Mistranslation-associated perturbations of proteostasis do not promote accumulation of amyloid beta and plaque deposition in aged mouse brain.

A common perception in age-related neurodegenerative diseases posits that a decline in proteostasis is key to the accumulation of neuropathogenic proteins, such as amyloid beta (Aß), and the development of sporadic Alzheimer's disease (AD). To experimentally challenge the role of protein homeostasis in the accumulation of Alzheimer's associated protein Aß and levels of associated Tau phosphorylation, we disturbed proteostasis in single APP knock-in mouse models of AD building upon Rps9 D95N, a recently identified mammalian ram mutation which confers heightened levels of error-prone translation together with an increased propensity for random protein aggregation and which is associated with accelerated aging. We crossed the Rps9 D95N mutation into knock-in mice expressing humanized Aß with different combinations of pathogenic mutations (wild-type, NL, NL-F, NL-G-F) causing a stepwise and quantifiable allele-dependent increase in the development of Aß accumulation, levels of phosphorylated Tau, and neuropathology. Surprisingly, the misfolding-prone environment of the Rps9 D95N ram mutation did not affect Aß accumulation and plaque formation, nor the level of phosphorylated Tau in any of the humanized APP knock-in lines. Our findings indicate that a misfolding-prone environment induced by error-prone translation with its inherent perturbations in protein homeostasis has little impact on the accumulation of pathogenic Aß, plaque formation and associated phosphorylated Tau.

Farm-level risk factors for digital dermatitis in dairy cows in mountainous regions.

Reduction of risk factors for bovine digital dermatitis (BDD) is crucial in current disease control. However, risk factors that might arise especially in mountainous regions are unknown until now, and an adapted BDD control program is consequently missing. The objective of this observational case-control study was to identify farm-level risk factors for BDD in dairy herds in mountainous regions. To investigate predictors for the occurrence of BDD, 100 farms were visited and information about herd characteristics and management practices, potentially relevant explanatory variables for either introduction or establishment of BDD, were gathered by completing a questionnaire with the farmer or herd manager. Within-herd prevalences of BDD assessed during 3 routine claw trimmings with an interval of 6 mo before the survey were used to define cases (BDD within-herd prevalence of ≥26% during each claw trimming) and controls (no BDD cases in each of the 3 routine claw trimmings before the survey). Data were analyzed using 2 separate binomial generalized linear models according to either establishment or introduction of BDD. After prescreening, 15 of 23 explanatory variables were included in the final analysis, which showed 3 variables related to introduction and establishment, each being significantly associated with the occurrence of BDD within a farm. Results of model 1 (i.e., aspects related to BDD introduction) revealed that access to mountain pastures during the summer season (odds ratio, 95% confidence interval: 0.12, 0.04-0.35), participation in dairy shows (0.32, 0.11-0.94), and the number of new animals introduced into the farm during the last 2 yr (1.28, 1.12-1.52) were significantly associated with the occurrence of BDD. Model 2 (i.e., aspects related to BDD establishment) showed that cows kept in freestalls were at higher risk for BDD compared with those kept in tiestalls (20.65, 1.59-649.37). Furthermore, number of days between diagnosis and treatment of a BDD lesion (10.31, 3.55-81.21) and the amount of concentrate feeding (median 5 kg) per cow and day (7.72, 2.46-6.47) were positively associated with BDD occurrence. In conclusion, the findings of this study provide a set of risk factors that are associated with BDD status within herds in mountainous regions. These results may help in development of adapted control programs for BDD in dairy cows.

Associations of antimicrobial use with antimicrobial susceptibility at the calf level in bacteria isolated from the respiratory and digestive tracts of veal calves before slaughter.

