Electronic Data Loggers Research Articles

Nonlinear Analysis and Solution for an Overhead Line Magnetic Energy Harvester with an Active Rectifier

Recently, there has been a significant focus on developing various energy harvesting technologies to power remote electronic sensors, data loggers, and communication devices for smart grid systems. Among these technologies, magnetic energy harvesting stands out as one straightforward method to extract substantial power from current-carrying overhead lines. Due to the relatively small size of the harvester, the high currents in the distribution system quickly saturate its magnetic core. Consequently, the magnetic harvester operates in a highly nonlinear manner. The nonlinear nature of the downstream AC to DC converters further complicates the process, making precise analytical modeling a challenging task. In this paper, a clamped type overhead line magnetic energy harvester with a controlled active rectifier generating significant DC output power is investigated. A piecewise nonlinear analytical model of the magnetic harvester is derived and reported. The modeling approach is based on the application of the Froelich equation. The chosen approximation method allowed for a complete piecewise nonlinear analytical treatise of the harvester’s behavior. The main findings of this study include a closed-form solution that accounts for both the core and rectifiers’ nonlinearities and provides an accurate quantitative prediction of the harvester’s key parameters such as the transfer window width, optimal pulse location, average DC output current, and average output power. To facilitate the study, a nonlinear model of the core was developed in simulation software, based on parameters extracted from core experimental data. Furthermore, theoretical predictions were verified through comparison with a computer simulation and experimental results of a laboratory prototype harvester. Good agreement between the theoretical, simulation, and experimental results was found.

Nonlinear Analysis and Closed-Form Solution for Overhead Line Magnetic Energy Harvester Behavior

Recently, much attention has been given to the development of various energy harvesting technologies to power remote electronic sensors, data loggers, and communicators that can be installed on smart grid systems. Magnetic energy harvesting is, perhaps, the most straightforward way to capture a significant amount of power from a current-carrying overhead line. Since the harvester is expected to have a small size, the high currents of the distribution system easily saturate its magnetic core. As a result, the operation of the magnetic harvester is highly nonlinear and makes precise analytical modeling difficult. The operation of an overhead line magnetic energy harvester (OLMEH) generating significant DC power output into a constant voltage load was investigated in this paper. The analysis method was based on the Froelich equation to analytically model the nonlinearity of the core’s BH characteristic. The main findings of this piecewise nonlinear analysis include a closed-form solution that accounts for both the core and rectifiers’ nonlinearities and provides an accurate prediction of OLMEH transfer window length, output current, and harvested power. Continuous and discontinuous operational modes are identified and the mode transition boundary is obtained quantitatively. The theoretical investigation was concluded by comparison with a computer simulation and also verified by the experimental results of a laboratory prototype harvester. A good agreement was found.

Effect of Temperature Humidity Index (THI) on resting pattern of dairy cows in different regions of Sri Lanka.

The ability to spend time resting is extremely important for dairy cattle welfare. Through this study, lying behaviour of dairy cows in to Up-Country (UP), Mid-Country (MC), Coconut-Triangle (CT) and Western-Province (WP) of Sri Lanka was studied to get an insight into their resting pattern. Resting pattern was assessed in 170 Holstein-Friesian/ Jersey crossed, tie-stalled lactating cows (UP = 49, MC = 49, CT = 48 and WP = 24) using electronic data loggers. Appropriate resting behaviours were attained in UP and MC regions, with longer lying time (11.7, 11.3 h/day) and lying bout durations (78.0, 84.9 min) respectively, where lower THI ranges were observed compared to other regions. WP and CT resulted with lower lying times (9.00, 9.26 h/day) and lying bout durations (48.3, 64.3 min) respectively with higher THI. There is a slight variation of the environmental temperature of each region with the time period of experiment. Cows in all regions prefer to lie on their left side (UP-6.1, MC-6.1, CT-4.4, WP-4.7 h/d) and with significant differences (P<0.05) between MC-WP, MC-CT, UP-CT and UP-WP. A negative significant (P<0.05) correlation was observed between THI and lying behaviours. There were significant effects of time (hour) and time × region interaction (P<0.05) on the lying down pattern. More lying down was observed in late night and early morning with a peak rest around the hours of 21:00-05:00. Overall, according to the results of the current study, the existing environmental conditions of four regions affected the resting pattern of dairy cows and, identification of possible mechanisms to modify the environment to enhance cow comfort is vital.

