This study evaluated the accuracy of a sensor-based device (AfiCollar) to automatically monitor and record grazing and rumination behaviours of grazing dairy cows on a real-time basis. Multiparous spring-calved dairy cows (n = 48) wearing the AfiCollar were selected for the visual observation of their grazing and rumination behaviours. The total observation period was 36 days, divided into four recording periods performed at different times of the year, using 12 cows in each period. Each recording period consisted of nine daily observation sessions (three days a week for three consecutive weeks). A continuous behaviour monitoring protocol was followed to visually observe four cows at a time for each daily observation session, from 9:00 a.m. to 5:00 p.m. Overall, 144 observations were collected and the data were presented as behaviour activity per daily observation session. The behaviours visually observed were also recorded through an automated AfiCollar device on a real-time basis over the observation period. Automatic recordings and visual observations were compared with each other using Pearson’s correlation coefficient (r), Concordance correlation coefficient (CCC), and linear regression. Compared to visual observation (VO), AfiCollar (AC) showed slightly higher (10%) grazing time and lower (4%) rumination time. AC results and VO results had strong associations with each other for grazing time (r = 0.91, CCC = 0.71) and rumination time (r = 0.89, CCC = 0.80). Regression analysis showed a significant linear relationship between AC and VO for grazing time (R² = 0.83, p < 0.05) and rumination time (R² = 0.78, p < 0.05). The relative prediction error (RPE) values for grazing time and rumination time were 0.17 and 0.40, respectively. Overall, the results indicated that AfiCollar is a reliable device to accurately monitor and record grazing and rumination behaviours of grazing dairy cows, although, some minor improvements can be made in algorithm calibrations to further improve its accuracy.

This study investigated the variations in the temporal distributions and the lengths of times utilized for grazing, ruminating, and idling behaviors by grazing dairy cows over 24 hours. Spring-calved lactating dairy cows (n = 54) from three breeds, Holstein-Friesian (HFR), Jersey (JE), and KiwiCross (KC) in different lactations (1 ^st, 2 ^nd, 3 ^rd) and with different breeding worth index values (103151) were selected. The cows were managed through a rotational grazing scheme and milked once a day at 5:00 hrs. The cows grazed mainly pasture and consumed additional feeds (maize silage and turnips) in the summer and autumn seasons. AfiCollar was used to recorded grazing and rumination behaviors (min/h) by the individual cows throughout the lactation period (~270 days). The time (min/h) neither utilized for grazing nor rumination was counted as idling behavior. A repeat measure design with PROC MIXED was performed in SAS considering the effects of breed, lactation, individual cow, the hour of the day, season, day within the season, and supplementary feed within the season to evaluate the difference in grazing, rumination, and idling behaviors. Hour of the day, season, day within season, and supplementary feed had significant effects on grazing, rumination, and idling behaviors. Regardless of the season and supplementary feed, cows spent most of the daytime grazing and most of the night-time ruminating. Grazing activity remained consistently high throughout the day with two peaks around dawn and dusk and a short peak around midnight. Rumination activity remained high from the late evening until early morning. Grazing and ruminating patterns were similar between different breeds and lactations, however, JE cows grazed slightly longer than HFR and KC, and first-lactation cows also grazed slightly longer than those in higher lactations. The onset and cessation of grazing by the cows were adjusted according to varying day lengths by season. Cows finished grazing earlier when they consumed additional supplements or silage along with pasture. Cows from different breed groups and lactations spent most of their 24 hours grazing followed by ruminating and idling. Season and supplementary feed potentially caused variations in behavior time budgets. These findings should support improving measures for grazing management to address pasture and additional feed demands, and animal welfare in varying environmental and/or managemental conditions.

This study investigated the variation in daily time spent grazing and rumination in spring-calved grazing dairy cows (n = 162) of three breeds, Holstein-Friesian (HFR), Jersey (JE), and KiwiCross (KC) with different breeding worth index, and in different years of lactation (1st, 2nd, 3rd, 4th). The cows were managed through a rotational grazing system and milked once a day at 05:00 a.m. The cows grazed mainly pasture and received supplementary feeds depending on the season. Automated AfiCollar device continuously monitored and recorded grazing time and rumination time of the individual cows throughout the lactation period for three study years (Year-1, Year-2, Year-3) with 54 cows per year. A general linear mixed model fitted with breed × lactation year with days in milk (DIM), breeding worth (BW) index value, individual cow, season, and feed, and their interactions was performed in SAS. Variance partitioning was used to quantify the effect size of study factors and their interactions. Individual cows, DIM, and BW (except Year-3) had effects on grazing and rumination times throughout the study years. Grazing time and rumination time were different for different seasons due to varying supplementary feeds. Grazing time varied among breeds in Year-2 and Year-3, and among lactation years only in Year-1. Although rumination time differed among breeds in Year-3, it remained the same within different lactation years. Grazing time and rumination time had a negative relationship with each other, and their regression lines varied for different seasons. The total variance explained by the model in grazing time was 36–39%, mainly contributed by the individual cow (12–20%), season (5–12%), supplementary feed (2–6%), breed (1–5%), and lactation year (1–6%). The total variance explained in rumination was 40–41%, mainly contributed by the individual cow (16–24%), season (2–17%), supplementary feed (1–2%), breed (2–8%), and lactation year (~1%). These findings could contribute to improving the measures for feed resource management during different seasons over the lactation period for a mixed herd comprising JE, HFR and KC breeds in different years of lactation.

This study examined how grazing, rumination and idling behaviour patterns varied in a pasture-based dairy system across different seasons, depending on the time of day, and the Temperature-Humidity Index (THI). Three visual observation trials (OT) were conducted in spring, summer, and autumn using 36 lactating, pasture-grazing Jersey, Holstein-Friesian and Holstein-Friesian x Jersey crossbred dairy cows (12 cows per OT) in different lactations. The study was performed at Dairy Unit 1 of Massey University, New Zealand. A continuous recording method was used to collect grazing (min/h) and rumination (min/h) behaviours data; Idling behaviour was considered when animals were neither grazing nor ruminating. A total of 72 hours of data were collected per OT, with 9 days of visual observation within each OT, and 8 hours (09:00-17:00) of observation per day. Four animals were observed at a time for three consecutive days with a new set of four animals in the next three days as the cycle repeats. A repeated measures mixed (PROC MIXED) model was used to analyse behaviour variations affected by OT, day within OT, THI, and their interactions. Grazing time was significantly affected by the hour of the day and THI, and cows grazed less during periods of high THI. Rumination time was mainly affected by the hour of the day and its interaction with THI, with a shift in rumination towards the low THI hours. Idling time was significantly affected by the day of OT and hour of the day, and their interactions with THI. With a rise in THI, the duration of idling behaviour increased. These behavioural adaptations highlight the importance of behaviour-based management practices to reduce the adverse effects of heat stress on dairy cows to improve their well-being and productivity.