Lameness In Dairy Cattle Research Articles

Different management methods on prevalence of lameness in 25 Holstein-Friesian herds in Hungary

Lameness in dairy cattle is the third most expensive outbreak after mastitis and reproductive disorders. 25 Holstein-Friesian herds in Hungary were observed for two years to estimate the impact of different trimming methods and managements for the controll of the incidence of lameness. Professional trimming was found to be more effective on farms with no nutritional disorders and where refurnishment works were carried out. The greatest decrease in the prevalence of lameness was observed on farms which provided professional trimming, effective footbathing, improved walking and resting surfaces and which treated severely lame cows between regular trimmings. The greatest increase in occurrence of lameness was reported on farms with on-farm trimmers and where building projects were carried out and nutritional disorders found.

Biochemical and molecular characterization of Treponema phagedenis-like spirochetes isolated from a bovine digital dermatitis lesion

BackgroundBovine papillomatous digital dermatitis (DD) is the leading cause of lameness in dairy cattle and represents a serious welfare and economic burden. Found primarily in high production dairy cattle worldwide, DD is characterized by the development of an often painful red, raw ulcerative or papillomatous lesion frequently located near the interdigital cleft and above the bulbs of the heel. While the exact etiology is unknown, several spirochete species have been isolated from lesion material. Four isolates of Treponema phagedenis-like spirochetes were isolated from dairy cows in Iowa. Given the distinct differences in host, environmental niche, and disease association, a closer analysis of phenotypic characteristics, growth characteristics, and genomic sequences of T. phagedenis, a human genitalia commensal, and the Iowa DD isolates was undertaken.ResultsPhenotypically, these isolates range from 8.0 to 9.7 μm in length with 6–8 flagella on each end. These isolates, like T. phagedenis, are strictly anaerobic, require serum and volatile fatty acids for growth, and are capable of fermenting fructose, mannitol, pectin, mannose, ribose, maltose, and glucose. Major glucose fermentation products produced are formate, acetate, and butyrate. Further study was conducted with a single isolate, 4A, showing an optimal growth pH of 7.0 (range of 6–8.5) and an optimal growth temperature of 40°C (range of 29°C-43°C). Comparison of partial genomic contigs of isolate 4A and contigs of T. phagedenis F0421 revealed > 95% amino acid sequence identity with amino acid sequence of 4A. In silico DNA-DNA whole genome hybridization and BLAT analysis indicated a DDH estimate of >80% between isolate 4A and T. phagedenis F0421, and estimates of 52.5% or less when compared to the fully sequenced genomes of other treponeme species.ConclusionUsing both physiological, biochemical and genomic analysis, there is a lack of evidence for difference between T. phagedenis and isolate 4A. The description of Treponema phagedenis should be expanded from human genital skin commensal to include being an inhabitant within DD lesions in cattle.

Reducing lameness in dairy herds – Overcoming some barriers

Incomplete detection, high tolerance of lameness, and shortage of time and labour have been identified as barriers to reducing lameness in dairy herds. The effects of farmer participation in a project aimed at reducing lameness in dairy cattle on these factors were investigated. Over the course of the project farmers’ detection of lameness improved and tolerance decreased. On farms entering the study with lameness prevalence below the median of 35%, improved detection was correlated with a reduction in lameness prevalence, but this was not the case for farms entering above the median prevalence. Lowered tolerance of lameness was correlated with reduced lameness regardless of initial prevalence. A greater importance given to lack of time as an initial barrier to progress was correlated with a greater reduction in lameness over the course of the project, suggesting that farmers who recognised limited time as a barrier were able to overcome this to some extent.

