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

Combined GNSS reflectometry–refractometry for automated and continuous in situ surface mass balance estimation on an Antarctic ice shelf

Reliable in situ surface mass balance (SMB) estimates in polar regions are scarce due to limited spatial and temporal data availability. This study aims at deriving automated and continuous specific SMB time series for fast-moving parts of ice sheets and shelves (flow velocity &gt; 10 m a−1) by developing a combined global navigation satellite system (GNSS) reflectometry and refractometry (GNSS-RR) method. In situ snow density, snow water equivalent (SWE), and snow deposition or erosion are estimated simultaneously as an average over an area of several square meters and independently on weather conditions. The combined GNSS-RR method is validated and investigated regarding its applicability to a moving, high-latitude ice shelf. A combined GNSS-RR system was therefore installed in November 2021 on the Ekström ice shelf (flow velocity ≈ 150 m a−1) in Dronning Maud Land, Antarctica. The reflected and refracted GNSS observations from the site are post-processed to obtain snow accumulation (deposition and erosion), SWE, and snow density estimates with a 15 min temporal resolution. The results of the first 16 months of data show a high level of agreement with manual and automated reference observations from the same site. Snow accumulation, SWE, and density are derived with uncertainties of around 9 cm, 40 kg m−2 a−1, and 72 kg m−3, respectively. This pilot study forms the basis for extending observational networks with GNSS-RR capabilities, particularly in polar regions. Regional climate models, local snow modeling, and extensive remote sensing data products will profit from calibration and validation based on such in situ time series, especially if many such sensors will be deployed over larger regional scales.</p

Agile 5G Scheduler for Improved E2E Performance and Flexibility for Different Network Implementations

In this article, we present a holistic overview of the agile multi-user scheduling functionality in 5G. An E2E perspective is given, including the enhanced QoS architecture that comes with 5G, and the large number of scheduling relatedoptions from the new access stratum sub-layer, MAC, and PHY layer. A survey of the 5G design agreements from the recently concluded 5G Study in 3GPP is presented, and it is explained how to best utilize all these new degrees of freedom to arrive at an agile scheduling design that offers superior E2E performance for a variety of services with highly diverse QoS requirements.Enhancements to ensure efficient implementation of the 5G scheduler for different Network architectures are outlined. Finally, state-of-the-art system level performance results are presented, showing the ability to efficiently multiplex services with highly diverse QoS requirements.In this article, we present a holistic overview of the agile multi-user scheduling functionality in 5G. An E2E perspective is given, including the enhanced QoS architecture that comes with 5G, and the large number of scheduling related options from the new access stratum sub-layer, MAC, and PHY layer. A survey of the 5G design agreements from the recently concluded 5G Study in 3GPP is presented, and it is explained how to best utilize all these new degrees of freedom to arrive at an agile scheduling design that offers superior E2E performance for a variety of services with highly diverse QoS requirements. Enhancements to ensure efficient implementation of the 5G scheduler for different network architectures are outlined. Finally, state-of-the-art system level performance results are presented, showing the ability to efficiently multiplex services with highly diverse QoS requirements

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

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