Communicating without words: Measuring nonverbal communication between veterinarians and farmers during routine herd health consultations.

Uptake of advice and the ability to facilitate change on-farm are key elements for successful veterinary practice. However, having the necessary clinical skills and knowledge is not enough to achieve this: effective communication skills are essential for veterinarians to realize their advisory role by exploring and understanding the farmer's worldview. Research of verbal aspects of veterinarian communication supports the use of a relationship-centered communication style; we next need to study how veterinarian-farmer nonverbal communication (NVC) can influence interactions and their outcomes, which has been examined in medical and companion animal practice. In this study, we considered which aspects of NVC should be measured, and how, to provide an essential first step toward understanding the significance of NVC for veterinarians working in dairy practice, which should be of interest to researchers, veterinary educators, and practitioners. Eleven video recordings of routine consultations in the UK were analyzed for farmer and veterinarian NVC. The NVC attributes with established links to positive patient and client outcomes from medical and social science studies were chosen, and a methodology developed for their measurement, by adapting measures typically used in NVC research. Each consultation was segmented into intervals defined by the main activity and location on farm: introduction, fertility examination, discussion, and closing. This approach allowed us to analyze the content more consistently, establish which aspects of NVC featured within each interval, and whether the activity and location influenced the observed NVC. We measured 12 NVC attributes, including body orientation, interpersonal distance, head position, and body lean, which have been shown to influence empathy, rapport, and trust: key components of relationship-centered communication. Future research should seek to establish the significance of NVC in effective communication between veterinarian and farmer, building on our findings that show it is possible to measure nonverbal attributes. Veterinarians may benefit from becoming skilled nonverbal communicators and have more effective conversations during routine consultations, motivating farmers to make changes and improve herd health.

Amoebic crab disease (ACD) in edible crab Cancer pagurus from the English Channel, UK.

The genera Paramoeba and Neoparamoeba (Amoebozoa, Dactylopodida, Paramoebidae) include well-known opportunistic pathogens associated with fish (N. peruans; amoebic gill disease), lobsters, molluscs and sea urchins, but only rarely with crabs (grey crab disease of blue crabs). Following reports of elevated post-capture mortality in edible crabs Cancer pagurus captured from a site within the English Channel fishery in the UK, a novel disease (amoebic crab disease, ACD) was detected in significant proportions of the catch. We present histopathological, transmission electron microscopy and molecular phylogenetic data, showing that this disease is defined by colonization of haemolymph, connective tissues and fixed phagocytes by amoeboid cells, leading to tissue destruction and presumably death in severely diseased hosts. The pathology was strongly associated with a novel amoeba with a phylogenetic position on 18S rRNA gene trees robustly sister to Janickina pigmentifera (which groups within the current circumscription of Paramoeba/Neoparamoeba), herein described as Janickina feisti n. sp. We provide evidence that J. feisti is associated with ACD in 50% of C. pagurus sampled from the mortality event. A diversity of other paramoebid sequence types, clustering with known radiations of N. pemaquidensis and N. aestuarina and a novel N. aestuarina sequence type, was detected by PCR in most of the crabs investigated, but their detection was much less strongly associated with clinical signs of disease. The discovery of ACD in edible crabs from the UK is discussed relative to published historical health surveys for this species.

Effects of routine treatment with nonsteroidal anti-inflammatory drugs at calving and when lame on the future probability of lameness and culling in dairy cows: A randomized controlled trial.

