A scoring system for grading corkscrew claws in dairy cattle.

Corkscrew claw (CC) in dairy cattle is increasingly reported in dairy herds. CC is a progressive deformity of the claw capsule with uncertain aetiology and pathogenesis. Genetics and specific environmental factors are suspected of contributing to the development of this irreversible condition. CC has been found in lame cows; however, the cause and effect has not been established. To perform analysis of risk factors, treatment and pathogenesis, a definition of severity scores is called for. The aim of this study was to measure and analyse CC characteristics from photos of cows' feet to describe and evaluate a scoring system for CC. Width of the visible part of the axial wall, degree of contact between the toe and the floor and angle of the distal part of the abaxial wall as a proxy for the deviation of the abaxial wall was measured from 393 pictures of CC. Based on the measurements on the claws, the parameter "width of the axial wall" was chosen to define the scores. The parameter was divided into three intervals to define either mild CC 0.3-2.0 cm, moderate CC 2.1-3.5 cm or severe CC>3.5 cm and correlation between the parameters; level of contact between the toe and the floor and the angle of the distal abaxial wall was evaluated. There was a significant positive linear correlation between width of the axial wall and angle of the distal part of the abaxial wall (r=0.91), the wider the axial wall, the more the abaxial wall deviated in the distal part. As the width of the axial wall increased the toe increasingly lost contact with the floor, this association was significant for mild CC and moderate CC but not for severe CC. The Interobserver agreement of the CC Scoring system was tested by 30 claw trimmers each scoring 32 cadaver feet and by 2 trained observers on 28 photos of feet using Cohen´s weighted kappa and showed substantial to almost perfect agreement between untrained and trained observers, respectively.

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.

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.

Changes in the soft-tissue thickness of the claw sole in Holstein heifers around calving.

Claw horn disruption lesions are a common cause of lameness in dairy cattle. It is commonly agreed that they develop due to excessive pressure from the distal phalanx on the horn-producing tissue in the sole. The distal phalanx is supported by the suspensory apparatus, a large proportion of which is made up of connective tissue. It has been hypothesized that increased laxity of the connective tissue due to hormonal changes around calving may lead to decreased support of the distal phalanx, resulting in a sinking of the bone and increased pressure on the horn-producing tissue. In this longitudinal study, our first objective was to determine whether the thickness of the soft tissue related to the claw sole (the combined depth of the digital cushion and corium; soft-tissue thickness, STT) in the weight-bearing hind claws of live heifers changed around calving (the period from approximately 3 wk before calving to 2 wk after calving). Our second objective was to evaluate the relationship between the body condition score (BCS) of recruited heifers and the STT estimates we obtained. We measured STT (defined as the distance between the distal phalanx and the sole horn) in the apex and the posterior part of the sole of the hind claws of 34 Holstein heifers 4 times over 3 to 4 wk around calving. We determined STT by ultrasonographic measurements through the sole horn on weight-bearing claws. The overall mean STT at site 1 was 3.3 mm [minimum-maximum (min-max): 1.8 to 5.2 mm], and the mean at site 2 was 3.7 mm (min-max: 2.2 to 5.8). The overall mean STT was thickest in the first examination before calving [site 1: 3.4 mm (min-max: 1.9 to 4.7); site 2: 4.1 mm (min-max: 2.7 to 5.8)] and thinnest at site 1 in the second examination after calving (3.2 mm, min-max: 1.8 to 5.2) and at site 2 at the first examination after calving (3.5 mm, min-max: 2.2 to 5.0). We observed an average reduction in STT of -0.2 mm (min-max: 0.8 to -0.9 mm) at site 1 during the study period, but we did not observe this reduction in all animals. At site 2, we found an average reduction in STT of -0.6 mm (min-max: 0.8 to -1.3 mm) from 10 d before calving to 5 d after calving, corresponding to a decrease of approximately 15% (min-max: 0 to 31%). We suggest that this reduction was caused by a rotation of the distal phalanx toward the posterior part of the sole horn in the weeks around calving. During the same period, heifer BCS decreased between 0.25 and 0.5 increments in the BCS scale, but we found no correlation between BCS and STT. However, the heifers experienced many changes related to management, feeding, and time budget during the study period, and the rotation of the distal phalanx and reduction of the STT might be explained not only by calving but also by other factors that affect heifers and their claws during the transition period.

