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Conventional locomotion scoring is a subjective, absolute, and discrete assessment of locomotion. Here we assess pairwise comparison scoring to improve upon the limited intra- and interobserver consistency typical of conventional locomotion scoring. Five observers performed conventional 4-level locomotion scoring using 50 video recordings of dairy cattle, and also assessed 90 pairs of videos (composed from the same 50 recordings) using relative pairwise scoring. Intra- and interobserver consistency of pairwise scores [intraobserver: percentage agreement (PA) = 82%, κ = 0.63; interobserver: PA = 79%, κ = 0.57] were greater than of 4-level absolute scores (intraobserver: PA = 72%, κw = 0.74; interobserver: PA = 56%, κw = 0.59). Pairwise scores were scaled with an optimization method to obtain the position of the 50 recordings on a continuous locomotion scale. These continuous locomotion scores (CLS) were compared with the conventional mean absolute visual locomotion scores (VLS). Correlation between CLS and VLS was strong (τ = 0.69), and consistency between binarized CLS and binarized VLS was high (PA = 84%, κ = 0.66 for threshold VLS ≥1). Just noticeable difference (JND) for locomotion scoring was 0.3 on a 4-level scale ranging from 0 to 3. Pairwise scoring and scaling had the scoring consistency of binary absolute scoring with finer continuous granularity than 4-level absolute scoring. The pairwise scoring method, and associated scaling, offer a more consistent and informative alternative to conventional absolute multilevel locomotion scoring.
John Gardenier; James Underwood; D.M. Weary; C.E.F. Clark. Pairwise comparison locomotion scoring for dairy cattle. Journal of Dairy Science 2021, 104, 6185 -6193.
AMA StyleJohn Gardenier, James Underwood, D.M. Weary, C.E.F. Clark. Pairwise comparison locomotion scoring for dairy cattle. Journal of Dairy Science. 2021; 104 (5):6185-6193.
Chicago/Turabian StyleJohn Gardenier; James Underwood; D.M. Weary; C.E.F. Clark. 2021. "Pairwise comparison locomotion scoring for dairy cattle." Journal of Dairy Science 104, no. 5: 6185-6193.
Mammalian vocalizations can encode contextual information in both the spectrographic components of their individual vocal units and in their temporal organization. Here we observed 23 Holstein-Friesian dairy cows immediately after birth during interactions with their calf and when their calf was separated to the other side of a fence line. We investigated whether the vocalizations emitted in these postpartum contexts would vary temporally. We also described the maternal and stress behaviors preceding and following postpartum vocal production using kinematic diagrams and characterized call sequence structure. The kinematic diagrams highlight the disruption of maternal responses caused by calf separation and show that behavioral and vocal patterns varied according to the cows' emotional states and proximity to the calf in both contexts. During calf interactions, cows mainly produced closed-mouth calls simultaneous to licking their calf, whereas an escalation of stress responses was observed during calf separation, with the cows approaching the fence line, becoming alert to the calf, and emitting more mixed and open-mouth calls. Call sequences were similarly structured across contexts, mostly containing repetitions of a single call type, with a mean interval of 0.57 s between calls and a greater cumulative vocalization duration, attributed to an increased number of vocal units per sequence. Overall, calf separation was associated with a greater proportion of calls emitted as a sequence (inverse of single isolated calls), a shorter interval between separate call sequences, and a greater number of vocal units per sequence, compared with calf interactions. These temporal vocal features varied predictably with the high stress expression from cows during calf separation and may represent temporal modulations of emotional expression. Despite the noisy farm soundscape, empirical call type and temporal vocal features were easy to measure; thus, findings could be applied to future cattle studies wishing to analyze vocalizations for on-farm welfare assessments.
Alexandra C. Green; Lena M. Lidfors; Sabrina Lomax; Livio Favaro; Cameron E.F. Clark. Vocal production in postpartum dairy cows: Temporal organization and association with maternal and stress behaviors. Journal of Dairy Science 2021, 104, 826 -838.
AMA StyleAlexandra C. Green, Lena M. Lidfors, Sabrina Lomax, Livio Favaro, Cameron E.F. Clark. Vocal production in postpartum dairy cows: Temporal organization and association with maternal and stress behaviors. Journal of Dairy Science. 2021; 104 (1):826-838.
Chicago/Turabian StyleAlexandra C. Green; Lena M. Lidfors; Sabrina Lomax; Livio Favaro; Cameron E.F. Clark. 2021. "Vocal production in postpartum dairy cows: Temporal organization and association with maternal and stress behaviors." Journal of Dairy Science 104, no. 1: 826-838.