Uptake and effectiveness of interventions to reduce claw lesions in 40 dairy herds in the UK

AbstractIn the final year of a three-year study of lameness in dairy cattle, 40 herds were allocated to either an intervention (22) or control (18) group. Farms in the intervention group were visited by a veterinarian who made up to 16 recommendations to reduce the incidence of lameness based on potential risks for lameness observed at that visit. Farms in the control group were visited and the same observations were made, but no changes recommended. All farms were visited on three further occasions to score the locomotion of all cows and collect information on changes made to the farm. Before intervention, the mean herd size, lactation average milk yield per cow and prevalence of severely lame cows were 122, 8,157 I and 9.85% for the control group and 109, 7,807 I and 9.14% for the intervention group. After the intervention there were no significant differences between the treatments in terms of the change in prevalence of severely lame cows or the change in rate of sole ulcer, white line disease or digital dermatitis. The overall uptake of recommendations was 41.3%. There were no significant correlations between the percentage of risks addressed and the rate of sole ulcer or prevalence of severely lame cows and only a non-significant trend for white line disease. Improvements to cubicle dimensions were associated with a reduction in the rate of sole ulcer, and changing nutrition and adding biotin to the ration were associated with a reduction in white line disease. Conversely, increasing the amount of sawdust to cubicle floors was associated with increased rate of sole ulcer and white line disease and improving cubicle dimensions was associated with increased rate of white line disease.

Determining the heritable component of dairy cattle foot lesions

Lameness and hoof health affect dairy cows as an animal welfare issue, in decreased milk production, and in premature culling. Selection schemes for dairy cattle focus on sire contribution to milk production, with little consideration of the cow’s physical structure or disease probability. On 3 commercial California dairies, 6 phenotypic binary hoof traits that contribute to lameness were recorded: white line disease, sole ulcer, other claw horn lesions, foot rot (interdigital phlegmon), foot warts (digital dermatitis), and other lesions. Monthly lactation records were collected from December 2006 to April 2009 with weekly observations of hoof lesions for lame and dry cows. In addition to hoof lesion information, data on cows (n=5,043) included parentage, birth date, freshening date, lactation number, and date of lameness diagnosis. The prevalence of hoof lesions ranged from a low of 2.2% (foot rot) to a high of 17.1% (foot warts). The farm environment increased the odds ratio depending upon the lesion. Lameness was more common in early lactation and as lactation number increased. Using a threshold model, heritabilities and repeatabilities were estimated for each binary trait. The heritability for risk varied by lesion, with the higher estimates being 0.40 (95% confidence interval: 0.20–0.67) for digital dermatitis and 0.30 (95% confidence interval: 0.08–0.63) for sole ulcer. Including terms to account for cow productivity on either a 305-d mature-equivalent basis or a per-lactation basis had minimal effect on the heritability estimates, suggesting that selection for hoof health is not correlated with response to selection for greater milk production and that improvement could be made for both traits. The genetic component lends support for further genetic studies to identify loci contributing to some of the lesion phenotypes such as foot warts or sole ulcers, 2 of the top 3 causes of lameness in dairy cattle.

An evaluation of the changes in distance from the external sole surface to the distal phalanx in heifers in their first lactation

Thin soles are a significant cause of lameness in dairy cattle but in most cases the diagnosis is based on subjective assessment. Ultrasonography has been used to more directly estimate sole thickness, but mostly on a one-off basis or over a short period of time. Data over a longer period of time (such as a lactation period) are lacking and there are no descriptions of the normal changes that occur over time and to show how sole thickness at calving relates to thickness later in lactation. This study measured the distance between the external sole surface and the distal phalanx (DP) in 25 mixed breed (Jersey cross Friesian and Friesian) heifers on five occasions over their first lactation (approximately 10, 60, 110, 160 and 220 days post calving). There was a significant effect of claw (medial/lateral) and of time after calving on DP. Mean DP was highest on day 10 and was lowest on day 110 at the tip of the distal phalanx (S1) and on day 160 25 mm towards the heel from the tip (S2). DP was greater at S1 in medial claws and S2 in lateral claws. Although mean DP decreased between days 10 and 110, this change was correlated to DP at day 10. At S1 claws with a DP of <7.5mm tended to increase in thickness between day 10 and 110. Claws which were ≤ 8.25 mm at day 10 were 2.43 (95% CI 0.86-6.89) times more likely to be thin (<7.0mm) at day 110, but of the 12 thin claws at day 110, six had had an adequate DP (>8.25 mm) at day 10. A single measurement of DP at calving was not an effective method for predicting which claws would became thin during lactation.

