Application note for the use of a wireless device measuring reticular pH under practice conditions in a Swiss dairy herd

Subacute ruminal acidosis (SARA) is caused by ingestion of diets high in rapidly fermentable carbohydrates and/ or deficient in physically active fiber, often suspected to occur in high yielding dairy cows. Although SARA has been defined as repeatedly occurring periods of low ruminal pH, both practical measuring methods and threshold values remain subject to research. Precision livestock farming comprises use of real-time monitoring and managing systems for livestock farmers. Reticular pH can be monitored continuously on individual cow level by use of an indwelling bolus situated in the reticulum, linked to a wireless data transmission system. Practical experience in use of such boluses is scarce. The first aim of this field application was to test a commercially available bolus under field conditions in a dairy herd, and to assess the data obtained on herd level. The second aim was to suggest criteria indicative of SARA on herd level. The threshold for this investigation was set at pH ≤ 5.5 for ≥ 3 h, simultaneously occurring in ≥ 3 cows, by combining a testing strategy and a threshold from two peer-reviewed publications. Of 15 boluses administered, 12 (80%) provided reliable data. Reticular pH was measured in 10-min intervals. Useful data were obtained during the first 80 days after bolus application. This was considerably lower than the 150 days as described by the manufacturer. Based on pH measurements, a mean individual pH curve for each cow was created through grouping pH values for each time point over the entire period. The mean individual curve showed a circadian pH change with low pH values in the evening and variation of mean individual pH values among cows. No event of three cows simultaneously showing a reticular pH ≤ 5.5 during a ≥ 3 h interval was recorded. Maximum time span during which pH was ≤ 5.5 in an individual cow was 4 h and 40 min. We conclude that use of the system on herd level is appropriate. Establishing a herd-level threshold for SARA based on continuous measuring systems requires integration of the mean individual pH curve, the individual minimal pH values, and the time span of low reticular pH

Locomotion behavior of dairy cows on traditional summer mountain farms in comparison with modern cubicle housing without access to pasture.

Pasture based systems enable cattle to express their natural behavior and are thus expected to provide better welfare than the majority of confinement systems. The aim of this study was to objectively measure locomotion activity of healthy dairy cattle kept on mountain pastures (n = 44) compared with cows kept in cubicle housing systems (n = 38). Selected cows were equipped with a validated 3D-accelerometer on one hind limb, and locomotion behavior was recorded for 48 hours. The 1-hour summaries of the variables lying time, walking time, standing bouts, walking bouts and number of strides were summed up to 24-hour summaries, and the means of the stride distance and stride duration were weighted by the variable number of strides. Mountain pasture cows had higher locomotor activity levels in comparison to cubicle cows. Mountain pasture cows spent less time lying down (528.1±109.5 min/day vs. 693.3±73.8 min/day; P<0.0001) and more time walking (75.6±25.9 min/day vs. 38.8±15.8 min/day; P <0.0001) than cubicle cows. Lying bout duration was longer in cubicle than in mountain pasture cows (90.9± 15.2 min/bout vs. 74.2 ± 21.1 min/bout; P = 0.0001), whilst the number of walking bouts was higher in mountain pasture cows than cubicle cows (199.1 ± 49.1 vs. 123.8 ± 43.8 bouts per day; P < 0.001). Likewise, the number of strides was higher in mountain pasture cows than cubicle cows (2040.5 ± 825.3 vs. 916.7 ± 408.6; P < 0.001). Mountain pasture cows had shorter stride duration (P < 0.0001) and shorter strides (P = 0.0002) than cubicle cows (1.8 ± 0.1 s/stride vs 2 ± 0.2 s/stride and 126.3 ± 18.1 vs 142.1 ± 17.8 m/stride, respectively). In summary, cows kept on mountain pasture were more active and spent longer than 12 hours / day standing. Lying markedly less than 12 hours per day seems to represent the normal behavior of pastured cows searching for fresh grass. This does not cause any obvious damage to the locomotor system as claws of cattle are well adapted to long periods of movement on mountain pastures

Case Report: Proximal Phalangeal Fracture Management in a European Bison (Bison bonasus).