There is a substantial opportunity to lift feed utilization and profitability on pasture-based dairy systems through both increased pasture monitoring accuracy and frequency. The first objective of this experiment was to determine the impact of the number of electronic rising plate meter (RPM) readings and walking pattern on the accuracy of the RPM to determine pasture biomass. The second objective was to evaluate current satellite technology (i.e., small CubeSats and traditional large satellites) in combination with the electronic RPM as an accurate tool for systematic pasture monitoring. The experiment was conducted from October to December 2019 at Camden, Australia. Two experimental paddocks, each of 1.1 ha, were sown with annual ryegrass and monitored with an electronic RPM integrated with Global Navigation Satellite System and with two different satellites (Planet CubeSats and Sentinel-2 satellite). Here we show that 70 RPM readings achieve a ± 5% error in the pasture biomass estimations (kg DM/ha), with no effect of the walking pattern on accuracy. The normalized difference vegetation index (NDVI) derived from satellites showed a good correlation with pasture biomass estimated using the electronic RPM (R2 0.74–0.94). Satellite pasture biomass and growth rate estimations were similar to RPM in one regrowth period but underestimated by ≈20% in the other. Our results also reveal that the accuracy of uncalibrated satellites (i.e., biomass estimated using NDVI to kg DM/ha standard equations) is low (R2 0.61, RMSE566–1307 kg DM/ha). However, satellites calibrated with a RPM showed greater accuracy in the estimations (R2 0.72, RMSE255 kg DM/ha). Current satellite technology, when used with the electronic RPM, has the potential to not only reduce the time required to monitor pasture biomass manually but provide finer scale measurements of pasture biomass within paddocks. Further work is required to test this hypothesis, both spatially and temporally.
Juan Gargiulo; Cameron Clark; Nicolas Lyons; Gaspard De Veyrac; Peter Beale; Sergio Garcia. Spatial and Temporal Pasture Biomass Estimation Integrating Electronic Plate Meter, Planet CubeSats and Sentinel-2 Satellite Data. Remote Sensing 2020, 12, 3222 .
AMA StyleJuan Gargiulo, Cameron Clark, Nicolas Lyons, Gaspard De Veyrac, Peter Beale, Sergio Garcia. Spatial and Temporal Pasture Biomass Estimation Integrating Electronic Plate Meter, Planet CubeSats and Sentinel-2 Satellite Data. Remote Sensing. 2020; 12 (19):3222.
Chicago/Turabian StyleJuan Gargiulo; Cameron Clark; Nicolas Lyons; Gaspard De Veyrac; Peter Beale; Sergio Garcia. 2020. "Spatial and Temporal Pasture Biomass Estimation Integrating Electronic Plate Meter, Planet CubeSats and Sentinel-2 Satellite Data." Remote Sensing 12, no. 19: 3222.
Pre-commercial virtual fence (VF) neckbands (eShepherd®, Agersens, Melbourne, Vic, Australia) can contain cows within a designated area without the need for physical fencing, through associative learning of a paired audio tone and electrical pulse. Cattle are gregarious, so there may be an impact of herd mates on the learning process. To evaluate this, a VF was set 30 m down one of three test paddocks with a feed attractant 70 m past the VF. Twenty-three Holstein-Friesian cows were all fitted with VF neckbands and trained as individuals or in groups (5–6) for four 10 min tests; then, cows were crossed over to the alternate context for two more 10 min tests. The number of cows breaking through the VF and the number of paired stimuli reduced across time (from 82% to 26% and 45% to 14%, respectively, p < 0.01). Cows trained in a group (88%) were more likely to interact with the VF in the crossover compared to those trained as individuals (36%) (p < 0.01), indicating an influence of group members on individual cow response. Individual training is impractical, therefore, future research should evaluate group training protocols ensuring all cows learn the VF to avoid any adverse impacts on animal welfare.
Patricia I. Colusso; Cameron E. F. Clark; Sabrina Lomax. Should Dairy Cattle be Trained to a Virtual Fence System as Individuals or in Groups? Animals 2020, 10, 1767 .
AMA StylePatricia I. Colusso, Cameron E. F. Clark, Sabrina Lomax. Should Dairy Cattle be Trained to a Virtual Fence System as Individuals or in Groups? Animals. 2020; 10 (10):1767.
Chicago/Turabian StylePatricia I. Colusso; Cameron E. F. Clark; Sabrina Lomax. 2020. "Should Dairy Cattle be Trained to a Virtual Fence System as Individuals or in Groups?" Animals 10, no. 10: 1767.
Heat stress causes significant economic losses by reducing the productivity and welfare of cattle whilst requiring a significant investment in resource for amelioration. Panting score (PS) is considered a robust indicator of cattle heat stress; however, individualised visual monitoring is impractical. Thermal index-based monitoring and mitigation decisions are applied at the herd level, but they have limited application for the individual animal. As such, an automated system to monitor the real-time animal response to heat stress is required for strategic mitigation. Our objectives were to validate an accelerometer-based ear tag sensor to monitor cattle panting and to determine individual variability in heat stress responses with reference to thermal indices. Two experiments were conducted: Experiment 1 validated the sensors, and Experiment 2 determined individual variability comparing sensor data against thermal indices. Ear tag sensors were fitted at feedlot entry to continuously monitor the behaviour of 100 steers of mixed breed in Experiment 1 and 200 steers and heifers of mixed breed in Experiment 2. Sensor-derived ‘heavy breathing’ was validated against visually observed PS. Sensor-derived behaviour bouts were analysed as ‘raw’, and single behaviour states were also converted to the preceding bout of ≥2 min, which was referred to as ‘fill’ data for the validation study. Our results demonstrate the sensors’ ability to accurately monitor panting in feedlot cattle. Sensor-recorded ‘heavy breathing’ duration per animal was highly correlated to observed panting duration for both raw (r = 0.89) and fill (r = 0.90) data; however, the concordance correlation co-efficient was lower for raw (0.45) as compared with fill (0.76). Predicted agreement for raw data were 75%, 45%, and 68% and predicted agreement for fill data were 65%, 54%, and 83% for PS0, PS1, and PS2, respectively. Sensitivity for raw data were 39%, 37%, and 45% and for fill data, they were 59%, 54% and 82% for all PS data, PS1 and PS2, respectively. Specificity and positive predictive values for both raw (77% and 79%, respectively) and fill (65% and 77%, respectively) data show the probability of reporting false positives by sensors to be low. Experiment 2 revealed that the duration of panting increased from 0800 to 1700 h alongside changes in thermal indices with significant differences between and within breed and coat colour categories of cattle, suggesting that grouping and allocating heat amelioration measures by breed and coat colour can be effective in commercial feedlots. However, there was high variability (CV > 80%) in the duration of panting between individuals within the same breed and same coat colour, revealing the potential for strategic management at an individual level, and with the same data, genetic selection for heat resilience.