Promoting farmer engagement and activity in the control of dairy cattle lameness

Many 'influencers' allied to the agricultural industry support farmers to implement management changes that affect animal welfare. Developing approaches to working with farmers that achieve both engagement and subsequently management changes is critical. As an example, the generation of action points and implementation of change to control dairy cattle lameness is reported and discussed here. Action plans were generated on farms receiving both lameness monitoring and intervention support (MS group; n=117) as part of a 3 year intervention project. At the start of year 1, MS farmers received action planning advice from a veterinary surgeon, and then at the start of years 2 and 3, farmers generated their own lameness control action plans with facilitator support. Engagement was achieved with 114 MS farmers who generated 692 action points in total. Two hundred and sixteen of these resulted from veterinary advice and 476 were generated by the farmers with facilitator support. In terms of activity, MS farms implemented a mean of 8.22 changes per farm as compared to 6.77 on farms which only received annual lameness monitoring (MO group; n=72). While these levels of change were similar, fewer changes implemented on the MS farms (8.5%) were judged 'likely to increase the risk of lameness' compared to the MO farms (16.5%). Farmers generated substantial numbers of lameness control action points for their own farms aided by a facilitator and, crucially, veterinary or facilitator involvement reduced changes that were likely to compromise lameness control.

Proteomics: A new tool in bovine claw disease research

Claw horn disruption (CHD) is a common underlying cause of lameness in dairy cattle which leads to compromised animal welfare and production losses. Despite an intense research effort over the last two decades, progress in reducing the prevalence of lameness due to CHD has been limited. In addition to current research strategies there is a need to develop novel approaches and methods that expand understanding of the disease mechanisms involved in CHD. The objectives of the present study were to explore the potential of liquid chromatography tandem mass spectrometry (LC-MS/MS) in mapping protein expression in three different bovine claw tissues, and to provide a relevant functional annotation of the proteins characterized in these tissues. LC-MS/MS was used to characterize protein expression in coronary band skin (C), claw dermal (D) and lamellar (L) tissues from two heifers. A total of 388 different proteins were identified, with 146 proteins available for identification in C, 279 proteins in D and 269 proteins in L. A functional annotation of the identified proteins was obtained using the on-line Blast2GO tool. Three hundred and sixteen of the identified proteins could be subsequently grouped manually to one or more of five major functional groups related to metabolism, cell structure, immunity, apoptosis and angiogenesis. These were chosen to represent basic cell functions and biological processes potentially involved in the pathogenesis of CHD. The LC-MS/MS-based proteomic analysis presented here is the largest published survey, so far, of the bovine claw tissue proteome.

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.

Economic, education, encouragement and enforcement influences within farm assurance schemes

Farm assurance schemes are voluntary certification schemes that aim to provide consumers and retailers with assurances on animal welfare, environment and food safety standards. Whilst current schemes have often been focused on resource-based standards there has been interest in schemes including more outcome-based assessments. In order to maximise the likely impact of including these outcome assessments it is important to consider the economic, education, encouragement and enforcement drivers that may improve welfare. Using dairy cattle lameness as an example, the potential mechanisms to use these drivers within farm assurance schemes is reviewed. Future development of schemes should focus on encouraging the active participation of farmers in monitoring and managing outcome measures. Economic and educational approaches have a role in supporting change. Where possible, economic drivers need to be working in the same direction as welfare (ie provide win-win situations). Educational initiatives, such as providing generic technical information and farm-specific advisory support, need to be available when requested. Finally, enforcement tools, based on existing noncompliance procedures, may be needed to stimulate activity if other initiatives prove ineffective on individual farms.

Economic, education, encouragement and enforcement influences within farm assurance schemes

AbstractFarm assurance schemes are voluntary certification schemes that aim to provide consumers and retailers with assurances on animal welfare, environment and food safety standards. Whilst current schemes have often been focused on resource-based standards there has been interest in schemes including more outcome-based assessments. In order to maximise the likely impact of including these outcome assessments it is important to consider the economic, education, encouragement and enforcement drivers that may improve welfare. Using dairy cattle lameness as an example, the potential mechanisms to use these drivers within farm assurance schemes is reviewed. Future development of schemes should focus on encouraging the active participation of farmers in monitoring and managing outcome measures. Economic and educational approaches have a role in supporting change. Where possible, economic drivers need to be working in the same direction as welfare (ie provide win-win situations). Educational initiatives, such as providing generic technical information and farm-specific advisory support, need to be available when requested. Finally, enforcement tools, based on existing noncompliance procedures, may be needed to stimulate activity if other initiatives prove ineffective on individual farms.

