Water quality data should be examined carefully before assigning a cause and effect relationship between cattle grazing and non point pollution. Natural background levels of nutrient and pathogen loading can be quite high during storm events. Non point pollution from pastured and rangeland livestock depends on the stock rate, length of grazing period, the season of use, manure deposition sites and concentration. Normally, pastures and rangelands have not presented water quality problems caused by cattle excrement, except under special circumstances. The main water quality concerns are from cattle feces and urine deposited directly into the water. Potential problems occur in cases where animals congregate for feeding, watering, resting, in proximity to waters. There is little scientific evidence that excrement from beef cattle on rangelands significantly impacts water quality. When significant nutrient contaminations do occur, especially phosphorus, they are more likely explained by erosion and sediment processes in the watershed. Cattle can effect the erosion and sediment process through vegetation removal. The scientific evidence implicating beef cattle as a significant source of C. Parvum or G. duodenalis for surface water contamination. Rangeland beef cattle excrement may increase pathogen contamination in water ways beyond background levels, but studies have shown that background levels are not zero. Wildlife species, including muskrats, coyotes, mule deer, waterfowl, elk, etc. shed pathogenic bacteria such as Campylobacter jejuni. Giardia has been repeatedly isolated from wildlife. Furthermore, high counts of indicator bacteria are often found upstream from grazed areas and are attributed to wildlife. Rangeland water quality can be managed by implementing spatial distribution of cattle through salting, upland water developments, fences for pasture rotation, and even by training or selection of the cattle grazed. These methods address the deposition of excrement near waterways, and also other, hydrologic, ecologic, and economic issues.
|Original language||English (US)|
|Number of pages||7|
|State||Published - Oct 1998|
ASJC Scopus subject areas
- Management, Monitoring, Policy and Law
- Geography, Planning and Development