Nj Bell

A descriptive review of the peer and non-peer reviewed literature on the treatment and prevention of foot lameness in cattle published between 2000 and 2011

The aim of this study was to collate and review the peer and non-peer reviewed English language literature on the treatment and prevention of foot lameness in cattle published since January 2000. The study aimed to identify deficits in knowledge and areas of disparity between what is recommended in the field by veterinarians, foot trimmers and advisors and what has been substantiated experimentally. Peer reviewed literature containing original work was gathered by searching three databases. Papers were categorised and reviewed if they contained material on treatment or prevention. Non-peer reviewed clinical materials were collated from a range of sources. The materials were reviewed and categorised based on whether they recommended a range of possible treatment and prevention strategies. The peer reviewed data base contained 591 papers, of which 286 contained information on treatment or prevention. The vast majority of papers (258) concerned prevention; only a small number covered treatment (31) and of these only three contained information on the treatment of sole ulcers or white line disease. The number of intervention studies and trials was low; most papers on prevention were observational. Generally, lesion specific outcomes were not described making the findings of these papers difficult to use clinically. The non-peer reviewed material contained 46 sources; they varied significantly in regard to the treatments they advocated with some texts directly contradicting each other. Some aspects of prevention recommended in these sources seemed poorly supported by findings from the research literature. Well designed intervention studies are required to address these deficits.

Classification of behaviour in housed dairy cows using an accelerometer-based activity monitoring system

BackgroundAdvances in bio-telemetry technology have made it possible to automatically monitor and classify behavioural activities in many animals, including domesticated species such as dairy cows. Automated behavioural classification has the potential to improve health and welfare monitoring processes as part of a Precision Livestock Farming approach. Recent studies have used accelerometers and pedometers to classify behavioural activities in dairy cows, but such approaches often cannot discriminate accurately between biologically important behaviours such as feeding, lying and standing or transition events between lying and standing. In this study we develop a decision-tree algorithm that uses tri-axial accelerometer data from a neck-mounted sensor to both classify biologically important behaviour in dairy cows and to detect transition events between lying and standing.ResultsData were collected from six dairy cows that were monitored continuously for 36 h. Direct visual observations of each cow were used to validate the algorithm. Results show that the decision-tree algorithm is able to accurately classify three types of biologically relevant behaviours: lying (77.42 % sensitivity, 98.63 % precision), standing (88.00 % sensitivity, 55.00 % precision), and feeding (98.78 % sensitivity, 93.10 % precision). Transitions between standing and lying were also detected accurately with an average sensitivity of 96.45 % and an average precision of 87.50 %. The sensitivity and precision of the decision-tree algorithm matches the performance of more computationally intensive algorithms such as hidden Markov models and support vector machines.ConclusionsBiologically important behavioural activities in housed dairy cows can be classified accurately using a simple decision-tree algorithm applied to data collected from a neck-mounted tri-axial accelerometer. The algorithm could form part of a real-time behavioural monitoring system in order to automatically detect dairy cow health and welfare status.

Evaluating an intervention to reduce lameness in dairy cattle

Lameness in dairy cattle remains a significant welfare concern for the UK dairy industry. Farms were recruited into a 3-yr study evaluating novel intervention approaches designed to encourage farmers to implement husbandry changes targeted toward reducing lameness. All farms completing the study were visited at least annually and received either monitoring only (MO, n=72) or monitoring and additional support (MS, n = 117) from the research team. The additional support included traditional technical advice on farm-specific solutions, facilitation techniques to encourage farmer participation, and application of social marketing principles to promote implementation of change. Lameness prevalence was lower in the MO (27.0 ± 1.94 SEM) and MS (21.4 ± 1.28) farms at the final visit compared with the same MO (38.9 ± 2.06) and MS (33.3 ± 1.76) farms on the initial visit. After accounting for initial lameness, intervention group status, and year of visit within a multilevel model, we observed an interaction between year and provision of support, with the reduction in lameness over time being greater in the MS group compared with the MO group. Farms in the MS group made a greater number of changes to their husbandry practices over the duration of the project (8.2 ± 0.39) compared with those farms in the MO group (6.5 ± 0.54). Because the lameness prevalence was lower in the MS group than the MO group at the start of the study, the contribution of the additional support was difficult to define. Lameness can be reduced on UK dairy farms although further work is needed to identify the optimum approaches.

