Prevalence of claw lesions in Norwegian dairy cattle housed in tie stalls and free stalls

Partial herd hoof trimming results in a higher economic net benefit than whole herd hoof trimming in dairy herds

Sole ulcers, a common cause of lameness is the costliest non-infectious foot lesion in dairy cows and one of the most prevalent non-infectious foot lesions in freestall housing systems. Costs associated with sole ulcers are treatment costs, plus increased labor and decreased productivity and fertility. Routine hoof trimming is part of a strategy to manage sole ulcers. However, hoof trimming strategies differ among farms. The two most frequently applied strategies are: 1) partial herd hoof trimming with a 2-month interval between trims; and 2) whole herd hoof trimming at 6-month intervals. A Markov model was developed to investigate whether every 2 months partial herd hoof trimming or whole herd hoof trimming every 6 months was the most cost-effective strategy to avoid costs associated with sole ulcers. In this model, the net benefits for a 100-cow herd and the average productive life span of a dairy cow in intensive dairy systems of 3 years were evaluated. Partial herd hoof trimming was the most cost-effective strategy 100% of the time compared to whole herd hoof trimming, with a difference in 3-year net benefits of US$4,337 (95% CI: US$2,713-US$5,830). Based on sensitivity analyses, variables that were the sources of the biggest uncertainty in the model were herd size, the probability of being trimmed in a partial herd trim, and the prevalence of sole ulcers. To further investigate the impacts of herd size and of probability of being trimmed, various scenario analyses were conducted. With increasing herd size, the difference in net benefits in favor of partial herd hoof trimming increased even more. Scenario analyses about the probability of getting trimmed all indicated that targeted intervention increased the difference in net benefits in favor of partial herd hoof trimming. However, if the selection of cows to be trimmed in a partial herd trim was random, the whole herd hoof trimming strategy became cost-effective. Therefore, targeted selection and early intervention are necessary to decrease costs associated with sole ulcers.

Prevalence of Painful Lesions of the Digits and Risk Factors Associated with Digital Dermatitis, Ulcers and White Line Disease on Swiss Cattle Farms

The first aim of this study was to calculate the prevalence of painful lesions of the digits ("alarm" lesions; ALs) in Swiss dairy herds and cow-calf operations over a three-year study period. The following ALs were included in the calculation: the M2 stage of digital dermatitis (DD M2), ulcers (U), white line fissures (WLF) of moderate and high severity, white line abscesses (WLA), interdigital phlegmon (IP) and swelling of the coronet and/or bulb (SW). Between February 2020 and February 2023, digit disorders were electronically recorded during routine trimmings by 40 specially trained hoof trimmers on Swiss cattle farms participating in the national claw health programme. The data set used consisted of over 35,000 observations from almost 25,000 cows from 702 herds. While at the herd-level, the predominant AL documented in 2022 was U with 50.3% followed by WLF with 38.1%, at the cow-level, in 2022, it was DD M2 with 5.4% followed by U with 3.7%. During the study period, within-herd prevalences of ALs ranged from 0.0% to a maximum of 66.1% in 2020. The second aim of this study was to determine herd- and cow-level risk factors associated with digital dermatitis (DD), U and white line disease (WL) in dairy cows using data from 2022. While for DD, analysed herd-level factors appeared to have a greater effect on the probability of its occurrence, the presence of U and WL was mainly associated with the analysed cow-level factors. The risk for DD increased with a higher herd trimming frequency. Herds kept in tie stalls had a lower risk for DD and WL and a higher risk for U compared to herds kept in loose housing systems. Herds with predominantly Holstein Friesian cows as well as Holstein Friesian cows had a higher risk for the occurrence of DD compared to herds and cows of other breeds. With increasing parity, cows had a higher risk of developing U and WL, whereas for DD, parity was negatively associated with prevalence. Cows trimmed during the grazing period had a higher risk of U and WL than cows trimmed during the housing period. These findings may contribute to improve management measures affecting the health of the digits in farms with structures similar to those evaluated in the current study, such as small herds with frequent access to pasture. Further research is warranted to demonstrate how measures addressing the current results combined with those of individual herd risk assessments might contribute to an improvement in the health of the digits in the respective dairy herds.

Development of a benchmarking tool to assess the welfare of dairy cattle on small-scale farms

Public concern about the welfare of farm animals and the livestock industry's awareness of the need to improve animal welfare have led to the implementation of new tools designed to meet this objective. Especially in the case of small-scale farms in marginalized areas, the lack of available data specifically for assessing welfare led to the present study. Its aim was to use animal- and resource-based indicators that are representative of small-scale farms, to establish an index and develop a benchmarking tool that can be used to dynamically evaluate the welfare of cattle on farms with different husbandry systems and provide farmers, veterinarians, extension officers, and stakeholders with reliable information that can be used as a decision support tool. For this reason, 1,891 cows from 204 herds housed in freestall (n = 111) and tiestall (n = 93) husbandry systems in South Tyrol (Northern Italy) were evaluated. The results showed that 17.6% of herds (36 farms) had an average score below 60 (out of 100), which means that immediate intervention should be adopted to improve welfare. South Tyrolean dairy farms performed well in terms of lameness, skin alterations, avoidance behavior, number and space of lying areas, and dystocia occurrence scores, whereas water supply, cow cleanliness status, claw conformation, and getting-up behavior offered significant potential for improvement. Significant differences were observed between housing systems scoring less than 60 out of 100 points in 9.9% (n = 11) and 26.9%, (n = 25), of the herds kept in freestalls and tiestalls, respectively. A slight difference was found when comparing the percentage of herds with high scores, which corresponded to 30.6% (n = 34) of herds housed in freestalls and 22.6% (n = 21) of herds housed in tiestall housing systems. In addition, it was shown that animals reared on farms with tiestalls more often had problems with body condition, cleanliness, and skin alterations. All individual welfare indicators in the top 25% of herds had scores above 80, indicating that this may be an attainable target for freestall and tiestall herds, respectively, to promote good dairy cow welfare. The overall aim must be to adopt measures to increase the scores on all farms closer to this level.

Changes in dairy cows' behaviour, health, and production after transition from tied to loose housing

BACKGROUND

Transition of dairy cows from a tied to a loose housing system may affect their behaviour, health and production. Such housing system changes have become more frequent in Estonia but knowledge is lacking on how cows adapt to a new system. The aim of this study was to evaluate how cows' behaviour, milk production and composition, and different aspects of their health changed after transition from tied to loose housing.

RESULTS

A herd of 400 dairy cows was moved to a new system on the same farm, so that effects of transport were not confounding factors. Behavioural observations were made for approximately 4 months following transition. Milk production data were recorded from 12 months before to 12 months after transition. Examination for skin alterations and cleanliness, as well as body condition scoring were carried out before transition, and thereafter monthly throughout the study. Significant effects on behaviour were observed just after the transition, with increases in the behaviour indicative of poor welfare, such as vocalisation and aggression, and decreases in those indicative of a good state of welfare, such as ruminating, resting and grooming. These effects were of short duration, with most returning to a steady state after the first week. Milk production declined already before the transition but fell significantly after transition, and this fall lasted longer in older cows. Likewise, somatic cell counts were higher in all cows following transition, but older cows were affected significantly more than cows in the first lactation. The frequency of lameness and skin alterations increased on average after transition. Body condition scores fell after transition but recovered by the second month. Therefore, there were adverse effects on the behaviour, health and production of the dairy cows transferred, although, apart from older cows, of short duration.

CONCLUSION

The transition from tied to loose housing first had negative impacts on the welfare of the cows, although by the tenth day the behavioural indicators had returned to normal values. Impacts were more severe in higher parity cows, indicating that the change was more of a challenge for older cows. The findings of this study suggest that animals' behaviour and health should be more carefully observed within about 2 weeks after transition. It is quite likely that more and more farmers in Estonia and elsewhere will recognize the benefits of keeping their dairy cattle in loose housing, aimed at improving animal welfare and the value of the production chain.