Ashraful Islam; Sabrina Lomax; Amanda K. Doughty; Mohammed R. Islam; Cameron E. F. Clark. Automated Monitoring of Panting for Feedlot Cattle: Sensor System Accuracy and Individual Variability. Animals 2020, 10, 1518 .
AMA StyleAshraful Islam, Sabrina Lomax, Amanda K. Doughty, Mohammed R. Islam, Cameron E. F. Clark. Automated Monitoring of Panting for Feedlot Cattle: Sensor System Accuracy and Individual Variability. Animals. 2020; 10 (9):1518.
Chicago/Turabian StyleAshraful Islam; Sabrina Lomax; Amanda K. Doughty; Mohammed R. Islam; Cameron E. F. Clark. 2020. "Automated Monitoring of Panting for Feedlot Cattle: Sensor System Accuracy and Individual Variability." Animals 10, no. 9: 1518.
Individual cattle identification is required for precision livestock farming. Current methods for individual cattle identification requires either visual, or unique radio frequency, ear tags. We propose a deep learning based framework to identify beef cattle using image sequences unifying the advantages of both CNN (Convolutional Neural Network) and LSTM (Long Short-Term Memory) network methods. A CNN network was used (Inception-V3) to extract features from a rear-view cattle video dataset and these extracted features were then used to train an LSTM model to capture temporal information and identify each individual animal. A total of 516 rear- view videos of 41 cattle at three time points separated by one month were collected. Our method achieved an accuracy of 88% and 91% for 15-frame and 20-frame video length, respectively. Our approach outperformed the framework that only uses CNN (identification accuracy 57%). Our framework will now be further improved using additional data before integrating the system into on-farm management processes.
Yongliang Qiao; Daobilige Su; He Kong; Salah Sukkarieh; Sabrina Lomax; Cameron Clark. Individual Cattle Identification Using a Deep Learning Based Framework. IFAC-PapersOnLine 2019, 52, 318 -323.
AMA StyleYongliang Qiao, Daobilige Su, He Kong, Salah Sukkarieh, Sabrina Lomax, Cameron Clark. Individual Cattle Identification Using a Deep Learning Based Framework. IFAC-PapersOnLine. 2019; 52 (30):318-323.
Chicago/Turabian StyleYongliang Qiao; Daobilige Su; He Kong; Salah Sukkarieh; Sabrina Lomax; Cameron Clark. 2019. "Individual Cattle Identification Using a Deep Learning Based Framework." IFAC-PapersOnLine 52, no. 30: 318-323.
Feed accounts for the greatest proportion of egg production costs and there is substantial variation in feed to egg conversion ratio (FCR) efficiency between individual hens. Despite this understanding, there is a paucity of information regarding layer hen feeding behaviour, diet selection and its impact on feed efficiency. It was hypothesised that variation in feed to egg conversion efficiency between hens may be influenced by feeding behaviour. For this experiment, two 35-bird groups of ISA Brown layers were selected from 450 individually caged hens at 25-30 weeks of age for either low FCR < 1.8 ± 0.02 (high feed efficiency (HFE) or high FCR > 2.1 ± 0.02 (low feed efficiency (LFE)). For each of these 70 hens, intake of an ad-libitum mash diet at 2-minute time intervals, 24 h a day, for 7 days was determined alongside behavioural assessment and estimation of the selection of components of the mash. The group selected for HFE had a lower feed intake, similar egg mass and associated lower FCR when compared with the LFE group. Whilst feed intake patterns were similar between HFE and LFE hens, there was a distinct intake pattern for all layer hens with intake rate increasing from 0300 to 1700 h with a sharp decline to 2200 h. High feed efficiency hens selected a diet with 25% more ash and 4% less gross energy than LFE hens. The LFE hens also spent more time eating with more walking events, but less time spent resting, drinking, preening and cage pecking events as compared with HFE hens. In summary, there was no contrasting diurnal pattern of feed consumption behaviour between the groups ranked on feed efficiency, however high feed efficiency hens consumed less feed and selected a diet with greater ash content and lower gross energy as compared with LFE hens. Our work is now focused on individual hen diet selection from mash diets with an aim of formulating precision, targeted diets for greater feed efficiency.
Cameron E. F. Clark; Yeasmin Akter; Alena Hungerford; Peter Thomson; Mohammed R. Islam; Peter J. Groves; Cormac J. O’Shea. The intake pattern and feed preference of layer hens selected for high or low feed conversion ratio. PLOS ONE 2019, 14, e0222304 .
AMA StyleCameron E. F. Clark, Yeasmin Akter, Alena Hungerford, Peter Thomson, Mohammed R. Islam, Peter J. Groves, Cormac J. O’Shea. The intake pattern and feed preference of layer hens selected for high or low feed conversion ratio. PLOS ONE. 2019; 14 (9):e0222304.