Claw horn lesions (CHL) are reported as the most common cause of lameness in intensive dairy systems. Despite their prevalence, the underlying pathological mechanisms and preventive strategies for CHL remain poorly understood. Recent advances have pointed to the role of inflammation in disease aetiopathogenesis. Moderating inflammation from first calving may lead to long-term benefits and a viable intervention for treating and preventing disease. We conducted a 34-mo randomized controlled trial to investigate the effects of routine treatment with the nonsteroidal anti-inflammatory drug ketoprofen at calving and during treatment for lameness, on the future probability of lameness and culling, caused by exposure to normal farm conditions. A cohort of dairy heifers were recruited from a single, commercial dairy herd between January 8, 2018, and June 22, 2020, and randomly allocated to one of 4 treatment groups before first calving. The lactating herd was lameness scored every 2 wk on a 0 to 3 scale, to identify animals that became lame (single score ≥2a) and hence required treatment. Animals in group 1 received a therapeutic trim and a hoof block on the sound claw (if deemed necessary) every time they were treated for lameness. Animals in group 2 received the same treatment as group 1 with the addition of a 3-d course of ketoprofen (single dose daily) every time they were treated for lameness. Animals in group 3 received the same treatment as group 2 with the addition of a 3-d course of ketoprofen (single dose daily) starting 24 to 36 h after each calving. Animals in group 4 received a 3-d course of ketoprofen (single dose daily) every time they were identified with lameness. No therapeutic trim was administered to this group, unless they were identified as severely lame (a single score ≥3a). Animals were followed for the duration of the study (ending October 23, 2020). Probability of lameness was assessed by a lameness outcome score collected every 14 d. Data on culling was extracted from farm records. One hundred thirty-two animals were recruited to each group, with data from 438 animals included in the final analysis (111 in group 1, 117 in group 2, 100 in group 3, and 110 in group 4). Mixed effect logistic regression models were used to evaluate the effect of treatment group on the ongoing probability of lameness. Compared with the control group (group 1), animals in group 3 were less likely to become lame (odds ratio: 0.66) and severely lame (odds ratio: 0.28). A Cox proportional hazards survival model was used to investigate the effect of treatment group on time to culling. Compared with group 1, animals in groups 2 and 3 were at reduced risk of culling (hazard ratios: 0.55 and 0.56, respectively). The lameness effect size we identified was large and indicated that treating a cohort of animals with the group 3 protocol, would lead to an absolute reduction in population lameness prevalence of approximately 10% and severe lameness prevalence of 3%, compared with animals treated in accordance with conventional best practice (group 1).

Cattle farmer psychosocial profiles and their association with control strategies for bovine viral diarrhea.

Bovine viral diarrhea (BVD) is endemic in the United Kingdom and causes major economic losses. Control is largely voluntary for individual farmers and is likely to be influenced by psychosocial factors, such as altruism, trust, and psychological proximity (feeling close) to relevant "others," such as farmers, veterinarians, the government, and their cows. These psychosocial factors (factors with both psychological and social aspects) are important determinants of how people make decisions related to their own health, many of which have not been studied in the context of infectious disease control by farmers. Farmer psychosocial profiles were investigated using multiple validated measures in an observational survey of 475 UK cattle farmers using the capability, opportunity, motivation-behavior (COM-B) framework. Farmers were clustered by their BVD control practices using latent class analysis. Farmers were split into 5 BVD control behavior classes, which were tested for associations with the psychosocial and COM-B factors using multinomial logistic regression, with doing nothing as the baseline class. Farmers who were controlling disease both for themselves and others were more likely to do something to control BVD (e.g., test, vaccinate). Farmers who did not trust other farmers, had high psychological capability (knowledge and understanding of how to control disease), and had high physical opportunity (time and money to control disease) were more likely to have a closed, separate herd and test. Farmers who did not trust other farmers were also more likely to undertake many prevention strategies with an open herd. Farmers with high automatic motivation (habits and emotions) and reflective motivation (decisions and goals) were more likely to vaccinate and test, alone or in combination with other controls. Farmers with high psychological proximity (feeling of closeness) to their veterinarian were more likely to undertake many prevention strategies in an open herd. Farmers with high psychological proximity to dairy farmers and low psychological proximity to beef farmers were more likely to keep their herd closed and separate and test or vaccinate and test. Farmers who had a lot of trust in other farmers and invested in them, rather than keeping everything for themselves, were more likely to be careful introducing new stock and test. In conclusion, farmer psychosocial factors were associated with strategies for BVD control in UK cattle farmers. Psychological proximity to veterinarians was a novel factor associated with proactive BVD control and was more important than the more extensively investigated trust. These findings highlight the importance of a close veterinarian-farmer relationship and are important for promoting effective BVD control by farmers, which has implications for successful nationwide BVD control and eradication schemes.

Multiple model triangulation to identify factors associated with lameness in British sheep flocks.

