Sole Hemorrhage Research Articles

A prospective cohort study of factors associated with the digital cushion thickness in dairy cattle

Key factors such as stage of lactation, parity, and body fat reserves have been associated with the digital cushion thickness (DCT), however, there are discrepancies between the results of previously published studies. The objective of this study was to examine the association of stage of lactation, body fat reserves, parity, and lesion incidence with DCT in a large cohort of intensively monitored cows. Across 4 UK farms, 2,352 cows were prospectively enrolled and assessed at 4 time points: before calving (T1-Precalving), immediately after calving (T2-Calving), in early lactation (T3-Early), and in late lactation (T4-Late). At each time point, BCS was recorded, the presence of sole lesions (sole ulcers and sole hemorrhage) and white line lesions was assessed by veterinarians, and an ultrasound image was taken to retrospectively measure the backfat thickness (BFT) in the pelvic region and the digital cushion on the hind left lateral claw. Mixed effects multivariable linear regression models, with the cow as a random effect, were fit to examine the association between the explanatory variables and DCT. The explanatory variables tested were farm, parity, stage of lactation, BCS, BFT, height, the presence of a lesion at the time of measurement, the chronicity of a lesion during early lactation, the predicted maximum daily milk yield, and the rate of milk production rise in early lactation. Stage of lactation and farm were both associated with DCT; however, an interaction was present, and this DCT pattern of change was farm-dependent. Two distinct patterns emerged; one indicated the nadir to occur shortly after calving, the other indicated the nadir to occur during early lactation. Neither BFT nor BCS were significantly associated with DCT. Heifers displayed thinner digital cushions compared with multiparous cows; however, this effect was dependent on the stage of lactation, with heifers having a thinner digital cushion up until late lactation, by which time DCT was commensurate with multiparous animals. Sole lesions and white line lesions at the time of measurement were associated with DCT (sole lesion: estimate = -0.07 mm, 95% CI = -0.14-0.00; white line lesion: estimate = 0.28 mm, 95% CI = 0.15-0.42).

Investigating the impact of 1 hour of daily outdoor access on the gait and hoof health of nonclinically lame cows housed in a movement-restricted environment

Tiestalls, known for restrictive housing, can reduce cows' locomotor skills over time. While outdoor access benefits clinically lame cows, its effect on nonclinically lame cows is less known. This study evaluated 1 h daily outdoor access on gait and hoof health of nonclinically lame Holstein cows in tiestalls. Thirty cows, blocked by parity and DIM, were assigned to exercise (1 h outdoor access 5 d/wk for 5 wk) or nonexercise groups. Visual scoring assessed 6 gait attributes and overall gait (on scales of 0–5 and 1–5, respectively) at pre-trial, post-trial, and 8-wk follow-up stages. A total of 15 cows (9 exercise, 6 nonexercise) underwent visual gait scoring, with logistical challenges and exclusion criteria leading to this selection. Hoof health for all 30 cows was evaluated during pre-trial and follow-up hoof trims, documenting claw lesions. Hoof thermography captured dorsal coronary band views in wk 1 and 5. No significant gait score changes were observed, but exercise cows showed a 1-point improvement in overall gait score and 3 gait attributes after 5 wk of outdoor access, which persisted at follow-up. Sole hemorrhages were the only claw lesions observed, and their prevalence and severity remained consistent between pre-trial and follow-up for both groups. Thermography showed consistent coronary band temperature metrics across groups and over time. In conclusion, brief outdoor sessions resulted in noticeable, albeit not statistically significant, improvements in the gait of nonclinically lame cows in restrictive housing settings without adverse hoof health effects. Further studies should evaluate different outdoor access benefits and use precise gait and hoof health analysis technologies for a more accurate detection of subtle changes.

A prospective cohort study examining the association of claw anatomy and sole temperature with the development of claw horn disruption lesions in dairy cattle