Chicago/Turabian StyleCameron E. F. Clark; Yeasmin Akter; Alena Hungerford; Peter Thomson; Mohammed R. Islam; Peter J. Groves; Cormac J. O’Shea. 2019. "The intake pattern and feed preference of layer hens selected for high or low feed conversion ratio." PLOS ONE 14, no. 9: e0222304.
Pasture management in Australia’s dairy industry requires the manual shifiting of temporary electric fences to maintain pasture quality and growth. Virtual fencing presents an alternative to save time and labour costs. We used automated virtual fence (VF) collars to determine the variation in learning of the virtual fence stimuli, and evaluated the success of the technology to contain cows in a predetermined area of pasture. Twelve Holstein-Friesian non-lactating multiparous dairy cows were fitted with the collars, and a VF was used to restrict cows to two grazing allocations (G1 and G2) across six days. Cows received an audio tone (AT) when they approached the virtual fence, and a paired electrical pulse (EP) if they continued forward. The VF contained cows within predetermined areas for 99% of time, but cows spent the least time near the fence (p < 0.01). The number of stimuli reduced through time, demonstrating the ability of cows to learn the VF (p = 0.01). However, the mean number of EP per day ranged from 1 to 6.5 between individuals (p < 0.01). Therefore, successful containment may have a welfare cost for some individuals. Further work should focus on this individual variation, including measures of welfare.
Sabrina Lomax; Patricia Colusso; Cameron E.F. Clark. Does Virtual Fencing Work for Grazing Dairy Cattle? Animals 2019, 9, 429 .
AMA StyleSabrina Lomax, Patricia Colusso, Cameron E.F. Clark. Does Virtual Fencing Work for Grazing Dairy Cattle? Animals. 2019; 9 (7):429.
Chicago/Turabian StyleSabrina Lomax; Patricia Colusso; Cameron E.F. Clark. 2019. "Does Virtual Fencing Work for Grazing Dairy Cattle?" Animals 9, no. 7: 429.
(1) Background: Pasture varies in its chemical composition from the top of the sward to the base and cattle prefer to eat the leaf fraction. In pasture-based dairy systems, cattle predominantly walk back to pasture voluntarily after each milking, with the first cattle arriving to pasture hours before the last. Here we study the impact of pasture composition according to milking order on milk yield and milk composition for dairy cattle offered grazed ryegrass pasture. (2) Methods: In the first experiment, individual cow milk yield data were recorded on six farms over 8 months. The herd was divided into groups of 50 cows for analysis according to milking order. In the second experiment, the impact of milking order on milk composition and pasture composition accessed was determined in addition to milk yield on three farms. (3) Results: After accounting for age and stage of lactation effects, cattle milked first in experiment 1 produced, on average, 4.5 L/cow/day (+18%; range 14 to 29%) more than cattle milked last. In experiment 2, dairy cattle milked first (first 50 cows) in farm 1 had greater milk, protein, and solids non-fat (SNF) yield; and less lactose content than those milked last (last 50 cows). In farm 2, dairy cattle milked first had greater milk yield, SNF yield, lactose yield, and fat yield; but less protein and SNF content than cattle milked last. In farm 3, cattle milked first produced milk with greater fat and protein content than cattle milked last. In line with these differences in milk yield and composition, the composition of pasture across vertical strata differed, particularly for crude protein (CP) and acid detergent fiber (ADF) content. Conclusion: This work highlights the opportunity to increase herd nutrient use efficiency for improved milk production through strategic pasture allowance and supplementation strategies.
Kamila Dias; Sergio Garcia; Mohammed (Rafiq) Islam; Cameron Clark. Milk Yield, Milk Composition, and the Nutritive Value of Feed Accessed Varies with Milking Order for Pasture-Based Dairy Cattle. Animals 2019, 9, 60 .
AMA StyleKamila Dias, Sergio Garcia, Mohammed (Rafiq) Islam, Cameron Clark. Milk Yield, Milk Composition, and the Nutritive Value of Feed Accessed Varies with Milking Order for Pasture-Based Dairy Cattle. Animals. 2019; 9 (2):60.
Chicago/Turabian StyleKamila Dias; Sergio Garcia; Mohammed (Rafiq) Islam; Cameron Clark. 2019. "Milk Yield, Milk Composition, and the Nutritive Value of Feed Accessed Varies with Milking Order for Pasture-Based Dairy Cattle." Animals 9, no. 2: 60.
Ashleigh M. Wildridge; Peter C. Thomson; Sergio C. Garcia; Ellen C. Jongman; Cameron E.F. Clark; Kendra L. Kerrisk. The impact of fetching at night on milking parlour visitation for pasture-based dairy cattle. Applied Animal Behaviour Science 2018, 201, 25 -30.
AMA StyleAshleigh M. Wildridge, Peter C. Thomson, Sergio C. Garcia, Ellen C. Jongman, Cameron E.F. Clark, Kendra L. Kerrisk. The impact of fetching at night on milking parlour visitation for pasture-based dairy cattle. Applied Animal Behaviour Science. 2018; 201 ():25-30.
Chicago/Turabian StyleAshleigh M. Wildridge; Peter C. Thomson; Sergio C. Garcia; Ellen C. Jongman; Cameron E.F. Clark; Kendra L. Kerrisk. 2018. "The impact of fetching at night on milking parlour visitation for pasture-based dairy cattle." Applied Animal Behaviour Science 201, no. : 25-30.
