title: Lameness Prevalence and Risk Factors in Large Dairy Farms in Upstate New York. Model Development for the Prediction of Claw Horn Disruption Lesions The development, implementation and testing of a lameness control programme based on HACCP principles and designed for heifers on dairy farms. The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials The effect of claw trimming on the hoof health of Swedish dairy cattle. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions Use of Extended Characteristics of Locomotion and Feeding Behavior for Automated Identification of Lame Dairy Cows A prospective cohort study of digital cushion and corium thickness. Part 1: Associations with body condition, lesion incidence, and proximity to calving. Prevalence of lameness and associated risk factors in Canadian Holstein-Friesian cows housed in freestall barns. The impact of parity and duration of biotin supplementation on white line disease lameness in dairy cattle. Visual locomotion scoring in the first seventy days in milk: impact on pregnancy and survival. The effect of lameness on the fertility of dairy cattle in a seasonally breeding pasture-based system. The risk of bias in observational studies of exposures (ROBINS-E) tool: concerns arising from application to observational studies of exposures Temporal associations between low body condition, lameness and milk yield in a UK dairy herd.
abstract: The main objectives of this prospect i ve cohort study were a ) to describe lameness prevalence at drying off in large high producing New York State herds based on visual locomotion score ( VLS ) and identify potential cow and herd level risk factors , and b ) to develop a model that will predict the probability of a cow developing claw horn disruption lesions ( CHDL ) in the subsequent lactation using cow level variables collected at drying off and /or available from farm management software . Data were collected from 23 large commercial dairy farms located in upstate New York . A total of 7,687 dry cows , that were less than 265 days in gestation , were enrolled in the study . Farms were visited between May 2012 and March 2013 , and cows were assessed for body condition score ( BCS ) and VLS . Data on the CHDL events recorded by the farm employees were extracted from the Dairy-Comp 305 data base , as well as information regarding the studied cows ’ health events , milk production , and reproductive records throughout the previous and subsequent lactation period . Univariable analyses and mixed multivariable logistic regression models were used to analyse the data at the cow level . The overall average prevalence of lameness ( VLS > 2 ) at drying off was 14 % . Lactation group , previous CHDL , mature equivalent 305-d milk yield ( ME305 ) , season , BCS at drying off and sire PTA for strength were all significantly associated with lameness at the drying off ( cow-level ) . Lameness at drying off was associated with CHDL incidence in the subsequent lactation , as well as lactation group , previous CHDL and ME305 . These risk factors for CHDL in the subsequent lactation were included in our predictive model and adjusted predicted probabilities for CHDL were calculated for all studied cows . ROC analysis identified an optimum cut-off point for these probabilities and using this cut-off point we could predict CHDL incidence in the subsequent lactation with an overall specificity of 75 % and sensitivity of 59 % . Using this approach , we would have detected 33 % of the studied population as being at risk , eventually identifying 59 % of future CHDL cases . Our predictive model could help dairy producers focusing their efforts on CHDL reduction by implementing aggressive preventive measures for high risk cows This paper describes the development and testing of a lameness control programme ( LCP ) for heifers on dairy farms . The LCP , which is based on the analysis of hazards and critical control points ( HACCP ) , was tested via a r and omised intervention study on 60 farms . Tangible hazards for each farm were identified , allotted to 11 categories of proximate hazard and scored on each farm to quantify the risks presented by each hazard . Feet were inspected for signs of claw horn disease and infection , such as digital dermatitis . Intervention was generally ineffective , primarily through failure to implement the LCP . However , retrospective analysis was able to demonstrate highly significant associations between risks attached to proximate hazards and probabilities of lameness and foot lesions , allowing the severity of these hazards to be ranked . The most significant proximate hazards of environmental origin were prolonged st and ing on concrete , st and ing in wet slurry and factors that cause claw trauma . The most severe proximate hazards however were those associated with failures of management , especially poor claw condition and inadequate foot care . Overall farm risks ( OFR ) were estimated by summing the products of the generic severity for proximate hazards with on-farm risks . Changes in OFR were significantly related to changes in outcome ( lameness and lesions ) Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more A 2-year experiment on the effect of claw trimming on hoof health was performed in 77 Swedish dairy herds ( 3444 dairy cattle ) selected on herd size , breed composition and