The Journeys of Wally and Wilma: How Scientists Reconstruct the Movements of Fish

Have you ever lost your phone and used its GPS function to locate it? To learn about fish, scientists are interested in where fish go and what they experience but GPS technology does not work underwater. Scientists therefore developed small electronic data loggers that can be attached to fish, to record conditions in a fish’s environment. When the fish is recaptured, this information can be downloaded and returned to the scientists. The fish’s movements can then be reconstructed by comparing the recorded measurements with the conditions in the sea. In this article, we explain how this method works and tell you the story of two cod with very different fates: Wally, who moved around to feed and to produce offspring, and Wilma, who went on an adventure with a surprising ending.

PERFORMANCE EVALUATION OF SOLAR PHOTOVOLTAIC PANEL MOUNTED ON SLOPED CORRUGATED METAL SHEET ROOF IN KANO STATE NORTHWEST NIGERIA

Installation of solar photovoltaic system on roof has advantages of proper utilization of space, help in avoiding shading effects and reduction of dust accumulation on the panels. However, electrical efficiency and lifespan of solar photovoltaic panel tends to decrease due to the increase in surface temperature above the operation temperature of the panels due to its contact with the roofing sheets. The performance of solar photovoltaic panels was experimentally investigated on corrugated metal sheet (CMS) roof at four different heights (0, 100, 200, and 300mm). Four polycrystalline silicon photovoltaic panels of 10 watts each were selected from the same manufacturer. The temperatures on the roof and on the photovoltaic panels’ surfaces were measured at different solar hours. Also, the outputs of the solar panels together with the irradiance available were measured at same hours using an electronic data logger and imported to an Excel software. Irradiance variation, gap between roof and photovoltaic panels, and heating effect on panels were found to be the parameters affecting the photovoltaic system’s performance. The highest temperature attained by the photovoltaic panel is when it was directly mounted on the roof as 76.5°C while the other photovoltaic panels mounted at a gap height of 100mm, 200mm and 300mm attained the highest temperature of 71.8oC, 69,6oC and 68.0oC respectively. The panels’ extra heat was originating from CMS roof vicinity. Output powers from the panels were unequal throughout the experiment whilst exhibited similar behavior. The panels’ temperature dropped...

Assessing the Performance of a Blackbody Solar Dryer

About 33.3% of global food production is lost to spoilage every year. At current rates, that amount is adequate for feeding an average of 300 million people around the world. This huge loss can be decimated to 13.17% if food spoilage is avoided or managed better. One technique for minimizing food waste is solar drying. West Africa and locations around the equatorial plane are described by average daily insolation of about 4-6 kWhm−2. In effect, this energy source could be applied to curb the problem of food spoilage and wastage. Another side attraction of drying with solar is that, it offers year-round availability of food crops. In this study, solar drying is investigated with the principle of blackbody radiation using an electronic data logger coupled with the Arduino Uno, SD Card Module, DHT22 Temperature and Humidity Sensor, SD Card, and Connecting wires to record temperature and humidity data. The output was 56.3°C and 46.8°C for the upper and lower limit of temperature respectively, yielding an average difference of about 10°C. The interaction of sensible blackbody radiation within a four-tier rock bed was crafted into a novel solar dryer design. With this relatively high-temperature gradient between the upper and lower, a blackbody solar dryer constructed was suitable to preserve the both quality and shelf life of agricultural produce.

The GENESIS-UV study on ultraviolet radiation exposure levels in 250 occupations to foster epidemiological and legislative efforts to combat nonmelanoma skin cancer.

Several hundred million of the 3 billion formally employed people worldwide are at risk from high levels of solar ultraviolet radiation (UVR). Chronic light damage to the skin can lead to nonmelanoma skin cancer (NMSC), especially when irradiation is too high and is acquired for decades. However, data with uniform metrics, high resolution over time and in-depth occupational profiles are not available. To build a worldwide usable matrix of UVR exposure in occupations and to show use cases for the data. One thousand test persons were recruited to wear electronic data logger dosimeters during their working time for 7 months each. The measurements yielded 3.7 billion data points for around 48 000 days with high-quality data capture covering more than 250 occupations and 650 activities. Scientific evaluation of the data included daily and half-hourly means, geographical transfer calculations to the world, threshold exceedance quotas, transcriptome effects, and occupational disease estimates. A compendium for global use is presented. In-depth analyses and the resulting implications for research have been elaborated to directly link exposure data to effects in the human body. Interestingly, the annual irradiances of the different occupations span a wide range of values: from about 650 to 50 standard erythemal doses, with different distributions over the months. Detailed exposure data per occupation were derived, and the risk on an occupational or activity basis assuming different exposure level quotas was quantified. This showed that, for example, in temperate latitudes, all activities with a duration of > 2 h outdoors are associated with increased NMSC risk. We offer our work to enable sound studies on the nature of ultraviolet-induced skin cancer, dose-response relationships, intermittency of skin exposure, and derivation of limit values. Sociological studies on prevention are now possible. Practitioners may use the findings for their daily work with employees.