In temperate grass-based dairy cattle grazing systems, summer dry conditions can reduce feed availability and quality, and limit milk production. This study reports the effects of including high nutritive value, drought tolerant forbs, chicory (Cichorium intybus L.) and plantain (Plantago lanceolata L.), in a grass-based diet of dairy cattle on intake, milk production and digestion. Forty-two mixed aged cattle in late lactation were randomly allocated to one of five dietary treatments in late summer: perennial ryegrass/white clover (PRG) or ryegrass/white clover (ryegrass) with either chicory (CHI) or plantain (PLA) comprising either 20 or 40% of the daily dry matter intake (DMI). Each treatment group included three cattle with a permanent rumen fistula. The experiment was conducted in an indoor feeding facility to allow individual intakes to be determined and comprised of two independent measurement weeks (Week I and Week II). Over the two measurement weeks, milk production and DMI were similar across diets and there were only minor differences in milk composition. Different effects of including chicory or plantain in the diet were observed, however, between measurement weeks. In Week I, DMI of cattle offered chicory or plantain (forbs) was 10% less than cattle offered PRG (14.7 vs. 16.4 kg dry matter (DM)/cow/d, p = 0.039) but milk yield (12.3 ± 0.53 kg/cow/d) and milk component (fat + protein) yield (1.01 ± 0.05 kg/cow/d) were similar across diets. In Week II, DMI was similar (14.2 kg DM/cow/d), but cattle offered forbs produced 19% more milk and 17% more milk component yield than those offered PRG. The decrease in DMI and milk production from Week I to II on the PRG treatment was accompanied by a decline in the estimated nutritive value of the ryegrass in the diets. In sacco incubations of fresh forages showed slower rates of DM degradation of ryegrass, relative to chicory or plantain (0.11 vs. 0.22 and 0.19%/h respectively; p < 0.001). Total rumen volatile fatty acid concentration and molar proportions measured in 6-hourly spot samplings was similar across diets. Rumen ammonia (NH3) and urine nitrogen (N) concentrations, however, were reduced by up to 37 and 38% in cattle where forb was included in the diet, with greater reductions observed with increasing percentage of forb in the diet (p < 0.01). This study suggests that chicory and plantain are suitable species to include in the diet of cattle grazing temperate grass-based swards to maintain or improve milk production in summer. Furthermore, the reductions in rumen NH3 and urine N observed, indicate potential environmental benefits could be gained from feeding forbs.
E.M.K. Minneé; G.C. Waghorn; J.M. Lee; C.E.F. Clark. Including chicory or plantain in a perennial ryegrass/white clover-based diet of dairy cattle in late lactation: Feed intake, milk production and rumen digestion. Animal Feed Science and Technology 2017, 227, 52 -61.
AMA StyleE.M.K. Minneé, G.C. Waghorn, J.M. Lee, C.E.F. Clark. Including chicory or plantain in a perennial ryegrass/white clover-based diet of dairy cattle in late lactation: Feed intake, milk production and rumen digestion. Animal Feed Science and Technology. 2017; 227 ():52-61.
Chicago/Turabian StyleE.M.K. Minneé; G.C. Waghorn; J.M. Lee; C.E.F. Clark. 2017. "Including chicory or plantain in a perennial ryegrass/white clover-based diet of dairy cattle in late lactation: Feed intake, milk production and rumen digestion." Animal Feed Science and Technology 227, no. : 52-61.
Mastitis adversely affects profit and animal welfare in the Australian dairy industry. Electrical conductivity (EC) is increasingly used to detect mastitis, but with variable results. The aim of the present study was to develop and evaluate a range of indexes and algorithms created from quarter-level EC data for the early detection of clinical mastitis at four different time windows (7 days, 14 days, 21 days, 27 days). Historical longitudinal data collected (4-week period) for 33 infected and 139 healthy quarters was used to compare the sensitivity (Se; target >80%), specificity (Sp; target >99%), accuracy (target >90%) and timing of ‘alert’ by three different approaches. These approaches involved the use of EC thresholds (range 7.5– 10 mS/cm), testing of over 250 indexes (created ad hoc), and a statistical process-control method. The indexes were developed by combining factors (and levels within each factor), such as conditional rolling average increase, percentage of variation, mean absolute deviation, mean error %; infected to non-infected ratio, all relative to the rolling average (3–9 data points) of either the affected quarter or the average of the four quarters. Using EC thresholds resulted in Se, Sp and accuracy ranging between 47% and 92%, 39% and 92% and 51% and 82% respectively (threshold 7.5 mS/cm performed best). The six highest performing indexes achieved Se, Sp and accuracy ranging between 68% and 84%, 60% and 85% and 56% and 81% respectively. The statistical process-control approach did not generate accurate predictions for early detection of clinical mastitis on the basis of EC data. Improved Sp was achieved when the time window before treatment was reduced regardless of the test approach. We concluded that EC alone cannot provide the accuracy required to detect infected quarters. Incorporating other information (e.g. milk yield, milk flow, number of incomplete milking) may increase accuracy of detection and ability to determine early onset of mastitis.
Momena Khatun; Cameron E. F. Clark; Nicolas A. Lyons; Peter Thomson; Kendra L. Kerrisk; Sergio C. García. Early detection of clinical mastitis from electrical conductivity data in an automatic milking system. Animal Production Science 2017, 57, 1226 -1232.