The effect of clinical lameness on liveweight in a seasonally calving, pasture-fed dairy herd

This study investigated the effect of lameness on liveweight (LW) in pasture-fed dairy cattle. The data comprised 222,446 averaged daily LW measurements from 828 lactations of 542 mixed-age cows in a seasonally calving, pasture-fed New Zealand dairy herd. The LW measurements for individual cows were aggregated into weekly averages and analyses conducted to evaluate the effect of a diagnosis of lameness on LW change after controlling for the effect of week in milk, parity, LW at calving, breed, calendar month, and season. In lame cows, LW decreased for up to 3wk before lameness was diagnosed and for up to 4wk after treatment. Total LW loss arising from a single lameness episode was, on average, 61kg (95% confidence interval: 47 to 74kg). The results from this study demonstrate how LW records for individual animals can be used to enhance a herd manager's ability to detect lame cows and present them for treatment. The methods presented here show how daily LW monitoring might be used as a tool for early detection of lameness in dairy cattle.

Effect of polymorphisms at the STAT5A and FGF2 gene loci on reproduction, milk yield and lameness of Holstein cows

The objective of this study was to investigate the association of polymorphisms at the STAT5A and FGF2 gene loci with fertility, lactation milk yield and lameness in dairy cattle. Five hundred and eighteen primiparous Holstein cows were included in the study. Several reproductive traits were considered including conception rate (0/1) at first insemination, conception rate (0/1) in a 305-day lactation, number of inseminations per conception, interval (days) from calving to conception for cows that conceived in the first 305 days of lactation and age at first calving. Milk yield and lameness incidence were also recorded. Genotyping was performed using PCR-RFLP. The effect of allele substitution at each gene locus on reproductive traits, milk yield and lameness was assessed with single-trait mixed linear models. No significant associations were found between reproduction traits and any of the studied polymorphisms, apart from age at first calving, for which STAT5A polymorphism had a suggestive effect ( P = 0.077). In addition, no significant effect of any polymorphism on lameness was found. Replacement of the C by G allele at the STAT5A locus was associated with a significant ( P < 0.05) increase in lactation milk yield, suggesting that this locus could be considered in gene assisted selection for the genetic improvement of milk production.

English

&nbsp; The aim of this study is to investigate the effect of aflatoxin levels in diet on milk production and composition, reproduction problems and indices and lameness in dairy cattle.&nbsp;To determine the levels of total aflatoxin and B1, B2, G1&nbsp;and G2&nbsp;in the feedstuff and M1&nbsp;in the milk, samples from two different dairy farms; A, low aflatoxin level (13.01 &micro;g/kg) and B, high aflatoxin level (110.63 &micro;g/kg), were collected and the determination of aflatoxin levels was performed by high performance liquid chromatography (HPLC). Milk yield and composition were measured during 60 days postpartum. Clinical examination and record data was used to indicate lameness and reproduction problems and indices during 50 to 100 days postpartum. The results showed that increase in the levels of aflatoxin concentration in the feedstuff was responsible for the increase in aflatoxin M1&nbsp;in milk samples. Also, levels of aflatoxin in diet and milk caused retained placenta which is a reproduction problem. Aflatoxin levels in feed and milk did not significantly increase reproduction indices and milk composition. However, prevalence of lameness was significantly affected by milk aflatoxin level&nbsp;(P &le; 0.05). It was concluded that there was a significant relationship between aflatoxin levels with lameness and retained placenta. &nbsp; Key words:&nbsp;Aflatoxin, diet, milk, reproduction, lameness, dairy cattle.