Foot characteristics have been linked to the development of sole lesions (sole hemorrhage and sole ulcers) and white line lesions, also known as claw horn disruption lesions (CHDL). The objective of this study was to examine the association of claw anatomy and sole temperature with the development of CHDL. A cohort of 2,352 cows was prospectively enrolled from 4 UK farms and assessed at 3 time points: before calving (T1-precalving), immediately after calving (T2-calving), and in early lactation. At each time point body condition score was recorded, a thermography image of each foot was taken for sole temperature measurement, the presence of CHDL was assessed by veterinary surgeons, and an ultrasound image was taken to retrospectively measure the digital cushion and sole horn thickness. Additionally, at the postcalving time point, foot angle and heel depth were recorded. Four multivariable logistic regression models were fit to separately examine the relationship of precalving and postcalving explanatory variables with the development of either white line lesions or sole lesions. Explanatory variables tested included digital cushion thickness, sole horn thickness, sole temperature, foot angle, and heel depth. Farm, parity, body condition score, and presence of lesion at the time of measurement were also included in the models. A thicker digital cushion shortly after calving was associated with decreased odds of cows developing sole lesions during early lactation (odds ratio [OR]: 0.74, 95% confidence interval [CI]: 0.65-0.84). No association was found between digital cushion thickness and development of white line lesions. Sole temperature after calving was associated with increased odds of the development of sole lesions (OR: 1.03, 95% CI: 1.02-1.05), and sole temperature before and after calving was associated with the development of white line lesions (T1-precalving OR: 1.04, 95% CI: 1.01-1.07; T2-calving OR: 0.96, 95% CI: 0.93-0.99). Neither foot angle nor heel depth was associated with the development of either lesion type. However, an increased sole horn thickness after calving reduced the odds of cows developing sole lesions during early lactation (OR: 0.88, 95% CI: 0.83-0.93), highlighting the importance of maintaining adequate sole horn when foot trimming. Before calving, animals with a lesion at the time of measurement and a thicker sole were more likely to develop a sole lesion (OR: 1.23, 95% CI: 1.09-1.40), compared with those without a sole lesion. The results presented here suggest that white line and sole lesions may have differing etiopathogenesis. Results also confirm the association between the thickness of the digital cushion and the development of sole lesions, highlight the association between sole horn thickness and sole lesions, and challenge the potential importance of foot angle and heel depth in the development of CHDL.

Genome-wide association and functional genomic analyses for various hoof health traits in North American Holstein cattle

Hoof diseases are a major welfare and economic issue in the global dairy cattle production industry, which can be minimized through improved management and breeding practices. Optimal genetic improvement of hoof health could benefit from a deep understanding of the genetic background and biological underpinning of indicators of hoof health. Therefore, the primary objectives of this study were to perform genome-wide association studies, using imputed high-density genetic markers data from North American Holstein cattle, for 8 hoof-related traits: digital dermatitis, sole ulcer, sole hemorrhage, white line lesion, heel horn erosion, interdigital dermatitis, interdigital hyperplasia, and toe ulcer, and a hoof health index. De-regressed estimated breeding values from 25,580 Holstein animals were used as pseudo-phenotypes for the association analyses. The genomic quality control, genotype phasing, and genotype imputation were performed using the PLINK (version 1.9), Eagle (version 2.4.1), and Minimac4 software, respectively. The functional genomic analyses were performed using the GALLO R package and the DAVID platform. We identified 22, 34, 14, 22, 28, 33, 24, 43, and 15 significant markers for digital dermatitis, heel horn erosion, interdigital dermatitis, interdigital hyperplasia, sole hemorrhage, sole ulcer, toe ulcer, white line lesion disease, and the hoof health index, respectively. The significant markers were located across all autosomes, except BTA10, BTA12, BTA20, BTA26, BTA27, and BTA28. Moreover, the genomic regions identified overlap with various previously reported quantitative trait loci for exterior, health, meat and carcass, milk, production, and reproduction traits. The enrichment analyses identified 44 significant gene ontology terms. These enriched genomic regions harbor various candidate genes previously associated with bone development, metabolism, and infectious and immunological diseases. These findings indicate that hoof health traits are highly polygenic and influenced by a wide range of biological processes.

316 Routine Claw Trimming Data Provides Insight into the Occurrence of Claw Lesions Holstein Herds in the Central Region of South Africa

Abstract Claw lesions in dairy cows are a primary contributor to lameness, posing severe welfare concerns due to the distress and discomfort experienced by affected cows. Claw disorders have a significant negative impact on herd efficiency, milk yield, reproductive performance, and involuntary culling. Despite increased awareness of the detrimental effects of lameness, its incidence has continued to rise. Reducing the occurrence of lameness remains a major challenge, especially in defining and recording of claw traits. In South Africa (SA), claw data is limited to private hoof trimmers with paper-based recording. The objective of this research was to examine the occurrence and recording of claw lesions in Holstein cattle from the central region of South Africa. Claw-trimming data from five intensively managed dairy farms (average herd size: 1,073) using both dirt lot (DL) and free-stall (FS) housing systems were analyzed over a six-year period (2014 to 2019). The Claw Lesion Identification in Dairy Cattle brochure, co-developed by Zinpro Corporation and the International Lameness Committee, was used as the reference for lesion identification by a local hoof trimmer. Digital dermatitis (D) showed the greatest prevalence (64.02% of all recorded lesions), followed by sole ulcers (U; 8.59%), white line disease (W; 6.27%), and sole hemorrhage (H; 4.28%), with most lesions occurring in the rear feet. A chi-square test of independence between lesion and housing was rejected (P < 0.0001). Correspondence analysis (CA) was then used to explore these dependencies. The first dimension of the graphical display explained 90.7% of the variation in the data. The CA indicated that the prevalence of D and F are strongly associated, and closely associated with U. The prevalence of these lesions is also associated with housing systems DL and FS. The CA also confirmed a close association between W and H, and the prevalence of these lesions in housing system DL+FS. Improving the precision of claw lesion identification and recording, especially with regard to lesions that tend to occur together, can furnish essential data to identify the most prevalent lesions in a population. This will enhance our comprehension of the causal factors behind these significant lesions and offer producers practical recommendations to use these data for prevention, early detection, management, and improvement of lameness.