Effects of High Concentrate-Induced Subacute Ruminal Acidosis Severity on Claw Health in First-Lactation Holstein Cows

This study aimed to evaluate the effects of diet-induced subacute rumen acidosis (SARA) severity during transition and the early lactation period on claw health in 24 first-lactation Holstein heifers. All heifers were fed a 30% concentrate (in dry matter) close-up ration three weeks before calving, then switched to a high-concentrate ration (60% dry matter), which was fed until the 70th day in milk (DIM) to induce SARA. Thereafter, all cows were fed the same post-SARA ration with around 36% concentrate in dry matter. Hoof trimming was performed before calving (visit 1), at 70 (visit 2) and at 160 DIM (visit 3). All claw lesions were recorded, and a Cow Claw Score (CCS) was calculated for each cow. Locomotion scores (LCS 1-5) were assessed at two-week intervals. Intraruminal sensors for continuous pH measurements were used to determine SARA (pH below 5.8 for more than 330 min in 24 h). The cluster analysis grouped the cows retrospectively into light (≤11%; n = 9), moderate (>11-<30%; n = 7), and severe (>30%; n = 8) SARA groups, based on the percentage of days individual cows experienced SARA. Statistically significant differences were found between SARA groups light and severe in terms of lameness incidence (p = 0.023), but not for LCS and claw lesion prevalence. Further, the analysis of maximum likelihood estimates revealed that for each day experiencing SARA, the likelihood of becoming lame increased by 2.52% (p = 0.0257). A significant increase in white line lesion prevalence was observed between visits 2 and 3 in the severe SARA group. The mean CCS in severe SARA group cows were higher at each visit compared to cows in the other two groups, but without statistical significance. Overall, this is the first study indicating that first-lactation cows fed a similar high-concentrate diet but with a higher severity of SARA tended to have poorer claw health, albeit with only partial statistical evidence.

Effect of claw blocks on the healing duration and lesion severities of claw lesions in lame cows in Western Thailand

Background and Aim: Lameness is a major complication in dairy cattle affecting health and milk production. Several factors are found to contribute to this condition and specific treatments are required, including the process of claw trimming. The elevation of the claw, such as with the application of a claw block, was reported to be beneficial in the more severe cases. This study aimed to determine the efficiency of a claw block on claw lesions of lame cows in dairy farms in Western Thailand. Materials and Methods: Locomotion scores of 376 dairy cows were determined by a veterinarian using a scale of 1–5 (1 = normal; 5 = severely lame) at the time of the visit. Cows with a score of 3 or greater were defined as clinically lame. In total, 134 clinically lame cows from 11 dairy farms in the Kanchanaburi and Ratchaburi provinces were included in the analysis. Claw lesions included a white line abscess, bruised sole, sole ulcer, sole abscess, white line separate, and double soles. Wooden or rubber claw blocks were applied to the unaffected claw of the same hoof as the injured claw of 116 cows, which were classified as the treatment cases, and 18 cows were left untreated and classified as the control cases. Each cow was checked on every week of the healing process for 2 months unless the cow was culled earlier. Survival analysis was based on the Kaplan–Meier estimator and Cox Proportional Hazard regression. Results: The median healing time for lame cows with and without claw blocks was 21 and 36 days, respectively. After adjusting for the lesion severity and type, the lame cows with and without a claw block had hazard ratios of 2.16 and 3.08, respectively. The healing times between the four lesion types in cows with a claw block were not significantly different. The healing time was longer in lame cows, with a severity score of 4. Conclusion: The results from this study reveal that the treatment of lame cows with claw blocks promoted the healing capacity of claw lesions after claw trimming.

Classification of digital dermatitis with image processing and machine learning methods

In this study, it was aimed to perform the detection and grading of Digital Dermatitis (DD) disease, which is common in dairy cattle and causes serious economic losses, using artificial intelligence techniques in a computer environment with high accuracy without the need for any expert intervention. Within the scope of the study, because of the examinations performed on 168 cows of Holstein breed, aged 4-7 years, whose lameness was detected in dairy farms located in the center and districts of Burdur region, pictures of lesions due to DD were taken, and 4 groups were formed according to the degree of size. The photographs obtained were first labelled according to the degree of disease by a faculty member specialized in podiatry. Afterwards, the tagged photographs were reproduced using artificial intelligence image augmentation techniques, and a sample of 1,000 datasets was carried out for each disease degree. The photographs that make up the dataset were processed using the inception v3 deep learning algorithm and more than 2,000 numerical features were extracted. Then, machine learning models were developed using 6 different machine learning algorithms to classify these features. The results obtained were examined in detail with the help of tables and graphics, and it showed that the developed artificial intelligence models could be used in the classification of DD case photos with a cumulative accuracy value above 0.87.

Status of claw recordings and claw health in Danish dairy cattle from 2013 to 2017

Since 2009, Danish claw trimmers have been able to record claw health digitally during trimming. The records are owned by the farmer and can be used locally in the herd and on a large scale by breeding organisations to improve claw health. The objective of this study was to describe data on claw recording routines and describe the prevalence of digital dermatitis (DD), interdigital hyperplasia (IH), sole ulcer (SU) and white line abscess (WLA) recorded by claw trimmers (TrimmerID) at trimming. More than 5.18 million records of cows with claw recordings and 2.75 million records of claw trimming with 2.4 million concurrent claw diseases from 62 TrimmerIDs from 705,803 animals from 1635 herds over a 5-year period from 2013 to 2017 were included in the dataset. Data on cow level was used for the descriptive statistics. The data was restricted to, and grouped by, heifers from 12 months of age, first, second and third or older parity cows from the breeds Holstein, Danish Red Dairy, Jersey and crossbreds. The number of recorded trimmings per TrimmerID per year varied from 132 to 48,040 with a mean of 9556 and increased during the period studied. The overall prevalence across breed and parity groups of DD, IH, SU and WLA was 21%, 6%, 7% and 3%, respectively. The prevalence of the lesions remained quite constant during the 5-year period. DD was recorded in 95% of the herds in 2017. The prevalence of IH, SU and WLA increased with increasing parity. Digital recording of claw lesions may be a good indicator of claw health. However, the recording routines and quality of the recordings must be considered.

Invited review: The welfare of dairy cattle housed in tiestalls compared to less-restrictive housing types: A systematic review

Many dairy cattle worldwide are housed in tiestalls, meaning that they are tethered by the neck to individual stalls. On some farms, tied cattle are permitted seasonal access to pasture, but otherwise their movements are restricted compared with cows housed in freestall barns or other loose housing systems. The aim of this systematic review is to summarize the scientific literature pertaining the welfare of tied dairy cattle through comparison with less-restrictive housing systems. Articles identified by PubMed and Web of Science underwent a 5-phase screening process, resulting in the inclusion of 102 papers. These papers addressed measures of welfare related to affective state, natural behavior, and health (with the lattermost category subdivided into hoof and leg disorders, lameness, mastitis, transition disease, and other diseases or conditions). Health was the most researched topic (discussed in 86% of articles); only 19% and 14% of studies addressed natural behavior and affective state, respectively. Our review highlights different health benefits for tethered and loose cattle. For example, tied cattle experience reduced prevalence of white line disease and digital dermatitis, whereas loose cattle experience fewer leg lesions and injuries. The prevalence of mastitis, transition diseases, and other conditions did not differ consistently across housing types. We found that the expression of certain natural behaviors, particularly those associated with lying down (e.g., time spent kneeling, unfulfilled intentions to lie down), were impaired in tiestalls. Articles addressing affective state found benefits to loose housing, but these studies focused almost exclusively on (1) physiological measurements and (2) cow comfort, a concept that lacks a consistent operational definition across studies. We call for future research into the affective state of tied cattle that extends beyond these explorations and employs more sophisticated methodologies.

Evaluation of test characteristics of 2 ELISA tests applied to bulk tank milk and claw-trimming records for herd-level diagnosis of bovine digital dermatitis using latent class analysis

Bovine digital dermatitis (DD) is an infectious claw disease with a negative effect on animal welfare and production. Treponema spp. is the main causative agent, and infected animals produce specific antibodies. Our aim was to estimate sensitivity (Se) and specificity (Sp) of 2 ELISA research tests, Medicago's ELISA test and GD Animal Health's in-house ELISA test, for detection of DD-associated Treponema antibodies in bulk tank milk. We used bulk tank milk samples from 154 Norwegian dairy cattle herds, 96 from an expected high-prevalence region and 58 from a low-prevalence region. Both tests were evaluated separately against herd-level (aggregated) claw-trimming records extracted from the Norwegian Dairy Herd Recording System using latent class models in a Bayesian analysis. Cutoff values were selected using an explorative approach, and both noninformative priors for all parameters and informative β priors for distribution of Se and Sp of claw trimming were explored. The estimated (median) true herd-level prevalence of digital dermatitis varied between 24 and 30% in the high-prevalence region and between 3 and 6% in the low-prevalence region. For Medicago's ELISA test, an Se (95% posterior credible interval) of 0.57 (0.32; 0.94) could be achieved without compromising Sp, and for GD Animal Health's in-house ELISA test, an Se of 0.60 (0.37; 0.92) was achieved. Our study showed that both ELISA tests can detect antibodies against DD-associated Treponema spp. in bulk tank milk. However, neither of the 2 ELISA tests produced satisfactory sensitivity without compromising specificity. Based on these results, inspection at claw trimming in a chute is necessary for surveillance and control of DD at the herd level in Norway, although these ELISA tests of bulk tank milk might be a useful supplement.