OBJECTIVES: Antimicrobial drugs are frequently administered in veal calves, but investigations on associations with antimicrobial susceptibility of bacteria are scarce and convey partly contradictory findings. The aim of this study was to investigate associations of antimicrobial use (AMU) during the fattening period with antimicrobial susceptibility shortly before slaughter. METHODS: Detailed treatment data of 1905 veal calves from 38 farms were collected prospectively during monthly farm visits for 1 year (n = 1864 treatments, n = 535 visits); 1582 Escherichia coli, 1059 Pasteurella multocida and 315 Mannheimia haemolytica were isolated from rectal and nasopharyngeal swabs collected before slaughter and subjected to antimicrobial susceptibility testing by microdilution. Associations of antimicrobial treatments with resistant isolates were investigated at the calf level. RESULTS: Associations of AMU with antimicrobial resistance were observed using generalized linear models. For E. coli, the odds of being resistant were increased with increased AMU (OR 1.36 when number of treatments >1, P = 0.066). Use of tetracyclines was associated with resistance to tetracycline (OR 1.86, P < 0.001) and use of penicillins was associated with resistance to ampicillin (OR 1.66, P = 0.014). No significant associations were observed for P. multocida (use of aminoglycosides: OR 3.66 for resistance to spectinomycin, P = 0.074). For M. haemolytica, the odds of being resistant were increased with increased AMU (OR 4.63, P < 0.001), and use of tetracyclines was associated with resistance to tetracycline (OR 6.49, P < 0.001). CONCLUSIONS: Occurrence of resistant bacteria shortly before slaughter was associated with AMU in veal calves. Prudent and appropriate use may contribute to limit the selection of resistant bacteria on veal farms.

Survey on the disposal of waste milk containing antimicrobial residues on Swiss dairy farms.

Feeding waste milk containing antimicrobial residues (WMA) to calves has been associated with increased antimicrobial resistance in calves' commensal bacterial flora. The objectives of this study were (1) to document practices related to the disposal of WMA on Swiss dairy farms and (2) to evaluate the association between farm characteristics and the feeding of WMA to calves. A web-based questionnaire on practices surrounding waste milk disposal was completed by 1,625 dairy producers (10.9% of solicited producers). Logistic regression models were built to evaluate the association between herd characteristics and the practice of feeding WMA. Waste milk produced during and up to the first milking after completion of antimicrobial treatment or during the withdrawal period was fed to at least some of the calves on 47.3% of respondents' farms. Farms in organic production had lower odds of feeding WMA to calves than nonorganic farms [odds ratio (OR) 0.59]. Farms located in the eastern region of Switzerland, as opposed to those in the western region, had increased odds of feeding WMA to calves (OR 2.01). A yearly average bulk tank somatic cell count ≥150,000 cells/mL was associated with increased odds of feeding WMA to calves compared with the reference category of <100,000 cells/mL (OR 1.62). An average cow-level annual milk production ≥8,500 L was associated with increased odds of feeding WMA to calves compared with farms in the interquartile range with a production of 6,500 to 8,499 L (OR 1.24). Further research is warranted to investigate dairy farmers' motivations affecting this practice, and to quantitatively define calves' exposure to antimicrobial residues and the resulting antimicrobial resistance in calves' commensal flora on these farms.

Preoperative skin asepsis protocols using chlorhexidine versus povidone-iodine in veterinary surgery: A systematic review and meta-analysis.

OBJECTIVE: To provide a systematic assessment of the efficacy of preoperative skin asepsis using chlorhexidine versus povidone-iodine based protocols for surgical site infection (SSI) prevention in veterinary surgery. STUDY DESIGN: Systematic meta-analytical review according to PRISMA-P guidelines. SAMPLE POPULATION: Studies comparing preoperative skin asepsis protocols using chlorhexidine versus povidone-iodine in veterinary surgery identified by systematic search between 1990 and 2020. METHODS: A search using MEDLINE/Pubmed, Web of Science and CAB Abstracts was performed, followed by secondary searches of Google Scholar, Proquest Dissertation and Theses, and relevant bibliographic articles. Primary and secondary outcome measures were the efficacy of skin asepsis protocols using chlorhexidine versus povidone-iodine on SSI incidence and skin bacterial colonization, respectively. A meta-analysis was performed with a random-effect model, with effect size calculated as risk ratio (RR) or mean standard deviation (MSD) with 95% CI. Statistical significance was set at P < .05. RESULTS: Among 1067 publications that met the initial search criteria, 9 relevant studies were eligible for analysis. No difference in the incidence of postoperative SSI or skin bacterial colonization between preoperative asepsis protocols using chlorhexidine versus povidone-iodine was found. Insufficient information and detail were frequent among studies and precluded a clear assessment of bias. CONCLUSION: This study showed that asepsis protocols using chlorhexidine were comparable to povidone-iodine in preventing postoperative SSI and reducing skin bacterial colonization. CLINICAL SIGNIFICANCE: Given the limitations of the studies that were included in terms of both quality and quantity, more high-quality randomized controlled trials are needed to confirm these conclusions.