An iterative approach to the development of a sole ulcer induction model in Holstein cows

Our objective was to develop a sole ulcer (SU) induction model that can be used to investigate new and more efficacious methods for the treatment and prevention of SU. Three iterations [phase (P)1, P2, and P3] of an SU induction model designed to mimic mechanical and presumed metabolic pathways for SU development were conducted. The results from P1 and P2 identified alterations for the subsequent phase. Each phase used cows with similar calving dates that were randomly assigned (n = 4) to treatments. Control cows (P1CON, P3CON) did not undergo any challenges to induce SU development. Treatment cows were challenged with a hoof block (B) applied to the right hind lateral hoof. Other treatments included restricted lying time (L), restricted feed intake (F), or systemic lipopolysaccharide (LPS) administration. Treatment comparisons were P1CON versus P1BL, P2B versus P2BL, and P3CON versus P3BLF and P3BLF+LPS for P1, P2, and P3, respectively. Pregnant nulliparous Holstein cows were used in P1 and P3, and the P1 cohort was used in P2 during mid-lactation [125.9 ± 7.20 d in milk (DIM)]. Challenges were applied during a set challenge period (P1: -14 to 14 DIM, P2: 126-168 DIM, P3: -14 to 28 DIM). The P1BL cows had a hoof block applied and lying time restricted for 5 h/d. The P2B and P2BL cows had a hoof block and P2BL cows also had their lying time restricted for 18 h/d for 2 d/wk. The P3BLF and P3BLF+LPS cows had a hoof block, 6 h/d of lying time restricted 2 d/wk, and had their DMI restricted by 30% for 2 d/wk. At weekly intervals during wk 1 to 3 postpartum, P3BLF+LPS cows received jugular administration of 0.031, 0.062, and 0.125 µg of LPS per kg of body weight, respectively. Primary response measurements included hoof lesion and locomotion scoring, lying time, hoof thermography, and weight distribution per hoof. No SU induction occurred but sole hemorrhages, a precursor to SU, occurred during the postchallenge period of all phases. Temperature of the blocked hoof at the end of the challenge period did not change for P3CON cows but increased by 5.5°C and 6.2°C for P3BLF and P3BLF+LPS, respectively. Notable increases in lameness and lack of weight-bearing on the blocked hind hoof occurred for challenge treatment cows during the challenge period of P2 and P3. These changes did not persist after the hoof blocks were removed, indicating that hoof blocks succeeded in altering cow gait mechanics, but not enough to induce long-term lameness or SU. Lying restriction challenged cows in P2 and P3, indicated by a compensatory increase in lying time on the day following lying restriction compared with that on the day before restriction. In P3, lying time had the greatest depression during restriction and compensation following restriction in P3BLF+LPS cows, with LPS challenges potentially increasing the other challenge's effects. Future iterations of the SU induction model should include hoof block use, evaluate longer and more frequent standing and inclusion of forced walking bouts, and include DMI and LPS metabolic challenges.

Single-step genome-wide association analyses of claw horn lesions in Holstein cattle using linear and threshold models

BackgroundLameness in dairy cattle is primarily caused by foot lesions including the claw horn lesions (CHL) of sole haemorrhage (SH), sole ulcers (SU), and white line disease (WL). This study investigated the genetic architecture of the three CHL based on detailed animal phenotypes of CHL susceptibility and severity. Estimation of genetic parameters and breeding values, single-step genome-wide association analyses, and functional enrichment analyses were performed.ResultsThe studied traits were under genetic control with a low to moderate heritability. Heritability estimates of SH and SU susceptibility on the liability scale were 0.29 and 0.35, respectively. Heritability of SH and SU severity were 0.12 and 0.07, respectively. Heritability of WL was relatively lower, indicating stronger environmental influence on the presence and development of WL than the other two CHL. Genetic correlations between SH and SU were high (0.98 for lesion susceptibility and 0.59 for lesion severity), whereas genetic correlations of SH and SU with WL also tended to be positive. Candidate quantitative trait loci (QTL) were identified for all CHL, including some on Bos taurus chromosome (BTA) 3 and 18 with potential pleiotropic effects associated with multiple foot lesion traits. A genomic window of 0.65 Mb on BTA3 explained 0.41, 0.50, 0.38, and 0.49% of the genetic variance for SH susceptibility, SH severity, WL susceptibility, and WL severity, respectively. Another window on BTA18 explained 0.66, 0.41, and 0.70% of the genetic variance for SH susceptibility, SU susceptibility, and SU severity, respectively. The candidate genomic regions associated with CHL harbour annotated genes that are linked to immune system function and inflammation responses, lipid metabolism, calcium ion activities, and neuronal excitability.ConclusionsThe studied CHL are complex traits with a polygenic mode of inheritance. Most traits exhibited genetic variation suggesting that animal resistance to CHL can be improved with breeding. The CHL traits were positively correlated, which will facilitate genetic improvement for resistance to CHL as a whole. Candidate genomic regions associated with lesion susceptibility and severity of SH, SU, and WL provide insights into a global profile of the genetic background underlying CHL and inform genetic improvement programmes aiming at enhancing foot health in dairy cattle.

