagnet with a triangular spin structure, the authors demonstrate a spin-hall effect without a perpendicular spin alignment.

Prophylactic biological mesh reinforcement versus standard closure of stoma site (ROCSS): a multicentre, randomised controlled trial

BACKGROUND

Closure of an abdominal stoma, a common elective operation, is associated with frequent complications; one of the commonest and impactful is incisional hernia formation. We aimed to investigate whether biological mesh (collagen tissue matrix) can safely reduce the incidence of incisional hernias at the stoma closure site.

METHODS

In this randomised controlled trial (ROCSS) done in 37 hospitals across three European countries (35 UK, one Denmark, one Netherlands), patients aged 18 years or older undergoing elective ileostomy or colostomy closure were randomly assigned using a computer-based algorithm in a 1:1 ratio to either biological mesh reinforcement or closure with sutures alone (control). Training in the novel technique was standardised across hospitals. Patients and outcome assessors were masked to treatment allocation. The primary outcome measure was occurrence of clinically detectable hernia 2 years after randomisation (intention to treat). A sample size of 790 patients was required to identify a 40% reduction (25% to 15%), with 90% power (15% drop-out rate). This study is registered with ClinicalTrials.gov, NCT02238964.

FINDINGS

Between Nov 28, 2012, and Nov 11, 2015, of 1286 screened patients, 790 were randomly assigned. 394 (50%) patients were randomly assigned to mesh closure and 396 (50%) to standard closure. In the mesh group, 373 (95%) of 394 patients successfully received mesh and in the control group, three patients received mesh. The clinically detectable hernia rate, the primary outcome, at 2 years was 12% (39 of 323) in the mesh group and 20% (64 of 327) in the control group (adjusted relative risk [RR] 0·62, 95% CI 0·43-0·90; p=0·012). In 455 patients for whom 1 year postoperative CT scans were available, there was a lower radiologically defined hernia rate in mesh versus control groups (20 [9%] of 229 vs 47 [21%] of 226, adjusted RR 0·42, 95% CI 0·26-0·69; p<0·001). There was also a reduction in symptomatic hernia (16%, 52 of 329 vs 19%, 64 of 331; adjusted relative risk 0·83, 0·60-1·16; p=0·29) and surgical reintervention (12%, 42 of 344 vs 16%, 54 of 346: adjusted relative risk 0·78, 0·54-1·13; p=0·19) at 2 years, but this result did not reach statistical significance. No significant differences were seen in wound infection rate, seroma rate, quality of life, pain scores, or serious adverse events.

INTERPRETATION

Reinforcement of the abdominal wall with a biological mesh at the time of stoma closure reduced clinically detectable incisional hernia within 24 months of surgery and with an acceptable safety profile. The results of this study support the use of biological mesh in stoma closure site reinforcement to reduce the early formation of incisional hernias.

FUNDING

National Institute for Health Research Research for Patient Benefit and Allergan.