Claw disorders as iceberg indicators of cattle welfare: Evidence-based on production system, severity, and associations with final muscle pH

This study presents a novel approach to use claw disorders in cattle as a retrospective welfare indicator characterized at the abattoir. A total of 1040 cattle (2080 front and back left claws) were analyzed from 143 batches, originating from feedlots, free-range, and dairy systems. Our results indicate that abnormal claw shapes (>55%) and fissures of the claw wall (>25%) had the highest prevalence, regardless of the system of origin. For the seven types of lesions monitored, numerous associations were found between lesions in the front and rear limbs typical of each production system. Ultimate meat pH was higher in animals with white line disease and skin wounds in feedlot and free-range cattle. We conclude that claw disorders can be used as an iceberg indicator to provide valuable information about animal fitness, and the ability to cope with the husbandry and pre-slaughter environment. These indicators can be used to improve the level of welfare of the animals.

Factors Associated With Lameness in Tie Stall Housed Dairy Cows in South Germany

Lameness remains a major concern for animal welfare and productivity in modern dairy production. Even though a trend toward loose housing systems exists and the public expects livestock to be kept under conditions where freedom of movement and the expression of natural behavior are ensured, restrictive housing systems continue to be the predominant type of housing in some regions. Factors associated with lameness were evaluated by application of multiple logistic regression modeling on data of 1,006 dairy cows from 56 tie stall farms in Bavaria, South Germany. In this population, approximately every fourth cow was lame (24.44% of scored animals). The mean farm level prevalence of lameness was 23.28%. In total, 22 factors were analyzed regarding their association with lameness. A low Body Condition Score (BCS) (OR 1.54 [95%-CI 1.05-2.25]) as well as increasing parity (OR 1.41 [95%-CI 1.29-1.54]) entailed greater odds of lameness. Moreover, higher milk yield (OR 0.98 [95%-CI 0.96-1.00]) and organic farming (OR 0.48 [95%-0.25-0.92]) appeared to be protectively associated with lameness. Cows with hock injuries (OR 2.57 [95%-CI 1.41-4.67]) or with swellings of the ribs (OR 2.55 [95%-CI 1.53-4.23]) had higher odds of lameness. A similar association was observed for the contamination of the lower legs with distinct plaques of manure (OR 1.88 [95%-CI 1.14-3.10]). As a central aspect of tie stall housing, the length of the stalls was associated with lameness; with stalls of medium [(>158-171 cm) (OR 2.15 [95%-CI 1.29-3.58]) and short (≤158 cm) length (OR 4.07 [95%-CI 2.35-7.05]) increasing the odds compared with long stalls (>171 cm). These results can help both gaining knowledge on relevant factors associated with lameness as well as approaching the problem of dairy cow lameness in tie stall operations.

Liability to diseases and their relation to dry matter intake and energy balance in German Holstein and Fleckvieh dairy cows

Dairy cow efficiency is increasingly important for future breeding decisions. The efficiency is determined mostly by dry matter intake (DMI). Reducing DMI seems to increase efficiency if milk yield remains the same, but resulting negative energy balance (EB) may cause health problems, especially in early lactation. Objectives of this study were to examine relationships between DMI and liability to diseases. Therefore, cow effects for DMI and EB were correlated with cow effects for 4 disease categories throughout lactation. Disease categories were mastitis, claw and leg diseases, metabolic diseases, and all diseases. In addition, this study presents relative percentages of diseased cows per days in milk (DIM), repeatability, and cow effect correlations for disease categories across DIM. A total of 1,370 German Holstein (GH) and 287 Fleckvieh (FV) primiparous and multiparous dairy cows from 12 dairy research farms in Germany were observed over a period of 2 yr. Farm staff and veterinarians recorded health data. We modeled health and production data with threshold random regression models and linear random regression models. From DIM 2 to 305 average daily DMI was 22.1 kg/d in GH and 20.2 kg/d in FV. Average weekly EB was 2.8 MJ of NE_L/d in GH and 0.6 MJ of NE_L/d in FV. Most diseases occurred in the first 20 DIM. Multiparous cows were more susceptible to diseases than primiparous cows. Relative percentages of diseased cows were highest for claw and leg diseases, followed by metabolic diseases and mastitis. Repeatability of disease categories and production traits was moderate to high. Cow effect correlations for disease categories were higher for adjacent lactation stages than for more distant lactation stages. Pearson correlation coefficients between cow effects for DMI, as well as EB, and disease categories were estimated from DIM 2 to 305. Almost all correlations were negative in GH, especially in early lactation. In FV, the course of correlations was similar to GH, but correlations were mostly more negative in early lactation. For the first 20 DIM, correlations ranged from -0.31 to 0.00 in GH and from -0.42 to -0.01 in FV. The results illustrate that future breeding for dairy cow efficiency should focus on DMI and EB in early lactation to avoid health problems.

[Changes in claw and leg health and hair cortisol concentration in dairy cows during the transition from tie-stall to free-stall housing - A study of a medium-sized farm]

OBJECTIVE

Claw health and carpal and tarsal lesions were assessed in a dairy herd during the transition from a tie-stall to a free-stall barn. The stress associated with the change in housing was also evaluated.

MATERIALS AND METHODS

The initial size of the herd was 57 dairy cows, which were evaluated 4 times, 4-5 months apart, in a hoof-trimming chute. Claw horn and skin lesions of the foot were considered separately. The carpi and hocks were assessed for hair loss and skin lesions, and the hocks were also evaluated for swelling. Tail hair samples were collected from all cows during the second visit, and the cortisol concentration of 3 different sections of the hair was measured.

RESULTS

The high prevalence of digital dermatitis and other skin lesions in the hind legs seen in the tie-stall barn (49 %) did not change significantly during the 14-month study period and was 46 % at the last visit. Heel horn erosions of the hind feet were rare in the tie-stall barn (14 %), but had a prevalence of 100 % at the end of the study. There was a trend for a decrease in the prevalence of other claw horn lesions. The prevalence and severity of carpal and hock lesions decreased significantly in the free-stall barn. Compared to values in cows at the tie-stall barn, the hair cortisol concentration was significantly higher during the transition period and at the free-stall barn.

DISCUSSION AND CONCLUSIONS

The target variables were subjected to a multitude of factors but it can be assumed that the more comfortable lying surface in the free-stall barn had the most significant effect on carpal and tarsal joint health. The fluctuating prevalence of claw horn lesions indicates that claws health should be monitored closely. The increase in hair cortisol concentration after the transition to the free-stall barn could imply increased stress, but washout of cortisol in more distal hair segments could not be ruled out.

CLINICAL RELEVANCE

The results of the present report cannot be directly applied to other herds; however, the significance of cow comfort is highlighted by the presence of fewer carpal and hock lesions. The significant increase in the prevalence of heel horn erosions indicates that the horn capsule is compromised under free-stall conditions.

Organic Dairy Cattle: Do European Union Regulations Promote Animal Welfare?

Simple Summary

This paper aims to identify improvements and gaps in the specific EU regulations for organic farming and whether they promote higher welfare standards for dairy cattle compared to the “minimum standards” set up for conventional farming. Based on the available scientific evidence, we identified areas in the organic regulations where the welfare status of the animals is improved, but some limitations and gaps exist.