Identification of factors associated with an outcome can be challenging when the number of explanatory variables is large in relation to the number of observations. Multiple model triangulation, where results from several model types are combined, improves the likelihood of identifying true predictor variables. The aim of this study was to use triangulation to identify covariates likely to be truly associated with the prevalence of lameness in sheep flocks in Great Britain. Data were collected using a questionnaire sent to 3200 sheep farmers in Great Britain in 2018. The useable response rate was 14.1 %. The geometric mean prevalence of lameness was 1.4 % (95 % CI 1.2-1.7) for ewes, and 0.6 % (95 % CI 0.5-0.9) for lambs, however, approximately 60 % flocks had >2% prevalence of lameness in ewes. Four model types were investigated, two generalised linear models (negative binomial and quasi-Poisson) built using stepwise selection, and two elastic net models (Poisson and Gaussian distributions) refined with selection stability estimation. Triangulated covariates were those selected in three or all four models - 10 for ewes and 12 for lambs. Higher prevalence of lameness in ewes was associated with 5-100% feet bleeding during routine foot trimming compared with not foot trimming, footbathing the flock to treat severe footrot (SFR) and always using formalin in footbaths, both compared with not footbathing, using FootVax™ for <1 year compared with not using FootVax™, and never quarantining new or returning sheep to the farm for >3 weeks compared with always. Lower prevalence of lameness in ewes was associated with vaccinating with FootVax™ for >5 years compared with not vaccinating, peat soil compared with no peat soil, and having no lame ewes to treat. Higher prevalence of lameness in lambs was associated with 5-100% feet bleeding during routine foot trimming, always foot trimming ewes with SFR, not knowingly selecting replacement ewes from ewes that were never lame compared with always, replacement sheep purchased and homebred compared with only homebred, treating lambs >3 days after recognition of lameness compared with 0-3 days and footbathing the flock to treat interdigital dermatitis compared with not footbathing at all. Lower prevalence of lameness in lambs was associated with peat soil, flocks in Scotland versus England, an altitude of >230-500 m compared with ≤230 m, never using antibiotic injection to treat lambs with SFR compared with always, and having no lame lambs to treat. We conclude triangulation identified reliable management practices for farmers to implement to minimise lameness in sheep.

Randomized controlled field trial comparing quarter and cow level selective dry cow treatment using the California Mastitis Test.

Selective use of antibiotic dry cow treatment can be implemented at the cow or quarter level, with the latter having the potential to further reduce antibiotic use. Our objective was to compare these 2 approaches in 6 herds in the United Kingdom in which environmental mastitis predominated. Eight hundred seven cows were enrolled and categorized as having a high cell count (n = 401) or low cell count (n = 406) in the last 3 mo of lactation and clinical mastitis history. All quarters of all enrolled cows received an internal teat sealant. Within each category, cows were randomly allocated to 1 of 3 groups; in one group antibiotic treatment was allocated at cow level (i.e., all 4 quarters received antibiotic), whereas in the 2 remaining groups antibiotic treatment was allocated at quarter level, based on California Mastitis Test (CMT) findings. Two different thresholds, score 1 and 2, were used to determine likely infection status. Quarter milk samples were collected at dry off and postcalving for bacteriological culture and somatic cell count (SCC). Cows were monitored for clinical mastitis from dry off until 100 d in milk. Cow level SCC and milk yield data were collated from farm records. Within each category, the 2 quarter level treatment groups were compared with cow level treatment at dry off. Leaving quarters untreated with intramammary antibiotic in cows in the high cell count group, with a CMT <2 or <1, reduced antibiotic use by 55% and 31%, respectively, and resulted in no difference in the odds of being infected with any pathogen postcalving, but was associated with a higher SCC at the first test day. Intramammary antibiotic treatment of quarters with a CMT ≥1 in cows in the low cell count category at dry off was not associated with any reduction in the odds of being infected with a major pathogen postcalving but was associated with a decrease in the odds of being infected with a minor mastitis pathogen postcalving. The use of antibiotics in quarters of cows categorized as low cell count at dry off, increased the proportion of quarters treated with antibiotic from 0% at cow level to 31% (CMT ≥ 1) and 12% (CMT ≥ 2) at quarter level, only resulting in a reduction in SCC of around 20,000 cells/mL at the first test day, if all quarters with CMT score ≥1 were treated with antibiotic. No differences in clinical mastitis incidence and milk yield in the first 100 d in milk were detected between any of the treatment groups. These study findings support selective quarter level dry off treatment only in cows with cow level SCC >200,000 cells/mL at dry off.

A history of lameness and low body condition score is associated with reduced digital cushion volume, measured by magnetic resonance imaging, in dairy cattle.