Analysis of Frequency and Polarization Scaling on Rain Attenuated Signal of a KU-Band Link in Jos, Nigeria.

This paper presents the analysis of frequency and polarization scaling on rain attenuated signal of a KU-Band link. The study was carried out in Jos, Plateau state, Nigeria (9.89650 N, 8.85830 E; 1192 meters) with Maximum, Average and Minimum Temperatures of 29.80C, 22.80C and 170C respectively. Data were obtained for the months of May, June, July, August, September and October 2020.Davis Vantage Vue weather station was used to measured and record one-minute rain-rates from a minimum of 0.8 mm/h up to a value of 460 mm/h, with an accuracy of 0.2 mm/h. The precipitation data, with date and time is captured on the micro-chip of the wireless electronic data logger, which, when calibrated, logs on data every minute. The down converted Ku-band signal was fed into the digital satellite meter and a spectrum analyzer for signal level analysis, logging and recording samples of viewed spectrum over finite periods of time on a computer system. Both satellite signal and precipitation measurements were done concurrently. Data were analyzed using Microsoft excel and results were obtained based on ITU-R model. Results obtained revealed that rain attenuated signal for vertical and horizontal polarization varies for different rain rate and months under reviewed. For the month of May 2020, rain attenuated signal is more severe from rain rate of 100mm/hr with the highest rain attenuation of 25.57dB, 30.37dB, and 39.84dB at frequencies of 12GHz, 15GHz and 18GHz respectively while the rain attenuated signal for vertical polarization is more severe from 80mm/hr with highest recorded rain attenuation of 27.96dB, 40.33dB and 45.71dB at frequencies of 12GHz, 15GHz and 18GHz respectively. For the month of July 2020, the results shows that rain attenuated signal for vertical polarization is more severe from rain rate of 80mm/hr with the highest rain attenuation of 60.57dB, 73.37dB, and 100.84dB for frequencies of 12GHz, 15GHz, and 18GHz respectively. At Horizontal polarization, signal losses are more severe from 60mm/hr. The results further proves that frequency and polarization scaling of rain attenuated signalare major factors to consider when designing a microwave link budget especially in the study area that experiences high amount of rainfall annually.

Development of Real-Time Monitoring System for an Off-Grid Photovoltaic System

In operating a photovoltaic system, it is required to employ hardware and software systems to monitor the parameter of the results of the solar panel conversion. Usually, monitoring the photovoltaic system is done by manual gauges and recording the measured results manually which would require a human hand. The present research designed and developed a real-time monitoring system for an off-grid photovoltaic system that could monitor the photovoltaic system performance automatically. The monitoring system design has 2 (two) subsystems. The first subsystem is a hardware system in the form of an electronic data logger system equipped with an SD card. This allowed data to be recorded on an SD card. The second sub-system is a software design developed using Microsoft in Visual Basic. The hardware and software were connected to monitor the photovoltaic results and recorded the obtained data in an SD card for further analysis.

Behavioral changes in dairy cows with metritis in seasonal calving pasture-based dairy system

The aims of this study were to determine changes in lying and rumination behavior of transition dairy cows that were healthy or affected by metritis during the autumn and spring calving season in a temperate climate and determine the effect of some weather variables (precipitation and heat stress) on these behaviors. A total of 103 multiparous cows were monitored during the autumn (February to April) and spring calving season (July to October) from 10 d before to 10 d after calving. Cows were chosen retrospectively by diagnosis of metritis [autumn season, (n = 11); spring season, (n = 13)] or as healthy [autumn season, (n = 25); spring season, (n = 25)] based on vaginal discharge characteristics evaluated during the first 10 days in milk. In all animals, electronic data loggers recorded lying (Hobo Pendant G Acceleration, Onset Computer Corp.) and rumination behavior (Hi-Tag rumination monitoring system, SCR Engineers Ltd.) during the study period. We included precipitation level (>1 mm/d = with rain, and ≤1 mm/d = without rain) and heat stress [no heat stress = temperature-humidity index (THI) < 68 vs. heat stress = THI ≥ 68] as weather factors that may have affected lying and rumination behavior during the spring and autumn season in a temperate climate, respectively. Metritis during the spring calving season was associated only with longer lying times (≥1.3 h/d) after calving. During the autumn calving season cows with metritis lay down longer the day of calving (~2.1 h/d) and had fewer lying bouts of longer duration during the prepartum period compared with healthy cows. Rumination time did not differ by health status during the spring calving season, whereas cows with metritis during autumn ruminated 30, 21, and 24 min/d less than healthy cows during the prepartum, calving, and postpartum period, respectively. Precipitation and heat stress were associated with decreased daily lying and rumination time in sick cows. Our results indicate that differences in lying and rumination behavior depended on the metritis status, and support the idea that weather factors such as rainfall or heat stress requires to be considered in analyses of transition cow behavior in seasonal calving pasture-based dairy systems.