Field survey to evaluate space allowances for dairy cows in Great Britain

Housing conditions can affect health of cows by increasing exposure to biological, chemical, and physical hazards, resulting in increased disease. A report in 2014 indicated that 99% of UK dairy cows are housed during winter months and that an increasing number of farms are committing to year-round indoor-housing management systems. Current literature does not provide a clear understanding of the relationship between cow health, welfare, and production, and the housing environment. Loafing space, in this case defined as non-feed, non-lying, and non-high traffic areas of the housed environment, is considered an important component of housing for dairy cows; however, the scientific literature associated with this subject is sparse internationally. The aim of this research was to explore current housing of dairy cows across Great Britain, with specific focus on understanding the practices and variability associated with space allowance. A secondary aim was to explore farmer opinions and knowledge on the value of living space. A single researcher visited 53 randomly selected farms, from a representative sample group, once during the winter housing period 2017-18. Data collection consisted of 3 elements: collation of basic farm details, precise measurement of adult dairy cow accommodation, and a questionnaire to capture farmer opinions on space allowances. Statistical analysis was undertaken to assess variation among farms in total space, loafing space, and living space per cow. A new metric, termed "living space," was defined to describe the additional space availability for dairy cows above that deemed to be a baseline requirement. Large variability was identified between farms in total space available per cow, with a range from 5.4 to 12.7 m² [mean = 8.3 m², median = 8.2 m², interquartile range (IQR) = 1.9 m²]. The mean living space was 2.5 m², with a range of 0.5 m² to 6.4 m² (median = 2.4 m², IQR = 1.6 to 3.2 m²). Responses from a farmer questionnaire on importance of loafing space revealed that farmers felt it was essential for cow welfare, over half of farmers scoring this ≥8 on a 0 to 10 scale. Farmers were categorized into 4 latent classes based on their attitudes toward the importance of loafing space. In a linear model to predict the "living space" provided on each farm, geographical location and latent class of farmer attitude were covariates significantly associated with the amount of space provided. This study is the first worldwide to quantify variability in loafing and living spaces for dairy herds; further research is required to evaluate the extent to which variation in quantity and quality of space influences cow health, welfare, and productivity, as well as farm economics and emissions.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Systemic Yersinia pseudotuberculosis as a Cause of Osteomyelitis in a Captive Ring-tailed Lemur (Lemur catta)

Yersinia pseudotuberculosis and Yersinia enterocolitica are ubiquitous pathogens with wildlife and domestic animal reservoirs. Outbreaks of 'non-plague' yersiniosis in man and non-human primates are reported frequently (including zoological specimens and research breeding colonies) and are usually characterized by enteritis, mesenteric lymphadenitis and occasionally organ abscessation. In people, non-septic reactive arthritis is a common sequela to yersiniosis. However, there have been rare reports in people of septic arthritis and osteomyelitis because of active systemic infection with Y. pseudotuberculosis. Osteomyelitis has also been reported rarely in historical yersiniosis outbreaks in farmed turkeys in England and the USA. This paper reports the first case of osteomyelitis caused by systemic infection with Y. pseudotuberculosis O:1 in a non-human primate, a captive ring-tailed lemur (Lemur catta). The lemur had a short clinical history of hyporexia and weight loss with reduction in mobility, especially of the left hindlimb. On post-mortem examination there was evidence of multi-organ abscessation. In addition, severe necrosis, inflammation and large bacterial colonies were present in the musculature, periosteum and bone marrow in the hip, ribs and a vertebra at the cervicothoracic junction. Osteomyelitis should be considered as a rare clinical presentation in non-human primates with systemic Y. pseudotuberculosis infection.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Metrics and methods for characterizing dairy farm intensification using farm survey data

Evaluation of agricultural intensification requires comprehensive analysis of trends in farm performance across physical and socio-economic aspects, which may diverge across farm types. Typical reporting of economic indicators at sectorial or the “average farm” level does not represent farm diversity and provides limited insight into the sustainability of specific intensification pathways. Using farm business data from a total of 7281 farm survey observations of English and Welsh dairy farms over a 14-year period we calculate a time series of 16 key performance indicators (KPIs) pertinent to farm structure, environmental and socio-economic aspects of sustainability. We then apply principle component analysis and model-based clustering analysis to identify statistically the number of distinct dairy farm typologies for each year of study, and link these clusters through time using multidimensional scaling. Between 2001 and 2014, dairy farms have largely consolidated and specialized into two distinct clusters: more extensive farms relying predominantly on grass, with lower milk yields but higher labour intensity, and more intensive farms producing more milk per cow with more concentrate and more maize, but lower labour intensity. There is some indication that these clusters are converging as the extensive cluster is intensifying slightly faster than the intensive cluster, in terms of milk yield per cow and use of concentrate feed. In 2014, annual milk yields were 6,835 and 7,500 l/cow for extensive and intensive farm types, respectively, whilst annual concentrate feed use was 1.3 and 1.5 tonnes per cow. For several KPIs such as milk yield the mean trend across all farms differed substantially from the extensive and intensive typologies mean. The indicators and analysis methodology developed allows identification of distinct farm types and industry trends using readily available survey data. The identified groups allow the accurate evaluation of the consequences of the reduction in dairy farm numbers and intensification at national and international scales.

