Vet Advice

According to some provincial environmental regulations, such as the AOPA (Agricultural Operation Practices Act) in Alberta, livestock are considered confined feeding operations (CFO) when they are fenced or enclosed in areas for growing, sustaining, finishing or breeding by means other than grazing.

Any operation that brings feed in and removes manure may be considered a CFO. Cow-calf operations falling under these definitions are required to follow CFO environmental regulations. Confinement can increase the risks of disease and environmental pollution. If cows are wintered, calved, and nursed together closely on the same grounds, the risk of diseases, such as scours and pneumonia, increases substantially. That is due partially to the build-up of infectious agents in the environment, which increases the dose of infectious agents that the cattle, particularly susceptible young calves, are exposed to.

Even if calves have protective colostral immunity from their dams, their immunity can be overwhelmed with high exposure rates to infectious agents. Close confinement also results in a quicker spread of infectious agents amongst animals, sometimes leading to explosive outbreaks of disease. This is particularly common with scours and pneumonia in calves. Often just spreading cow-calf pairs out on a few acres of land from a corral situation can significantly reduce the severity of a disease outbreak.

When cattle are closely confined in the winter, manure builds up. This manure may contain bacteria (E. coli, salmonella), viruses (rota, corona, BVD), and protozoa (cryptosporidia, giardia) that can cause calf scours. Some of these infectious agents are also of concern in manure runoff. Manure runoff contains bacteria, protozoa and nutrients, such as nitrogen and phosphorus, which can negatively impact water quality. Some of the bacteria and protozoa are zoonotic; that is, they can cause human disease (cryptosporidia, giarida, salmonella, verotoxigenic E. coli).

Nitrogen, while more of a ground water concern, can cause blue baby syndrome, if sufficiently high levels are present in water, although this has been rarely reported. And phosphorus results in algae growth in lakes, rivers and streams, which reduces the oxygen in the water and may reduce fish survival. The algae is also a nuisance for recreation and irrigation, and occasionally, it impacts the clarity, smell and taste of water as well, making it undesirable for human consumption.

There are two reasons to manage wintering sites properly. First, to reduce the risk and severity of disease in calves; second, to reduce environmental pollution. Having separate wintering, calving, and nursing grounds will reduce the risk of scours. Spreading cattle out by increasing the acres per head will reduce the exposure level to infectious agents. As well, it will spread out the nutrients from manure, which is better for the land, and it will reduce the risk of point source runoff into water bodies.

Cattle can be spread out by moving shelters regularly and by rotating bedding, feeding and watering areas. Even having feeding and watering sources separate is useful, since it makes cattle move around. Clearing snow as soon as possible will effectively increase the available space per animal. Moving cow/calf pairs out of corrals as soon as possible after calving, if housed there, will help reduce the risk of scours and pneumonia.

Wintering sites should be located so at spring thaw, run-off does not directly enter a water body. Wintering sites should not be located on steep slopes that drain directly into a river or lake, and they should not be located on frozen lakes or rivers. Runoff should be contained by berms or dikes or filtered by vegetative filter strips along watercourses. Manure stockpiles should be cleaned regularly, and the manure can be used on land as an organic fertilizer.

By practicing good wintering site management practices, the risk of diseases, such as calf scours and pneumonia, and the risk of environmental pollution can be minimized. For further information, contact Alberta Agriculture and Food for information on environmental regulations in Alberta and the Alberta Cattle Commission for its Cattle Wintering Site publication (403-275-4400).