Partial hepatectomy for treatment of multiple liver abscess in a calf: a case report.

BACKGROUND: Umbilical vein bacterial infections may cause liver abscesses during bacterial ascent. A single liver abscess can be surgically treated by marsupialization, but a risk of recurrence or non-healing remains. Moreover, there is no effective treatment for multiple abscesses. CASE PRESENTATION: A 17-day-old Holstein female calf exhibited reduced general condition, swelling and drainage of the umbilicus, and pressure sores in the area of the carpus, resulting in reluctance to stand up. The umbilicus showed pain at palpation; deep abdominal palpation indicated a swollen umbilical vein coursing from the umbilicus toward the liver. Ultrasonography confirmed a swollen umbilical vein with pus accumulation and multiple abscesses in the liver. Contrast-enhanced computed tomography (CT) examination confirmed that the swollen umbilical vein with fluid continued to the liver, and multiple unenhanced lesions, most likely abscesses, were confirmed in the liver. Partial hepatectomy was performed to remove as many abscesses as possible. For the resection, a vessel sealing device (LigaSureTM) was used to excise a part of the left liver lobe. As we could not remove all the abscesses in the liver during the operation, cefazolin sodium (5 mg/kg) was administered for 14 days after surgery. Post-operatively, blood accumulation was observed in the abdominal cavity, but no signs of peritonitis were found. The calf returned to the farm on day 38 after surgery. Follow-up information was obtained after 1 year, and complications were not reported. CONCLUSIONS: To our knowledge, this is the first report of partial hepatectomy using a vessel sealing device for a calf with multiple liver abscesses. This case report suggests that the combination of partial hepatectomy and long-term administration of antibacterial drugs may restore the health of calves with multiple liver abscesses.

Treponema phagedenis (ex Noguchi 1912) Brumpt 1922 sp. nov., nom. rev., isolated from bovine digital dermatitis.

'Treponema phagedenis' was originally described in 1912 by Noguchi but the name was not validly published and no type strain was designated. The taxon was not included in the Approved Lists of Bacterial Names and hence has no standing in nomenclature. Six Treponema strains positive in a 'T. phagedenis' phylogroup-specific PCR test were isolated from digital dermatitis (DD) lesions of cattle and further characterized and compared with the human strain 'T. phagedenis' ATCC 27087. Results of phenotypic and genotypic analyses including API ZYM, VITEK2, MALDI-TOF and electron microscopy, as well as whole genome sequence data, respectively, showed that they form a cluster of species identity. Moreover, this species identity was shared with 'T. phagedenis'-like strains reported in the literature to be regularly isolated from bovine DD. High average nucleotide identity values between the genomes of bovine and human 'T. phagedenis' were observed. Slight genomic as well as phenotypic variations allowed us to differentiate bovine from human isolates, indicating host adaptation. Based on the fact that this species is regularly isolated from bovine DD and that the name is well dispersed in the literature, we propose the species Treponema phagedenis sp. nov., nom. rev. The species can phenotypically and genetically be identified and is clearly separated from other Treponema species. The valid species designation will allow to further explore its role in bovine DD. The type strain for Treponema phagedenis sp. nov., nom. rev. is B43.1T (=DSM 110455T=NCTC 14362T) isolated from a bovine DD lesion in Switzerland.

Arthroscopic approaches to and anatomy of the shoulder joint of cattle: a cadaver study.