AMA StyleMomena Khatun, Cameron E. F. Clark, Nicolas A. Lyons, Peter Thomson, Kendra L. Kerrisk, Sergio C. García. Early detection of clinical mastitis from electrical conductivity data in an automatic milking system. Animal Production Science. 2017; 57 (7):1226-1232.
Chicago/Turabian StyleMomena Khatun; Cameron E. F. Clark; Nicolas A. Lyons; Peter Thomson; Kendra L. Kerrisk; Sergio C. García. 2017. "Early detection of clinical mastitis from electrical conductivity data in an automatic milking system." Animal Production Science 57, no. 7: 1226-1232.
The aim of the present study was to evaluate the accuracy of a newer version of an activity- and rumination-monitoring system by comparison against direct visual observations, for the following three different types of behaviour: grazing, resting (described as lying or standing idle) and ruminating for cows grazing either annual ryegrass or chicory-based swards. Eight non-lactating Holstein–Friesian cows were fitted with the sensor tags, and grazed on annual ryegrass pasture for a target consumption of 10 kg DM ryegrass/cow.day for 7 days. The experiment was then repeated with cattle offered a similar allowance of chicory. Observations were conducted by two trained observers in two observation periods each day, to capture the above described behaviours. In each period, electronic behavioural measurements were recorded continuously by the sensors, while visual observations were also continuous (during observation periods), and the two datasets were matched. On average, each cow was visually observed for 87.2 min/day. For each behavioural state (at 1-min intervals, n = 6963), probability of agreement, sensitivity, specificity and positive predicted value were determined for grazing as 98%, 98.3%, 97.3% and 98.9% respectively, for resting as 80%, 77.5%, 99.1% and 92.9% and for ruminating as 87%, 86.9%, 98.4% and 90.68%. Concordance correlation coefficient (CCC) and Pearson correlations (r) were used to investigate the relationships between visual observations and data generated from the tags. Different behaviours were analysed separately. Significant correlations were found for the three behaviours (grazing: CCC = 0.99, r = 0.99; resting: CCC = 0.95, r = 0.97; ruminating: CCC = 0.80, r = 0.80), with no differences detected between the two forages. We conclude that, under the conditions of the present study, the activity- and rumination-monitoring system tag measured grazing, resting and ruminating behaviours with high accuracy on the basis of comparison to visual observations.
Juan Molfino; Cameron E. F. Clark; Kendra L. Kerrisk; Sergio C. García. Evaluation of an activity and rumination monitor in dairy cattle grazing two types of forages. Animal Production Science 2017, 57, 1557 -1562.
AMA StyleJuan Molfino, Cameron E. F. Clark, Kendra L. Kerrisk, Sergio C. García. Evaluation of an activity and rumination monitor in dairy cattle grazing two types of forages. Animal Production Science. 2017; 57 (7):1557-1562.
Chicago/Turabian StyleJuan Molfino; Cameron E. F. Clark; Kendra L. Kerrisk; Sergio C. García. 2017. "Evaluation of an activity and rumination monitor in dairy cattle grazing two types of forages." Animal Production Science 57, no. 7: 1557-1562.
C. E. F. Clark; S. R. Farina; Sergio Carlos (Yani) Garcia; M. R. Islam; K. L. Kerrisk; W. J. Fulkerson. A comparison of conventional and automatic milking system pasture utilization and pre- and post-grazing pasture mass. Grass and Forage Science 2015, 71, 153 -159.
AMA StyleC. E. F. Clark, S. R. Farina, Sergio Carlos (Yani) Garcia, M. R. Islam, K. L. Kerrisk, W. J. Fulkerson. A comparison of conventional and automatic milking system pasture utilization and pre- and post-grazing pasture mass. Grass and Forage Science. 2015; 71 (1):153-159.
Chicago/Turabian StyleC. E. F. Clark; S. R. Farina; Sergio Carlos (Yani) Garcia; M. R. Islam; K. L. Kerrisk; W. J. Fulkerson. 2015. "A comparison of conventional and automatic milking system pasture utilization and pre- and post-grazing pasture mass." Grass and Forage Science 71, no. 1: 153-159.
Chicory (Cichorium intybus L.) and narrow-leaved plantain (Plantago lanceolata L.) are capable of producing a large amount of high quality feed during summer. Like many species, grazing management decisions influence their dry matter (DM) production. One of the factors implicated in the grazing-management effect on yield of other forages are plant non-structural carbohydrate (NSC) or nitrogen (N) reserves. The aim of this experiment was to characterise the patterns of NSC and N reserve depletion and replenishment for chicory and plantain during a 35-day regrowth cycle in summer, and investigate the impact of residual height on NSC and N reserves. In chicory roots, the NSC concentration tended (P = 0.09) to decline for 7 days post-defoliation before replenishment began and pre-defoliation concentrations were attained by Day 21 of regrowth (310 growing degree-days; GDD). Similarly, the amount of NSC in plantain roots declined for 14 days post-defoliation (P < 0.001), increasing again from Day 21 and with full replenishment to pre-defoliation levels by Day 35 of regrowth (532 GDD). The two residual heights tested (30 and 60 mm) had minimal impact on NSC reserves during regrowth in either chicory or plantain, likely because the majority of NSC reserves are stored in the roots rather than the stubble. In other plant species, a failure to replenish NSC reserves before the next defoliation is one factor associated with reduced DM production. This also appears to be the case with chicory and plantain, with reductions in DM production occurring if swards are defoliated during NSC mobilisation or the early stages of replenishment (i.e. before 21 days of regrowth or 310 GDD in chicory and 35 days of regrowth or 532 GDD in plantain).