Evaluation of treatments for claw horn lesions in dairy cows in a randomized controlled trial

Lameness is one of the most significant endemic disease problems facing the dairy industry. Claw horn lesions (principally sole hemorrhage, sole ulcer, and white line disease) are some of the most prevalent conditions. Despite the fact that thousands of animals are treated for these conditions every year, experimental evidence is limited on the most effective treatment protocols. A randomized, positively controlled clinical trial was conducted to test the recovery of newly lame cows with claw horn lesions. Animals on 5 farms were locomotion scored every 2wk. Cows were eligible for recruitment if they had 2 nonlame scores followed by a lame score and had a claw horn lesion on a single claw of a single foot. Following a therapeutic trim, enrolled cows were randomly allocated to 1 of 4 treatments: treatment 1-no further treatment (positive control; TRM), treatment 2-trim plus a block on the sound claw (TB), treatment 3-trim plus a 3-d course of the nonsteroidal anti-inflammatory drug (NSAID) ketoprofen (TN), treatment 4-trim plus a block plus ketoprofen (TBN). The primary outcome measure was locomotion score 35d after treatment, by an observer blind to treatment group. Descriptive statistics suggested that treatment groups were balanced at the time of enrollment, that is, randomization was successful. Based on a sound locomotion score (score 0) 35d after treatment, the number of cures was 11 of 45 (24.4%) for TRM, 14 of 39 (35.9%) for TB, 12 of 42 (28.6%) for TN, and 23 of 41 (56.1%) for TBN. The difference between TBN and TRM was significant. To test for confounding imbalances between treatment groups, logistic regression models were built with 2 outcomes, either sound (score 0) or nonlame (score 0 or 1) 35d after treatment. Compared with TRM, animals that received TBN were significantly more likely to cure to a sound outcome. Farm, treatment season, lesion diagnosis, limb affected, treatment operator, and stage of lactation were included in the final models. Our work suggests that lameness cure is maximized with NSAID treatment in addition to the common practices of therapeutic trimming and elevation of the diseased claw using a block when cows are newly and predominantly mildly lame.

Measuring the response to therapeutic foot trimming in dairy cows with fortnightly lameness scoring

Lameness scoring (0-3) was carried out on four UK dairy farms during the housing period over three consecutive years (2010-2012). At the start of the study cows were matched by parity and stage of lactation and randomly allocated into a treatment (TX) and a control (CX) group. Cows were enrolled when two sound scores (0 or 1) were followed by a lame score (2). Farmers were immediately notified of score 3 cows, which were then excluded from the study, irrespective of whether they were in treatment or control groups. The animals in the TX group received treatment 3-48 h after being scored lame. Farmers remained blind to the treatment group. Throughout the study the participating farmers continued to identify and treat lame cows according to their usual approaches, this included treating animals in the CX or TX group if they so chose. The fortnightly lameness scoring and treatment of the TX group resulted in higher cure rates at each scoring session following treatment when compared with the CX group (P < 0.001). Two weeks after inclusion, 78% (SE  ±  3.2) of TX cows were sound, compared with 66% (SE  ±  3.1) of CX cows. At 18  weeks following initial recruitment this had fallen to 41% (SE  ±  6.3) (TX) and 13% (SE  ±  4.7) (CX). The percentage of total scores which were sound scores in the TX and CX groups following inclusion in the trial was 81% and 66.1%, respectively (P < 0.001). The main lesions found on treatment in the TX group were sole haemorrhage (41% of cases) and digital dermatitis (33%). Severe lesions (sole ulcers and toe necrosis) were only found in 6.6% of cases. In the treated CX animals the percentage of severe lesions was 14%.

