Monitoring standing and lying behaviour of dairy cows at pasture under different grazing management plans

Our objective was to examine differences in dairy cow standing and lying behaviour patterns across different grazing management plans that varied in pasture supply and management intensity. We hypothesized that cows in a higher pressure grazing system, with reduced pasture availability and higher competition, would display greater standing times and reduced lying behaviour. Ten focal cows were selected from each of three spring grazing management plans, balanced for breed, parity and body weight. Treatments represented low pressure (LOW; 1,100 kg DM/ha grass available at calving, 2.75 cows/ha and 90% pasture diet), moderate pressure (MOD; 900 kg DM/ha grass available at calving, 2.75 cows/ha and 90% pasture diet), and high pressure (HIGH; 700 kg DM/ha grass available at calving, 3.25 cows/ha and 80% pasture diet) grazing plans. Groups were monitored from March - May 2018. Daily standing time, lying time, and lying bout and step frequency data were collected using accelerometers secured to the rear leg of each cow. Data from three, 10 d periods corresponding to the Early, Mid and Late spring grazing season were summarised by cow, day, treatment and period, and analysed for differences in behaviour. HIGH pressure cows tended to have reduced lying time and greater standing times (P = 0.07). Grazing period significantly influenced standing and lying time (P = 0.02), with a decrease in standing time and increase in lying time from Early to Late spring grazing. Additionally, lying bout frequency decreased while step frequency increased over the grazing period (P < 0.001).