Rachel Clifton

Dr. Rachel Clifton

orcid

Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 July 2024 in Animals
Verified
Journal Article
Open access
PDF file
KLKatharine Eleanor Lewis
Katharine Eleanor Lewis
MGMartin Green
Martin Green
RCRachel Clifton
Rachel Clifton
EMEmma Margaret Monaghan
Emma Margaret Monaghan
NPNaomi Sarah Prosser
Naomi Sarah Prosser
Laura GreenLaura Green
Laura Green
Since 2004, the prevalence of lameness in sheep flocks in England has reduced as farmers have adopted evidence-based management practices to control lameness. In 2011, the Farm Animal Welfare Council proposed a target prevalence of <2% lameness in sheep by 2021. This study investigated whether that target had been achieved and determined which practices were associated with prevalence of lameness. A postal questionnaire was sent to 1000 randomly selected farmers to investigate the prevalence of lameness and management practices in 2022. The geometric mean prevalence of lameness was <2% in ewes and lambs, but the median was 3%; approximately 26% flocks had <2% lameness. Data were analysed using robust variable selection with multivariable linear models. Farmers that quarantined ewes for ≥3 weeks and did not use foot bathing or foot trimming to prevent lameness had 40–50% lower prevalence of lameness than those not using these practices. Fewer farmers (19.0%) were always using parenteral antimicrobials to treat footrot, an effective practice, than in previous research (49.7%). We conclude that the target of <2% lameness in England has been achieved by 26% of farmers, and further work is required for more farmers to follow the evidence-based management practices to minimise lameness.

1 December 2024 in Journal of Dairy Science
Verified
Journal Article
Open access
MBMatthew Barden
Matthew Barden
RHRobert Hyde
Robert Hyde
MGMartin Green
Martin Green
ABAndrew Bradley
Andrew Bradley
ECEdna Can
Edna Can
LOLuke O'GRady
Luke O'GRady
One suggested approach to improve the reproductive performance of dairy herds is through the targeted management of subgroups of biologically similar animals, such as those with similar probabilities of becoming pregnant, termed pregnancy risk. We aimed to use readily available farm data to develop predictive models of pregnancy risk in dairy cows. Data from a convenience sample of 108 dairy herds in the UK were collated and each herd was randomly allocated, at a ratio of 80:20, to either training or testing data sets. Following data cleaning, there were a total of 78 herds in the training data set and 20 herds in the testing data set. Data were further split by parity into nulliparous, primiparous, and multiparous subsets. An XGBoost model was trained to predict the insemination outcome in each parity subset, with predictors from farm records of breeding, calving and milk recording. Training data comprised 74,511 inseminations in 45,909 nulliparous animals, 86,420 inseminations in 39,439 primiparous animals, and 158,294 inseminations in 32,520 multiparous animals. The final models were evaluated by predicting with the testing data, comprising 31,740 inseminations in 19,647 nulliparous animals, 38,588 inseminations in 16,215 primiparous animals, and 65,049 inseminations in 12,439 multiparous animals. Model discrimination was assessed by calculating the area under receiver operating characteristic curves (AUC); model calibration was assessed by plotting calibration curves and compared across test herds by calculating the expected calibration error (ECE) in each test herd. The models were unable to discriminate between insemination outcomes with high accuracy, with an AUC of 0.63, 0.59 and 0.62 in the nulliparous, primiparous and multiparous subsets, respectively. The models were generally well-calibrated, meaning the model-predicted pregnancy risks were similar to the observed pregnancy risks. The mean (SD) ECE in the test herds was 0.038 (0.023), 0.028 (0.012) and 0.020 (0.008) in the nulliparous, primiparous and multiparous subsets respectively. The predictive models reported here could theoretically be used to identify subgroups of animals with similar pregnancy risk to facilitate targeted reproductive management; or provide information about cows' relative pregnancy risk compared with the herd average, which may support on-farm decision-making. Further research is needed to evaluate the generalizability of these predictive models and understand the source of variation in ECE between herds; however, this study demonstrates that it is possible to accurately predict pregnancy risk in dairy cows using readily available farm data.