Abstract

Animal welfare is an emerging concept in EU law; with the advent of specific regulations intending to protect animals. The approach taken by European lawmakers is to provide “minimum standards” for conventional farming; argued by some as failing to adequately protect animals. In contrast, the EU organic farming regulations aim to “establish a sustainable management system for agriculture” and promote “high animal welfare standards”. The first aim of this review was to identify key areas where there are clear improvements in quality of life for dairy cattle housed under the EU organic regulations when compared to the conventional EU regulations. Using the available scientific evidence, our second aim was to identify areas where the organic regulations fail to provide clear guidance in their pursuit to promote high standards of dairy cattle welfare. The greater emphasis placed on natural living conditions, the ban of some (but unfortunately not all) physical mutilations combined with clearer recommendations regarding housing conditions potentially position the organic dairy industry to achieve high standards of welfare. However, improvements in some sections are needed given that the regulations are often conveyed using vague language, provide exceptions or remain silent on some aspects. This review provides a critical reflection of some of these key areas related to on-farm aspects. To a lesser extent, post farm gate aspects are also discussed

In vitro biomechanical properties of sole tissues: Comparison between healthy and ulcerated bovine claws

Sole ulcers are reportedly one of the most prevalent diseases associated with lameness in dairy cattle, significantly affecting animal welfare and farm profitability. The degree to which sole soft tissues, healthy or ulcerated, are able to maintain their structure and function when subjected to compressive forces remains unknown. Therefore, the aims of the present study were to assess sole tissue biomechanics in healthy and ulcerated claws and to describe correlated histology. Cylindrical samples were harvested from zones 4 and 6, as described by the international foot map, from hind lateral healthy (n = 12) and ulcerated bovine claws (n = 8; animals n = 12). Tissue biomechanics and morphology were evaluated via compressive tests and hematoxylin-eosin-phloxine-saffron staining, respectively. A 2-sample t-test was used to compare zones' mechanical properties between healthy and ulcerated tissues, and the Cochran-Mantel-Haenszel test was used to measure the effect of claw zone on histology. The fibril modulus (E_f) and permeability (k) respectively increased and decreased in ulcerated claws (E_f = 0.201 ± 0.104 MPa; k = 0.128 ± 0.069 mm²/MPa·s) compared with healthy claws (E_f = 0.105 ± 0.050 MPa; k = 0.452 ± 0.365 mm²/MPa·s) only for zone 6. Histology scores equal to or greater than 3 were associated with macroscopic presence of ulceration. A higher proportion of adipose tissue (30% or more) was associated with zone 6 compared with zone 4, but no difference was seen between healthy and ulcerated claws. Ulcerated claws had a higher prevalence of exostoses compared with healthy ones (33% vs. 8%). Sole soft tissues showed, as hypothesized, a viscoelastic behavior using unconfined compression testing, which, however, may not reflect in vivo loading conditions. Clinical and histological signs of sole ulceration were not associated with decreased strength of the supportive apparatus of the distal phalanx in zone 4 in this study.

Univariate associations between housing, management, and facility design factors and the prevalence of lameness lesions in fourteen small-scale dairy farms in Northeastern Algeria

Background and Aim:

This cross-sectional study aimed to analyze the associations between different types of housing, management, and facilities on the prevalence of lame, causing lesions in smallholder dairy farms in Algeria.

Materials and Methods:

The on-site investigation took place between December 2012 and May 2015. All cows were locomotion scored on a four-point scale, and foot lesions causing lame were diagnosed and recorded. Factors related to the farm and the cows’ conditions were also assessed. The association between the possible risk factors and lame lesions was assessed using univariate analysis.

Results:

Of the 349 cows evaluated, 13% were lame (lameness score ≥2), with higher lameness values recorded for the hind feet than for the forefeet. Cows without lameness were classified as healthy. The two most frequent lesion diagnoses observed in lame cows were interdigital dermatitis/heel horn erosion (ID/HE; 39%) and interdigital phlegmon (IP; 35%), followed by traumatic lesions (T; 11%), digital dermatitis (DD; 8.7%), and laminitis-related diseases (L; 6.5%). The risk of being lame was increased in large herds with cows of the Holstein breed, and those in the third parity and above. Tie housing, concrete floor, concentrate feeding, zero-grazing, and the use of foot trimming occasionally were associated with increased risk for the presence of lame lesions. The region and footbathing frequency had no association with the prevalence of lame lesions (p≥0.05).

Conclusion:

These results have important implications; they indicate that several aspects of housing, management, and facility design are common protective factors for the prevalence of lame lesions. These factors should be maintained correctly to not only reduce the number of lame cows in these herds but also decrease the direct and indirect costs associated with cases of lameness.

Risk factors for claw disorders in intensively finished Charolais beef cattle

This cross-sectional study aimed at performing a risk factor analysis of on-farm housing and management factors associated with infectious and non-infectious claw disorders of intensively finished Charolais young bulls and heifers. Claws' health condition of a total of 1305 animals belonging to 88 batches finished in farms located in the Eastern Po Valley (Italy) was assessed at slaughterhouse. Batch prevalence of feet affected by sole hemorrhage (SH) and white line abscess (WLA) was calculated and foot condition was summarized by infectious lesion (ILS) and non-infectious lesion (NILS) scores according to diseases' etiology. Batch prevalence of feet with SH, WLA, and assigned to the worst score classes were the outcomes in the risk factor analysis. Information about rearing facilities and health management of the tested batches were gathered in each origin farm along with a dietary sample used for chemical and physical analyses. Five categorized factors and 30 continuous covariates were considered as independent predictors and a cluster analysis of the continuous covariates was performed to select the most representative ones. Percentage of feet/batch affected by SH was on average 57.0 ± 32.5 % (SD) and by WLA was 9.94 ± 12.7 %. Percentage of feet/batch with the worst ILS and NILS was 29.6 ± 32.8 % and 12.5 ± 14.1 %, respectively. Charolais bulls showed a higher risk of SH and WLA than heifers and an increasing dietary NDF content acted as preventive factor. Concrete slats increased the risk of SH. Animals slaughtered in winter had the highest risk of WLA and the increasing level of dietary water-soluble carbohydrates (WSC) was a further risk factor. The risk for the worst NILS was lowest in spring and in presence of ventilation systems. It increased for bulls and in those batches fed diets with higher WSC content. Batches for which the farmer reported a higher prevalence of urgently slaughtered animals during finishing showed a higher risk of WLA and infectious claw diseases. The risk for infectious claw diseases was reduced in animals slaughtered in summer, housed on deep litter and fed diet with increased NDF content. It increased in farms where diet formulation was not under the nutritionist control. As general outcomes of the study, benefits for the claw health of finishing Charolaise may come from the use of the deep litter and ventilation systems, the involvement of a nutritionist in diet formulation, and the provision of diets with reduced WSC and increased NDF contents.

Genetic parameters and genomic breeding values for digital dermatitis in Holstein Friesian dairy cattle: host susceptibility, infectivity and the basic reproduction ratio

Background

For infectious diseases, the probability that an animal gets infected depends on its own susceptibility, and on the number of infectious herd mates and their infectivity. Together with the duration of the infectious period, susceptibility and infectivity determine the basic reproduction ratio of the disease (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0). \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0 is the average number of secondary cases caused by a typical infectious individual in an otherwise uninfected population. An infectious disease dies out when \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0 is lower than 1. Thus, breeding strategies that aim at reducing disease prevalence should focus on reducing \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0, preferably to a value lower than 1. In animal breeding, however, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0 has received little attention. Here, we estimate the additive genetic variance in host susceptibility, host infectivity, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0 for the endemic claw disease digital dermatitis (DD) in Holstein Friesian dairy cattle, and estimate genomic breeding values (GEBV) for these traits. We recorded DD disease status of both hind claws of 1513 cows from 12 Dutch dairy farms, every 2 weeks, 11 times. The genotype data consisted of 75,904 single nucleotide polymorphisms (SNPs) for 1401 of the cows. We modelled the probability that a cow got infected between recordings, and compared four generalized linear mixed models. All models included a genetic effect for susceptibility; Models 2 and 4 also included a genetic effect for infectivity, while Models 1 and 2 included a farm*period interaction. We corrected for variation in exposure to infectious herd mates via an offset.

Results

GEBV for \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0 from the model that included genetic effects for susceptibility only had an accuracy of ~ 0.39 based on cross-validation between farms, which is very high given the limited amount of data and the complexity of the trait. Models with a genetic effect for infectivity showed a larger bias, but also a slightly higher accuracy of GEBV. Additive genetic standard deviation for \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0 was large, i.e. ~ 1.17, while the mean \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0 was 2.36.

Conclusions

GEBV for \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0 showed substantial variation. The mean \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ R_{0} $$\end{document}R0 was only about one genetic standard deviation greater than 1. These results suggest that lowering DD prevalence by selective breeding is promising.