BACKGROUND: Arthroscopic surgery is described as a minimally invasive technique for diagnosis, exploration and treatment of joint disorders. It allows intraarticular structures to be assessed accurately, thereby improving the diagnostic capabilities, and it broadens the spectrum of surgical techniques feasible for treatment of articular pathologies in cattle. This study aimed to assess for cattle the described arthroscopic approaches to the shoulder joint of horses, and to describe the appearance of the corresponding intraarticular structures of the shoulder joint. Additionally, to perform histological examination where tissues were identified and assessed arthroscopically, but the tissue type was uncertain using cadaveric limbs from cattle of different age categories without any signs of orthopedic diseases of the front limbs. RESULTS: An anatomic and arthroscopic investigation with 34-cadaveric forelimbs from 20-cattle was performed. The arthroscope was inserted either immediately cranial or 1-cm caudal to the tendon of the infraspinatus muscle for the cranial and caudal approaches, respectively. The shoulder joints were examined with the limbs in either horizontal non-pulled position, abducted non-pulled position using a three-pod limb holder adjustable in height, or horizontal manually pulled position. Arthroscopy was performed using a rigid 30°arthroscope (18-cm length, 4-mm outer diameter) to view the synovial pouches with their synovial villi and the following structures: cranial rim of the glenoid, cranial portion of the humeral head, incisura-glenoidalis, caudal rim of the glenoid, caudal portion of the humeral head, and cranial and caudal cul-de-sac. Abduction of the limb allowed improved visualization of the lateral portion of the joint. Pulling the limb facilitated investigation of the medial portion of the joint. Generally, the distention range was higher in younger as compared to adult cattle, and visualization of the medial portion of the joint was, therefore, facilitated in younger animals. The main complications observed were subcutaneous fluid extravasations and partial-thickness articular cartilages wear-lines. CONCLUSION: The described arthroscopic techniques allowed good overall visualization of the most relevant anatomical structures within the healthy cadaveric joint. Further investigations are warranted to evaluate the diagnostic and therapeutic applications of these techniques and the prognosis of arthroscopic surgery as a tool for the treatment of joint lesions.

Validation of a noseband pressure sensor algorithm as a tool for evaluation of feeding behaviour in dairy Mediterranean buffalo (Bubalus Bubalis).

This research communication addresses the goal of validating an algorithm to monitor natural occurrence of feeding behaviours in dairy Mediterranean buffalo based on the output of a noseband pressure sensor (RumiWatch®, halter). Several characteristics of the feeding behaviour were detected with a very high (ruminating boluses), high (chews per bolus) and moderate degree of correlation (chews per minute) with video analyses (gold standard). All of them were associated with a low mean difference with the gold standard, and the mean relative measurement error ranged between low (ruminating boluses) and moderate (chews per bolus and chews per minute). The proportion of correctly detected events for the variables rumination and eating time was 98 and 99%, respectively. The collection of data and subsequent evaluation of the parameters investigated may provide objective information on Mediterranean Buffalo behaviours allowing for reliable studies of the animal welfare in this ruminant in the future.

Lateral radioulnar subluxation in three cattle: clinical findings, treatment, and outcome.

OBJECTIVE: To describe the clinical signs, conservative treatment, and short- and long-term outcomes of lateral radioulnar subluxation in cattle. ANIMALS: Three cattle with lateral radioulnar subluxation. STUDY DESIGN: Case series. METHODS: One 3-year-old Red Holstein cow, one 2-year-old Red Holstein cow, and one 9-month-old Holstein heifer were presented with acute, grade greater than 3 of 5, mixed lameness in one forelimb. Clinical, radiographic, and ultrasonographic examination results revealed radioulnar subluxation with lateral displacement in all cases. RESULTS: The subluxations were manually reduced under general anesthesia by simultaneous maximum flexion of the elbow and carpal joints, medial rotation of the forearm, and application of strong pressure to the radial head and olecranon. The short-term clinical outcome after stall rest was excellent in all three cases. Clinical and radiographic follow-up examinations were performed at varying intervals, with a final on-farm examination in all three cattle 12, 7, and 9 months after reduction. Osteoarthritic changes were visible in all three cases, mainly at the medial humeral trochlea, but lameness had completely resolved in all three animals. CONCLUSION: Conservative management of lateral radioulnar subluxation had an excellent clinical outcome in all three cattle. Follow-up radiographs revealed osseous proliferation mainly in the region of the medial trochlea of the humerus and subtle signs of osteoarthritic changes. CLINICAL SIGNIFICANCE: Lateral radio-ulnar subluxation is a rare but possibly underdiagnosed cause of lameness in cattle. It should be part of the differential diagnosis in cattle with elbow joint pain.