Claw horn lesions (CHL) are the result of a failing of the functional anatomy of the hoof in dairy cows. The digital cushion is understood to be a vital structure in the prevention of CHL. Claw horn lesions have previously been shown to lead to pathological change to the pedal bone; however, their effects on the digital cushion are unknown. The primary aim of this study was to examine associations between the history of CHL through an animal's life and the structure of the digital cushion at slaughter using magnetic resonance imaging. The retrospective cohort study resulted in the scanning of 102 pairs of hindfeet, collected from adult Holstein dairy cows culled from a research herd, using a 3-Tesla research-grade magnetic resonance imaging scanner. Volume and fat measurements were calculated for each digital cushion within each claw from a modified Dixon Quant sequence. Animal-level variables were constructed around the animals' lactating lifetime, with lameness scores and body condition score collected at least every 2 wk. The combined volume of digital cushion in the lateral claws was used as the outcome variable in multivariable linear models. The volume of the digital cushion was negatively associated with the number of lameness events or CHL recorded. Furthermore, animals with body condition score >3, culled later in lactation, or of a greater body weight were more likely to have a higher volume of digital cushion in the lateral claws. We propose that the observations made in the current study are the effects of a range of factors broadly associated with genetic, developmental, and disease-related inputs. Our understanding of how we can select for genetically more robust animals and how we can precondition the hoof before first calving needs to be improved to reduce the risk of future CHL in adult dairy cattle. Furthermore, understanding optimal treatment regimens and their effect on hoof anatomy may reduce the recurrence of CHL in the current lactation and future lactations.

γδ T cells compose a developmentally regulated intrauterine population and protect against vaginal candidiasis.

This most comprehensive analysis to date of γδ T cells in the murine uterus reveals them to compose a unique local T-cell compartment. Consistent with earlier reports, most cells expressed a canonical Vγ6Vδ1 TCR, and produced interleukin (IL)-17A upon stimulation. Nonetheless, contrasting with earlier reports, uterine γδ T cells were not obviously intraepithelial, being more akin to sub-epithelial Vγ6Vδ1+ T cells at several other anatomical sites. By contrast to other tissues however, the uterine compartment also included non-Vγ6+, IFN-γ-producing cells; was strikingly enriched in young mice; expressed genes hitherto associated with the uterus, including the progesterone receptor; and did not require microbes for development and/or maintenance. This notwithstanding, γδ T-cell deficiency severely impaired resistance to reproductive tract infection by Candida albicans, associated with decreased responses of IL-17-dependent neutrophils. These findings emphasise tissue-specific complexities of different mucosal γδ cell compartments, and their evident importance in lymphoid stress-surveillance against barrier infection.

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.

Tunable dispersibility and wettability of graphene oxide through one-pot functionalization and reduction.

HYPOTHESIS: Surface functionalization is an effective method to tune the wettability and dispersibility of graphene oxide (GO) nanosheets, but functionalization methods often require long reaction times and expensive reagents. To meet this GO processing need, we propose a quick, industrially scalable GO functionalization scheme based upon Fischer esterification and epoxide ring-opening reactions; we expect this method to yield hydrophobic graphene with tuned wettability and dispersibility properties through the attachment of various alkyl groups. EXPERIMENT: N-pentyl and t-butyl groups were grafted onto GO in a one-pot functionalization and reduction scheme and chemical functionalization was confirmed by various techniques. Subsequently, the wettability of the functionalized GO was investigated through contact angle measurements and the dispersibility of GO in various solvents was observed. FINDINGS: The contact angle of n-pentyl functionalized GO increased to 134.0°, a value comparable or superior to those achieved for functionalized GO in the literature. Furthermore, dispersibility studies showed that functionalized GO had distinct affinities for organic solvents, with t-butyl functionalized GO being highly dispersible in chloroform and n-pentyl GO being highly dispersible in toluene. We propose that this functionalization and reduction method could be successfully applied on the industrial scale to engineer reduced graphene oxide with tuned dispersibility and wettability properties.

Associations between routinely collected Dairy Herd Improvement data and insemination outcome in UK dairy herds.