Julia M. Lee; Elena M. K. Minnee; Cameron E. F. Clark. Patterns in non-structural carbohydrate and nitrogen reserves in chicory (Cichorium intybus L.) and plantain (Plantago lanceolata L.) during regrowth in summer. Crop and Pasture Science 2015, 66, 1071 -1078.
AMA StyleJulia M. Lee, Elena M. K. Minnee, Cameron E. F. Clark. Patterns in non-structural carbohydrate and nitrogen reserves in chicory (Cichorium intybus L.) and plantain (Plantago lanceolata L.) during regrowth in summer. Crop and Pasture Science. 2015; 66 (10):1071-1078.
Chicago/Turabian StyleJulia M. Lee; Elena M. K. Minnee; Cameron E. F. Clark. 2015. "Patterns in non-structural carbohydrate and nitrogen reserves in chicory (Cichorium intybus L.) and plantain (Plantago lanceolata L.) during regrowth in summer." Crop and Pasture Science 66, no. 10: 1071-1078.
Chicory (Cichorium intybus L.) and narrow-leaved plantain (Plantago lanceolata L.) are able to grow a large amount of high-quality summer feed. Limited information is available on the effect of grazing management on plantain, and no comparison been undertaken of modern chicory and plantain cultivars used in dairy production systems. This study determined the effect of defoliation interval (as determined by the extended leaf height, ELH) and residual height on the yield, nutritive characteristics and plant density of chicory and plantain over 18 months. Chicory leaf yield was reduced in swards defoliated at 150 mm ELH compared with those defoliated at 250, 350 or 550 mm (14.3 v. 17.5 t DM ha–1), and chicory stem yield was least in swards defoliated at 150 or 250 mm. Plantain swards defoliated at 350 or 450 mm ELH yielded more leaf than those defoliated at 150 or 250 mm (20.4 v. 16.7 t DM ha–1); however, stem yield also increased with increasing defoliation interval. Over all seasons, as defoliation interval increased, generally, neutral detergent fibre content increased and crude protein, ash and digestibility declined. Residual height had less of an effect on yield and nutritive characteristics than did defoliation interval. To maximise chicory leaf growth while minimising growth of lower quality stem, the optimal ELH over 18 months was 250 mm, or if the chicory was used only as a 9-month ‘summer’ crop, 350 mm. Recommendations for plantain are not as simple because longer defoliation intervals increase both leaf and stem yield and reduce nutritive value. Defoliating plantain swards at 250 mm ELH appeared to provide a balance between yield and nutritive value; however, further work is required to determine the impact of applying these recommendations on a dairy farm system.
Julia M. Lee; Nivonne R. Hemmingson; Elena M. K. Minnee; Cameron E. F. Clark. Management strategies for chicory (Cichorium intybus) and plantain (Plantago lanceolata): impact on dry matter yield, nutritive characteristics and plant density. Crop and Pasture Science 2015, 66, 168 -183.
AMA StyleJulia M. Lee, Nivonne R. Hemmingson, Elena M. K. Minnee, Cameron E. F. Clark. Management strategies for chicory (Cichorium intybus) and plantain (Plantago lanceolata): impact on dry matter yield, nutritive characteristics and plant density. Crop and Pasture Science. 2015; 66 (2):168-183.
Chicago/Turabian StyleJulia M. Lee; Nivonne R. Hemmingson; Elena M. K. Minnee; Cameron E. F. Clark. 2015. "Management strategies for chicory (Cichorium intybus) and plantain (Plantago lanceolata): impact on dry matter yield, nutritive characteristics and plant density." Crop and Pasture Science 66, no. 2: 168-183.
Automatic milking systems (AMS) rely upon voluntary cow traffic (the voluntary movement of cattle around a farm) for milk harvesting and feed consumption. Previous research on conventional milking systems has shown differences between dairy cow breeds for intake and milk production, however, the ability to manipulate voluntary cow traffic and milking frequency on AMS farms through breed selection is unknown. This study investigated the effect of breed (Holstein Friesian versus Illawarra) on voluntary cow traffic as determined by gate passes at the Camden AMS research farm dairy facility. Daily data on days in milk, milk yield, gate passes and milking frequency for 158 Holstein Friesian cows and 24 Illawarra cows were collated by month for the 2007 and 2008 years. Illawarra cows had 9% more gate passes/day than Holstein cows over the duration of the study; however, the milking frequency and milk yield of both breeds were similar. Gate passes were greatest for both breeds in early lactation and in the winter (June to August) and summer (December to February) seasons. These findings highlight an opportunity to translate increased voluntary cow movement associated with breed selection into increased milking frequencies, milk production and overall pasture-based AMS performance.
C. E. F. Clark; N. B. P. Kwinten; D. A. J. M. Van Gastel; K. L. Kerrisk; N. A. Lyons; S. C. Garcia. Differences in Voluntary Cow Traffic between Holstein and Illawarra Breeds of Dairy Cattle in a Pasture-based Automatic Milking System. Asian-Australasian Journal of Animal Sciences 2014, 27, 587 -591.
AMA StyleC. E. F. Clark, N. B. P. Kwinten, D. A. J. M. Van Gastel, K. L. Kerrisk, N. A. Lyons, S. C. Garcia. Differences in Voluntary Cow Traffic between Holstein and Illawarra Breeds of Dairy Cattle in a Pasture-based Automatic Milking System. Asian-Australasian Journal of Animal Sciences. 2014; 27 (4):587-591.