Climate mitigation by dairy intensification depends on intensive use of spared grassland

Milk and beef production cause 9% of global greenhouse gas (GHG) emissions. Previous life cycle assessment (LCA) studies have shown that dairy intensification reduces the carbon footprint of milk by increasing animal productivity and feed conversion efficiency. None of these studies simultaneously evaluated indirect GHG effects incurred via teleconnections with expansion of feed crop production and replacement suckler-beef production. We applied consequential LCA to incorporate these effects into GHG mitigation calculations for intensification scenarios among grazing-based dairy farms in an industrialized country (UK), in which milk production shifts from average to intensive farm typologies, involving higher milk yields per cow and more maize and concentrate feed in cattle diets. Attributional LCA indicated a reduction of up to 0.10 kg CO₂ e kg^-1 milk following intensification, reflecting improved feed conversion efficiency. However, consequential LCA indicated that land use change associated with increased demand for maize and concentrate feed, plus additional suckler-beef production to replace reduced dairy-beef output, significantly increased GHG emissions following intensification. International displacement of replacement suckler-beef production to the "global beef frontier" in Brazil resulted in small GHG savings for the UK GHG inventory, but contributed to a net increase in international GHG emissions equivalent to 0.63 kg CO₂ e kg^-1 milk. Use of spared dairy grassland for intensive beef production can lead to net GHG mitigation by replacing extensive beef production, enabling afforestation on larger areas of lower quality grassland, or by avoiding expansion of international (Brazilian) beef production. We recommend that LCA boundaries are expanded when evaluating livestock intensification pathways, to avoid potentially misleading conclusions being drawn from "snapshot" carbon footprints. We conclude that dairy intensification in industrialized countries can lead to significant international carbon leakage, and only achieves GHG mitigation when spared dairy grassland is used to intensify beef production, freeing up larger areas for afforestation.

Producer estimates of prevalence and perceived importance of lameness in dairy herds with tiestalls, freestalls, and automated milking systems

Lameness is one of the most important welfare and productivity concerns in the dairy industry. Our objectives were to obtain producers' estimates of its prevalence and their perceptions of lameness, and to investigate how producers monitor lameness in tiestall (TS), freestall with milking parlor (FS), and automated milking system (AMS) herds. Forty focal cows per farm in 237 Canadian dairy herds were scored for lameness by trained researchers. On the same day, the producers completed a questionnaire. Mean herd-level prevalence of lameness estimated by producers was 9.0% (±0.9%; ±SE), whereas the researchers observed a mean prevalence of 22.2% (±0.9%). Correlation between producer- and researcher-estimated lameness prevalence was low (r = 0.19) and mean researcher prevalence was 1.6, 1.8, and 4.1 times higher in AMS, FS, and TS farms, respectively. A total of 48% of producers thought lameness was a moderate or major problem in their herds (TS = 34%; AMS =53%; FS = 59%). One third of producers considered lameness the highest ranked health problem they were trying to control, whereas two-thirds of producers (TS = 43%; AMS = 63%; FS = 71%) stated that they had made management changes to deal with lameness in the past 2 yr. Almost all producers (98%) stated they routinely check cows to identify new cases of lameness; however, 40% of producers did not keep records of lameness (AMS = 24%; FS = 23%; TS = 60%). A majority (69%) of producers treated lame cows themselves immediately after detection, whereas 13% relied on hoof-trimmer or veterinarians to plan treatment. Producers are aware of lameness as an issue in dairy herds and almost all monitor lameness as part of their daily routine. However, producers underestimate lameness prevalence, which highlights that lameness detection continues to be difficult in in all housing systems, especially in TS herds. Training to improve detection, record keeping, identification of farm-specific risk factors, and treatment planning for lame cows is likely to help decrease lameness prevalence.

New synthetic lipid antigens for rapid serological diagnosis of tuberculosis

Background

During pulmonary tuberculosis (PTB) antibodies are generated to trehalose esters of mycolic acids which are cell wall lipids of Mycobacterium tuberculosis (Mtb). Attempts have been made to use these complex natural mixtures in serological tests for PTB diagnosis.