Serum 1H nuclear magnetic resonance–based metabolomics of sole lesion development in Holstein cows

Sole hemorrhage and sole ulcers, referred to as sole lesions, are important causes of lameness in dairy cattle. We aimed to compare the serum metabolome of dairy cows that developed sole lesions in early lactation with that of cows that remained unaffected. We prospectively enrolled a cohort of 1,169 Holstein dairy cows from a single dairy herd and assessed animals at 4 time points: before calving, immediately after calving, early lactation, and late lactation. Sole lesions were recorded by veterinary surgeons at each time point, and serum samples were collected at the first 3 time points. Cases were defined by the presence of sole lesions in early lactation and further subdivided by whether sole lesions had been previously recorded; unaffected controls were randomly selected to match cases. Serum samples from a case-control subset of 228 animals were analyzed with proton nuclear magnetic resonance spectroscopy. Spectral signals, corresponding to 34 provisionally annotated metabolites and 51 unlabeled metabolites, were analyzed in subsets relating to time point, parity cohort, and sole lesion outcome. We used 3 analytic methods (partial least squares discriminant analysis, least absolute shrinkage and selection operator regression, and random forest) to determine the predictive capacity of the serum metabolome and identify informative metabolites. We applied bootstrapped selection stability, triangulation, and permutation to support the inference of variable selection. The average balanced accuracy of class prediction ranged from 50 to 62% depending on the subset. Across all 17 subsets, 20 variables had a high probability of being informative; those with the strongest evidence of being associated with sole lesions corresponded to phenylalanine and 4 unlabeled metabolites. We conclude that the serum metabolome, as characterized by proton nuclear magnetic resonance spectroscopy, does not appear able to predict sole lesion presence or future development of lesions. A small number of metabolites may be associated with sole lesions although, given the poor prediction accuracies, these metabolites are likely to explain only a small proportion of the differences between affected and unaffected animals. Future metabolomic studies may reveal underlying metabolic mechanisms of sole lesion etiopathogenesis in dairy cows; however, the experimental design and analysis need to effectively control for interanimal and extraneous sources of spectral variation.

Genetic parameters of sole lesion recovery in Holstein cows

Sole hemorrhage and sole ulcers, referred to as sole lesions, are important causes of lameness in dairy cattle. The objective of this study was to estimate the genetic parameters of a novel trait reflecting how well cows recovered from sole lesions and the genetic correlation of this trait with overall susceptibility to sole lesions. A cohort of Holstein dairy cows was prospectively enrolled on 4 farms and assessed at 4 timepoints: before calving, immediately after calving, in early lactation, and in late lactation. At each timepoint, sole lesions were recorded at the claw level by veterinary surgeons and used to define 2 binary traits: (1) susceptibility to sole lesions-whether animals were affected with sole lesions at least once during the study or were unaffected at every assessment, and (2) sole lesion recovery-whether sole lesions healed between early and late lactation. Animals were genotyped and pedigree details extracted from the national database. Analyses were conducted with BLUPF90 software in a single-step framework; genetic parameters were estimated from animal threshold models using Gibbs sampling. The genetic correlation between both traits was approximated as the correlation between genomic estimated breeding values, adjusting for their reliabilities. A total of 2,025 animals were used to estimate the genetic parameters of sole lesion susceptibility; 44% of animals recorded a sole lesion at least once during the study period. The heritability of sole lesion susceptibility, on the liability scale, was 0.25 (95% highest density interval = 0.16-0.34). A total of 498 animals were used to estimate the genetic parameters of sole lesion recovery; 71% of animals had recovered between the early and late lactation assessments. The heritability of sole lesion recovery, on the liability scale, was 0.27 (95% highest density interval = 0.02-0.52). The approximate genetic correlation between each trait was -0.11 (95% confidence interval = -0.20 to -0.02). Our results indicate that recovery from sole lesions is heritable. If this finding is corroborated in further studies, it may be possible to use selective breeding to reduce the frequency of chronically lame cows. As sole lesion recovery appears to be weakly genetically related to sole lesion susceptibility, successful genetic improvement of sole lesion recovery would benefit from selection on this trait directly.

Genetic parameters and genome-wide association study of digital cushion thickness in Holstein cows.