Evaluation of arterial digital blood flow in dairy cows with claw horn disruption lesions using Doppler ultrasonography

Vascular changes play an important role in the pathogenesis of claw horn disruption lesions in cattle. The aim of the study was to measure arterial blood flow in the hind limbs of German Holstein cows with claw horn disruption lesions. A 10-MHz linear transducer was used to assess blood flow in the interdigital artery in the dorsal pastern region in the hind limbs of 11 non-lame and 33 lame German Holstein cows in which lameness was scored clinically. Qualitative and quantitative blood flow parameters were compared in affected limbs and unaffected contralateral hind limbs in lame cows and in the hind limbs of lame cows and non-lame cows. A pulsed-wave Doppler signal suitable for analysis was obtained in 78 of 88 limbs (33 affected and contralateral limbs, 22 limbs of control cows). Blood flow curve types 1 and 2 were predominant in the hind limbs of lame cows. Vessel diameter, end-diastolic velocity, and blood flow rate were significantly greater in lame cows than in non-lame cows and were numerically greater in moderately lame cows than in mildly lame cows. The differences in the qualitative and quantitative parameters between lame and non-lame cows were most likely caused by inflammation of the pododerm. The role of weight distribution between the paired hind limbs and the existence of claw horn disruption appeared to have an effect on the differences in local circulation in the affected and unaffected contralateral hind limbs in lame cows.

A genome-wide association study for susceptibility and infectivity of Holstein Friesian dairy cattle to digital dermatitis

Selection and breeding can be used to fight transmission of infectious diseases in livestock. The prevalence in a population depends on the susceptibility and infectivity of the animals. Knowledge on the genetic background of those traits would facilitate efficient selection for lower disease prevalence. We investigated the genetic background of host susceptibility and infectivity for digital dermatitis (DD), an endemic infectious claw disease in dairy cattle, with a genome-wide association study (GWAS), using either a simple linear mixed model or a generalized linear mixed model based on epidemiological theory. In total, 1,513 Holstein-Friesian cows of 12 Dutch dairy farms were scored for DD infection status and class (M0 to M4.1) every 2 wk for 11 times; 1,401 of these cows were genotyped with a 75k SNP chip. We performed a GWAS with a linear mixed model on 10 host disease status traits, and with a generalized linear mixed model with a complementary log-log link function (GLMM) on the probability that a cow would get infected between 2 scorings. With the GLMM, we fitted SNP effects for host susceptibility and host infectivity, while taking the variation in exposure of the susceptible cow to infectious herd mates into account. With the linear model we detected 4 suggestive SNP (false discovery rate < 0.20), 2 for the fraction of observations a cow had an active lesion on chromosomes 1 and 14, one for the fraction of observations a cow had an M2 lesion on at least one claw on chromosome 1 (the same SNP as for the fraction of observations with an active lesion), and one for the fraction of observations a cow had an M4.1 lesion on at least one claw on chromosome 10. Heritability estimates ranged from 0.09 to 0.37. With the GLMM we did not detect significant nor suggestive SNP. The SNP effects on disease status analyzed with the linear model had a correlation coefficient of only 0.70 with SNP effects on susceptibility of the GLMM, indicating that both models capture partly different effects. Because the GLMM better accounts for the epidemiological mechanisms determining individual disease status and for the distribution of the y-variable, results of the GLMM may be more reliable, despite the absence of suggestive associations. We expect that with an extended GLMM that better accounts for the full genetic variation in infectivity via the environment, the accuracy of SNP effects may increase.

Evaluation of a biocide footbath solution in the occurrence and healing of digital dermatitis lesions in dairy cows: A clinical trial

The objective of this study was to evaluate the effect of the implementation of different footbathing practices using a new biocide solution (Pink-Step™, Qalian, France) in the healing and the occurrence of bovine digital dermatitis (bDD) lesions. The investigation was conducted through a controlled within cow clinical trial in which the hind feet of cows from each farm were allocated either to the control group or to a moderate (MR) or (IR) intensive footbath-regimen groups. The trial involved 1036 cows (2072 feet) from 10 dairy farms located in western France where bDD was endemic. Split-footbaths were placed at the exit of the milking parlor of each farm, allowing the biocide to be administered to one side of the cows while using the other empty side as a negative control. The administration frequency for MR was of 2 days/week/1st-month, then 2 days/2 weeks/2nd-month, and then 2 days/month, and for IR was of 2 days/week/1st-2nd months, and then 2 days/2 weeks. Footbaths were administered during 140 days (approx.), and feet were evaluated for the at least once a month in the milking parlor. Nested survival models were used to estimate the relative impact of the footbath regimens and other concomitant risk factors on the time that bDD lesions occurred or healed. No effect of Pink-Step™ was evidenced on the bDD occurrence during the trial. The risk for bDD occurrence was increased by poor feet cleanliness at both the cow (HR 1.69, CI 1.21-2.39) and farm level (HR 2.06, CI 1.44-2.94). Otherwise, the use of Pink-Step™ in an IR was effective in improving the healing of bDD lesions (HR 1.79, CI 1.12-2.88). The time to healing was also improved in inactive lesions (HR 2.19, CI 1.42-3.37). Conversely, the time to healing was delayed in feet receiving hoof-trimming (HR 0.41, CI 0.26-0.62), in cows with a contralateral bDD lesion (HR 0.32, CI 0.22-0.46) or in late lactation (HR 0.61, CI 0.43-0.85), and finally in farms with more than 100 cows (HR 0.48, CI 0.34-0.67). These findings reinforce the crucial role of hygiene in bDD dynamics and highlight the importance of implementing multiple control measures simultaneously, such as hygiene improvements in the barn, early detection and treatment of bDD lesions and the correct usage of individual and collective treatments. The implementation of Pink-Step™ represents a promising strategy for reducing the persistence of bDD lesions in affected herds.

An overview of claw disorders at slaughter in finishing beef cattle reared in intensive indoor systems through a cross-sectional study

This cross-sectional study aimed to assess in post-mortem the prevalence of specific claw disorders and their location on the sole in hind feet of finishing beef cattle reared indoors under intensive production systems. Evaluation was made on animals that were introduced in the ordinary slaughterhouse planning, presumably with no signs of impaired locomotion or severe lameness. A total of 4292 hind feet (right and left) belonging to 153 batches were collected (average feet/batch 28.1 ± 5.62 (SD)) in 3 abattoirs in Northern Italy at 3 time points (April-June and September-October 2016; February-March 2017). One veterinarian performed the claw trimming first and then scored the presence of specific claw disorders and their position on the sole considering 7 zones (in the digital and interdigital areas). All claw disorders in a specific zone were recorded as binary (presence/absence). Infectious (ILS), non-infectious (NILS), and global (GLS) scores were calculated considering both the type of claw disorder detected and the number of zones affected. Non-infectious disorders were the most common diagnoses among batches, mainly on the lateral claws and in the heel-sole junction area. In particular, white line abscesses and ulcers (sole and toe ulcers) were also found as two of the most debilitating and painful lesions with a non-negligible frequency. Infectious diseases, when occurring in a batch, spread to almost all feet. As expected, GLS distribution on the total feet inspected showed a non-harmful condition, given that the worst scores from 3 to 13 were assigned to a restricted sample of feet (15%) and were far from the maximum potential value of 50. However, the GLS of all batches monitored revealed 10 critical batches having no healthy feet or more than 50% of feet graded with the worst scores. Since right and left feet of the same animal showed similar clinical diagnoses, a more efficient claw health evaluation system should consider only one foot. Although all cattle inspected were supposed to have no evident locomotory problems before slaughter, the detection of several foot disorders and the considerable distribution in some batches might suggest poor conditions on farms affecting finishing beef cattle health, behaviour, and welfare. It is therefore advisable that possible predisposing factors of specific claw disorders on the farms of origin be investigated more deeply.