Milk constituent concentrations in samples taken during early lactation are often used to generate proxy measures for energy balance in dairy herds. This study aimed to explore associations between these and other measures routinely recorded by Dairy Herd Improvement schemes and insemination outcome, with an emphasis on the likely predictiveness of such measures for conception risk (the proportion of inseminations that are successful) at herd level. Data from 312 UK dairy herds were restructured so that each unit of data represented an insemination at less than 100 d in milk (DIM). Milk constituent concentrations from the first and second test days (corrected for the effects of season and DIM at sampling) were used as potential predictors of insemination outcome in a logistic regression model. Other predictors included representations of milk yield and other information routinely collected by Dairy Herd Improvement Associations; random effects were used to account for clustering at cow and herd levels. The final model included a large number of predictors, with several interaction and nonlinear terms. The relative effect sizes of the measures of early lactation milk constituent concentrations were small. The full model predicted just under 64% of observed variation in herd-year conception risk (i.e., the proportion of inseminations that were successful in each herd in each calendar year); however, around 40% was accounted for by the herd-level random effect. The predictors based on early lactation milk constituent concentrations accounted for less than 0.5% of observed variation, and representations of milk yield (both overall level of yield and early lactation curve shape) accounted for around 7%; DIM at insemination, parity, interservice interval, year, and month accounted for the remaining 15%. These results suggest that early lactation milk constituent information is unlikely to predict herd conception risk to a useful extent. The large proportion of observed variation explained by the herd-level random effect suggests that there are unmeasured (in this study) or unmeasurable factors that are consistent within a herd and are highly influential in determining herd conception risk.

Use of statistical modelling to investigate the pathogenesis of claw horn disruption lesions in dairy cattle.

Claw horn disruption lesions (CHDLs) in dairy cattle account for a large proportion of lameness. The aim of this review is to provide an update on the evidence surrounding the pathogenesis of CHDLs, in the context of how statistical modelling has contributed to the validity of available evidence and current thinking. Historically, 'subclinical laminitis' has often been used to describe the commonly accepted underlying pathology associated with these lesions, however progress in understanding the aetiopathogenesis of CHDLs and a lack of clear evidence to support the traditional laminitis hypothesis, means use of this terminology has been challenged. With advancements in statistical modelling capabilities within the veterinary field, the multifactorial and complex nature of CHDLs can be more fully explored. This has led to an increased understanding of environmental and animal-based risk factors and their role in the pathogenesis of CHDLs, as well as highlighting future research areas. There is still a need for further research using intervention studies to demonstrate causality for identified risk factors to date, as well as quantifying the impact of these risk factors at the population level. Some important considerations when using and interpreting statistical models in lameness research are discussed with a critical assessment of the key statistical issues in published research investigating the pathogenesis of CHDLs.

Short- and long-term association between individual levels of milk antibody against Ostertagia ostertagi and first-lactation heifer's production performances.

It is agreed that exposure of adult dairy cattle to helminths on pasture can negatively affect production performances as milking herd. Young animals, especially replacement heifers, represent the future of a dairy farm and are among the most vulnerable to helminth infections in a dairy herd. For this reason, dairy farmers tend to frequently treat heifers against helminths, although the impact of helminths on heifers' production performances is still poorly understood. Using different epidemiological and serological tools, this study examines the relationship between heifer exposure to helminths on pasture and production performances over time. During a one-year period, 1,454 individual milk samples were collected from first-lactation heifers in England and tested for Ostertagia ostertagi (O. ostertagi) antibodies. After controlling for other confounders, increasing milk antibody levels against O. ostertagi were significantly associated with decreased milk yield at sampling but not at day 305 of heifer lactation. We did not observe any relationship between milk antibody levels against O. ostertagi in heifers and yields in fat and protein. However, heifers with a high level of milk antibodies against O. ostertagi were more likely to produce dead calf at first calving and present a delay in second calving. Moreover, these heifers had significantly higher levels of milk antibodies against Mycobacterium paratuberculosis (M. paratuberculosis) during their first lactation and were more likely to die before the end of the study. We argue that epidemiological approaches can be useful but must be complemented by other methodologies to better understand the impact of helminth infections in dairy heifers. In order to address the complex dynamics of helminth infections in dairy cattle production we require more comprehensive approaches that include triangulation between data sources and interdisciplinary studies.

Associations between dairy cow inter-service interval and probability of conception.