Prevalence of abomasal lesions in Danish Holstein cows at the time of slaughter.

Abomasal lesions in cattle are challenging to diagnose because the clinical signs are often subtle and nonspecific. An increasing number of studies suggests that abomasal lesions are commonly found in cattle of all ages, but the number of recent prevalence studies in dairy cows is limited. The main objective of this study was to estimate the prevalence of abomasal lesions in a population of Danish Holstein dairy cattle in Denmark. An abattoir survey of 1,327 dairy cows apparently suitable for slaughter was performed in 2016 and 2017. Abomasal lesions are usually classified using a standardized protocol with the following types: abomasal ulcer type I: erosions and nonperforating ulcers; type II: ulcers with arterial bleeding; type III: perforating ulcer with localized peritonitis; and type IV: perforating ulcer with diffuse peritonitis. A further subdivision of the nonperforating abomasal ulcers type I were classified as subtype Ia: erosions; subtype Ib: small ulcers with localized hemorrhage; subtype Ic: ulcers with a crater-like appearance; and subtype Id: retention of the mucosa due to tissue loss with either radial wrinkles converging at a central point or perforations of the spiral folds. Type I abomasal lesions were found in 84% of the examined cows. No ulcers with arterial bleeding (type II) or perforating ulcers with diffuse peritonitis (type IV) were found, but one perforating abomasal ulcer (type III) was observed. The total number of lesions found was 7,418 and when the lesion subtypes were evaluated individually the majority of subtypes Ia and Ic were found in the pyloric area (85 and 94%, respectively), whereas lesion subtypes Ib and Id dominated the fundus/corpus area (71 and 67%, respectively). When considering lesion subtypes according to parity, there was a high prevalence of subtype Ib across the 3 groups of parity (51, 58, and 55% for parity 1, 2, and ≥3, respectively). The prevalence of lesion subtype Id seemed to increase with increasing parity, and the prevalence of lesion subtype Ia seemed to decrease with increasing parity. The prevalence of abomasal lesions was higher than that shown in similar studies of cattle at the time of slaughter. However, the expectedly most painful cases were rare, with only one perforating and no arterial bleeding ulcers found. The etiology of the different subtype I lesions is still unknown, and further investigations are needed to establish the possible influence these lesions might have on welfare and production.

Ultrasonographical examination of bovine claws through the sole horn on weight-bearing claws.

Claw horn disruptions in the bovine claw are believed to be a consequence of pressure on the sole corium from the third phalanx, which may be caused by a weakening of the suspensory apparatus in the claw. We aimed to develop an ultrasonographic method that would make it possible to measure the thickness of the soft tissue between the third phalanx and the sole horn on a weight-bearing claw. A device was developed to record the sole horn and soft tissue thickness indirectly through a polyethylene plate, and 52 feet from slaughtered cows were examined using ultrasonography, both directly and indirectly. Soft tissue and sole horn thickness measurements in the apex and the plantar part of the sole were compared with anatomical measurements of transected claws. To assess the method on weight-bearing versus non-weight-bearing claws, we examined the hind claws of 10 live cattle without transection. We found a weak correlation between the soft tissue thickness measured by ultrasound and anatomical measurements. A strong correlation was observed between the direct ultrasound approach and the developed indirect method. There was a considerable difference between weight-bearing and non-weight-bearing claws, signifying a weak or nonexistent correlation. However, this part of the study was only done on 10 live cows and the results should be interpreted with caution. We concluded that it would be possible to measure the soft tissue using an indirect ultrasound approach on a weight-bearing-claw standing on a polyethylene plate. The major difference between the results of weight-bearing versus non-weight-bearing claws suggests that future studies of the suspensory apparatus could focus on weight-bearing claws.

A clinical and histopathological comparison of the effectiveness of salicylic acid to a compound of inorganic acids for the treatment of digital dermatitis in cattle.