Associations between lesion-specific lameness and the milk yield of 1,635 dairy cows from seven herds in the Xth region of Chile and implications for management of lame dairy cows worldwide

AbstractLameness is one of the greatest infringements of welfare in dairy cows. The objective of this study was to investigate associations between milk yield and foot lesions causing lameness in Chilean dairy cattle with the hypothesis that if we can demonstrate that lameness reduces yield, and so income, from lame dairy cows then we have both economic and welfare arguments for reducing lameness in dairy cattle. For one year, all lame cows from seven farms with Holstein Friesian cattle were treated by their herdsmen. Herdsmen were trained by the researcher and a colour atlas was utilised to assist in diagnosis of lesions. All abnormalities on the foot and the suspected cause of lameness were recorded, and cattle were treated. A two-level hierarchical model with repeated monthly test-day yields within cows was used to investigate the impact of double sole (DS), sole ulcer (SU), white line disease (WLD), digital dermatitis (DD) and all ‘other’ causes of lameness on milk yield before and after treatment. There were 1,635 cows with complete data. Cattle with a DS were higher yielding than cattle that were never lame with a reduction in yield from four months before treatment. Cattle lame with DD were higher yielding than non-lame cattle before and after treatment. For all causes of lameness, yield increased the month after treatment. We conclude that lesions causing lameness reduced the milk yield of dairy cows in these seven herds in Chile. We discuss the current evidence base for prevention of lameness in dairy cows and hypothesise that rapid treatment is a feasible current approach to improve cow welfare immediately and probably reduce milk lost; more evidence for effective prevention is required.

Behavior during transition differs for cows diagnosed with claw horn lesions in mid lactation

Claw horn lesions, including sole hemorrhages and sole ulcers, are a major cause of lameness in dairy cattle. These lesions often develop in the weeks around calving and become visible 8 to 12 wk later. The aim was to determine whether cows that are diagnosed with claw horn lesions several weeks after calving behave differently during the calving period when the lesions are thought to first develop. The claws of 26 multiparous Holstein dairy cows were scored for sole hemorrhage severity and presence of sole ulcers 2 wk before calving, 3 wk after calving, and every 4 wk thereafter until 15 wk after calving. Of the 26 cows, 13 cows had no or low lesion scores up to 15 wk and 13 cows had at least 1 new severe lesion or sole ulcer diagnosed between 7 and 15 wk after calving. Behavior (dry matter intake, feeding time and rate, number and size of meals, standing time, number and duration of standing bouts, location of standing, and displacements at the feed bunk) was recorded from 2 wk before calving to 3 wk after calving. Behavior during the 2 wk before calving, first 24h after calving, 1 wk after calving, and 2 to 3 wk after calving was compared between cows with and without lesions in mid lactation. Multivariate regression was used to determine the predictive value of each behavior and combination of behaviors on lesion diagnosis. Cows diagnosed with lesions in mid lactation spent more time standing than cows without lesions during the 2 wk before (832±29 vs. 711±29 min/d) and 24h after (935±46 vs. 693±46 min/d) calving. These differences were driven by an increase in the time spent perching with front feet in the stall (241±22 vs. 147±22 min/d at 2 wk before calving) and an increase in standing bout duration (101±10 vs. 56±10 min/bout at 24h after calving). Compared with cows without lesions, cows with lesions consumed feed at a faster rate (86±3 vs. 77±3g/min) during the 2 wk before calving and consumed more feed (17.9±0.9 vs. 12.3±0.9kg/d) during the 24h after calving. The number of displacements at the feeder was not different between groups. These results indicate that a combination of feeding and standing behavior during the transition can serve as early indicators of claw horn lesions in mid lactation.

Sampling strategies for monitoring lameness in dairy cattle

Evaluating the prevalence of lameness within herds of dairy cattle is important for management and certification purposes; however, sampling strategies that could reduce the time taken for an assessment would be valuable. The prevalence of lame and severely lame cows on 224 United Kingdom dairy farms was available for analysis. Presence of more than 1 severely lame cow on a farm was a useful indication of a lameness problem. The vast majority (80%) of the 182 farms that had ≥1 severely lame cow present had an overall lameness prevalence >25%, whereas only 24% of the 42 farms that had no severely lame cows had an overall prevalence >25%. Information was available on individual milking order through the parlor on the day of the lameness assessment. On 37 farms where cows were housed in a group, lameness prevalence was 11.9% greater in the last third compared with the first third of the milking order. For 36 herds that were larger than 100 cows, sampling a maximum of 100 cows from the middle of the milking order produced an estimate of prevalence within 5% of the true prevalence on 83% of farms. A reasonable sampling strategy may, therefore, be to observe up to 100 cows from the middle of the milking order. Also, presence of severely lame cows at the end of milking may be useful for identifying those farms likely to benefit from further support.