Effect of timing of prepartum vaccination relative to pen change with an acidogenic diet on lying time and metabolic profile in Holstein dairy cows

The objective was to assess the effect of prepartum vaccination timing relative to pen change with an acidogenic diet at 28 or 21 d before expected parturition (dpp) on lying time (LT), prepartum serum energy status (glucose, IGF-1, and nonesterified fatty acids), urine pH, and serum Ca at calving in pregnant Holstein dairy cows. Pregnant multiparous Holstein cows (n = 308) from 1 large dairy herd were randomly allocated into 1 of 3 treatment groups at 35 ± 3 dpp as follows: (1) vaccination at 28 dpp and pen change at 21 dpp (V28PC21; n = 108), (2) vaccination and pen change at 28 dpp (V28PC28; n = 99), and (3) vaccination and pen change at 21 dpp (V21PC21; n = 101). When cows changed pens, an acidogenic diet was introduced. Every other week, a group of 43 to 53 animals were enrolled and electronic data loggers (IceQube, IceRobotics) were fitted to the hind leg of individual cows to assess their LT. Blood samples were collected at 28, 26, 21, 19, 14 dpp and at calving. Parity, body condition score, days dry, and gestation length were not different among groups. Overall, V28PC28 cows had 7 additional days in prepartum pens consuming an acidogenic diet compared with V28PC21 or V21PC21 cows. Regardless of treatment group, cows in the far-off pen had 43 min/d less LT (709 vs. 753 min/d) and increased day-to-day coefficient of variation of LT (0.21 vs. 0.10) compared with cows within the prepartum pen. On average, for the 7 d following vaccination alone (28 to 22 dpp period), V28PC21 cows had ~22 min/d less LT compared with V21PC21 cows. Serum concentrations of glucose, nonesterified fatty acids, and IGF-1 were altered following vaccination alone, pen change alone, or vaccination plus pen change with an acidogenic diet before calving. At calving, V28PC21 cows had greater glucose concentrations (6.45 mmol/L) compared with V21PC21 cows (5.76 mmol/L), with V28PC28 cows intermediate (6.11 mmol/L). The assessment of Ca status at calving revealed that V28PC21 cows had greater Ca concentration (2.34 mmol/L) with lower subclinical hypocalcemia (<2.0 mmol/L; 17.3%) compared with V21PC21 cows (2.17 mmol/L and 31.9%), with V28PC28 cows intermediate (2.28 mmol/L and 25.2%). Serum concentrations of IGF-1 at calving were also greater for V28PC21 (3.43 nmol/L) cows compared with V21PC21 (2.69 nmol/L), with V28PC28 cows intermediate (3.07 nmol/L). Overall, V28PC21 cows had greater serum glucose, IGF-1, and ~46% reduction in subclinical hypocalcemia (from 31.9 to 17.3%) compared with V21PC21 cows but did not differ from V28PC28 cows (25.2%). These findings provided evidence that vaccinating cows at 28 dpp, followed 7 d later by pen change with an acidogenic diet at 21 dpp, would be beneficial.

Associations of freestall design and cleanliness with cow lying behavior, hygiene, lameness, and risk of high somatic cell count