Längenasymmetrie der Zehen bei Kühen mit Rusterholz’schen Sohlengeschwüren

Gegenstand und Ziel: Untersuchung der Längendifferenz zwischen lateraler und medialer Zehe bei Hinterfüßen von Schlachtkühen mit Rusterholz’schen Sohlengeschwüren und klauengesunden Füßen. Material und Methoden: Untersucht wurden insgesamt 100 Füße von Schlachtkühen, davon 25 mit einer Verfärbung des Horns an der Prädilektionsstelle des Rusterholz’schen Sohlengeschwürs, 26 mit einem Sohlengeschwür von < 1 cm2 Durchmesser und 24 mit einem Sohlengeschwür von > 1,5 cm2 Durchmesser. Als Kontrollgruppe dienten 25 Füße von klauengesunden Schlachtkühen. Anhand von plantarodorsalen Röntgenbildern wurden die Längen der Röhrbeinepiphysen sowie der Phalangen (Ph) vermessen und drei Gesamtlängen bestimmt. Die Daten wurden mithilfe des Statistikprogramms SPSS analysiert. Ergebnisse: Die Mittelwerte der Längen von Ph1, Ph2 und der drei Gesamtlängen der lateralen Zehe waren größer als diejenigen der medialen Zehe. Demgegenüber war die Ph3 an der medialen Zehe länger. Mit einer Ausnahme, dem Vergleich der Gesamtlänge 2 zwischen der Kontrollgruppe und der Gruppe mit Hornverfärbung an der Prädilektionsstelle, wiesen die Füße mit Sohlengeschwüren keinen signifikant größeren Längenunterschied zwischen Außen- und Innenzehe auf als die Kontrollfüße. Schlussfolgerung und klinische Relevanz: Diese Ergebnisse bestätigen die Längenasymmetrie der Zehen des Rindes, deren Auswirkung auf die Entstehung von Sohlengeschwüren allerdings weiterer Untersuchungen bedarf.

Digital Dermatitis in dairy cattle: The contribution of different disease classes to transmission

Digital Dermatitis (DD) is a claw disease mainly affecting the hind feet of dairy cattle. Digital Dermatitis is an infectious disease, transmitted via the environment, where the infectious "agent" is a combination of bacteria. The standardized classification for DD lesions developed by Döpfer et al. (1997) and extended by Berry et al. (2012) has six distinct classes: healthy (M0), an active granulomatous area of 0-2 cm (M1), an ulcerative lesion of >2 cm (M2), an ulcerative lesion covered by a scab (M3), alteration of the skin (M4), and a combination of M4 and M1 (M4.1). We hypothesize that classes M1, M2, M3, M4, and M4.1 are the potentially infectious classes that can contribute to the basic reproduction ratio (R₀), the average number of new infections caused by a typical infected individual. Here, we determine differences in infectivity between the classes, the sojourn time in each of the classes, and the contribution of each class to R_0. The analysis is based on data from twelve farms in the Netherlands that were visited every two weeks, eleven times. We found that 93.89% of the transitions from M0 was observed as a transition to class M4, and feet with another class-at-infection rapidly transitioned to class M4. As a consequence, about 70% of the infectious time was spent in class M4. Transmission rate parameters of class-at-infection M1, M2, M3, and M4 were not significantly different from each other, but differed from class-at-infection M4.1. However, due to the relative large amount of time spend in class M4, regardless of the class-at-infection, R₀ was almost completely determined by this class. The R₀ was 2.36, to which class-at-infection M4 alone contributed 88.5%. Thus, M4 lesions should be prevented to lower R₀ to a value below one, while painful M2 lesions should be prevented for animal welfare reasons.

Missing pieces of the puzzle to effectively control digital dermatitis

Since the first report of bovine digital dermatitis (DD) in 1974, there is a large body of the literature published; however, effective prevention and control of the disease remain elusive. Although many aspects of the pathogenesis of DD have been investigated, even some of the most basic questions such as the aetiology of this disease remain under debate. Treponema spp. have been strongly associated with DD lesions and occur in abundance in advanced lesions; however, efforts to induce disease with pure cultures of these organisms have been largely underwhelming and inconsistent. Furthermore, although the disease has been presented for several decades, there is limited scientific evidence regarding effective treatment of DD. Apparent discrepancies between effectiveness in vitro and in vivo have challenged the scientific community to identify new potential treatment options. With no treatment resulting in a 100% cure rate, the current expectation is manageable control, but prospects for the eradication of the disease are unlikely using current approaches. In order to develop more effective approaches to control DD on-farm, there is a critical need for a deeper understanding regarding the causation, ecology, transmission and treatment of this disease. In this article, we attempt to provide insights into specific research needs related to DD in order to assist the industry, researchers, pharmaceutical companies and research sponsors with decision-making and identified research gaps.

Producer estimates of prevalence and perceived importance of lameness in dairy herds with tiestalls, freestalls, and automated milking systems

Lameness is one of the most important welfare and productivity concerns in the dairy industry. Our objectives were to obtain producers' estimates of its prevalence and their perceptions of lameness, and to investigate how producers monitor lameness in tiestall (TS), freestall with milking parlor (FS), and automated milking system (AMS) herds. Forty focal cows per farm in 237 Canadian dairy herds were scored for lameness by trained researchers. On the same day, the producers completed a questionnaire. Mean herd-level prevalence of lameness estimated by producers was 9.0% (±0.9%; ±SE), whereas the researchers observed a mean prevalence of 22.2% (±0.9%). Correlation between producer- and researcher-estimated lameness prevalence was low (r = 0.19) and mean researcher prevalence was 1.6, 1.8, and 4.1 times higher in AMS, FS, and TS farms, respectively. A total of 48% of producers thought lameness was a moderate or major problem in their herds (TS = 34%; AMS =53%; FS = 59%). One third of producers considered lameness the highest ranked health problem they were trying to control, whereas two-thirds of producers (TS = 43%; AMS = 63%; FS = 71%) stated that they had made management changes to deal with lameness in the past 2 yr. Almost all producers (98%) stated they routinely check cows to identify new cases of lameness; however, 40% of producers did not keep records of lameness (AMS = 24%; FS = 23%; TS = 60%). A majority (69%) of producers treated lame cows themselves immediately after detection, whereas 13% relied on hoof-trimmer or veterinarians to plan treatment. Producers are aware of lameness as an issue in dairy herds and almost all monitor lameness as part of their daily routine. However, producers underestimate lameness prevalence, which highlights that lameness detection continues to be difficult in in all housing systems, especially in TS herds. Training to improve detection, record keeping, identification of farm-specific risk factors, and treatment planning for lame cows is likely to help decrease lameness prevalence.

INVITED REVIEW: Farm size and animal welfare

Critics of agricultural intensification have argued that the transition from smaller to larger farms has compromised animal welfare. To critically examine evidence relevant to this claim, we reviewed more than 150 publications that examined the relationship between farm size and at least one animal welfare indicator. Although much of this literature focuses on dairy cattle, we also reference other farmed species where appropriate. We found little evidence of any simple relationship, negative or positive, between farm size and animal welfare. Instead, the evidence suggests that larger farms provide some opportunities to improve animal welfare but may also create welfare risks. For example, larger farms permit more specialized and professional management of animal health but can make it more difficult to accommodate outdoor access that some view as integral to animal welfare. Future research should attempt to specify the underlying casual mechanisms by which statistical associations between farm size and indicators of welfare are believed to occur. We also suggest that policy and advocacy efforts aimed at reversing increases in farm size would be better directed toward improving welfare on farms of all sizes.

Investigation of feet functions of large ruminants with a decoupled model of equivalent mechanism

Cloven hooves of ruminants adapt to diverse terrain, provide propulsive force and support the whole body during movement in natural environments. To reveal how the feet ensure terrain adaptability by choosing the proper configurations and terrain conditions, we model the feet of ruminants as an equivalent mechanism with flexion-extension and lateral movement decoupled. The upper part of the equivalent mechanism can flex and extend, while the lower part performs the lateral movement. Combination of the two parts can adapt to longitudinal slope (anterior-posterior) and transverse slope (medial-lateral), respectively. When one of two digits closes laterally, the workspace of the other decreases. The distal interdigital ligament between two digits limits their motion by elastic force and stores energy during movement. Differences in elastic energy variation of the ligament on different transverse slopes are characterized based on the configurations of two digits and the elastic energy between them. If the upper one of two symmetric digits is fixed, the foot landing on the grade surface (2°) shows greater capacity for absorbing energy; otherwise, level ground is the best choice for ruminants. As for the asymmetric digits, longer lateral digits enhance the optimal adaptive lateral angle. The asymmetry predisposes the feet to damage on the hard ground, which indicates soft ground is more suitable.

Summary: This study shows that level and soft grounds are best for symmetric and asymmetric digits, respectively, as revealed by kinematic analysis using a decoupled equivalent mechanism of the foot of ruminants.

The Relationship of Cow Comfort and Flooring to Lameness Disorders in Dairy Cattle

Cow comfort and flooring contribute to lameness incidence in dairy herds. The trigger factors for lameness can all be exacerbated by poor cow comfort. Reduced cow comfort influences lameness incidence by increasing the risk for development of new cases and the time it takes for a cow to recover. Reduction in resting time will increase the cow's exposure to hard flooring surfaces. Many factors are associated with lameness prevalence. Housing and management factors should be optimized to reduce lameness incidence on dairy farms.