Fracture of the digits is a well-known orthopedic condition in adult cattle, and mainly the distal phalanx (P3) is involved. To our knowledge, the treatment of fractures of the middle (P2) and proximal (P1) phalanges with orthopedic claw blocks has not yet been described in cattle and other ruminants. This report describes the first case of the successful management of a P1 fracture in an adult European bison. A 5-year-old female European bison (Bison bonasus) presented with severe weight bearing lameness of the left hind limb and a marked soft tissue swelling accentuated over the plantar and lateral aspects of the proximal and middle phalanges, associated with multifocal light bluish discoloration of the skin (hematoma) and increased local temperature. The cow was examined and managed because of a severely comminuted fracture of the lateral P1 of the left hind limb. Application of an orthopedic block on the healthy medial partner claw allowed to reduce the load of the affected digit. Combined with the administration of non-steroidal anti-inflammatory drugs, it supported immobilization and recovery. Radiographic re-evaluations at weeks 6, 9, and 11 after the injury revealed progressive callus formation and fracture consolidation. From week 9 onwards, until the end of treatment, no lameness was observed. The healing process was good, and both clinical and radiographical improvement were evident after immobilizing the affected digit by applying an orthopedic claw block on the healthy partner claw and administering non-steroidal anti-inflammatory drugs

Detection and localisation of unilateral hindlimb pathologies in cattle using the cow pedogram.

ISSN:0042-490

Field Validation of a Non-carcinogenic and Eco-Friendly Disinfectant in a Stand-In Footbath for Treatment of Footrot Associated With aprV2-Positive Strains of Dichelobacter nodosus in Swiss Sheep Flocks.

A national control program for virulent footrot is currently planned in Switzerland. Since commonly used disinfectants either contain heavy metals or are carcinogenic, the aim of this study was to verify the effectiveness of an eco-friendly and non-carcinogenic candidate disinfectant against aprV2-positive strains of Dichelobacter nodosus. Additionally, the effect of the selective use of long-acting oxytetracyclines was evaluated. A total of 18 farms with confirmed footrot infection, randomly allocated to two treatment groups: (1) with antibiotics (AB; n = 9) and, (2) no antibiotics (NAB; n = 9), were included. Claws were carefully trimmed and scored using a scale from 0 (clinically healthy) to 5 (complete loss of the horn capsule) and a prewash waterbath was implemented on 11 farms. Twice-weekly, repeated whole-flock stand-in footbaths with the candidate disinfectant (6%) were performed. Additionally, animals of group AB with a score ≥ 3 were administered oxytetracyclines by injection. On all farms, 10 days after last treatment, aprV2-positive strains could not be detected by risk-based sampling for real-time PCR analysis after 7-21 (median = 12) footbaths with a minimal culling rate of non-responders on nine farms. Farms without contact to other sheep remained without clinical signs of footrot for a minimum of 245 days (mean ± standard deviation: 293.6 ± 23.6). Antibiotic treatment did not reduce the number of footbaths needed. In contrast, a mean of 3.3 disinfecting footbaths could be saved by implementing a prewash waterbath. At animal level, individual and selective use of oxytetracyclines lead to a higher chance (odds ratio = 9.95; 95% CI: 3.54-27.95; p < 0.001) for a lesion score ≥ 3 to improve to a lesion score < 3 within 2 weeks compared to treatment without antibiotics. The test disinfectant is an effective and eco-friendly alternative for the planned Swiss footrot control program and selective use of oxytetracycline has a beneficial impact on the recovery of animals with lesion scores ≥ 3

The Role of Infrared Thermography as a Non-Invasive Tool for the Detection of Lameness in Cattle

The use of infrared thermography for the identification of lameness in cattle has increased in recent years largely because of its non-invasive properties, ease of automation and continued cost reductions. Thermography can be used to identify and determine thermal abnormalities in animals by characterizing an increase or decrease in the surface temperature of their skin. The variation in superficial thermal patterns resulting from changes in blood flow in particular can be used to detect inflammation or injury associated with conditions such as foot lesions. Thermography has been used not only as a diagnostic tool, but also to evaluate routine farm management. Since 2000, 14 peer reviewed papers which discuss the assessment of thermography to identify and manage lameness in cattle have been published. There was a large difference in thermography performance in these reported studies. However, thermography was demonstrated to have utility for the detection of contralateral temperature difference and maximum foot temperature on areas of interest. Also apparent in these publications was that a controlled environment is an important issue that should be considered before image scanning

"Non-healing" claw horn lesions in dairy cows: Clinical, histopathological and molecular biological characterization of four cases.