The digital cushion is linked to the development of claw horn lesions (CHL) in dairy cattle. The objectives of this study were to (1) estimate genetic parameters for digital cushion thickness (DCT), (2) estimate the genetic correlation between DCT and CHL, and (3) identify candidate genes associated with DCT. A cohort of 2,352 Holstein dairy cows were prospectively enrolled on 4 farms and assessed at 4 time points: before calving, immediately after calving, in early lactation, and in late lactation. At each time point, CHL was recorded by veterinary surgeons, and ultrasonographic images of the digital cushion were stored and retrospectively measured at 2 anatomical locations. Animals were genotyped and pedigree details extracted from the national database. Genetic parameters were estimated following a single-step approach implemented in AIREMLF90. Four traits were analyzed: the 2 DCT measurements, sole lesions (sole hemorrhage and sole ulcers), and white line lesions. All traits were analyzed with univariate linear mixed models; bivariate models were fit to estimate the genetic correlation between traits within and between time points. Single-marker and window-based genome-wide association analyses of DCT traits were conducted at each time point; candidate genes were mapped near (<0.2 Mb) or within the genomic markers or windows with the largest effects. Heritability estimates of DCT ranged from 0.14 to 0.44 depending on the location of DCT measurement and assessment time point. The genetic correlation between DCT and sole lesions was generally negative, notably between DCT immediately after calving and sole lesions in early or late lactation, and between DCT in early or late lactation and sole lesion severity in early or late lactation. Digital cushion thickness was not genetically correlated with white line lesions. A polygenic background to DCT was found; genes associated with inflammation, fat metabolism, and bone development were mapped near or within the top markers and windows. The moderate heritability of DCT provides an opportunity to use selective breeding to change DCT in a population. The negative genetic correlation between DCT and sole lesions at different stages of production lends support to current hypotheses of sole lesion pathogenesis. Highlighted candidate genes provide information regarding the complex genetic background of DCT in Holstein cows, but further studies are needed to explore and corroborate these findings.

Comparison of claw horn disruption lesions in four dairy herds using two different trimming techniques: A case study

Claw disorders are a major problem for health, welfare, and economy in dairy production. This retrospective observational study investigated the association between cow-level prevalence of claw horn disruptive lesions and two different trimming methods - the traditional Danish Method (DAM) and the White Line Atlas Method (WLAM). Trimming records from four herds in Denmark over a 4-year period were analysed. Within each herd, claw trimming was performed with the DAM for the first 2 years, and the WLAM for the next 2 years. The data comprised 3316 claw trimmings of 1027 cows with the WLAM and 3898 claw trimmings of 1080 cows with the DAM. The association between claw trimming method and claw lesions was determined using binominal logistic analysis. There were significant differences between trimming methods for sole haemorrhage (odds ratio = 0.44), sole ulcer (odds ratio = 0.42), and white line separation (odds ratio = 0.64), with a lower prevalence during the period of trimming with the WLAM. No significant difference between trimming methods could be found in the occurrence of white line abscess or double sole. The lower prevalence of claw horn disruption lesions found in this study when cows were trimmed with WLAM justifies and necessitates further experimental studies of claw trimming methods to validate these findings.

Dairy cattle lameness: a roundtable discussion

Foreword Lameness in dairy cattle is a high prevalence condition with significant negative impact on the welfare and economics of the dairy herd. Most lameness is attributable to four main conditions: sole bruising (also referred to as sole haemorrhage), sole ulcer, white line disease and digital dermatitis. Understanding of the pathogenesis of major claw horn diseases has undergone a transformation in the last 20 years, with a shift from a primary nutritional aetiology to a biomechanical one. This has led to significant research into factors relating to claw biomechanics and interventions targeting the inflammatory process. Even for infectious conditions, the benefit of non-steroidal anti-inflammatory drugs to cow welfare and recovery cannot be underrated. In this roundtable discussion, the panel explore the clinical relevance of the findings of research exploring biomechanics and managing inflammation.

Association between a genetic index for lameness resistance and the incidence of claw horn lesions in Holstein cows.

This study aimed to determine the association between the lameness advantage genetic index and four outcomes: sole haemorrhage (SH), sole ulcers (SU), white line lesions (WL), and lameness during mobility scoring. We enrolled 2352 Holstein cows from four predominantly housed dairy herds in the UK. Cows were mobility scored and foot lesions recorded at four time points from before calving to late lactation. Cows were genotyped and genetic indexes were assigned to each cow following national genetic evaluations. Lameness records and genetic indexes were matched for 2107 cows. Four separate multivariable logistic regression models, which included farm and parity as covariables, were used to quantify the association between the lameness advantage index and whether animals were affected by SH, SU, WL, or lameness. The odds ratios (95% confidence intervals) for one-point increases in the lameness advantage index were 0.79 (0.72-0.86), 0.68 (0.59-0.78), 0.94 (0.84-1.04), and 0.82 (0.74-0.91) for SH, SU, WL, and lameness, respectively. The same trends were present when the sire's lameness advantage index was evaluated in place of the animal's own, although the strength of this association was generally weaker. The lameness advantage index is associated with SH, SU, and lameness, therefore selection on the lameness advantage index could be considered in herds aiming to reduce lameness. Where genomic testing of heifers is not conducted, sire lameness advantage index may still be effective to reduce SH and SU incidence.