Aim

The aim of this work was to determine whether a serological test based on a panel of defined individual trehalose esters of characteristic synthetic mycolic acids has improved diagnostic accuracy in distinguishing patients with culture positive PTB from individuals who were Mtb culture negative.

Method

One hundred serum samples from well-characterized patients with presumptive tuberculosis, and diagnosed as having pulmonary smear and culture positive TB, or being culture and smear negative were evaluated by ELISA using different combinations of synthetic antigens and secondary antibodies. Using cut-off values determined from these samples, we validated this study blind in samples from a further 249 presumptive TB patients.

Results

With the first 100 samples, detailed responses depended both on the precise structure of the antigen and on the secondary antibody. Using a single antigen, a sensitivity/specificity combination for smear and culture positive PTB detection of 85 and 88% respectively was achieved; this increased to 96% and 95% respectively by a statistical combination of the results with seven antigens. In the blind study a sensitivity/specificity of 87% and 83% was reached with a single antigen. With some synthetic antigens, the responses from all 349 samples were significantly better than those with the natural mixture. Combining the results for seven antigens allowed a distinction between culture positive and negative with a ROC AUC of 0.95.

Conclusion

We have identified promising antigen candidates for serological assays that could be used to diagnose PTB and which could be the basis of a much-needed, simple, rapid diagnostic test that would bring care closer to communities.

Abstract CT151: CNS activity of ensartinib in ALK-positive non-small cell lung cancer patients

Background: Ensartinib (X-396) is a novel, potent anaplastic lymphoma kinase (ALK) small molecule tyrosine kinase inhibitor (TKI) with additional activity against MET, ABL, Axl, EPHA2, LTK, ROS1 and SLK. In animal studies, brain concentration of ensartinib in mice given at the therapeutic dose was 4 times higher than the IC50 for growth inhibition of ALK positive cells in vitro. Ensartinib was significantly more effective than crizotinib at inhibiting the intracranial growth of the SH-SY5Y neuroblastoma model harboring the F1174L mutation. We subsequently evaluated the CNS activity of ensartinib in patients with ALK positive non-small cell lung cancer (NSCLC).

Methods: In this multicenter phase I/II study, patients (pts) with advanced solid tumors were enrolled and given ensartinib orally on a continuous 28-day schedule (NCT01625234). Doses from 25 mg up to 250 mg once daily were evaluated and 225 mg was selected for further evaluation in the phase II expansion. We report on patients enrolled with CNS metastases (with or without systemic disease) who were ALK TKI naïve or had received prior crizotinib or a second generation ALK TKI. Patients with untreated asymptomatic CNS metastases were allowed to enroll. All pts were assessed for adverse events using CTCAE version 4.03, and response to therapy was assessed using RECIST 1.1. Patients with only CNS disease had to have at least one measurable target lesion ≥ 3 mm in diameter.

Results: As of the December 13, 2016 data cutoff, 26 pts with ALK+ NSCLC and baseline CNS metastases have been treated at ≥ 200 mg. Of the 26 pts, 13 pts had baseline target lesions (8 of which also had non-target lesions) and 13 pts had baseline non-target lesions only. Median age is 52 (21-72) years and the majority of patients had ECOG performance status of 1 (69%). CNS responses have been observed in both ALK TKI naïve pts and pts that received prior crizotinib. In the 13 pts with baseline target CNS lesions, intracranial response was achieved in 9 pts (69%), including 1 CR, and 4 pts (31%) had SD, a 100% disease control rate. In the 13 pts with non-target baseline lesions only, 1 CR was achieved and 8 pts had SD. All 3 (100%) ALK TKI naïve pts with baseline target lesions achieved CR or PR, and 5/8 pts (62%) that received prior crizotinib only and had baseline target lesions responded. The median duration of intracranial response in the 10 pts who responded (9 with target lesions, 1 with non-target lesions only) is 5.8+ months, with the longest duration being 24 months.