Recent research has indicated that the interval between inseminations in modern dairy cattle is often longer than the commonly accepted cycle length of 18-24 days. This study analysed 257,396 inseminations in 75,745 cows from 312 herds in England and Wales. The interval between subsequent inseminations in the same cow in the same lactation (inter-service interval, ISI) were calculated and inseminations categorised as successful or unsuccessful depending on whether there was a corresponding calving event. Conception risk was calculated for each individual ISI between 16 and 28 days. A random effects logistic regression model was fitted to the data with pregnancy as the outcome variable and ISI (in days) included in the model as a categorical variable. The modal ISI was 22 days and the peak conception risk was 44% for ISIs of 21 days rising from 27% at 16 days. The logistic regression model revealed significant associations of conception risk with ISI as well as 305 day milk yield, insemination number, parity and days in milk. Predicted conception risk was lower for ISIs of 16, 17 and 18 days and higher for ISIs of 20, 21 and 22 days compared to 25 day ISIs. A mixture model was specified to identify clusters in insemination frequency and conception risk for ISIs between 3 and 50 days. A "high conception risk, high insemination frequency" cluster was identified between 19 and 26 days which indicated that this time period was the true latent distribution for ISI with optimal reproductive outcome. These findings suggest that the period of increased numbers of inseminations around 22 days identified in existing work coincides with the period of increased probability of conception and therefore likely represents true return estrus events.

A longitudinal study of gastrointestinal parasites in English dairy farms. Practices and factors associated with first lactation heifer exposure to Ostertagia ostertagi on pasture.

The gastrointestinal nematode Ostertagia ostertagi is an important cause of lost production, health, and welfare in cattle. Detailed records were obtained over a 5-yr period (2010-2015) by questionnaires and qualitative interviews to investigate the practices adopted by dairy farmers to control cattle helminth infections and the factors associated with heifer exposure to O. ostertagi on pasture. In total, 1,454 heifers' individual milk samples were collected over a 1-yr period (2014-2015) in 43 dairy farms in England and tested for O. ostertagi antibody by ELISA. Multilevel linear regression models were used to investigate the association between individual milk optical density ratio (ODR) against O. ostertagi and heifer management from birth to time of sampling. Farm and heifer median ODR against O. ostertagi were 0.98 (interquartile range = 0.76-1.02) and 0.64 (interquartile range = 0.42-0.84), respectively. The majority of heifers (88%) received an anthelmintic treatment before sampling in this study. After controlling for the effect of anthelmintic treatments, heifer individual milk ODR against O. ostertagi significantly increased with high stocking rate at first grazing and co-grazing with adult cows before calving. Conversely, heifer individual milk ODR against O. ostertagi significantly decreased when heifers had co-grazed with sheep and pasture grass had frequently been mowed. Overall, these results provide evidence to support targeting grazing management toward limiting the use of anthelmintics in dairy young stock to enable sustainable control of cattle helminth infections in England. However, to be accepted and adopted by farmers, these best practices would need to take into account farmers' perspectives and contextual challenges.

Effects of childhood trauma on left inferior frontal gyrus function during response inhibition across psychotic disorders.

BACKGROUND: Childhood trauma is a risk factor for psychosis. Deficits in response inhibition are common to psychosis and trauma-exposed populations, and associated brain functions may be affected by trauma exposure in psychotic disorders. We aimed to identify the influence of trauma-exposure on brain activation and functional connectivity during a response inhibition task. METHODS: We used functional magnetic resonance imaging to examine brain function within regions-of-interest [left and right inferior frontal gyrus (IFG), right dorsolateral prefrontal cortex, right supplementary motor area, right inferior parietal lobule and dorsal anterior cingulate cortex], during the performance of a Go/No-Go Flanker task, in 112 clinical cases with psychotic disorders and 53 healthy controls (HCs). Among the participants, 71 clinical cases and 21 HCs reported significant levels of childhood trauma exposure, while 41 clinical cases and 32 HCs did not. RESULTS: In the absence of effects on response inhibition performance, childhood trauma exposure was associated with increased activation in the left IFG, and increased connectivity between the left IFG seed region and the cerebellum and calcarine sulcus, in both cases and healthy individuals. There was no main effect of psychosis, and no trauma-by-psychosis interaction for any other region-of-interest. Within the clinical sample, the effects of trauma-exposure on the left IFG activation were mediated by symptom severity. CONCLUSIONS: Trauma-related increases in activation of the left IFG were not associated with performance differences, or dependent on clinical diagnostic status; increased IFG functionality may represent a compensatory (overactivation) mechanism required to exert adequate inhibitory control of the motor response.