1 January 1991 in Developmental Psychology
Verified
Journal Article
Closed access
RCRachel Clifton
Rachel Clifton
EPEve E. Perris
Eve E. Perris
ABAndre Bullinger
Andre Bullinger

11 June 2024 in Animals
Verified
Journal Article
Open access
PDF file
RCRachel Clifton
Rachel Clifton
RHRobert Hyde
Robert Hyde
ECEdna Can
Edna Can
MBMatthew Barden
Matthew Barden
AMAl Manning
Al Manning
LOLuke O’grady
Luke O’grady
Mobility scoring data can be used to estimate the prevalence, incidence, and duration of lameness in dairy herds. Mobility scoring is often performed infrequently with variable sensitivity, but how this impacts the estimation of lameness parameters is largely unknown. We developed a simulation model to investigate the impact of the frequency and accuracy of mobility scoring on the estimation of lameness parameters for different herd scenarios. Herds with a varying prevalence (10, 30, or 50%) and duration (distributed around median days 18, 36, 54, 72, or 108) of lameness were simulated at daily time steps for five years. The lameness parameters investigated were prevalence, duration, new case rate, time to first lameness, and probability of remaining sound in the first year. True parameters were calculated from daily data and compared to those calculated when replicating different frequencies (weekly, two-weekly, monthly, quarterly), sensitivities (60–100%), and specificities (95–100%) of mobility scoring. Our results showed that over-estimation of incidence and under-estimation of duration can occur when the sensitivity and specificity of mobility scoring are <100%. This effect increases with more frequent scoring. Lameness prevalence was the only parameter that could be estimated with reasonable accuracy when simulating quarterly mobility scoring. These findings can help inform mobility scoring practices and the interpretation of mobility scoring data.

1 February 2026 in Veterinary Record
Verified
Journal Article
Open access
MGMichael Glover
Michael Glover
LGLaura E. Green
Laura E. Green
RCRachel Clifton
Rachel Clifton
Background: Laparoscopic intrauterine artificial insemination (Lap‐AI) is used in sheep genetic improvement programmes. However, the lambing rate (LR) (i.e., the proportion of inseminated ewes that lamb) following Lap‐AI is variable. Previously, one small UK study investigated factors associated with LR, but it did not adjust for dependencies or confounding in the data. Methods: Data were collected from 11,493 Lap‐AIs carried out commercially in Southwest England and Wales between 1995 and 2005. Multilevel multivariable analyses were then used to identify factors associated with LR. Results: The mean unadjusted average LR was 71%. However, ewes inseminated with fresh semen on days when the maximum ambient temperature (MAT°C) was lower than 25°C had a higher LR (adjusted LR ∼78%; OR 1.51, 95% CI 1.30‐1.77) than ewes inseminated with frozen semen (adjusted LR ~70%). LRs were lower on days when MAT°C was ≥25°C (adjusted LRs: fresh ~64%; frozen ~65%). LR decreased as the time between sponge removal and insemination increased (OR: 0.08, 95% CI: 0.01‒0.87) and varied between months and years. Limitations: Due to the design of the study, individual ewe‐ and ram‐level factors could not be investigated. Furthermore, some breeds were less well represented, which hindered breed‐level analysis. Conclusion: Keeping ewes and rams cool on the day of insemination and inseminating ewes earlier after sponge removal may improve LR.

9 June 2023 in Frontiers in Veterinary Science
Verified
Journal Article
Open access
RCRachel Clifton
Rachel Clifton
KBKate Bamford
Kate Bamford
LGLaura Green
Laura Green
Introduction: Great Britain has over 15 million ewes. Lameness is one of the top three most economically important diseases for the sheep industry, costing about £80 million per annum. The prevalence of lameness reduced from 10% to 5% between 2004 and 2013 but further reduction is unlikely because many farmers and agricultural students still believe in, and use, ineffective practices to control lameness. Unfortunately, many veterinary practitioners consider themselves insufficiently knowledgeable to work confidently with sheep farmers, and many sheep farmers agree with them. Another route to improve control of lameness is to ensure that all new veterinary graduates are competent to advise farmers.Methods: Our study investigated how veterinary students are taught about management of lameness in sheep. Ten lecturers from eight veterinary schools were interviewed, and 33 students from four veterinary schools participated in four focus groups; all were recorded, transcribed, and analysed using directed qualitative content analysis.Results: Teaching time and opportunities for students to gain clinical experience of lameness were very limited. Students were not confident they could diagnose causes of lameness and listed many practices, including ineffective ones, to manage footrot.Discussion: We conclude that GB veterinary students are graduating without evidence-based understanding and clinical experience necessary to advise farmers on management of lameness in sheep. Given the importance of lameness in sheep in GB we conclude that an alternative approach to education on lameness in sheep could help to ensure that new graduate veterinarians can contribute to control of lameness in sheep.