Cross-sectional study of the prevalence of and risk factors for hoof disorders in horses in The Netherlands

Information is scarce on the prevalence of hoof disorders in horses. In this study, we examined the prevalence of and risk factors for hoof disorders in a population of horses in The Netherlands. In a group of 942 randomly selected horses, hoof health was scored during regular foot trimming (one horse/farm). Hooves were assessed for the occurrence of one of 12 hoof disorders by a group of 21 certified farriers in two periods i.e. winter and summer of 2015. The mean age of the group of horses was 11.2±5.6years. They were mainly used for recreation (28.2%), dressage (26.8%), other disciplines (such as carriage driving and breeding) (18.7%), showjumping (17.6%) or combinations of these activities (8.6%). The horse farms studied were evenly distributed throughout the country. The horses were housed on different types of bedding, including straw (51.0%), shavings (17.5%), flax (16.1%) or other materials (11.0%), or were kept at pasture (4.4%). In 85% of the horses, at least one hoof disorder was observed during regular foot trimming. Most of the lesions were mild. The most frequently diagnosed hoof disorders were: thrush (T; 45.0%); superficial hoof wall cracks (SHWC; 30.4%); growth rings (GR; 26.3%); and sole bruises (SB; 24.7%). Less frequently observed hoof disorders included: perforating hoof wall cracks (PHWC; 16.4%); white line disease (WLD; 17.8%); and white line widening (WLW; 11.8%). Horizontal hoof cracks (5.2%), chronic laminitis (3.9%), quarter cracks (2.7%), keratoma (1.8%) and frog cancer (1.0%) were less frequently observed. Factors significantly associated with the occurrence of thrush comprised a wet stable floor (OR 1.6 and 2.9, for somewhat wet to wet respectively, compared to dry), the use of straw as bedding (OR=1.5, compared to flax), the housing strategy (e.g. permanent housing in contrast to permanent pasturing) (OR=1.7) and poor horn quality (OR=3.4). A higher prevalence of WLD was associated with less frequent hoof picking (OR=2.1 if performed weekly instead of daily), the use of flax bedding (OR=2.1, compared to straw) and poor horn quality (OR=8.1). A higher prevalence of SB was observed in horses used for multiple disciplines (OR=3.5, compared to dressage), with white-coloured hooves (OR=5.0, compared to black hooves), with longer intervals between trimming sessions (OR=4.8 in case of 8-10 weeks compared to weekly) and with poor horn quality (OR=5.4). A higher prevalence of WLW was observed in older horses (OR=15.5 for horses >19years, compared to <5years), in those with longer intervals between trimming sessions (OR=1.8 in case of 8-10 weeks compared to weekly), and in certain breeds (OR=3.2 for Friesian horses, 2.9 for Welsh ponies and 13.1 for Shetland ponies, all compared to Dutch Warmblood). In conclusion, although most of the hoof disorders identified were only in a mild stage, still an unexpectedly high prevalence of hoof disorders was observed during regular hoof trimming. Analysis of the data showed that some parameters, such as the use of flax bedding, may be protective for certain hoof disorders but a risk factor for others. This study provides useful guidelines for monitoring hoof health, reducing lameness and optimizing equine welfare.

Effects of Manure Bedding on the Rate of Claw Diseases in Dairy Cows

This study was conducted to determine the prevalence of claw diseases in dairy cows housed on two different bedding systems: deep straw bedding and unsterilized recycled manure solids. On the farm (farm A) with the straw bedding, 403 and on the farm (farm B) with manure solid bedding, 226 dairy cows were examined. The prevalence of cows with one or more claw lesions on the farm with straw bedding and with manure solids were 37 % and 69 %, respectively (P < 0.001). In both bedding systems, two claw lesions dominated: digital dermatitis and inflammatory disorders of corium (white line diseases, toe ulcer, and sole ulcer). The prevalence of the digital dermatitis housed in deep-bedded freestalls and in freestalls with manure solids were 17.8 % and 53.1 % (P < 0.001), respectively. The prevalence of the white line diseases and toe ulcer were 12.1 % and 15.7 % on farm A and 3.88 % and 2.59 % on farm B, respectively (P < 0.001). There was no significant difference in the prevalence of the sole ulcer between farms. These data indicate a relatively high prevalence of claw lesions on the studied dairy farms. Moreover, a long-term contact of claws with manure (boxes and corridors) on the farm with unsterilized recycled manure solids seems to be associated with a higher prevalence of digital dermatitis.

Prevalence and distribution of foot lesions in dairy cattle in Alberta, Canada

The objectives of this cross-sectional study were to determine the prevalence and distribution of foot lesions and associated cow- and herd-level risk factors in dairy cows in Alberta, Canada. Foot lesion data were recorded electronically by 7 hoof trimmers on 28,607 cows in 156 dairy farms from June 2009 to November 2012. Foot lesion prevalence estimates differed between farms that had the whole herd trimmed at once (≥80% of lactating cows were trimmed; n=69 farms and 8,020 cows) and farms on which part of the herd was trimmed (selection of cows was determined by farmer and <80% of lactating cows were trimmed; n=87 and 20,587 cows). Estimates were consistently higher for the latter likely because farmers presumably prioritized lame cows in partial-herd trims. On farms with whole-herd trims, digital dermatitis was the most common lesion among all housing types, present in 15% of cows and 94% of herds. Sole ulcers and white line disease were detected in 6 and 4% of the cows and 92 and 93% of herds, respectively. Other infectious and claw horn lesions each affected 1 to 2% of cows and 62 to 78% of herds. Intraclass correlation coefficients for hoof trimmers ranged from 0.01 to 0.20 for all lesions, indicating some clustering of recorded lesions by trimmer. Multilevel mixed logistic regression models were constructed (including hoof trimmer as fixed and farm as random effects) for the 3 most frequently identified lesions. Prevalence of digital dermatitis decreased with increasing parity, but this effect interacted with days in milk (DIM); primiparous cows had higher odds of digital dermatitis in mid lactation (100-199 DIM) and late lactation (≥200 DIM) compared with cows at other stages of lactation. In contrast, prevalence of sole ulcers and white line disease increased with increasing parity; compared with cows in parity 1, those in parity 4 had 5 or 7 times higher odds of having these lesions, respectively. Cows in mid lactation and late lactation had higher odds of sole ulcers and white line disease than cows at other stages of lactation, regardless of parity. Digital dermatitis prevalence was 2 times higher in herds housed in barns with access to an exercise area. The odds of sole ulcers and white line disease were ≥2 times higher in cows housed in freestalls than those housed in deep-bedded packs. Therefore, preventive measures for control of digital dermatitis merit emphasis, especially in primiparous cows and on farms with exercise areas. In addition, improving housing environment by providing a deep-bedded area for older cows in mid lactation or late lactation could reduce prevalence of claw horn lesions. We inferred that foot lesion data recorded by hoof trimmers can provide useful information not only to develop effective foot health programs at herd level, but also for disease surveillance and genetic improvement at regional and national levels.

Radiographic Measurement of Hindlimb Digit Length in Standing Heifers

The digital skeleton of the hindlimbs was evaluated radiographically in 27 standing Brown Swiss heifers. The lateral digital skeleton was significantly longer than its medial counterpart on both a hard (wooden block) and a softer (wooden block covered with a thin rubber mat) surface. There were no significant differences between lengths measured on the hard and the soft surface. The difference between the length of the lateral and medial digits originated at the level of the condyles and increased with P1 and P2. It was partially compensated by a higher third phalanx (P3) in the medial digit, but this did not offset the overall length difference. The findings of this study confirmed that the length asymmetry of the paired digits of cattle documented previously in post-mortem specimens is also present in living cattle. Further investigation is required to determine the clinical relevance of the length asymmetry of the digital skeleton in cattle.

Indoor Confined Feedlots

Indoor confined feedlots offer advantages that make them desirable in northern climates where high rainfall and snowfall occur. These facilities increase the risk of certain health risks, including lameness and tail injuries. Closed confinement can also facilitate the rapid spread of infectious disease. Veterinarians can help to manage these health risks by implementing management practices to reduce their occurrence.