membership in the official milk-recording scheme . In the autumn , cows within each herd were blocked according to breed , parity and stage of lactation and allocated to two treatments : autumn trimming ( AT ) or no autumn trimming ( NAT ) . Outcome variables were claw measurements and prevalence of hoof lesions and lameness ( measured at spring trimming ) and the need for hoof treatments between scheduled trimmings . At spring trimming , NAT cows had longer and shallower claws than AT cows . The average net growth of the toe wall was greater for AT than for NAT cattle , with a marked variation between housing systems . Most hoof lesions present at AT had disappeared at the subsequent spring trimming . Controlled for clustering by herd-within-year and for the effects of individual- and herd-level covariates , AT cattle at spring trimmings had significantly lower odds of lameness ( OR=0.66 ) and of haemorrhages of the sole or white-line ( OR=0.86 ) , sole ulcer ( OR=0.59 ) and white-line fissure or double sole (OR=0.71)-but not of moderate-to-severe heel-horn erosion or dermatitis ( OR=0.96 ) . Acute hoof treatments between claw trimmings were more common in the NAT group ( OR=2.02 ) Non-r and omised studies of the effects of interventions are critical to many areas of healthcare evaluation , but their results may be biased . It is therefore important to underst and and appraise their strengths and weaknesses . We developed ROBINS-I ( “ Risk Of Bias In Non-r and omised Studies - of Interventions ” ) , a new tool for evaluating risk of bias in estimates of the comparative effectiveness ( harm or benefit ) of interventions from studies that did not use r and omisation  to allocate units ( individuals or clusters of individuals ) to comparison groups . The tool will be particularly useful to those undertaking systematic review s that include non-r and omised studies This study was carried out to detect differences in locomotion and feeding behavior in lame ( group L ; n = 41 ; gait score ≥ 2.5 ) and non-lame ( group C ; n = 12 ; gait score ≤ 2 ) multiparous Holstein cows in a cross-sectional study design . A model for automatic lameness detection was created , using data from accelerometers attached to the hind limbs and noseb and sensors attached to the head . Each cow ’s gait was videotaped and scored on a 5-point scale before and after a period of 3 consecutive days of behavioral data recording . The mean value of 3 independent experienced observers was taken as a definite gait score and considered to be the gold st and ard . For statistical analysis , data from the noseb and sensor and one of two accelerometers per cow ( r and omly selected ) of 2 out of 3 r and omly selected days was used . For comparison between group L and group C , the T-test , the Aspin-Welch Test and the Wilcoxon Test were used . The sensitivity and specificity for lameness detection was determined with logistic regression and ROC- analysis . Group L compared to group C had significantly lower eating and ruminating time , fewer eating chews , ruminating chews and ruminating boluses , longer lying time and lying bout duration , lower st and ing time , fewer st and ing and walking bouts , fewer , slower and shorter strides and a lower walking speed . The model considering the number of st and ing bouts and walking speed was the best predictor of cows being lame with a sensitivity of 90.2 % and specificity of 91.7 % . Sensitivity and specificity of the lameness detection model were considered to be very high , even without the use of halter data . It was concluded that under the conditions of the study farm , accelerometer data were suitable for accurately distinguishing between lame and non-lame dairy cows , even in cases of slight lameness with a gait score of 2.5 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 prospect i ve 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 ( st and ard deviation : 0.95 ) . The SST was thickest 8 wk before calving ( 5.22 mm , st and ard deviation : 0.91 ) and thinnest 1 wk postcalving ( 4.68 mm , st and ard 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 Lameness is a severe welfare problem and a production-limiting disease in dairy farming . The objectives of this study were to determine prevalence of lameness and investigate cow- and herd-level factors associated with lameness in dairy cows housed in freestall barns in 3 Canadian provinces . A purposive sample of 40 Holstein-Friesian cows was selected from each of 141 dairy farms in Québec , Ontario , and Alberta . In total , 5,637 cows were scored once for lameness ( presence of limping when walking ) . Data collected included information on individual cows ( hock lesions , claw length , body condition score , parity , days in milk , and milk production ) , management practice s ( floor and stall cleaning routine , bedding routine , and footbath practice s ) , and facility design ( stall dimensions , stall base and bedding type , width of feed alley , flooring type , and slipperiness ) hypothesized to be risk factors for lameness . Multilevel mixed logistic regression models were constructed ( including farm as a r and om effect and province as a fixed effect ) . Herd-level lameness prevalence ranged from 0 to 69 % ( mean = 21 % ) . Lameness prevalence increased with increasing parity ; compared with first parity , cows in parity 2 , 3 , and ≥ 4 had 1.6 , 3.3 , and 4 times , respectively , higher odds of being lame . Furthermore , the odds of lameness were 1.6 times greater in cows with low body condition score ( ≤ 2.5 ) than in cows with a higher body condition score . In addition , injured hocks and overgrown claws were associated with 1.4- and 1.7-fold increased odds of being lame , respectively , whereas every 1 kg increase in daily milk production was associated with a 3 % decrease in the odds of being lame . Lameness prevalence was higher in herds with ≤ 100 cows , but lower in barns with a s and or dirt stall base , or with bedding ≥ 2 cm deep . Cows exposed to very slippery floors had 2 times the odds of being lame compared with cows exposed to nonslippery floors . We attributed the wide range of lameness prevalence to the great variability in facilities and management practice s among farms . Finally , we inferred that the prevalence of lameness could be decreased by improving management of multiparous , thin , or injured cows and by adopting management practice s intended to improve cow comfort , namely the floor 's slip resistance and the stall 's lying surface A field study was conducted to examine effects of oral biotin supplementation for up to 18 mo on risks of lameness in dairy cows . The study included a total of 900 cattle from five dairy farms in Gloucestershire , southwest U.K. , in a within-herd r and omized control trial . The data from this trial were used in this paper to investigate the impact of parity and duration of supplementation with oral biotin at 20 mg/d on white line disease ( WLD ) lameness . Analysis of the data indicated that WLD increased with increasing parity independent of biotin supplementation from approximately two cases per 100 cow years in primiparous cows to 15.5 cases per 100 cow years in all multiparous cows , but up to 47.7 cases per 100 cow years for cows in parities > or = 5 . Supplementation with biotin reduced WLD lameness by 45 % in multiparous cows down to 8.5 cases per 100 cow years , whereas the effect of biotin supplementation in primiparous cows was not significant . Although numerical reductions in WLD lameness were observed for shorter periods of supplementation , a supplementation length of at least 6 mo was required to significantly reduce the risk of WLD lameness in multiparous cows . The effect of biotin supplementation in reducing lameness has potential impact for both animal welfare and farm economics Our hypotheses were that cows classified as lame during the first 70 d in milk have more days from calving to conception and a greater hazard of dying or being culled compared with cows that were not classified as lame . Our objective was to estimate the detrimental effects of lameness on calving-to-conception interval and hazard of dying or being culled in lactating Holstein cows . Data were collected from 5 dairy farms located in upstate New York from November 2004 to June 2006 . The design was a prospect i ve observational cohort study . Cows were assigned a  visual locomotion score ( VLS ) using a 5-point scale : 1 = normal , 2 = presence of a slightly asymmetric gait , 3 = the cow clearly favored 1 or more limbs ( moderately lame ) , 4 = severely lame , to 5 = extremely lame ( nonweight-bearing lame ) . In total 1,799 cows were enrolled . In 2 alternative categorizations , cows were considered lame if at least 1 VLS was > or =3 during the first 70 d in milk , and if at least 1 VLS was > or = 4 for the same period they were considered lame . Lameness ( VLS > or =3 ) was detected at least once in 26.5 , 54.2 , 33.9 , 51.8 , and 39.3 % of all cows in farms 1 to 5 , respectively . The hazard ratio of being detected pregnant was 0.85 for lame cows ( VLS > or =3 ) vs. nonlame cows ; hence , lame cows were at a 15 % lower risk of pregnancy than nonlame cows . When lameness was redefined as VLS > or = 4 , the hazard ratio of been detected pregnant was 0.76 for lame cows vs. cows with VLS < 4 . Lameness increased the hazard ratio of culling/death , 1.45 and 1.74 for VLS > or =3 and VLS > or = 4 , respectively , vs. cows with VLS <3 and VLS < 4 , respectively . In summary , lameness significantly decreased the hazard of pregnancy and increased the hazard of culling/death . The detrimental effects were amplified when considering only severely lame and non-weight-bearing cows The effect of lameness on the fertility of dairy cattle is well recognized . But , the effect of lameness on the fertility of seasonally breeding cattle in pasture-based systems is less well characterized . This prospect i ve cohort study of 463 cows on 1 farm in the lower North Isl and of New Zeal and was design ed to assess the effect of clinical lameness , as identified by farm staff , on the hazard of conception after the planned start-of-mating date . A Cox proportional hazards model with time-varying covariates was used . After controlling for the effect of parity , breed , body weight at calving , and calving-to-planned start of mating interval , the daily hazard of conception for cows identified as lame was 0.78 ( 95 % confidence interval : 0.68 - 0.86 ) compared with non-lame cows . Lame cows took 12 d longer to get pregnant compared with their non-lame counterparts Background Systematic review s , which assess the risk of bias in included studies , are increasingly used to develop environmental hazard