A properly selected cattle wintering site is an excellent way to protect water from manure contamination, says an Alberta Agriculture water specialist.
Bob Buchanan said several factors influence the management and environmental suitability of a cattle wintering site.
“Some physical characteristics such as slope, soil type, water table and climate are beyond the producer’s control,” he said.
“Factors that can be managed include cattle density, runoff control, feeding method and location of water supply. Whenever possible, try to pick a wintering site away from water sources and where little or no runoff flows down through the site. Also set up an alternative water supply to protect the water source.”
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Manure is a valuable source of nutrients for growing crops on the farm, but it also contains nutrients, organic matter and microorganisms that can contaminate water sources.
“In some areas a fairly common practice for cattle producers is to feed and bed cattle in low, sheltered areas beside creeks, rivers, lakes or dugouts,” Buchanan said.
Accumulated manure can contaminate these water sources during spring snowmelt or heavy rainfall.
Cattle with unrestricted access to water sources can contaminate them with manure and sediment trampled in from the stream banks.
Cattle that are allowed continuous access to streams for watering and grazing will eventually destroy all the rooted vegetation along the stream banks, which leads to serious stream bank erosion.
The sediment deteriorates water quality and riparian habitat for fish and other aquatic life.
“Some Alberta studies have shown that even small cow-calf operations with fewer than 50 cow-calf pairs can impact water quality,” he said.
Nutrients such as phosphorus from manure can rapidly increase the algal growth in dugouts, lakes and rivers.
There is enough phosphorus in one cow’s manure for one day to cause a significant algae bloom in one million litres of dugout water.
Decomposing algae can deplete dissolved oxygen in the water and kill fish. It can also generate offensive taste and odor problems in water. Blue green algae toxins can be fatal to livestock.
Manure-contaminated water contains fecal coliform bacteria and may have other disease-causing microorganisms such as cryptosporidium and giardia. They are a threat to public health and reduce weights and cattle productivity.