The contribution of previous lameness events and body condition score to the occurrence of lameness in dairy herds: A study of 2 herds.

It has been demonstrated that low body condition and previous occurrence of lameness increase the risk of future lameness in dairy cows. To date the population attributable fraction (PAF), which provides an estimate of the contribution that a risk factor makes toward the total number of disease events in a population, has not been explored for lameness using longitudinal data with repeated measures. Estimation of PAF helps to identify control measures that could lead to the largest improvements on-farm. The aim of this study was to use longitudinal data to evaluate the proportion of lameness that could be avoided in 2 separate herds (2 populations) through (1) reduced recurrence of previous lameness events, (2) and moving body condition score (BCS) into more optimal ranges. Data were obtained from 2 UK dairy herds: herd A, a 200-cow herd with 8 yr of data from a total of 724 cows where lameness events were based on weekly locomotion scores (LS; 1 to 5 scale), and herd B, a 600-cow herd with data recorded over 44 mo from a total of 1,040 cows where treatment of clinical cases was used to identify lameness events. The PAF for categories of BCS were estimated using a closed equation appropriate for multiple exposure categories. Simulation models were used to explore theoretical scenarios to reflect changes in BCS and recurrence of previous lameness events in each herd. For herd A, 21.5% of the total risk periods (cow-weeks) contained a lameness event (LS 3, 4, or 5), 96% of which were repeat events and 19% were recorded with BCS <2 (3 wk previously; 0 to 5 scale). When lameness events were based on 2 consecutive weeks of LS 4 or 5, 4% of risk periods were recorded as lame, of which 89.5% were repeat events. For herd B, 16.3% of the total risk periods (consecutive 30 d) contained a lameness event (72.6% were repeat events) and 20% were recorded with BCS ≤2 (0 to 120 d previously). The median PAF for all previous lameness was between 79 and 83% in the 2 herds. Between 9 and 21% of lameness events could be attributed to previous lameness occurring >16 wk before a risk period. The median PAF estimated for changes in BCS were in the region of 4 to 11%, depending on severity of lameness. Repeated bouts of lameness made a very large contribution to the total number of lameness events. This could either be because certain cows are initially susceptible and remain susceptible, due to the increased risk associated with previous lameness events, or due to interactions with environmental factors. This area requires further research.

Factors affecting the cost-effectiveness of on-farm culture prior to the treatment of clinical mastitis in dairy cows.

The objective of this study was to use probabilistic sensitivity analysis to evaluate the cost-effectiveness of using an on-farm culture (OFC) approach to the treatment of clinical mastitis in dairy cows and compare this to a 'standard' treatment approach. A specific aim was to identify the herd circumstances under which an OFC approach would be most likely to be cost-effective. A stochastic Monte Carlo model was developed to simulate 5000 cases of clinical mastitis at the cow level and to calculate the associated costs simultaneously when treated according to 2 different treatment protocols; i) a 'conventional' approach (3 tubes of intramammary antibiotic) and ii) an OFC programme, whereby cows are treated according to the results of OFC. Model parameters were taken from recent peer reviewed literature on the use of OFC prior to treatment of clinical mastitis. Spearman rank correlation coefficients were used to evaluate the relationships between model input values and the estimated difference in cost between the standard and OFC treatment protocols. The simulation analyses revealed that both the difference in the bacteriological cure rate due to a delay in treatment when using OFC and the proportion of Gram-positive cases that occur on a dairy unit would have a fundamental impact on whether OFC would be cost-effective. The results of this study illustrated that an OFC approach for the treatment of clinical mastitis would probably not be cost-effective in many circumstances, in particular, not those in which Gram-positive pathogens were responsible for more than 20% of all clinical cases. The results highlight an ethical dilemma surrounding reduced use of antimicrobials for clinical mastitis since it may be associated with financial losses and poorer cow welfare in many instances.

A prospective cohort study of digital cushion and corium thickness. Part 2: Does thinning of the digital cushion and corium lead to lameness and claw horn disruption lesions?