Invited review: Changes in the dairy industry affecting dairy cattle health and welfare

The dairy industry in the developed world has undergone profound changes over recent decades. In this paper, we present an overview of some of the most important recent changes in the dairy industry that affect health and welfare of dairy cows, as well as the science associated with these changes. Additionally, knowledge gaps are identified where research is needed to guide the dairy industry through changes that are occurring now or that we expect will occur in the future. The number of farms has decreased considerably, whereas herd size has increased. As a result, an increasing number of dairy farms depend on hired (nonfamily) labor. Regular professional communication and establishment of farm-specific protocols are essential to minimize human errors and ensure consistency of practices. Average milk production per cow has increased, partly because of improvements in nutrition and management but also because of genetic selection for milk production. Adoption of new technologies (e.g., automated calf feeders, cow activity monitors, and automated milking systems) is accelerating. However, utilization of the data and action lists that these systems generate for health and welfare of livestock is still largely unrealized, and more training of dairy farmers, their employees, and their advisors is necessary. Concurrently, to remain competitive and to preserve their social license to operate, farmers are increasingly required to adopt increased standards for food safety and biosecurity, become less reliant on the use of antimicrobials and hormones, and provide assurances regarding animal welfare. Partly because of increasing herd size but also in response to animal welfare regulations in some countries, the proportion of dairy herds housed in tiestalls has decreased considerably. Although in some countries access to pasture is regulated, in countries that traditionally practiced seasonal grazing, fewer farmers let their dairy cows graze in the summer. The proportion of organic dairy farms has increased globally and, given the pressure to decrease the use of antimicrobials and hormones, conventional farms may be able to learn from well-managed organic farms. The possibilities of using milk for disease diagnostics and monitoring are considerable, and dairy herd improvement associations will continue to expand the number of tests offered to diagnose diseases and pregnancy. Genetic and genomic selection for increased resistance to disease offers substantial potential but requires collection of additional phenotypic data. There is every expectation that changes in the dairy industry will be further accentuated and additional novel technologies and different management practices will be adopted in the future.

Prevalence of lameness and associated risk factors in Canadian Holstein-Friesian cows housed in freestall barns

Lameness is a severe welfare problem and a production-limiting disease in dairy farming. The objectives of this study were to determine prevalence of lameness and investigate cow- and herd-level factors associated with lameness in dairy cows housed in freestall barns in 3 Canadian provinces. A purposive sample of 40 Holstein-Friesian cows was selected from each of 141 dairy farms in Québec, Ontario, and Alberta. In total, 5,637 cows were scored once for lameness (presence of limping when walking). Data collected included information on individual cows (hock lesions, claw length, body condition score, parity, days in milk, and milk production), management practices (floor and stall cleaning routine, bedding routine, and footbath practices), and facility design (stall dimensions, stall base and bedding type, width of feed alley, flooring type, and slipperiness) hypothesized to be risk factors for lameness. Multilevel mixed logistic regression models were constructed (including farm as a random effect and province as a fixed effect). Herd-level lameness prevalence ranged from 0 to 69% (mean = 21%). Lameness prevalence increased with increasing parity; compared with first parity, cows in parity 2, 3, and ≥ 4 had 1.6, 3.3, and 4 times, respectively, higher odds of being lame. Furthermore, the odds of lameness were 1.6 times greater in cows with low body condition score (≤ 2.5) than in cows with a higher body condition score. In addition, injured hocks and overgrown claws were associated with 1.4- and 1.7-fold increased odds of being lame, respectively, whereas every 1 kg increase in daily milk production was associated with a 3% decrease in the odds of being lame. Lameness prevalence was higher in herds with ≤ 100 cows, but lower in barns with a sand or dirt stall base, or with bedding ≥ 2 cm deep. Cows exposed to very slippery floors had 2 times the odds of being lame compared with cows exposed to nonslippery floors. We attributed the wide range of lameness prevalence to the great variability in facilities and management practices among farms. Finally, we inferred that the prevalence of lameness could be decreased by improving management of multiparous, thin, or injured cows and by adopting management practices intended to improve cow comfort, namely the floor's slip resistance and the stall's lying surface.

Water footbath, automatic flushing, and disinfection to improve the health of bovine feet

Disinfecting footbaths are used to treat and prevent interdigital dermatitis (ID) and heel horn erosion (HHE). However, many disinfectants are disadvantageous for the environment and, as an alternative, washing of the feet has been introduced. Our aim was to investigate the effect of water footbaths (trial 1), footbaths with CuSO4 (trial 2), automatic water flushing (trial 3), and water flushing followed by disinfection with a glutaraldehyde-based compound (trial 4) in 4 randomized controlled clinical trials performed in a freestall dairy herd of approximately 45 Norwegian Red cows. At trimming before and after each trial, hind foot diseases, hardness of the claw horn (in D-units), locomotion, and cleanliness of the claws were recorded. Before each trial, the cows were divided in comparable study and control groups, based on prevalence of ID and HHE, parity, and days in milk. Using a transponder-regulated gate, the study groups were led through a footbath (trials 1 and 2) or an automatic washer (trials 3 and 4), whereas the control groups were left untreated. Each trial lasted 3 mo and the curative effect in diseased cows and the preventive effect in cows with healthy feet on ID, HHE, and ID + HHE were analyzed. In trial 2, a preventive effect of CuSO4 on HHE compared with the untreated cows was observed. During trial 1, 100% (11/11) of the treated cows with ID got better and 22% (2/9) without ID became diseased, whereas 92% (11/12) of the treated cows with ID + HHE got better and 38% (3/8) without ID + HHE became diseased. During trial 2, 69% (9/13) of the treated cows with ID got better and 11% (1/9) without ID became diseased. During trial 4, 19% (3/16) of the untreated cows with ID + HHE got better and 71% (5/7) without ID + HHE became diseased. In trial 3, no significant effects on ID, HHE, or ID + HHE were revealed. In trial 2 (CuSO4), the treated cows' claw horn was harder after the trial compared with the controls (D-unit difference: 13.25). In trial 3 (stationary water flushing) the treated cows' claw horn was softer after the trial when compared with the controls (D-unit difference: -15.66). The CuSO4 footbaths were useful to prevent HHE and indicate that automatic stationary flushing with only water had no beneficial effect on ID or HHE. The claw horn of cows walking through CuSO4 became harder and the claw horn of cows that had their hind feet flushed with water became softer compared with the controls.

Interdigital dermatitis, heel horn erosion, and digital dermatitis in 14 Norwegian dairy herds

The aim of this study was to assess infectious foot diseases, including identification and characterization of Dichelobacter nodosus and Treponema spp., in herds having problems with interdigital dermatitis (ID) and heel horn erosion (E) and in control herds expected to have few problems. We also wanted to compare diseased and healthy cows in all herds. The study included 14 dairy herds with a total of 633 cows. Eight herds had a history of ID and E, and 6 were control herds. All cows were scored for lameness, and infectious foot diseases on the hind feet were recorded after trimming. Swabs and biopsies were taken from the skin of 10 cows in each herd for bacterial analyses. In total, samples were taken from 34 cows with ID, 11 with E, 40 with both ID and E, and 8 with digital dermatitis (DD), and from 47 cows with healthy feet. Swabs were analyzed for identification and characterization of D. nodosus by PCR, culture, virulence testing, and serotyping. Biopsies were analyzed by fluorescent in situ hybridization regarding histopathology, identification, and characterization of Treponema spp., and identification of D. nodosus. Interdigital dermatitis was the most frequent foot disease, with a prevalence of 50.4% in problem herds compared with 26.8% in control herds. Heel horn erosion was recorded in 34.8% of the cows in problem herds compared with 22.1% in control herds. Dichelobacter nodosus was detected in 97.1% of the cows with ID, in 36.4% with E, in all cows with both ID and E, in all cows with DD, and in 66.0% of cows with healthy feet. All serogroups of D. nodosus except F and M were detected, and all isolates were defined as benign by the gelatin gel test. Treponema spp. were detected in 50.0% of the cows with ID, in 9.1% with E, in 67.5% with ID and E, in all cows with DD, and in 6.4% of those with healthy feet. In total, 6 previously described phylotypes (PT) of Treponema were detected: PT1, PT3, PT6, PT13, and PT15 in cows with ID, PT1 in a cow with E, and PT1, PT2, PT3, PT6, and PT13 in cows with both ID and E. One new phylotype (PT19) was identified. The epidermal damage score was higher but the difference in inflammatory response of the dermis was minor in cows with ID versus those with healthy feet. Fisher's exact test revealed an association between ID and D. nodosus, and between ID and Treponema spp. Logistic regression revealed an association between both ID and E and dirty claws (odds ratios=1.9 and 2.0, respectively). Our study indicates that D. nodosus, Treponema spp., and hygiene are involved in the pathogenesis of ID.