The objective of this study was to investigate associations of freestall design and cleanliness with cow lying behavior, hygiene, lameness, and risk of new high somatic cell count (SCC). Cows from 18 commercial freestall dairy herds (22 ± 15 cows/farm; mean ± SD) in Ontario, Canada, were enrolled in a longitudinal study. Four hundred focal cows that were <120 d in milk, had no mastitis treatment in the last 3 mo, and had an SCC <100,000 cells/mL at their most recent milk test were selected for the study. Data on SCC were collected through Dairy Herd Improvement Association milk testing (at ~5-wk intervals). Each farm was visited 5 ± 3 d (mean ± SD) after each milk test until 3 tests were completed (~105 d), for a total of 3 observation periods per cow. Elevated SCC was used as an indicator of subclinical mastitis. An incident of new high SCC was defined as a cow having SCC >200,000 cells/mL at the end of an observation period, when SCC was <100,000 cells/mL at the beginning of that period. Lying behavior was recorded for 6 d after each milk sampling, using electronic data loggers. Cows were scored during each period for lameness (5-point scale, with scores ≥3 = lame), body condition score (BCS; 5-point scale; 1 = thin to 5 = fat), and hygiene (4-point scale). Stall cleanliness was assessed during each period with a 1.20 × 1.65-m metal grid, containing 88 squares. The grid was centered between stall partitions of every tenth stall on each farm, and the squares containing visible urine or fecal matter (or both) were counted. Cow lying time averaged 10.9 ± 1.9 h/d. On average, cows with low BCS (≤2.5) spent 37 ± 16.6 min/d less time lying down than high-BCS cows (≥4.0). On average, cows tended to spend 36 ± 18.3 min/d more time lying down in deep-bedded versus mattress-based stalls. Mean proportion of soiled squares per stall was 20.1 ± 0.50%. Across farms, cow lying time decreased as the proportion of soiled squares per stall increased. A difference in daily lying time of ~80 more min/d was modeled for cows housed in barns with the cleanest stalls compared with those with the dirtiest stalls. Higher neck rail height [for every 1 SD (10 cm) increase] increased the odds (odds ratio = 1.5) of cows having a dirty upper leg-flank and udder. The odds of a cow having a dirty upper leg-flank, udder, and lower legs were 1.5, 2.0, and 1.9 times greater, respectively, for cows housed with dirtier stalls. Also, cows housed on farms with dirtier stalls had 1.3 times greater odds of being lame at the time of observation. Over the study period, 50 new high-SCC cases were detected, resulting in an incidence rate of 0.45 cases of new high SCC per cow-year at risk. No measured factors were detected to be associated with risk of a new high SCC. Overall, our results confirm that cows lie down longer in cleaner and more comfortable environments. Further, these results highlight the need for improved stall cleanliness to optimize lying time and potentially reduce lameness.

Association of prepartum lying time with nonesterified fatty acids and stillbirth in prepartum dairy heifers and cows

The objective of the present study was to assess the association of prepartum lying time (LT) and the coefficient of variation (CV) of LT within 7 d before calving with prepartum serum nonesterified fatty acid (NEFA) concentration at 7 ± 3 d prepartum (dpp) and stillbirth. Prepartum pregnant Holstein heifers and cows from 3 dairy herds were used (n = 1,044). Animals were housed in freestall barns using a prepartum pen 21 d before the expected calving date and were moved into a contiguous maternity pen at parturition. Monthly, cohorts of 20 to 36 animals (heifers and cows combined) were enrolled at each farm and electronic data loggers (IceQube, IceRobotics, Edinburgh, UK) were fitted to the hind leg of individual animals to assess their behavioral activity. Stillbirth was defined as a calf born dead or died during the first 24 h after parturition in dams with normal gestation length. The LT was recorded for the last 7 dpp to assess differences among dams with stillbirth versus those with a calf born alive. Mean LT within 7 d before blood NEFA collection was assessed to determine the association with prepartum serum NEFA at 7 ± 3 dpp. Blood samples for the assessment of serum NEFA concentration were collected from prepartum animals at 14 ± 3 and at 7 ± 3 dpp. Blood samples for total serum calcium concentration were collected from postpartum cows within 48 h after parturition to assess differences among cows with stillbirth versus those with a calf born alive. Data were analyzed using CORR, MIXED, or GLIMMIX procedures of SAS (SAS Institute Inc., Cary, NC). Dams experiencing dystocic births had a greater proportion of stillbirth, but herd, parity, and season did not have an effect. Dams with a stillborn calf had reduced LT and increased CV of LT within the last 7 dpp compared with dams with a calf born alive, regardless of parity. Multiparous cows with a stillborn calf had higher prepartum serum NEFA concentration compared with multiparous cows with a calf born alive, but this did not differ for first-calf heifers. Regardless of parity, the proportion of postpartum cows with hypocalcemia was higher for dams with a stillborn calf compared with those with a calf born alive. Regardless of parity, LT of prepartum dams was strongly correlated with the CV of LT (as LT increased, the CV decreased), and prepartum dams with a mean LT between 11 and 15 h/d had the lowest serum NEFA concentration compared with dams with LT of 8 to 10 or >16 h/d. Serum NEFA concentrations at 7 ± 3 dpp was positively correlated with the CV of LT within 7 d before blood sample. These results show that the dam's prepartum LT and its consistency over time are associated with prepartum serum NEFA and calf survival at calving.