Locomotion score and body condition shows a low relative contribution to the occurrence of foot disorders in dairy cows

This study aims to evaluate the occurrence and distribution of foot lesion and body condition scores to define which lesions are determinant for the manifestation of locomotion scores in dairy cows. A database from 482 Holstein cows was evaluated considering information on body condition scores (BCS), locomotion scores (LS), and cows with hoof lesions. Sole hemorrhage was the hoof lesion with the greatest occurrence (74.15%), followed by nail hypoplasia (11.35%). Most cows with LS 1 showed a 3 and 4 BCS, in contrast to most animals with 2.5 and 3.5 LS, which showed a 2 and 3 LS. Linear correlations indicate that a 0 LS is inversely associated with sole hemorrhage lesions (r = -0.19), and sole hemorrhage and digital dermatitis (r = -0.26), whereas LS 1 cows are inversely related to sole hemorrhage and digital dermatitis (r = 0.14). Regardless of the categorization between healthy and lame animals, most individuals in the system showed a BCS between 3.0 and 3.5. However, we found that locomotion and body condition scores showed a low relative contribution to the occurrence of foot disorders.

Prospective cohort study of the association between early lactation mastitis and the presence of sole ulcers in dairy cows.

The objective of this study was to investigate the association between (sub)clinical mastitis (CM) in the first 30 days in milk (DIM) and the presence of sole ulcers (SU) later in lactation. Holstein cows and heifers were examined for presence of sole haemorrhage and SU before calving, in the first 14 days postcalving and in early lactation (after 30 DIM). CM episodes and somatic cell counts (SCC) measurements were obtained from farm records. Multivariable logistic regression was used for data analysis. Odds of SU in early lactation were 2.44 times greater (95% confidence interval [CI] 0.97-5.54) in cows that had CM in the first 30 DIM compared to cows that did not have CM in the first 30 DIM. When cows that had SU precalving or at the calving check were excluded from the dataset, an association of CM in the first 30 DIM with later presence of SU was no longer statistically significant but the same numeric trend still existed (odds ratio [OR] 2.25, 95% CI 0.81-5.34). The odds of SU in early lactation were 1.70 times greater in cows that had high SCC compared to cows that did not have high SCC in the first 100 DIM (95% CI 1.13-2.55). An association was found between CM in the first 30 DIM and presence of SU in early lactation (after 30 DIM). Elucidating the mechanism behind this relationship could improve our understanding of the aetiopathogenesis of both diseases and lead to new preventive strategies.

Simulating the mechanics behind sub-optimal mobility and the associated economic losses in dairy production

Hoof disorders and sub-optimal mobility (SOM) are economically important health issues in dairy farming. Although the dynamics of hoof disorders have an important effect on cow mobility, they have not been considered in previous simulation models that estimate the economic loss of SOM. Furthermore, these models do not consider the varying severities of SOM. The objective of this study was to develop a novel bio-economic simulation model to simulate the dynamics of 8 hoof disorders: digital dermatitis (DD), interdigital hyperplasia (HYP), interdigital dermatitis/heel-horn erosion (IDHE), interdigital phlegmon (IP), overgrown hoof (OH), sole haemorrhage (SH), sole ulcer (SU) and white-line disease (WLD), their role in SOM, and estimate the economic loss of SOM in a herd of 125 dairy cows. A Reed-Frost model was used for DD and a Greenwood model for the other 7 hoof disorders. Economic analysis was conducted per mobility score according to a 5-point mobility scoring method (1 = perfect mobility; 5 = severely impaired mobility) by comparing a scenario with SOM and one without SOM. Parameters used in the model were based on literature and expert opinion and deemed credible during model validation rounds. Results showed that the mean cumulative incidence for maximum mobility scores 2–5 SOM episodes were respectively 34, 16, 7 and <1 episodes per 100 cows per pasture period and 39, 19, 8, <1 episodes per 100 cows per housing period. The mean total annual economic loss due to SOM resulting from the hoof disorders under study was €15,342: €122 per cow per year. The economic analysis uncovered direct economic losses that could be directly linked to SOM episodes and indirect economic losses that could not be directly linked to SOM episodes but arose due to the presence of SOM. The mean total annual direct economic loss for maximum mobility score 2–5 SOM episodes was €1129, €3098, €4354 and €480, respectively. The mean total annual indirect economic loss varied considerably between the 5th and 95th percentiles: €−6174 and €19,499, and had a mean of €6281. This loss was composed of additional indirect culling due to SOM (∼65%) and changes in the overall herd milk production (∼35%) because of additional younger replacement heifers entering the herd due to increased culling rates. The bio-economic model presented novel results with respect to indirect economic losses arising due to SOM. The results can be used to stimulate farmer awareness and promote better SOM management.