Bovine digital dermatitis (DD) is a painful infectious disease, causing lameness, reduced animal welfare, and production losses in dairy herds. The main factors contributing to DD are an infection with Treponema spp. and poor hygiene. Topical treatment has primarily consisted of antibiotics; however, the demand for effective nonantibiotic alternatives is increasing. The objective was to evaluate the performance of 3 nonantibiotic topical treatments (salicylic acid and a compound of inorganic acids in a 20% solution and in a dry form) on DD in a commercial dairy herd. Within the 30-d test period, 42 DD lesions on 33 Holstein cows were assigned to receive 1 of the 3 treatments. Lesions were biopsied before and after treatment and were clinically evaluated 5 times. Improved lesions were clinically defined as either healed (regeneration of the skin) or healing (dry lesions covered by a scab). Unhealed lesions were defined as either active [with a raw, moist, strawberry-like (granulating) surface] or mature (with a raised papillomatous appearance). The effectiveness of treatment was evaluated histopathologically using the following scores: 0 (no spirochetes present), 1 (small number of spirochetes present in the epidermis), 2 (moderate number of spirochetes present and reaching an intermediary level in the epidermis), and 3 (large number of spirochetes present and reaching the deepest part of the epidermis or the superficial dermis). The improvement rate was 10/14 (71%) for salicylic acid, 11/15 (73%) for the inorganic acid solution, and 8/13 (62%) for the inorganic acid powder. The analysis showed no difference among treatments. The association between clinical score and histopathological score was determined by an odds ratio. The odds ratio of a healed lesion having spirochetes in the epidermis was 0.58 and that of an active DD lesion having spirochetes in the epidermis was 26.5.

Efficacy of salicylic acid in the treatment of digital dermatitis in dairy cattle.

Digital dermatitis (DD) is one of the most important causes of lameness in dairy cattle worldwide. The objective of this study was to evaluate the efficacy of salicylic acid in the treatment of the disease. A total of 201 DD lesions from 173 cows from four commercial dairy herds were evaluated at day 0 during routine hoof trimming and were allocated into two groups, namely, a control group given chlortetracycline spray, and a treatment group given 10 g of salicylic acid powder applied topically within a bandage. Pain, lesion size and clinical appearance (scored M0 to M4) were evaluated on days 3, 14 and 34 post-treatment. A change to M0 was defined as healing, while changes of M2 or M4 to M1 or M3 were classified as clinical improvements. Healing rates did not differ significantly between treatment groups at days 3 and 14. By day 34 the healing rate was fivefold better (P=0.01) for the treatment vs. the control group, with healing rates of 13.6% and 3.1%, respectively. By day 3, the rate of improvement was 2.5-fold better (P=0.02) for the controls. By day 34 the overall positive effect (i.e. healing and improvement) was 1.75-fold better (P=0.05) for the treatment group. Lesions from the control group were 2.2 times more likely (P=0.09) to have a pain score equal to 2 by day 14. The proportion of lesions getting smaller by days 14 and 34 was 2.5 times higher (P<0.08) for the treatment vs. the control group. The findings suggest salicylic acid should be considered as an alternative to chlortetracycline for the treatment of DD as it appears more efficacious and would assist in reducing antibiotic use.

Infection dynamics of digital dermatitis in first-lactation Holstein cows in an infected herd.

Digital dermatitis (DD) refers to painful lesions primarily affecting the skin in the interdigital region of dairy cattle. The purpose of this study was to evaluate the dynamics of DD in 39 cows, observed at approximately 3-d intervals, for the first 6 mo of lactation. Specifically, the study aimed at evaluating different levels of DD susceptibility in cows, identifying the bacterial colonization of the interdigital skin, and exploring the relationship between clinical DD diagnosis and laboratory findings. Three different susceptibility categories were identified for DD: 1=consistently healthy cow; 2=intermittently infected cow; and 3=consistently infected cow. Susceptibility categories were associated with age at calving. The average age at calving was 775 d (SD ±43.4), with the youngest heifer calving at age 669 d and the oldest heifer at 858 d. Advancing age at calving was associated with greater odds of being intermittently or consistently infected. This corresponded with an odds ratio of 2.02 over a period of 30 d. During the study period, 161 DD lesions were identified in 28 of the 39 cows (72%). Of those 28 cows, 13 cows were consistently infected. The remaining 11 of the 39 cows (28%) showed slight thickening of the skin with no pain (5 cows) and no signs of skin changes (6 cows). Histopathology and fluorescence in situ hybridization were possible to perform on 132 biopsy samples. A clinical diagnosis of DD was confirmed in 70% of the lesions by histopathology, and colonization of Treponema spp. Dichelobacter nodosus was found in 35 samples (29%).