A DIY Thermocouple Datalogger is Suitably Comparable to a Commercial System for Wildland Fire Research

Thermocouple probes have long been standard equipment for wildland fire scientists. But despite substantial advancements in the electronic datalogger technology necessary to read and store data from thermocouples, the effective cost per thermocouple sensor of commercial systems has not decreased such that most researchers can afford to deploy enough sensors to account for the high degree of variability in wildland fire behavior. Because the equipment must endure the extreme conditions of wildland fire, is unlikely that any thermocouple datalogger system will be considered “cheap.” However, the growing number of applications of open-source, do-it-yourself (DIY) microcontroller systems in scientific research suggests these products might be employed in thermocouple datalogging systems if (1) their performance can be shown to be comparable to commercial systems and (2) they can be protected from exposure in the wildland fire environment. In this paper, we compare the performance of an Arduino MEGA microcontroller board relative to a Campbell Scientific CR1000, reading standard K-type metal overbraided ceramic fiber insulated thermocouple probes, under the constant temperature of a drying oven and the variable flame of a Bunsen burner. In both comparisons, we found that the variability among individual thermocouples, which are known to have a $$\pm\, 2\,^{\circ }\hbox {C}{-}6\,^{\circ }\hbox {C}$$ margin of error, was greater than between the dataloggers. We also describe a compact and mobile Arduino-based system capable of recording wildland fire flame temperatures in agris. In considering these three systems, it is clear that Arduino-based open-source, DIY components can support a compact, low-cost datalogger that accommodates more sensors for lower cost than proprietary commercial systems with no sacrifice in data quality. The combination of low-cost, multi-sensor units can contribute to better understanding of variability in wildland fire behavior.

Periparturient stocking density affects lying and ruminating behavior and one-week-calf performance of Holstein cows

ObjectiveThis study aimed to investigate the effect of stocking density on the behavior, productivity, and metabolism of periparturient Holstein cows as well as calf performance.MethodsA total of 48 periparturient cows were randomly assigned into three groups at 28 days (±3 days) before their expected calving date. The stocking densities of the groups, relative to the standard cubicle and feed bunk number, were i) 80% (13 cows), ii) 100% (16 cows), and iii) 120% (19 cows). Lying and rumination behavior was recorded using electronic data loggers and HR-Tags from d −21 (“d-” means days before calving) until the calving date, d 0. Lying time was assessed to determine the diurnal total hours spent lying per day. Rumination time was averaged in 2 hours interval periods over 24 hours during the experimental period.ResultsCows in the 80% group spent more time lying and ruminating between d −21 and d −7 and tended to ruminate more between d −14 and d 0. Calcium levels tended to be higher for cows in the 80% group, no other observable differences were found in monitored blood parameters. Moreover, 3.5% fat corrected milk and energy corrected milk yields were higher in 80% group in the first month of lactation. No other observable differences were found in the yield and composition of colostrum and milk in the first 10 months of lactation. The growth and performance of calves in the first week of life was not affected by stocking density of the dams.ConclusionWe concluded that lower stocking density may increase lying and ruminating behavior of prepartum Holstein cows. However, this did not translate into improved productivity and metabolism.

Behavioral changes associated with fever in transition dairy cows

Dairy cows are often diagnosed with fever without showing clinical symptoms of disease. The aim of this study was to investigate changes in feeding, social, and lying behaviors of cows with fever but without clinical disease, as compared with healthy cows. After parturition, dairy cows of mixed parities were housed in a dynamic group of 20. In the freestall pen, cows had access to 12 electronic feed bins, 2 electronic water bins, and 24 lying stalls. Feeding and social behaviors were recorded using the electronic feed bins, and lying behaviors were measured using electronic data loggers attached to the cow. Rectal body temperature was assessed on a daily basis, and fever defined as a body temperature >39.5°C. All cows were examined for metritis every third day after calving, and all other diseases (e.g., mastitis, ketosis) were diagnosed as per farm protocol. Cows with multiple days of fever (n = 8) and cows with 1 d of fever (n = 18) that were not diagnosed with a clinical disease were compared with a matched sample of healthy cows (i.e., cows that were not clinically ill and never had a fever recorded) of the same parity (categorized as primiparous vs. multiparous). Feeding, social, and lying behaviors were compared for the first 2 d of fever in cows with multiple days of fever, and the day of fever in cows with 1 d of fever. Cows of both fever groups spent less time feeding compared with controls (135 vs. 181 ± 7.6 min/d for multiple fever days, and 158 vs. 185 ± 9.7 min/d for 1 d of fever). Cows with 1 d of fever ate at a faster rate (109 vs. 91 ± 5 g/min) and had a lower number of replacements at the feed bunk (actor replacements: 9.7 vs. 14.6 ± 1.7 no./d; reactor replacements: 11.1 vs. 15.9 ± 1.6 no./d) compared with healthy controls. Overall, cows with fever showed behavioral changes such as decreased feeding time that are consistent with sickness responses described in other species.