Immunization against GnRF in adult cattle: a prospective field study.

BACKGROUND: Suppression of cyclic activity in cattle is often desired in alpine farming and for feedlot cattle, not intended for breeding. A cattle specific anti-GnRF vaccine (Bopriva™) is registered for use in heifers and bulls in different countries. In adult cows vaccinated with Bopriva™, the median period until recurrence of class III follicles was 78 days from the day of the 2nd vaccination and reversibility could be proven, as out of 11 experimental cows 10 cows became pregnant at first, and one cow at second insemination. In the present study, 76 healthy, cyclic Eringer heifers and cows were vaccinated twice with Bopriva™ 3-7 weeks apart, to prevent estrus during alpine pasturing. Blood samples were taken for progesterone and GnRF antibody titer analysis on the day of inclusion (7-9 d before the first vaccination) and at the first vaccination. At the same time, gynaecological examinations were performed. When estrus occurred in the course of the alpine pasturing season, a gynaecological examination was done including analysis of a blood sample (progesterone, anti-GnRF antibody titer). Cows were followed for fertility out to 26 months post second vaccination. RESULTS: Median duration of estrus suppression was 191 days after the second vaccination (when the 2 vaccinations were given 28-35 days apart). From n = 13 cows showing signs of estrus on the alpine pasture, n = 7 could not be confirmed in estrus (serum progesterone value >2 ng/ml, no class III follicles seen using ultrasonography). Median duration between second vaccination and next calving was 496 days (25%/75% quartiles: 478/532 days). CONCLUSION: Bopriva™ induced a reliable and reversible suppression of estrus for more than 3 months in over 90% of the cows.

Validation of a pedometer algorithm as a tool for evaluation of locomotor behaviour in dairy Mediterranean buffalo.

This research communication validates an algorithm to monitor natural occurrence of locomotor behaviours in dairy Mediterranean buffalo based on the output of a 3-dimensional accelerometer (RumiWatch®, pedometer). Several characteristics of the locomotor behaviour were detected with a very high (up-right, lying and standing time) or high degree of correlation (walking time and number of strides) and a low mean difference with the video recording. The proportion of correctly detected events exceeded 99 % for the following variables: stand up and lie down events, as well as number of lying, standing or walking bouts. The mean relative measurement error was less than 10 % for the variables: lying, standing, up-right times and number of strides as compared with gold standard. This new algorithm may represent the base for a future early and real-time disease warning system aiming to gain higher health standard in these ruminants.

Assessment of foot health and animal welfare: clinical findings in 229 dairy Mediterranean Buffaloes (Bubalus bubalis) affected by foot disorders.