Reliability of categorical versus continuous scoring of welfare indicators: lameness in cows as a case study

AbstractMany animal welfare traits vary on a continuous scale but are commonly scored using an ordinal scale with few categories. The rationale behind this practice is rarely stated but appears largely based on the debatable conviction that it increases data reliability. Using 54 observers of varying levels of expertise, inter-observer reliability (IOR) and user-satisfaction were compared between a 3-point ordinal scale (OS) and a continuous modified visual analogue scale with multiple anchors (VAS) for scoring lameness in dairy cattle from video. IOR was significantly better for the VAS than for the OS. IOR increased with self-reported level of expertise for the VAS, whereas for the OS it was highest for observers with a moderate level of expertise. The mean continuous scores and the mean categorical scores were highly correlated. Three times as many observers stated a preference for the VAS (n = 27) compared to the OS (n = 9) in investigating differences in lameness between herds. Contrary to common perception, these results illustrate that it is possible for a continuous cattle lameness score to be more reliable and to have greater user acceptability than a simple categorical scale. As continuous scales are also potentially more sensitive, and produce data more amenable to algebraic processing and more powerful parametric analyses, the scepticism against their application for assessing animal welfare traits should be reconsidered.

Lameness in Dairy Cattle: A Debilitating Disease or a Disease of Debilitated Cattle?

Lameness is the most significant challenge for the dairy industry to overcome given its obvious disruption of animal welfare and severe economic losses. Sole ulcers and white line abscesses are ubiquitous diseases with chronic nature and with the highest associated economic losses amongst all foot lesions. Their underlying causes are still not fully understood. The objectives of the study were to assess the association of digital cushion thickness (DCT), the risk of claw horn disruption lesions, and to assess the dynamics of DCT by stage of lactation and body condition score (BCS). It was hypothesized that DCT would be negatively associated with the risk of digital lesions and that DCT would be positively associated with BCS.

Lameness in dairy cattle: A debilitating disease or a disease of debilitated cattle? A cross-sectional study of lameness prevalence and thickness of the digital cushion

Lameness is the most significant challenge for the dairy industry to overcome, given its obvious disruption of animal welfare and severe economic losses. Sole ulcers and white line abscesses are ubiquitous chronic diseases with the highest associated economic losses among all foot lesions. Their underlying causes are still not fully understood. An observational cross-sectional study was carried out to investigate the association between claw horn lesions and the thickness of the digital cushion. The thickness of the digital cushion was evaluated by ultrasonographic examination of the sole at the typical ulcer site. A total of 501 lactating Holstein dairy cows were enrolled in the study. The prevalence of sole ulcers was 4.2 and 27.8% for parity 1 and parity >1, respectively. The prevalence of white line disease was 1.0 and 6.5% for parity 1 and >1, respectively. The prevalence of lameness (visual locomotion score ≥3) was 19.8 and 48.2% for parity 1 and >1, respectively. The prevalence of sole ulcers and white line diseases was significantly associated with thickness of the digital cushion; cows in the upper quartile of digital cushion thickness had an adjusted prevalence of lameness 15 percentage points lower than the lower quartile. Body condition scores were positively associated with digital cushion thickness. The mean gray value of the sonographic image of the digital cushion had a negative linear association with digital cushion thickness (R2=0.14), indicating that the composition of the digital cushion may have changed with its thickness. Furthermore, digital cushion thickness decreased steadily from the first month of lactation and reached a nadir 120 d after parturition. These results support the concept that sole ulcers and white line abscesses are related to contusions within the claw horn capsule and such contusions are a consequence of the lesser capacity of the digital cushion to dampen the pressure exerted by the third phalanx on the soft tissue beneath.