Conclusions: Our clinical findings support the preclinical results that the use of ensartinib at doses generally well-tolerated in the clinic may result in favorable therapeutic outcomes in pts with ALK+ NSCLC with baseline CNS metastases. The ongoing phase III eXalt3 study will assess CNS response rate and time to CNS progression in pts receiving first-line ensartinib vs crizotinib (NCT02767804 and NCT01625234).

Citation Format: Leora Horn, Karen L. Reckamp, Sandip Patel, George Blumenschein, Joel W. Neal, Barbara Gitlitz, Saiama Waqar, Geoffrey Oxnard, Christina Brzezniak, Gary Dukart, Fenlai Tan, Kimberly Harrow, Chris Liang, James Gibbons, Heather A. Wakelee. CNS activity of ensartinib in ALK-positive non-small cell lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT151. doi:10.1158/1538-7445.AM2017-CT151

A comparison of the pharmacokinetics and safety of enzalutamide in subjects with hepatic impairment and matched healthy subjects

WHAT IS KNOWN AND OBJECTIVE

Enzalutamide is an androgen receptor inhibitor approved for treatment of metastatic castration-resistant prostate cancer. Enzalutamide is highly protein bound and eliminated primarily by hepatic metabolism; therefore, it is important to understand whether enzalutamide pharmacokinetics is altered by hepatic impairment.

METHODS

Pharmacokinetic data were obtained from two non-randomized, open-label, single-dose, phase 1 studies conducted in patients with mild (Child-Pugh class A, n = 6) or moderate (Child-Pugh class B, n = 8) hepatic impairment (NCT01901133) or severe (Child-Pugh class C, n = 8) hepatic impairment (NCT02138162) and their corresponding matched healthy controls; data from both studies are presented here. Subjects with hepatic impairment had liver cirrhosis (n = 19) or chronic hepatitis (n = 3). All subjects received a single oral dose of 160 mg enzalutamide under fasting conditions, with blood samples collected predose and up to 49 days post-dose.

RESULTS AND DISCUSSION

Exposure to enzalutamide active moieties, based on the area under the curve of the sum of enzalutamide and N-desmethyl enzalutamide (an active metabolite with similar potency to enzalutamide), increased by 13%, 18% and 4% in subjects with mild, moderate and severe hepatic impairment, respectively, relative to matched controls. Compared with healthy controls, the mean maximum plasma concentration for enzalutamide active moieties was 24% higher in subjects with mild hepatic impairment and 11% and 41% lower in subjects with moderate and severe hepatic impairment, respectively. Enzalutamide was generally well tolerated, with no clinically significant trends in abnormal laboratory findings, vital signs or electrocardiograms.

WHAT IS NEW AND CONCLUSIONS

No major differences in single-dose pharmacokinetics were observed in subjects with hepatic impairment vs. matched healthy controls. Therefore, these studies indicate that no initial dose adjustment is necessary when administering enzalutamide to patients with hepatic impairment.

New therapeutic strategies in neuroblastoma: combined targeting of a novel tyrosine kinase inhibitor and liposomal siRNAs against ALK

Many different aberrations in the Anaplastic Lymphoma Kinase (ALK) were found to be oncogenic drivers in several cancers including neuroblastoma (NB), therefore ALK is now considered a critical player in NB oncogenesis and a promising therapeutic target. The ALK-inhibitor crizotinib has a limited activity against the various ALK mutations identified in NB patients.

We tested: the activity of the novel ALK-inhibitor X-396 administered alone or in combination with Targeted Liposomes carrying ALK-siRNAs (TL[ALK-siRNA]) that are active irrespective of ALK gene mutational status; the pharmacokinetic profiles and the biodistribution of X-396; the efficacy of X-396 versus crizotinib treatment in NB xenografts; whether the combination of X-396 with the TL[ALK-siRNA] could promote long-term survival in NB mouse models.

X-396 revealed good bioavailability, moderate half-life, high mean plasma and tumor concentrations. X-396 was more effective than crizotinib in inhibiting in vitro cell proliferation of NB cells and in reducing tumor volume in subcutaneous NB models in a dose-dependent manner.