BACKGROUND: Lameness represents the third most important health-related cause of economic loss in the dairy industry after fertility and mastitis. Although, dairy Mediterranean Buffaloes (MB) and dairy cows share similar breeding systems predisposing to similar herd problems, published studies exploring its relevance and role in these ruminants are still rare and incomplete. The aims of this study were to describe the clinical findings of foot disorders (FDs) in dairy MB and their influence on animal welfare, determined by assessment of locomotion score (LS), body condition score (BCS) and cleanliness score (CS). RESULTS: Of 1297 multiparous MB submitted to routine trimming procedures, 229 buffaloes showed at least one FD. The prevalence of buffaloes affected by FDs was 17.7 %, while motility and lameness indexes were 84.1 % (1091/1297) and 15.9 % (206/1297), respectively. Overgrowth was present in 17.0 % (220/1297), corkscrew claw in 15.8 % (205/1297), interdigital phlegmon in 0.9 % (12/1297), white line abscess in 0.8 % (11/1297), digital dermatitis in 0.1 % (1/1297) and interdigital hyperplasia in 0.1 % (1/1297). Simultaneous presence of FDs was recorded in 17.0 % of MB (221/1297): overgrowth and corkscrew claw occurred together in 15.8 % of cases (205/1297), overgrowth and interdigital phlegmon in 0.3 % (4/1297), overgrowth and white line abscess in 0.8 % (11/1297), digital dermatitis and interdigital hyperplasia in 0.1 % (1/1297). The presence of FDs was always associated with lameness (LS > 2), except from 23 MB with simultaneous overgrowth and interdigital phlegmon occurrence. The majority of MB within the under-conditioned group (95.5 %, 43/45) and all those with CS > 2 (122/122) had a locomotion score above the threshold of normality (LS > 2). Furthermore, foot diseases such as interdigital hyperplasia, white line abscess and digital dermatitis or interdigital hyperplasia seemed to occur more frequently associated with decreased BCS and increased CS scores. CONCLUSIONS: This study describes for the first time the involvement of white line disease, interdigital phlegmona, digital dermatitis and interdigital hyperplasia in foot disorders of dairy Mediterranean buffalo and shows their association with an impairment of animal welfare.

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.

Simultaneous detection and discrimination of virulent and benign Dichelobacter nodosus in sheep of flocks affected by foot rot and in clinically healthy flocks by competitive real-time PCR.

Ovine foot rot caused by Dichelobacter nodosus is affecting sheep worldwide. The current diagnostic methods are difficult and cumbersome. Here, we present a competitive real-time PCR based on allelic discrimination of the protease genes aprV2 and aprB2. This method allows direct detection and differentiation of virulent and benign D. nodosus from interdigital skin swabs in a single test. Clinically affected sheep harbored high loads of only virulent strains, whereas healthy sheep had lower loads of predominantly benign strains.

Experience with the delegation of anaesthesia for disbudding and castration to trained and certified livestock owners.

BACKGROUND: Anaesthesia is mandatory for disbudding and castrating calves and lambs of any age, in Switzerland. According to the "anaesthesia delegation model" (ADM), anaesthesia for disbudding calves <3 weeks of age and castrating calves and lambs <2 weeks of age may be administered by certified farmers. Experience with this unique model is not available. The aim was to evaluate the experience of the veterinary practitioners with the ADM. The response rate was 42%. The survey consisted of one questionnaire for each procedure. Procedure I was the delegation of anaesthesia for disbudding calves and procedures II and III were anaesthesia for castrating calves and lambs. RESULTS: Procedure I was performed with local anaesthesia in all farms of 51.8% of the veterinary practices, while this was only 39.3% and 7.6% for procedures II and III (p < 0.001). Anaesthesia for procedure I was administered technically correctly by farmers in at least 66% of the farms of 58.3% of the practitioners, while this was 45.4% and only 23.6% for procedures II and III (p < 0.001). The ADM was assessed as a moderate to very good model to reinforce the legal obligations for procedures I, II, or III by 74.8%, 76.5% and 62.0% of the veterinary practitioners (p < 0.005). CONCLUSIONS: The delegation of anaesthesia to certified farmers may be a promising model to reinforce the obligation to provide local anaesthesia for disbudding and castrating calves, but to a lesser extent for castrating lambs.

Feeding mastitis milk to organic dairy calves: effect on health and performance during suckling and on udder health at first calving.