Open-source Arduino-compatible data loggers designed for field research

Abstract. Automated electronic data loggers revolutionized environmental monitoring by enabling reliable high-frequency measurements. However, the potential to monitor the complex environmental interactions involved in global change has not been fully realized due to the high cost and lack of modularity of commercially available data loggers. Responding to this need, we developed the ALog (Arduino logger) series of three open-source data loggers, based on the popular and easy-to-program Arduino microcontroller platform. ALog data loggers are low cost, lightweight, and low power; they function between −30 and +60 ∘C, can be powered by readily available alkaline batteries, and can store up to 32 GB of data locally. They are compatible with standard environmental sensors, and the ALog firmware library may be expanded to add additional sensor support. The ALog has measured parameters linked to weather, streamflow, and glacier melt during deployments of days to years at field sites in the USA, Canada, Argentina, and Ecuador. The result of this work is a robust and field-tested open-source data logger that is the direct descendant of dozens of individuals' contributions to the growing open-source electronics movement.

Associations of pre- and postpartum lying time with metabolic, inflammation, and health status of lactating dairy cows

The objective was to evaluate the associations of pre- and postpartum lying time (LT) with serum total calcium (Ca), nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), and haptoglobin concentrations, hemogram, and health status of dairy cows. A total of 1,052 Holstein cattle (401 nulliparous heifers and 651 parous cows) from 3 commercial dairy farms were fitted with electronic data loggers (IceQube, IceRobotics, Edinburgh, UK) on a hind leg 14 ± 3 d before parturition (dpp) and removed at 14 ± 3 d in milk (DIM) to assess their LT. Lying time data were summarized and reported daily (min/d or h/d). Serum concentrations of NEFA (at 14 ± 3 and 7 ± 3 dpp), total serum calcium within 48 h after calving, and BHB (at 7 ± 3 and 14 ± 3 DIM) were determined. Serum concentration of haptoglobin was determined and a hemogram was performed on a subsample of 577 cows (237 primiparous and 340 multiparous) at 7 ± 3 DIM. Cases of milk fever, retained placenta, metritis, mastitis, pneumonia, and digestive disorders within 30 DIM were recorded and cows were categorized into 1 of 4 groups: (1) nondiseased (ND, n = 613; cows without ketosis and any other health conditions); (2) cows with only ketosis (KET, n = 152); (3) sick cows experiencing ≥1 health conditions, but without ketosis (SICK, n = 198); or (4) cows with ketosis plus at least one other health condition (KET+, n = 61). Data were analyzed using mixed linear regression models or logistic regression (MIXED or GLIMMIX procedures). Lying time within 14 dpp had a significant positive quadratic association with serum NEFA concentrations at 14 ± 3 and 7 ± 3 dpp but was not significantly associated with serum Ca concentration within 48 h after calving. Lying time during the first 14 DIM after parturition had a significant linear association with the risk of ketosis within 14 DIM. For every 1-h increment in mean LT (from 8 to 15 h/d) within the first 14 DIM after calving, the risk of diagnosis with ketosis within 14 DIM increased by 3.7 percentage points. Regardless of parity, a greater proportion of KET and KET+ groups had increased serum prepartum NEFA concentration (≥400 µEq/L) and increased body condition loss from 14 dpp to 28 DIM compared with SICK and ND cows. A greater proportion of multiparous KET and KET+ cows had hypocalcemia within 48 h after calving compared with ND and SICK cows, but we did not detect a significant association between hypocalcemia and health status on primiparous cows. Multiparous KET+ cows had significantly reduced neutrophils and white blood cell count compared with ND cows, but lymphocytes did not differ. Regardless of parity, KET+ and SICK cows had significantly higher concentrations of serum haptoglobin compared with ND cows. These results suggest that LT along with energy and Ca balance are critical for transition cow health.