Prevalence of claw disorders in swiss cattle farms

The project «Healthy claws - the foundation for the future» aims to establish a Swiss national claw health monitoring based on digital recordings by claw trimmers during claw trimming. To assess claw health on the participating farms, between-herd prevalence, within-herd prevalence and cow prevalence of all claw disorders based on the «ICAR Claw Health Atlas» were calculated during this study. Claw trimmers underwent an intensive training and examination in order to ensure data quality. To guarantee the representativity of the prevalences, only farm claw trimmings were considered, where ≥ 80 % of the cows in a herd were trimmed. The calculations were based on 7108 cows and 403 heifers from 238 farms, during the period from February 2020 to February 2021. At least one claw disorder was present in 99,2 % of the farms, with 49,6 % of the heifers and 77,7 % of the cows having at least one claw disorder. The high prevalence is seen as a result of all ICAR claw disorders being considered, whereas not all of them are painful and consequently not all of them cause lameness. The absence of lameness assessment limits the evaluation of existing herd problems. High between-herd and cow prevalences were observed for the following claw disorders: heel horn erosion (92,9 %/64,7 %), digital dermatitis (55,9 %/20,7 %), white line disease (81,5 %/17,7 %) and sole hemorrhage (66,4 %/11,6 %). Asymmetric claws, corkscrew claws, scissor claws, horn fissure, interdigital phlegmon, swelling of the coronet and/or bulb and toe necrosis had low prevalences. The proportion of cows treated with a hoof block (0,5 %) was comparatively small in regard of the cows suffering from ulcers (5,6 %) and white line abscesses (2,5 %). The median within-herd prevalence of digital dermatitis was 5,6 %, with a maximal within-herd prevalence of 87,5 %. Despite the contagious nature of digital dermatitis, no increase of between-herd and cow prevalence has been observed in the past ten years throughout Switzerland. Based on this data, the Swiss claw health situation can be monitored, compared over time and improved in the future.

Standing behavior and sole horn lesions: A prospective observational longitudinal study

Studies performed on individual research farms have reported that dairy cattle developing sole hemorrhages or sole ulcers in peak to mid lactation spent more time standing during the weeks around calving. The aim of this prospective observational longitudinal study was to evaluate whether this relationship is evident in commercial dairy herds. A convenience sample of 8 herds were visited every other week, and animals without previous severe horn lesions and deemed sound at 4 to 8 wk before calving were enrolled. Standing behavior was measured with data loggers attached to a rear leg, and standing time and duration of the longest standing bout were determined for each cow. Standing behavior was summarized into 3 periods: before (d -14 to -2), around (d -1 to 1), and after (d 2 to 14) calving. Average daily standing time and average daily longest standing bout were determined for each cow and period. Average daily standing time was normally distributed, with a mean ± standard deviation of 12.1 ± 1.6, 14.4 ± 2.2, and 13.8 ± 1.7 h/d for the 3 periods, respectively. Average daily longest standing bout was right skewed with a median of 3.6 h/d [interquartile range (IQR): 3.0 to 4.3; range: 1.7 to 12.1], 3.9 h/d (IQR: 3.1 to 4.8; range: 1.3 to 11.5), and 3.7 (IQR: 3.2 to 4.4; range: 1.5 to 11.7) h/d before, around, and after calving, respectively. Hoof trimming was performed 8 to 12 wk postpartum; hoof lesion data were summarized per cow, and the most serious injury of each type of lesion was noted. Sole hemorrhages or sole ulcers were found in 25 of 256 cows. Mixed-effect logistic regression models with herd as random effect were used to analyze the risk of developing sole hemorrhages and sole ulcers, using animals without hoof lesions as reference category. Separate models were fitted for the 2 standing behaviors, and for the periods before, around, and after calving. Change in standing behavior from before to after calving was also analyzed. Body condition score at calving, body condition score loss in early lactation, milk yield, parity, and days in milk at trimming were included as covariates. In this study, no evidence for an association was found between sole hemorrhages and sole ulcers and standing behavior before or around calving. Longer standing time and longer standing bouts after calving were associated with increased odds of developing sole hemorrhages and sole ulcers, as was an increase in standing bout duration from before to after calving. Animals with sole horn or white line lesions had higher unconditional sample odds of becoming lame (odds ratio = 2.5) and severely lame (odds ratio = 11.7) after calving, compared with animals with no registered lesions at trimming. Multiparous animals had higher lameness incidence, both before and after calving. Avoiding practices that exacerbate increases in standing time and standing bout duration in early lactation may reduce the incidence of sole hemorrhages and sole ulcers.