In orthotopic NB xenografts, X-396 significantly increased life span independently of the ALK mutation status. In combination studies, all effects were significantly improved in the mice treated with TL[ALK-siRNA] and X-396 compared to mice receiving the single agents.

Our findings provide a rational basis to design innovative molecular-based treatment combinations for clinical application in ALK-driven NB tumors.

The impact of environmental conditions on Campylobacter jejuni survival in broiler faeces and litter

INTRODUCTION

Campylobacter jejuni is the leading bacterial food-borne pathogen within the European Union, and poultry meat is an important vehicle for its transmission to humans. However, there is limited knowledge about how this organism persists in broiler litter and faeces. The aim of this study was to assess the impact of a number of environmental parameters, such as temperature, humidity, and oxygen, on Campylobacter survival in both broiler litter and faeces.

MATERIALS AND METHODS

Used litter was collected from a Campylobacter-negative broiler house after final depopulation and fresh faeces were collected from transport crates. Samples were confirmed as Campylobacter negative according to modified ISO methods for veterinary samples. Both sample matrices were inoculated with 9 log10 CFU/ml C. jejuni and incubated under high (≥85%) and low (≤70%) relative humidity conditions at three different temperatures (20°C, 25°C, and 30°C) under both aerobic and microaerophilic atmospheres. Inoculated litter samples were then tested for Campylobacter concentrations at time zero and every 2 hours for 12 hours, while faecal samples were examined at time zero and every 24 hours for 120 hours. A two-tailed t-test assuming unequal variance was used to compare mean Campylobacter concentrations in samples under the various temperature, humidity, and atmospheric conditions.

RESULTS AND DISCUSSION

C. jejuni survived significantly longer (P≤0.01) in faeces, with a minimum survival time of 48 hours, compared with 4 hours in used broiler litter. C. jejuni survival was significantly enhanced at 20°C in all environmental conditions in both sample matrices tested compared with survival at 25°C and 30°C. In general, survival was greater in microaerophilic compared with aerobic conditions in both sample matrices. Humidity, at the levels examined, did not appear to significantly impact C. jejuni survival in any sample matrix. The persistence of Campylobacter in broiler litter and faeces under various environmental conditions has implications for farm litter management, hygiene, and disinfection practices.

The impact of biosecurity and partial depopulation on Campylobacter prevalence in Irish broiler flocks with differing levels of hygiene and economic performance

Background

Campylobacter jejuni is the leading bacterial food-borne pathogen within the European Union (EU), and poultry meat is the primary route for transmission to humans.

Material and methods

This study examined the impact of partial depopulation (thinning), season, and farm performance (economic, hygiene, and biosecurity) on Campylobacter prevalence in Irish broilers over a 13-month period. Ten caecal samples were taken per flock, for a total of 211 flocks from 23 farms during the duration of the study. Campylobacter was isolated and enumerated according to modified published ISO methods for veterinary samples. Biosecurity was evaluated through a questionnaire based on risk factors for Campylobacter identified in previous studies. Hygiene compliance was assessed from audit records taken over the course of 1 year. All information relating to biosecurity and hygiene was obtained directly from the processing company. This was done to ensure farmers were unaware they were being monitored for Campylobacter prevalence and prevent changes to their behaviour.

Results and discussion

Farms with high performance were found to have significantly lower Campylobacter prevalence at first depopulation compared with low-performance farms across all seasons (P≤0.01). Peak Campylobacter levels were observed during the summer season at first thin in both the high- and low-performance groups. Campylobacter prevalence was found to increase to ≥85% in both high- and low-performance farms across all seasons at final depopulation, suggesting that Campylobacter was introduced during the first depopulation. On low-performance farms, four biosecurity interventions were found to significantly reduce the odds of a flock being Campylobacter positive (physical step-over barrier OR=0.17, house-specific footwear OR=0.13, absence of water body within 0.5 km OR=0.13, two or more broiler houses on a farm OR=0.16), compared with farms without these interventions. For high-performance farms, no single biosecurity intervention was identified as significant as this group had full compliance with multiple factors. High-performance farms had significantly better feed conversion ratios compared with low-performance farms (1.61 v 1.67 (P≤0.01)). No differences in flock mortality rates were observed (P≥0.05). This highlights the impact of season, biosecurity, partial depopulation, and farm performance on Campylobacter prevalence in Irish broilers.