Recovery of chronically lame dairy cows following treatment for claw horn lesions: a randomised controlled trial

A positively controlled, randomised controlled trial (RCT) was undertaken to test recovery of cows with claw horn lesions resulting in lameness of greater than two weeks duration. Cows on seven commercial farms were mobility scored fortnightly and selected by lameness severity and chronicity. Study cows all received a therapeutic trim then random allocation of: no further treatment (trim only (TRM)), plastic shoe (TS) or plastic shoe and NSAID (TSN). Recovery was assessed by mobility score at 42 (±4) days post treatment by an observer blind to treatment group. Multivariable analysis showed no significant effect of treatment with an almost identical, low response rate to treatment across all groups (Percentage non-lame at outcome: TRM – 15 per cent, TS – 15 per cent, TSN – 16 per cent). When compared with results of a similar RCT on acutely lame cows, where response rates to treatment were substantially higher, it can be concluded that any delay in treatment is likely to reduce the rate of recovery, suggesting early identification and treatment is key. Thirty-eight per cent of animals treated in this study were lame on the contralateral limb at outcome suggesting that both hindlimbs should be examined and a preventive or if necessary a therapeutic foot trim performed when lameness is identified particularly if the duration of lameness is unknown.

A survey of the on-farm treatment of sole ulcer and white line disease in dairy cattle

A telephone survey of UK dairy farmers was conducted to investigate current on-farm practice in the treatment of mild sole ulcer (SU)/sole bruising (SB), and white line disease (WLD), and the potential barriers associated with therapy. A total of 84 dairy farmers were questioned about the process of detecting and treating lame cows on their farm as well as about the specific treatments they applied. Farmers were also canvassed for their views on the efficacy of different potential treatments for mild SU/SB and WLD. In general, respondents discussed treatments for SU and WLD rather than specifically for mild SU/SB and WLD. Furthermore, when describing treatment methods, farmers rarely differentiated between SU and WLD. Trimming the affected claw with or without the additional use of orthopaedic blocks was the most commonly reported treatment method considered effective and practical by the majority of farmers. Antibiotics and/or analgesics were used by a small number of farmers, and some housed their most severely lame cows in straw pens. Lack of time, inadequate equipment and poor farm layout were identified by many survey respondents as barriers to the prompt and/or effective treatment of their lame animals.

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.

Isolation of digital dermatitis treponemes from cattle hock skin lesions

BACKGROUND Bovine hock lesions present a serious welfare and production issue on dairy farms worldwide. Current theories suggest that trauma is an important factor in the formation of hock lesions, although infection may also play a role in increasing their severity and duration. HYPOTHESIS Digital dermatitis (DD) lesions in dairy cows are strongly associated with specific treponeme bacteria which are opportunistic invaders of other skin regions. Hock lesions were tested to ascertain if they too contained treponemes. ANIMALS Swab and tissue samples were taken from hock lesions from two farms in South West England. METHODS Hock lesions were classified into two categories: open lesions, which were often bleeding and ulcerated, or were encrusted; and closed lesions, which were classified as hair loss with no skin breakage. PCR assays and bacterial isolation were used to detect treponemes in hock lesions. RESULTS All three phylogroups of digital dermatitis treponemes were detectable and isolated from open hock lesions only, with closed lesions showing no evidence of treponeme infection, either by PCR or bacterial culture. When analysed by 16S rRNA gene sequencing, the cultured treponeme DNA showed complete homology or was very similar to that found in foot lesions. Additionally, skin swabs from near the open hock wounds were also positive by PCR assay and isolation for the DD treponemes. CONCLUSIONS AND CLINICAL IMPORTANCE Identification of the contribution of these infectious agents will allow for more optimal treatments to be developed that reduce the prevalence and healing times of both hock and DD lesions.

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.