Associations of postpartum lying time with culling, milk yield, cyclicity, and reproductive performance of lactating dairy cows

The objectives were to evaluate the associations of lying time (LT) during the first 14 d in milk (DIM) with milk yield, cyclicity (CYC), culling within 60 DIM (CULL), and reproductive performance of lactating dairy cows. A total of 1,052 Holstein cattle (401 nulliparous heifers and 651 parous cows) from 3 commercial dairy farms had electronic data loggers (IceQube, IceRobotics, Edinburgh, UK) placed on a hind leg 14 ± 3 d before the expected parturition date and removed at 14 ± 3 DIM to assess their LT. Serum concentrations of β-hydroxybutyrate were determined at 7 ± 3 and 14 ± 3 DIM. Cases of retained placenta, metritis, mastitis, pneumonia, and digestive disorders within 30 DIM were recorded and lactating cows were categorized into 1 of 4 groups: (1) nondiseased (ND, n = 613; cows without ketosis or any other diagnosed health condition); (2) cows with only ketosis (KET, n = 152); (3) sick cows experiencing ≥1 health conditions but without ketosis (SICK, n = 198); or (4) cows with ketosis plus ≥1 health condition (KET+, n = 61). Ultrasound was performed at 28 ± 3 and 42 ± 3 DIM to assess ovarian cyclicity (presence or absence of corpus luteum). Milk yield at first Dairy Herd Improvement Association test was not associated with LT during the first 14 DIM, but it was negatively correlated with the coefficient of variation of LT during the first 14 DIM. Lactating dairy cows experiencing KET+ had the lowest milk yield compared with ND, regardless of parity. Parity, health status, and season were significantly associated with CYC and CULL. Lying time had a significantly linear association with the risk of being culled: for every 1-h increment of LT during 0 to 14 DIM, the risk of culling within 60 DIM increased by 1 percentage point. Lying time had a negative quadratic association with cyclicity at 42 DIM. Multiparous cows with a LT of 9 to 13 h/d had a significantly greater probability of pregnancy up to 300 DIM compared with cows with a LT >13 h/d. Regardless of parity, KET+ cows had significantly higher proportion of culling within 60 DIM and decreased probability of pregnancy up to 300 DIM compared with ND cows. These findings suggest that there is an optimum daily LT range for early postpartum cows housed in freestall barns, different from that reported for mid-lactation cows, with the potential for improved survival, health, and the overall performance (milk yield and reproduction).

Claw horn lesions in mid-lactation primiparous dairy cows under pasture-based systems: Association with behavioral and metabolic changes around calving

The objectives of this study were to describe the lying behavior of primiparous dairy cows under pasture-based systems during the pre- and postcalving period and characterize the association of lying behavior and analytes related to energy metabolism during this period with claw horn disruption lesion development later in lactation. Our convenience sample included 39 primiparous Holstein cows from 3 commercial farms that were assessed for body condition score (BCS; 5-point scale, 0.25-point increments) and had blood collected at wk -3, -2, -1, 1, 2, and 3 relative to calving date. Blood samples were assayed for nonesterified fatty acids, β-hydroxybutyrate (BHB), and cholesterol concentrations. Electronic data loggers (HOBO Pendant G Acceleration, Onset Computer Corporation, Bourne, MA) recorded lying behavior at 1-min intervals from 3 wk before calving to 3 wk after calving. Starting at 4 wk after calving and until 16 wk after calving, cows were examined for claw lesions at approximately 4-wk intervals. Sole lesions and white line lesions were scored on a 0 to 10 scale. Of the 39 primiparous cows, 19 cows scored 0 at all exams during the entire study period and 20 cows had at least 1 severe lesion (score ≥4) between 8 and 16 wk after calving. Time spent lying before calving averaged 10.3 ± 0.3 h/d, but declined to 7.3 ± 0.3 h/d after calving (least squares means ± standard error). At calving, we noted an increase in the number of lying bouts (12.9 ± 0.45 bouts/d) compared with the pre- and postcalving averages of 11.6 (±0.53) and 9.1 (±0.47) bouts, respectively. Cows that developed claw lesions later in mid lactation spent less time lying down than cows without lesions during wk 3 after calving compared with healthy cows (7.29 ± 0.22 vs. 8.51 ± 0.16 h/d). Lesion cows had fewer lying bouts per day, and these bouts were of longer duration than no-lesion cows after calving. Increased odds of lesion were found to be associated with shorter lying times and fewer number of lying bouts during wk 3 (odds ratio = 1.23). Nonesterified fatty acids (747 ± 58 vs. 990 ± 86.85 µmol/L) and BHB (0.77 ± 0.06 vs. 0.60 ± 0.04 mmol/L) concentrations during wk 1 were greater in cows that developed claw lesions relative to cows that did not develop lesions. The BHB concentrations also remained higher in wk 2 for cows that developed claw lesions (0.63 ± 0.04 vs. 0.46 ± 0.03 mmol/L) compared with cows that did not develop any lesions. Cows that developed lesions experienced greater losses in BCS from wk -3 to 3 than cows without lesions (0.74 ± 0.01 and 0.61 ± 0.01 BCS change, respectively). In summary, changes in lying behavior and energy metabolic status after calving were associated with claw horn disruption lesions in mid-lactation primiparous cows under pasture-based systems.