Evaluation of the usefulness at national level of the dairy cattle health and production recording systems in Great Britain

The aim of this study was to formally evaluate, qualitatively, the ability of existing recording systems to generate accurate and reliable estimates of the frequency of selected health conditions in the dairy herd of Great Britain. Fifty-nine recording systems were identified, of which 36 had their key characteristics defined through a web-based questionnaire. Nineteen of them were further assessed following the SERVAL, a SuRveillance EVALuation framework against a set of 12 attributes: benefit, bias, communication, coverage, data collection, data management, data analysis, data completeness, flexibility, multiple utility, representativeness and stability/sustainability. The evaluated systems showed considerable differences in their coverage, implementation and objectives. There were overlaps in recorded conditions, with Johne's disease, bovine viral diarrhoea, mastitis and lameness being recorded by most of the systems. Selection bias, data ownership and lack of integration of data from different systems appeared to be a key limitation on the future use of existing systems for nationwide monitoring. The results showed that even though the individual systems can provide reliable estimates of dairy health for individual farmers, none of the systems alone could provide accurate and reliable estimates for any of the conditions of interest at national level.

Prevalence and patterns of antimicrobial resistance among Escherichia coli isolated from Zambian dairy cattle across different production systems

This study focused on the use of antibiotics on small, medium and commercial-sized dairy farms in the central region of Zambia and its relationship to antibiotic resistance in Escherichia coli. A stratified random sample of 104 farms was studied, representing approximately 20% of all dairy farms in the region. On each farm, faecal samples were collected from a random sample of animals and a standardised questionnaire on the usage of antibiotics was completed. An E. coli isolate was obtained from 98.67% (371/376) of the sampled animals and tested for resistance to six classes of antibiotics. The estimated prevalence of resistance across the different farming systems was: tetracycline (10.61; 95%CI: 7.40–13.82), ampicillin (6.02; 95%CI: 3.31–8.73), sulfamethoxazole/ trimethoprim (4.49; 95%CI: 2.42–6.56), cefpodoxime (1.91; 95%CI: 0.46–3.36), gentamicin (0.89; 95%CI: 0.06–1.84) and ciprofloxacin (0%). Univariate analyses indicated certain diseases, exotic breeds, location, farm size and certain management practices as risk factors for detection of resistance, whereas multivariate analyses showed an association with lumpy skin disease and a protective effect for older animals (>25 months). This study has provided novel insights into the drivers of antibiotic use and their association with antibiotic resistance in an under-studied region of Southern Africa.

On the fate of particles liberated from hydroxyapatite coatings in vivo

PURPOSE

Hydroxyapatite (HA) has been used as a coating for orthopaedic implants for over 30 years to help promote the fixation of orthopaedic implants into the surrounding bone. However, concerns exist about the fate of the hydroxyapatite coating and hydroxyapatite particles in vivo, especially in the wake of recent concerns about particulates from metal-on-metal bearings.

METHODS

Here, we assess the mechanisms of particle detachment from coated orthopaedic devices as well as the safety and performance concerns and biomedical implications arising from the liberation of the particles by review of the literature.

FINDINGS

The mechanisms that can result in the detachment of the HA coating from the implant can be mechanical or biochemical, or both. Mechanical mechanisms include implant insertion, abrasion, fatigue and micro-motion. Biochemical mechanisms that contribute to the liberation of HA particles include dissolution into extra-cellular fluid, cell-mediated processes and crystallisation of amorphous phases. The form the particles take once liberated is influenced by a number of factors such as coating method, the raw powder morphology, processing parameters, coating thickness and coating structure.

CONCLUSIONS

This review summarises and discusses each of these factors and concludes that HA is a safe biomimetic material to use as a coating and does not cause any problems in particulate form if liberated as debris from an orthopaedic implant.