Chicago/Turabian StyleC. E. F. Clark; N. B. P. Kwinten; D. A. J. M. Van Gastel; K. L. Kerrisk; N. A. Lyons; S. C. Garcia. 2014. "Differences in Voluntary Cow Traffic between Holstein and Illawarra Breeds of Dairy Cattle in a Pasture-based Automatic Milking System." Asian-Australasian Journal of Animal Sciences 27, no. 4: 587-591.
Pasture-based automatic milking systems (AMS) require cow traffic to enable cows to be milked. The interval between milkings can be manipulated by strategically allocating pasture. The current experiment investigated the effect of replacing an allocation of grazed pasture with grazed soybean (Glycine max) with the hypothesis that incorporating soybean would increase voluntary cow traffic and milk production. One hundred and eighty mixed age, primiparous and multiparous Holstein-Friesian/Illawarra cows were randomly assigned to two treatment groups (n = 90/group) with a 2×2 Latin square design. Each group was either offered treatments of kikuyu grass (Pennisetum clandestinum Hoach ex Chiov.) pasture (pasture) or soybean from 0900 h to 1500 h during the experimental period which consisted of 2 periods of 3 days following 5 days of training and adaptation in each period with groups crossing over treatments after the first period. The number of cows trafficking to each treatment was similar together with milk yield (mean ≈18 L/cow/d) in this experiment. For the cows that arrived at soybean or pasture there were significant differences in their behaviour and consequently the number of cows exiting each treatment paddock. There was greater cow traffic (more cows and sooner) exiting pasture allocations. Cows that arrived at soybean stayed on the allocation for 25% more time and ate more forage (8.5 kg/cow/d/allocation) relative to pasture (4.7 kg/cow/d/allocation). Pasture cows predominantly replaced eating time with rumination. These findings suggest that replacing pasture with alternative grazeable forages provides no additional incentive to increase voluntary cow traffic to an allocation of feed in AMS. This work highlights the opportunity to increase forage intakes in AMS through the incorporation of alternative forages.
C. E. F. Clark; A. Horadagoda; K. L. Kerrisk; V. Scott; M. R. Islam; R. Kaur; S. C. Garcia. Grazing Soybean to Increase Voluntary Cow Traffic in a Pasture-based Automatic Milking System. Asian-Australasian Journal of Animal Sciences 2014, 27, 422 -430.
AMA StyleC. E. F. Clark, A. Horadagoda, K. L. Kerrisk, V. Scott, M. R. Islam, R. Kaur, S. C. Garcia. Grazing Soybean to Increase Voluntary Cow Traffic in a Pasture-based Automatic Milking System. Asian-Australasian Journal of Animal Sciences. 2014; 27 (3):422-430.
Chicago/Turabian StyleC. E. F. Clark; A. Horadagoda; K. L. Kerrisk; V. Scott; M. R. Islam; R. Kaur; S. C. Garcia. 2014. "Grazing Soybean to Increase Voluntary Cow Traffic in a Pasture-based Automatic Milking System." Asian-Australasian Journal of Animal Sciences 27, no. 3: 422-430.
Despite native grasses occupying a large area of land in Australia, there has been limited work on the responses of these species to the addition of phosphorus (P). The main objective of this study was to investigate the effect of the addition of P to create a range of P contents in the soil on the productivity and morphology of two native grasses at two times of harvests. Two contrasting perennial native grasses, namely kangaroo grass (Themeda triandra Forssk. syn. T. australis R. Br. Stapf) and weeping grass [Microlaena stipoides var. stipoides (Labill.) R. Br.] were grown in a glasshouse with the addition of P to create five contents of P in the soil (7, 17, 32, 107 and 307 mg kg–1 soil) using a completely randomised design with four replicates per treatment. Grasses were harvested to 5 cm above the substrate surface, and the number of tillers and leaf area were recorded on Day 84 (harvest 1) and Day 112 (harvest 2) of the experiment. Dry matter production for kangaroo and weeping grass increased with P contents of the soil of 32 mg and ≥107 mg P kg–1 soil, respectively. Increased dry matter production for both species was the result of increased leaf area, tiller number and root growth. These results provide data that help to understand the disappearance sequence of kangaroo grass from more fertile soils and an increase in weeping grass, particularly in soils with greater fertility. Further research is required to determine if these results hold for other grass ecotypes.
Cameron E. F. Clark; Meredith Mitchell; Mohammed R. Islam; Brent Jacobs. Phosphorus content of the soil influences the growth and productivity of Themeda triandra Forssk. and Microlaena stipoides (Labill.) R.Br. The Rangeland Journal 2014, 36, 233 -237.
AMA StyleCameron E. F. Clark, Meredith Mitchell, Mohammed R. Islam, Brent Jacobs. Phosphorus content of the soil influences the growth and productivity of Themeda triandra Forssk. and Microlaena stipoides (Labill.) R.Br. The Rangeland Journal. 2014; 36 (3):233-237.
Chicago/Turabian StyleCameron E. F. Clark; Meredith Mitchell; Mohammed R. Islam; Brent Jacobs. 2014. "Phosphorus content of the soil influences the growth and productivity of Themeda triandra Forssk. and Microlaena stipoides (Labill.) R.Br." The Rangeland Journal 36, no. 3: 233-237.