assessment s and public health guidelines . These research areas typically rely on evidence from human observational studies of exposures , yet there are currently no universally accepted st and ards for assessing risk of bias in such studies . The risk of bias in non-r and omised studies of exposures ( ROBINS-E ) tool has been developed by building upon tools for risk of bias assessment of r and omised trials , diagnostic test accuracy studies and observational studies of interventions . This paper reports our experience with the application of the ROBINS-E tool . Methods We applied ROBINS-E to 74 exposure studies ( 60 cohort studies , 14 case-control studies ) in 3 areas : environmental risk , dietary exposure and drug harm . All investigators provided written feedback , and we documented verbal discussion of the tool . We inductively and iteratively classified the feedback into 7 themes based on commonalities and differences until all the feedback was accounted for in the themes . We present a description of each theme . Results We identified practical concerns with the premise that ROBINS-E is a structured comparison of the observational study being rated to the ‘ ideal ’ r and omised controlled trial . ROBINS-E assesses 7 domains of bias , but relevant questions related to some critical sources of bias , such as exposure and funding source , are not assessed . ROBINS-E fails to discriminate between studies with a single risk of bias or multiple risks of bias .  ROBINS-E is severely limited at determining whether confounders will bias study outcomes . The construct of co-exposures was difficult to distinguish from confounders . Applying ROBINS-E was time-consuming and confusing . Conclusions Our experience suggests that the ROBINS-E tool does not meet the need for an international st and ard for evaluating human observational studies for questions of harm relevant to public and environmental health . We propose that a simpler tool , based on empirical evidence of bias , would provide accurate measures of risk of bias and is more likely to meet the needs of the environmental and public health community Previous work has hypothesised that cows in low body condition become lame . We tested this in a prospect i ve longitudinal study . Body condition score ( BCS ) , causes of lameness and milk yield were collected from a 600-cow herd over 44-months . Mixed effect binomial models and a continuous outcome model were used to investigate the associations between lameness , BCS and milk yield . In total , 14,320 risk periods were obtained from 1137 cows . There were 1510 lameness treatments : the most common causes of lameness were sole ulcer ( SU ) ( 39 % ) , sole haemorrhage ( SH ) ( 13 % ) , digital dermatitis ( DD ) ( 10 % ) and white line disease ( WLD ) ( 8 % ) . These varied by year and year quarter . Body condition was scored at 60-day intervals . BCS ranged from 1 to 5 with a mean of 2.5 , scores were higher in very early lactation but varied widely throughout lactation ; approximately 45 % of scores were < 2.5 . The key finding was that BCS<2.5 was associated with an increased risk of treatment for lameness in the following 0 - 2 months and > 2 - 4 months for all causes of lameness and also specifically for SU/WLD lameness . BCS<2.5 was associated with an increased risk of treatment for SH in the following 0 - 2 months but not > 2 - 4 months . There was no such association with DD . All lameness , SU/WLD , SH and DD were significantly more likely to occur in cows that had been lame previously , but the effect of BCS was present even when all repeat cases of lameness were excluded from the analysis . Milk yield was significantly higher and fell in the month before treatment in cows lame with SU/WLD but it was not significantly higher for cows that were treated for DD compared with non-lame cows . These findings support the hypothesis that low BCS contributes to the development of horn related claw lameness but not infectious claw diseases in dairy cows . One link between low BCS and lameness is a thin digital cushion which has been proposed as a trigger for claw horn disease . Cows with BCS 2 produced more milk than cows with BCS 2.5 , however , this was only approximately 100 kg difference in yield over a 305-day lactation . Given the increased risk of lameness in cows with BCS 2 , the direct costs of lameness and the small variability in milk yield by BCS , preventing cows from falling to BCS<2.5 would improve cow welfare and be economically beneficial
target: A higher risk of being lame was found for the presence of claw overgrowth , the first 120 days in milk , larger herd sizes , and increasing parity .
background: Background Lameness in dairy cows has been an ongoing concern of great relevance to animal welfare and productivity in modern dairy production .
  Many studies have examined associations between various factors related to housing , management , and the individual animal and the occurrence of lameness .
  The objective of this systematic review was to answer the research question “ what are risk factors associated with lameness in dairy cows that are housed in free stall barns or tie stall facilities ” .
  Furthermore , we performed a synthesis of current evidence on certain risk factors by means of a meta- analysis to illustrate the strength of their association with bovine lameness .