Automated monitoring of urination events from grazing cattle
作者：T. H. Misselbrook, Hannah Fleming, V. Camp, Christina Umstätter, Carol-Anne Duthie, Laura Nicoll, A. Waterhouse · 发表于：Agriculture Ecosystems & Environment · 年份：2016 · DOI：10.1016/j.agee.2016.06.006
Urine patches deposited by grazing cattle represent 'hot-spots' of very high nitrogen (N) loading from which environmentally important losses of N may occur (ammonia and nitrous oxide emissions, nitrate leaching). Information on the quantities of N deposited to grazed pastures as urine, the spatial and temporal distribution of urine patches and how these may be influenced by pasture management practices is limited. The objectives of this study were to assess the potential of recently developed urine sensors for providing data on urination behaviour by grazing cattle and relate this to measurements of ammonia emissions from the grazed paddocks. A total of six trials were conducted across two sites; two on a 1 ha paddock at Easter Bush near Edinburgh using beef cattle (c. 630 kg live weight) and four on a 0.5 ha paddock at North Wyke in Devon using in-calf dairy heifers (c. 450 kg live weight). Laboratory calibrations were conducted to provide sensor-specific functions for urine volume and N concentration. The quantity and quality of data from the urine sensors improved with successive trials through modifications to the method of attachment to the cow. The number of urination events per animal per day was greater for the dairy heifers, with a mean value of 11.6 (se 0.70) compared with 7.6 (se 0.76) for the beef cattle. Volume per urination event (mean 1.8, range 0.4–6.4 L) and urine N concentration (range 0.6–31.5 g L−1, excluding outliers) were similar for the two groups of c...