An assessment tool to help producers improve cow comfort on their farms

Effective management and an appropriate environment are essential for dairy cattle health and welfare. Codes of practice provide dairy producers with best practice guidance for the care and handling of their cattle. New Canadian recommendations have been established for the dairy industry. The objectives of this study were to develop an on-farm assessment tool that helps producers assess how well they are meeting their code of practice and that identifies management and environment modifications that could improve dairy cow comfort on their farms. The assessment tool addressed critical areas of dairy cow comfort, including accommodation and housing (stall design, space allowance, stall management, pen management, milking parlor, and transfer alleys), feed and water (body condition scoring, nutrition), and health and welfare (lameness, claw health, and hoof-trimming). Targets of good practices were identified from the requirements and recommendations of the code of practice. Each farm received a score for each target, ranging from 0 (target not reached) to 100 (target reached). One hundred tiestall and 110 freestall farms were surveyed in 3 provinces of Canada (Quebec, Ontario, and Alberta). The duration of the assessment, in 2 visits lasting, on average, 8 and 9h (range between freestall and tiestall farms) and 4 and 4.1h, was beyond the targeted 3 to 4h due mainly to the animal-based measures; strategies to reduce the duration of the assessment were discussed. Standard operating procedures were developed to ensure consistency in measuring and recording data. Periodical checks were conducted by trainers to ensure all 15 assessors remained above target agreement of weighted kappa ≥0.6. Average scores for all critical areas ranged from 25 to 89% for freestall farms and from 48 to 95% for tiestall farms. These scores need to be considered with caution when comparing farms because scores could not always be calculated the same way between housing systems. An evaluation report was provided and discussed with each producer, identifying strengths and areas for improvement that could benefit dairy cow comfort on their farms. The producers were convinced of the effectiveness of our tool for assessing cow comfort (freestall: 86%; tiestall: 95%) and in assisting them to make decisions for improvements (freestall: 83%; tiestall: 93%). Our cow comfort assessment tool served as background material for the Dairy Farmers of Canada animal care assessment program.

Comparison of bacteriological culture and PCR for detection of bacteria in ovine milk--sheep are not small cows

Mastitis, inflammation of the mammary gland, is an important cause of disease, mortality, and production losses in dairy and meat sheep. Mastitis is commonly caused by intramammary infection with bacteria, which can be detected by bacterial culture or PCR. PathoProof (Thermo Fisher Scientific Ltd., Vantaa, Finland) is a commercially available real-time PCR system for the detection of bovine mastitis pathogens. Sheep differ from cattle in the bacterial species or bacterial strains that cause mastitis, as well as in the composition of their milk. The aim of this study was to evaluate whether the PathoProof system was suitable for detection of mastitis pathogens in sheep milk. Milk samples were collected aseptically from 219 udder halves of 113 clinically healthy ewes in a single flock. Aliquots were used for bacteriological culture and real-time PCR-based detection of bacteria. For species identified by culture, the diagnosis was confirmed by species-specific conventional PCR or by sequencing of a housekeeping gene. The majority of samples were negative by culture (74.4% of 219 samples) and real-time PCR (82.3% of 192 samples). Agreement was observed for 138 of 192 samples. Thirty-four samples were positive by culture only, mostly due to presence of species that are not covered by primers in the PCR system (e.g., Mannheimia spp.). Two samples were positive for Streptococcus uberis by culture but not by PCR directly from the milk samples. This was not due to inability of the PCR primers to amplify ovine Streptococcus uberis, as diluted DNA extracts from the same samples and DNA extracts from the bacterial isolates were positive by real-time PCR. For samples containing Staphylococcus spp., 11 samples were positive by culture and PCR, 9 by culture only, and 20 by PCR only. Samples that were negative by either method had lower bacterial load than samples that were positive for both methods, whereas no clear relation with species identity was observed. This study provides proof of principle that real-time PCR can be used for detection of mastitis pathogens in ovine milk. Routine use in sheep may require inclusion of primer sets for sheep-specific mastitis pathogens.