Influence of Housing and Management on Claw Health in Swiss Dairy Goats.

Simple SummarySwiss dairy goats are commonly housed on deep littler, at least during the winter season. Due to the lack of horn wear, their claws often show overgrown wall horn. However, little is known about the impact of wall horn overgrowth on claw health and whether wall horn overgrowth impairs the goats’ locomotion behavior. Data was collected on 28 Swiss commercial dairy goat farms during autumn and spring. It was shown that severe wall horn overgrowth dominated during the indoor housing period and was associated with an increase in the proportion of claws with sole hemorrhages. Furthermore, wall horn overgrowth did not seem to have an effect on the goats’ locomotion behavior. The results of this study underline the importance of regular and careful claw trimming. Due to a rising demand for goat milk and goat milk products worldwide, it is likely that dairy goat production will be intensified in the future, with larger herds per farm. In Switzerland, as in many other countries with intensive farming systems, dairy goats are typically housed on deep litter, with little access to hard abrasive surfaces. Such housing conditions will result in wall horn overgrowth. The aim of this study was to gain profound knowledge on the occurrence of overgrown wall horn, its impact on claw health and locomotor behavior, and possible adverse effects on animal welfare. Additionally, housing and management factors that may contribute to non-physiological claw conditions were evaluated. To compare claw conditions after the summer grazing period and the winter indoor housing period, data were collected on 28 Swiss dairy goat farms in autumn and spring (621 goats in total). Claw lesions were recorded with the help of a “claw card” documenting each claw. Furthermore, pictures were taken of each claw to determine the severity of wall horn overgrowth. Locomotion behavior (activity, lying time and lying bouts) was recorded with three-dimensional accelerometers fixed to the goats’ hind legs. In autumn, 66.7% of the examined claws showed moderate overgrowth, 32.4% severe overgrowth and 0.9% no overgrowth. In spring, 47.4% of the examined claws were affected with moderate overgrowth, 52.6% with severe overgrowth and 0.0% with no overgrowth. Horn separation (48.1% of examined claws) and sole hemorrhages (16.0% of examined claws) were the most frequent lesions. In goats with severely overgrown claws, the risk of developing sole hemorrhages was doubled compared with moderate overgrowth. The occurrence rate of horn separation was lower if the trimmer had attended a special skills training course (p < 0.001). Furthermore, locomotor activity (p < 0.01) and the number of lying bouts per day (p < 0.01) were higher in spring than autumn. Neither the goats’ activity nor the number of lying bouts per day differed before and after claw trimming. Finally, season and trimming were not associated with the goats’ total lying time. A certain extent of wall horn overgrowth in dairy goat claws cannot be avoided under the housing conditions typical for Swiss farms. Severe wall horn overgrowth is associated with an increase in the proportion of claws with sole hemorrhages. Therefore, regular and careful functional claw trimming, taking the housing situation (deep bedding, access to pasture, grazing on alpine pasture) into account, should be promoted.

PREVALENCE OF LAMENESS AND ASSOCIATED FOOT LESIONS IN SAHIWAL DAIRY COWS

Lameness is 3rd most prevalent disease after mastitis and infertility, in the dairy industry today and is an important welfare issue causing significant impact on dairy economics. Lameness leads to involuntary culling of lactating dairy cattle due to significant effect on production and reproduction.Mostly lameness occurs due to foot lesions irrespective of breed, management and of animal. Two hundred and four Sahiwal dairy cows were evaluated for lameness and associated claw lesionsin the study from local dairy farms of Punjab. Clinical lameness (lameness score 2 &amp; 3) was evident in 6 per cent of animals. After lameness scoring, each animal was restrained in chute and hooves were examined before and after paring 1 mm of hoof tissue from weight bearing surface. Seventy three per cent animals had at least one lesion in their hooves. On animal level, under run soles (45%) were found to be most prevalent claw lesion followed by white line lesions (29%), overgrown soles (7%), cork screw hooves (5%), sole avulsions (5%), sole hemorrhages (3%), heel erosions (3%), double soles (2%) and wall cracks (1%). At claw level, prevalence of lesions was 35.3 per cent, among which under run soles were the most prevalent lesion (19.3%) followed by white line lesions (16.3%), overgrown soles (2.82%), cork screw hooves (1.84%), sole avulsions (1.47%), sole hemorrhages (1.04%), heel horn erosions (0.61%), double soles (0.49%), wall cracks (0.25%) and toe hemorrhages (0.12%). Lactation length and parity had no effect on lameness. Comparatively more lesions were seen in hind limb hooves (56.8%) as compared to forelimb hooves (43.2%). Fore lateral and hind medial claws had more lesions (58.8% and 76.47%, respectively) as compared to contralateral claws 52.9% and 70.5%, respectively). Overall, a low prevalence of clinical lameness was seen in Sahiwal dairy cows.