The increasing prevalence of bovine digital dermatitis (BDD) contributes to a higher occurrence of secondary infections of exposed corium with Treponema spp. in bovine claws. "Non-healing" claw horn lesions (NHL) clinically resemble BDD lesions. They are severe, cause chronic lameness, and may persist for several months. They poorly respond to standard treatments of BDD and represent a serious welfare issue. In this study, four cases of NHL were classified clinically either as BDD-associated axial horn fissures (BDD-HFA; n = 3) or BDD-associated sole ulcer (BDD-SU; n = 1). In all four cases, pronounced multifocal keratinolysis of the stratum corneum, ulceration, and severe chronic lymphoplasmacytic perivascular to interstitial dermatitis were observed. All lesional samples tested positive for Treponema spp., Fusobacterium (F.) necrophorum, and Porphyromonas (P.) levii by PCRs. BDD-HFA lesions contained Treponema pedis as revealed by genetic identities of 93, 99, and 100%. Treponemes in the BDD-SU lesion were 94% homologous to Treponema phylotype PT3. Fluorescent in situ hybridization (FISH) revealed extensive epidermal infiltration by treponemes that made up > 90% of the total bacterial population in all four lesions. FISH also tested positive for P. levii and negative for F. necrophorum in all four cases, whilst only one BDD-HFA contained Dichelobacter nodosus. Our data point to BDD-associated treponemes and P. levii constituting potential etiological agents in the development of "non-healing" claw horn lesions in cattle

Detection of treponemes in digital dermatitis lesions of captive European bison (Bison bonasus).

A newly-discovered foot disease of unknown origin in captive European Bison (Bison bonasus) was recently detected at Berne Animal Park. Dermatitis of the interdigital cleft of varying degrees of severity was diagnosed in all animals (n = 10). The aim of this study was to describe the gross and histological lesions of the interdigital cleft found in 10 captive European bison and to identify involved potential pathogens in affected feet using molecular-based methods for Treponema spp., Dichelobacter nodosus and Fusobacterium necrophorum. Lesions were scored according to the degree of gross pathology at limb level. In a single animal, the gross lesions were restricted to focal lesions on the dorsal aspect of the digital skin of each foot (score 1), whereas all other animals showed at least one foot with extended lesions including the interdigital cleft (score 2). The presence of viable spirochaetes was observed in all animals using dark field microscopy. Applying fluorescence in situ hybridisation (FISH) on biopsies, Treponema spp. were identified, infiltrating the skin lesions in varying numbers in nine animals. Nested PCRs for Treponema medium, Treponema phagedenis and Treponema pedis of swab samples showed three positive animals out of ten for the latter two, whereas pooled biopsy samples were positive in all ten animals for at least T. phagedenis (9/10) and/or T. pedis (7/10), while all samples were negative for T. medium. However, none of these Treponema species could be isolated and sequence analysis of the amplified products showed 100% match of 365 base pairs (bp) to Treponema phylotype PT3 and almost full match (530 of 532 bp, 99.6%) to Treponema phylotype PT13. The presence of T. phagedenis, PT3 and PT13 phylotypes was confirmed by FISH analyses. The phylotypes of T. phagedenis were present in all hybridized positive biopsies of Treponema spp., and PT13 and PT3 were less abundant. Neither D. nodosus nor F. necrophorum were detected. The histological Treponema score was mostly mild. Digital dermatitis in captive European Bison is contagious and differs from bovine digital dermatitis, concerning associated pathogens as well as gross appearance

Proof of an optimized salicylic acid paste-based treatment concept of ulcerative M2-stage digital dermatitis lesions in 21 dairy cows.

The efficacy of salicylic acid paste (SA) in the treatment of ulcerative bovine digital dermatitis (BDD) was assessed by combining clinical and histopathological analyses with molecular biological techniques. The latter were conducted in a blinded manner to reach maximum objectivity. Prior to treatment, M2-stage BDD lesions (n = 26, diagnosed in 21 dairy cows) exhibited ulceration, with severe perivascular, chronic, lymphoplasmacytic dermatitis and extensive keratinolysis being noted in most cases. Pretreatment biopsy samples (n = 12) followed by povidone-iodine ointment under bandage for one week before administration of SA paste were tested positive for Treponema spp. by blinded PCR and fluorescent in situ hybridization (FISH). Subsequent treatment consisted of application of SA and bandaging at weekly intervals until lesions had completely resolved. The treatment duration ranged between 2 and 4 weeks. Complete healing was achieved in 100% of cases, with 2/21 animals requiring a second round of treatment upon disease reoccurrence. Importantly, only 3/26 biopsies taken from previously affected sites still tested positive by Treponema PCR, and in another biopsy, the outermost layers of the stratum corneum scored weakly positive by Treponema-specific FISH. None of these Treponema DNA-positive biopsies showed signs of ulceration. One case exhibited focal keratinolysis. Positive PCR or FISH in these cases may have arisen from DNA traces of dead bacteria or environmental contamination during biopsy harvesting. To our knowledge, this is the first study on blinded molecular biological monitoring of the therapeutic efficacy of SA with respect to treponemal infection, and on complete BDD M2-stage remission in all animals achieved by SA treatment according to an optimized protocol. Although the etiology of BDD is considered as multifactorial, our data further support the concept that treponemes have a decisive role in BDD pathogenesis