The aim of this study was to determine whether a decrease in thickness of the sole soft tissues (SST) beneath the flexor tuberosity of the distal phalanx (i.e., the digital cushion and corium) predisposed a claw to develop claw horn disruption lesions (CHDL) or a leg to lameness. Data were analyzed from a longitudinal study of 179 cows, which had been examined at 5 assessment points -8, +1, +9, +17, and +29 wk relative to their first, second, third, or fourth calving. At each assessment point, SST were measured using ultrasonography. Additional assessment point data included sole lesions and back fat thickness (BFT), and cows had been locomotion scored every 2 wk from calving. One hundred fifty-eight cows completed the study. Separate logistic regression survival analyses were constructed to assess the outcomes, either lameness on a leg or CHDL on a claw; combinations of lameness and lesions were tested as outcomes. Cow level variables tested included farm and lactation number. Variables were tested describing previous SST thickness, minimum previous SST thickness, BFT, and change in either variable between prior assessment points. Prior lesions/lameness strongly predicted repeat cases and the final models had the outcome first lesion or lameness on a claw or leg. In the reported lameness models, lameness was defined as a leg being recorded as lame twice within 3 consecutive scores, and in the reported lesion models, lesion was defined as the first presence of either a sole ulcer or a severe sole hemorrhage on a claw. Thin SST increased the likelihood of lesion occurrence; thin SST on the lateral claw predicted subsequent lameness on a leg. Thin BFT and thinning of BFT between previous assessment points increased the likelihood of future lesion occurrence. Thin SST and thinning of BFT had additional effects on the likelihood of lesion occurrence, suggesting that BFT and sole SST had independent effects on lesion occurrence. However, change in SST thickness between assessment points did not influence the likelihood of future lesions or lameness. This suggests that thin SST were not simply a result of depletion of body fat and challenges the theory that thinning of the digital cushion with body fat mobilization leads to CHDL. Other possible mechanisms by which SST become thin are discussed and could include changes in integrity of the suspensory apparatus with physiological events.

A prospective cohort study of digital cushion and corium thickness. Part 1: Associations with body condition, lesion incidence, and proximity to calving.

Claw horn disruption lesions (CHDL) are a major cause of lameness in dairy cattle and are likely a result of excessive forces being applied to the germinal epithelium that produces the claw horn. The digital cushion is a connective tissue structure, containing depots of adipose tissue, that sits beneath the distal phalanx and has been shown to be thicker in fatter cows. Body condition score (BCS) loss is a risk factor for CHDL, and one possible explanation is that fat is mobilized from the digital cushion during negative energy balance, causing the digital cushion to thin and lose force-dissipating capacity, leading to disruption of claw horn growth. This prospective cohort study investigated the association between measures of body fat and sole soft tissue (SST) thickness (a combined measure of the corium and digital cushion beneath the distal phalanx) in a longitudinal manner. The SST of 179 cows in 2 high-yielding dairy herds were measured at 5 assessment points between 8 wk before and 35 wk postcalving. The BCS, back fat thickness (BFT), and lesion incidence were recorded. Data were analyzed in a 4-level mixed effects regression model, with the outcome being SST thickness beneath the flexor tuberosity of the distal phalanx. Data from 827 assessment points were available for analysis. The overall mean of SST was 4.99 mm (standard deviation: 0.95). The SST was thickest 8 wk before calving (5.22 mm, standard deviation: 0.91) and thinnest 1 wk postcalving (4.68 mm, standard deviation: 0.87), suggesting an effect of calving on SST. The BFT was positively correlated with SST in the model with a small effect size (a 10 mm decrease in BFT corresponded with a 0.13 mm decrease in SST), yet the nadir of BFT was 11.0 mm at 9 to 17 wk postcalving (when SST was ∼4.95 mm), rather than occurring with the nadir of SST immediately after calving. The SST also varied with other variables [e.g., cows that developed a sole ulcer or severe sole hemorrhage during the study had thinner SST (-0.24 mm)], except when a sole ulcer was present, when it was thicker (+0.53 mm). Cows that developed lesions had a thinner digital cushion before the lesion occurrence, which became thickened with sole ulcer presence, perhaps representing inflammation. Furthermore, although BFT was correlated with SST over time, SST may also have been influenced by other factors such as integrity of the suspensory apparatus, which could have a major effect on CHDL. Measures of body fat likely contributed to having thin SST, but other factors including calving, herd, and lesion presence also had an effect.