Oligofructose overload induces lameness in cattle.

The aim was to describe the clinical orthopedic implications of oligofructose overload. A group of 8 nonpregnant dairy heifers were given an oral dose of oligofructose (17 g/kg of body weight). At predefined times during a period spanning 3 d before and 9 d after oligofructose overload, the heifers underwent a clinical examination including locomotion scoring, hoof-testing, and palpation of tarso-crural joints, as well as the collection of blood and ruminal fluid samples. Locomotion sessions were videotaped; subsequently, locomotion was blind-scored. Locomotion scores increased after oligofructose overload and declined toward the end of the study period. The greatest locomotion scores were recorded on d 3 to 5 (60 to 120 h) where 12 of 42 (29%) locomotion scores were 3 and 13 of 42 (32%) were score 2. Positive reactions to hoof-testing were observed from 30 h after oligofructose overload and reached a maximum on d 7 and 9 where 12 of 28 (43%) reactions were marked positive. Distension of the tarso-crural joints was observed from 24 h after oligofructose overload, with maximum distension being observed on d 2, in which 44 of 56 (79%) of observed joints were either moderately or severely distended. The heifers developed classic signs of acute ruminal and systemic acidosis after the oligofructose overload (ruminal pH 4.3 +/- 0.07, standard base excess -10.8 +/- 2.3 at 18 h). With few exceptions, clinical and laboratory variables returned to normal within 9 d of oligofructose overload. But, good body condition and previous feeding with grass apparently predisposed the heifers to more severe systemic affection. Oligofructose overload in dairy heifers induced ruminal and systemic acidosis, diarrhea, dehydration, and, subsequently, lameness, claw pain, and joint effusion, collectively interpreted as signs of acute laminitis. Oligofructose overload at 17 g/kg of body weight represented a relatively mild laminitis model in cattle, as demonstrated by a reasonably quick recovery from systemic as well as orthopedic signs.

Prevalence of foot lesions in Danish Holstein cows.

In a cross-sectional study of 6240 Danish Holstein cows in 55 herds using loose-housing systems, sole haemorrhages and heel horn erosions occurred frequently in almost all the herds. Digital dermatitis occurred in 47 of the 55 herds (85 per cent). Spearman correlation coefficients revealed relationships between lameness and sole ulcer (0.36), between heel horn erosion and sole haemorrhage (0.39), between heel horn erosion and interdigital dermatitis (0.29) and between sole ulcer and double sole (0.26). The prevalence of heel horn erosion, sole haemorrhage, interdigital dermatitis and digital dermatitis appeared to be most affected by herd-level factors. The associations between individual foot trimmers and all the foot lesions were statistically significant. The risk of interdigital dermatitis increased with decreasing amounts of bedding. Cows housed throughout the year had a marginally higher risk of sole haemorrhage.

Conformation of hind legs and lameness in Danish Holstein heifers.

Lameness causes major financial losses and welfare problems in dairy herds. Prevention of foot lesions may suffice in the majority of lameness cases. The objectives of this longitudinal study were to describe the dynamics and associations between abnormal hind leg conformation, asymmetric claws, lameness, and foot lesions in 122 Danish Holstein heifers from an average of 41 d before first calving until dry off or culling. The cattle were housed either in a free-stall system with cubicles or in deep-bedded straw yard. The claws of all cattle were examined on up to 5 occasions. The associations between foot lesions, lameness, symmetry of the claws, shape of the dorsal toe-wall, and the conformation of the hind legs were examined statistically using mixed models. A large proportion (81%) of the heifers had cow-hocked conformation, with wide-based stance, hocks together, and lateral rotation of the foot before calving, and 25% of the heifers had locomotion scores above 2, indicating signs of lameness, before calving. Our results indicate that lameness, abnormal conformation, and lesions acquired precalving persist throughout the first lactation. Thinner cows were more cow-hocked, and cow-hocked cows had a higher frequency of sole hemorrhages. Increased severity of white line lesion was associated with greater claw asymmetry. More severe lameness and sole hemorrhages were found in symmetric claws.