BACKGROUND: Infection pathways of S. aureus udder infections in heifers are still not well understood. One hypothesis is that calves become infected with S. aureus via feeding mastitis milk. Especially on small-scale farms, pasteurisers are not economic. The purpose of this randomised comparative study was to investigate the influence of feeding milk containing S. aureus genotype B (SAGTB) on the health and development of calves and udder health of the respective heifers. Additionally, a method reducing the bacterial load to obtain safer feeding milk was tested. Thirty-four calves were fed mastitis milk from cows with subclinical SAGTB mastitis. One group was fed untreated milk (UMG). For the other group, milk was thermised at 61°C for one minute (heat treated milk group = HMG). After weaning, calves were followed up until first calving. A milk sample of these heifers was taken at first milking to compare udder health of both groups. RESULTS: Thermisation of milk led to an effective reduction of S. aureus in the feeding milk. 78% of the analysed pools were free of S. aureus, a reduction of at least one log was obtained in the other pools. CONCLUSIONS: Under the conditions of this study, no effects of feeding milk containing SAGTB on udder health after first calving were observed. But a power analysis indicated that the sample size in the current setup is insufficient to allow for assessment on mastitis risk after SAGTB exposition, as a minimal number of 4 calves infected (vs. 0 in the HMG) would have shown significant effects. High bacterial load, however, was associated with an increased incidence rate of diarrhoea. Thus, thermisation as a minimal preventive measure before feeding mastitis milk to calves might be beneficial for maintaining calf health.

Ultrasound-guided proximal paravertebral anaesthesia in cattle.

OBJECTIVE: To develop and evaluate a method for ultrasound-guidance in performing the proximal paravertebral block for flank anaesthesia in cattle through a cadaveric study, followed by clinical application. STUDY DESIGN: prospective experimental cadaveric study and clinical series. ANIMALS: Previously frozen lumbar sections of cows without known spinal abnormalities were used. The clinical case group comprised of ten animals for which a right flank laparotomy was indicated. METHODS: Twenty cow cadavers were used to perform ultrasound-guided bilateral injections of 1.0 mL dye (1.0 mL 1% Toluidine Blue in 1% Borax) at the intervertebral foramen at the level of T13, L1 and L2 spinal nerves. Distance and depth of injection, staining of the dorsal and ventral nerve branches, and deviation from the target were evaluated. The investigator's confidence as to visualisation and expected success at staining the nerve was assessed. Ten clinical cases received the ultrasound-guided proximal paravertebral anaesthesia. Analgesic success was evaluated using a 4-grade scoring system at 10 minutes after the injection and during surgery, respectively. Categorical variables were described using frequencies and proportions. RESULTS: Both dorsal and ventral branches of the spinal nerves T13, L1 or L2 were at least partially stained in 41% of injections, while in 77% of injections one of the branches was stained. Five out of ten clinical cases had a satisfactory anaesthesia. There was no significant association between confidence at injection and either staining or analgesic success. CONCLUSION: Results from the cadaveric and clinical study suggest no significant improvement using ultrasound guidance to perform proximal paravertebral block in cows compared to our previous clinical experience and to references in the literature using the blind method. CLINICAL RELEVANCE: Further research should be conducted to improve the ultrasound-guided technique described in this study.

Appetitively motivated tasks in the IntelliCage reveal a higher motivational cost of spatial learning in male than female mice.

The IntelliCage (IC) permits the assessment of the behavior and learning abilities of mice in a social home cage context. To overcome water deprivation as an aversive driver of learning, we developed protocols in which spatial learning is motivated appetitively by the preference of mice for sweetened over plain water. While plain water is available at all times, only correct task responses give access to sweetened water rewards. Under these conditions, C57BL/6J mice successfully mastered a corner preference task with the reversal and also learned a more difficult time-place task with reversal. However, the rate of responding to sweetened water decreased strongly with increasing task difficulty, indicating that learning challenges and reduced success in obtaining rewards decreased the motivation of the animals to seek sweetened water. While C57BL/6J mice of both sexes showed similar initial taste preferences and learned similarly well in simple learning tasks, the rate of responding to sweetened water and performance dropped more rapidly in male than in female mice in response to increasing learning challenges. Taken together, our data indicate that male mice can have a disadvantage relative to females in mastering difficult, appetitively motivated learning tasks, likely due to sex differences in value-based decision-making.

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.