Author
 |
Ganskopp, David |
|
CRUZ, RUBEN - OREGON STATE UNIVERSITY |
|
Submitted to: Oregon Agriculture Experiment Station Special Report
Publication Type: Experiment Station Publication Acceptance Date: 4/1/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Beef cattle frequently use only a portion of the forage available to them in rugged, extensive rangeland pastures. This wastes valuable forage that could generate additional income for beef producers if animal distribution could be improved. For the last two years we have been using GPS (global positioning systems) and GIS (geographic information systems) technologies to help us understand why cattle use or avoid certain portions of their environment. As a portion of that project we wanted to determine whether GIS could accurately predict where cattle might establish trails. We used a GPS unit to map all the cattle trails in three 2000+ acre pastures managed under a season-long grazing program. Each pasture supported 40 cow/calf pairs. These trails were superimposed on topo maps. Selected points were chosen, and we asked GIS to plot least-effort pathways to those points. We mapped 31 m. of trails in all the pastures. None of them explored the highest elev. in any of the pastures, but the lowest elev. were visited in 2 of 3 pastures. Cattle lowered the energy required for travel by traversing relatively gentle slopes. The average slope in the pastures was 13.5%, and the average slope of areas crossed by cattle was 8%. By moving across slopes, travel effort was further reduced, and the actual slope of the cattle trails averaged 5%. Computer selected pathways were close approx. of cattle trails, but cattle selected routes about 11% shorter and traversed terrain that was not quite as steep as the pathways. We also noted that cattle do not always use the same routes to enter and exit a particular area. We suggest that GIS software might be a useful tool for developing cattle trails, but we need to verify that trail development is an effective means of manipulating livestock distribution. Technical Abstract: Beef cattle frequently use only a portion of the forage available to them in rugged, extensive rangeland pastures. This wastes valuable forage that could generate additional income for beef producers if animal distribution could be improved. For the last two years we have been using GPS (global positioning systems) and GIS (geographic information systems) technologies to help us understand why cattle use or avoid certain portions of their environment. As a portion of that project we wanted to determine whether GIS could accurately predict where cattle might establish trails. We used a GPS unit to map all the cattle trails in three 2000+ acre pastures managed under a season-long grazing program. Each pasture supported 40 cow/calf pairs. These trails were superimposed on topo maps. Selected points were chosen, and we asked GIS to plot least-effort pathways to those points. We mapped 31 m. of trails in all the pastures. None of them explored the highest elev. in any of the pastures, but the lowest elev. were visited in 2 of 3 pastures. Cattle lowered the energy required for travel by traversing relatively gentle slopes. The average slope in the pastures was 13.5%, and the average slope of areas crossed by cattle was 8%. By moving across slopes, travel effort was further reduced, and the actual slope of the cattle trails averaged 5%. Computer selected pathways were close approx. of cattle trails, but cattle selected routes about 11% shorter and traversed terrain that was not quite as steep as the pathways. We also noted that cattle do not always use the same routes to enter and exit a particular area. We suggest that GIS software might be a useful tool for developing cattle trails, but we need to verify that trail development is an effective means of manipulating livestock distribution. |
