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Mastitis Case Studies

Housing and Environment

This resource describes aspects of dairy cow housing and management.

Herd location: Location of a herd is relevent to mastitis mainly in terms of local differences in weather. For example, warm, humid weather is experienced in the southern states for a longer period than the northern states. This means that the period of time to be concerned about flies as a mastitis vector is longer in Louisanna than in Wisconsin. Typical seasonal weather for a location also will partially dictate the type of housing that is used for the cows.

Season & Weather: Hot and humid weather, such as occurs in many parts of the US in the summer, results in an increased risk of mastitis for a several reasons. The hot and humid conditions put more stress on the cow's immune system and the cow's ability to resist disease. There are more flies around that may transmit mastitis organisms to the cows' teats. If outside in a pasture, cows look for cool places to get away from the heat. That means they will congregate under shade trees if available. This concentration of animals is accompanied by a concentration of feces and urine in the area that they congregate. Many will lie down in this muddy, manure/urine soaked soil. Also, cows in hot conditions are more likley to wade into a pond or creek than normally. Again, the concentration of feces in that environment can enhance their chances of getting mastitis. On the other hand, if cows are kept indoors in winter months when the ground is frozen and they cannot get the usual exercise time, probably means that they are lying in a dirty barn more often. In freestall units, the manure often freezes in very cold weather and is very difficult to scrape out. It is not unusual under those circumstances for the manager to cut back on the barn cleaning effort. Providing adequate ventilation and a clean environment for cows at all time so year is important.

Even beyond the exposure to environmental pathogens, cold weather can cause chapped or cracked teats. This is just like your hands getting chapped or cracked in winter. The skin's protective barrier becomes compromised and bacteria may be able to colonize the cracks in the skin. These may then be transfered into the gland at milking and cause mastitis. Teat care, especially in the cold seasons, is important for control of mastitis. If you are familair with the product "Bag Balm" that some people buy for their hands in winter, this is a product that was developed long ago and is still used for treating cows' teats in winter. It contains lanoline that helps keep the skin from chapping.

Herd size: Herd size does not directly impact incidence of mastitis. Small herds have as much problem with mastitis as large herds. However, herd size does impact the type of facility and how the animals are managed, both of which can impact incidence of mastitis.

Barn & stall design: The are several types of barns in which cows may be housed. Design of the barn and the stalls for the cows can be relevant to control of mastitis. Free stall barns typically have concrete walkways and raised stalls with steel dividing bars. The floor of the stalls may be bedded with various materials (see below for Bedding). If the stalls are designed properly then cows can go in and out of the stall easily, lie down in comfort, and lie in a relatively clean bedding. Cows are more likley to defecate in the walkways than on the bedding in the raised stall. Manure in the walkways is scraped or flushed with water, usually once per day. Cows have access to water from automatic waterers and access to feed through some style of headgate. Most dairy cows today are housed in some form of a freestall barn.

Freestalls with cows.
Freestalls with cows.
Freestalls, showing steel dividing bars and raised bedded area for cows to lie down.
Cows lying in freestalls. Note how the area where the cows are lying is raised above the walkway
Automatic waterer in freestall barn.
Cows eating in freestall barn.
Automatic waterer in freestall barn.
Cows eating in freestall barn.
Cows eating in freestall barn.
Cows in a freestall barn. Note that at any given time, several cows will be up eating, some will be wandering around, and many will be lying down.

The other major type of barn is often refered to as a "flat barn." This includes barns that have stanchions or tie-chains to restrain the cow in its stall. In these cases, the cow can only move in and out of the stall when they are released, usually for milking or for exercise. Stall design is important here, as well. If a cow is too short for the stall (for example a Jersey cow in a stall designed for Holstein cows), then there is more likelihood that the cow will defecate within the back of the stall and then lie in the manure. In some cases, people may still milk cows in a flat barn. In those cases the milk pipeline would be raised over the cows' heads (high milk line; see resource on the Milking Machine). Flat barns, either stanchion or tie stall or a combination of both (such as the UIUC South Barn) were common in times past. In some areas, especially where the winter months are very cold, flat barns are still common.

Cow lying in a stanchion stall.
Cow in a tie-stall.
Cow lying in a stanchion stall.
This Brown Swiss cow in a tie-stall has a little more mobility than if she were in a stanchion.

Another type of housing sometimes used for cows, especially heifers or dry cows, is a three- or four-sided shed that is an open pen with no individual stalls. This arrangement typically is bedded with some organic bedding (most often straw, but sometimes with corn cobs or other inexpensive orgtanic bedding). When the barn is clean and the bedding fresh, this arrangement should be effective at minimizing mastitis. However, a typical management approach is to leave the soiled bedding in the barn and put fresh bedding on top. This eventually forms a pack of bedding and provides a well insulated floor covering for cows to lie down on. However, this also is an excellent source of environmental mastitis-causing bacteria, especially those associated with feces.

Bedding: When a cow lies down, her udder and teats come into contact with whatever she is lying on. The type of bedding and how that bedding is kept clean are critical issues for control ofenvironmental mastitis. The ideal beeding for limiting environmental mastitis would be a clean inorganic material. Sand is the only such material available is substantial quantities. If kept clean, sand allows urine to drain down away from the cow. And sand is less likely to have bacteria growing in it than an organic bedding. However, sand can be expensive and it is more difficult to eliminate the feces-spoiled waste, compared with organic forms of bedding.

Freestalls bedded with sand.
Freestalls bedded with sand.

The primary forms of organic bebdings used today are sawdust and straw. In addition to straw, other types of plant materials from wastage of crop harvesting have been used and some are still used (such as corn cobs). Shreaded newspaper is used by some producers if a source is available. Organic beddings soak up fluids from urine, but also are good media for bacterial growth. Feces-spoiled sawdust or straw can be a major source of environmental pathogens for causing mastitis. In addition, green sawdust, that is sawdust that is from uncured wood, can harbor some types of Klebsiella bacteria, even before it becomes soiled with feces.

Pile of sawdust .
Pile of sawdust to be used for bedding barns and freestalls.

Exercise area: Cows that are maintained in a freestall type of housing are free to wonder around the barn, and therefore do not need a separate exercise area. However, cows that are tethered in a tie-stall barn or stancheon barn need to be put out into an open area dairy for exercise. Typically this is done after the morning milking and during the time when the barn is being cleaned. Exercise lots may be on concrete, sand or dirt. Cows should be observed in the exercise lots for signs of estrus (heat; mounting behavior).

Cows  in a dirt exercise lot.
Cows in a dirt exercise lot.

Pastures, creeks, ponds: Pastures can be a very clean environment for cows. However, space availability, soil types, and other factors will determine whether a producer keeps the cows housed or runs them on a pasture. Pasture management is critical for effective use of the pasture grass as a supplemental forage for the cows. Pastures relate to mastitis when they become too wet and muddy. See the discussion above on Season & Weather.

If the major source of water for the cows while on pasture is a stream, creek or pond, these may relate to mastitis, as well. Cows in hot weather will walk into water to cool off. They may also defecate in the water. If the water is deep enough to contaminate their teats then the glands may become infected. Contaminated water, such as a creek or pond, and especially during the hot months of summer, can harbor several types of mastitis-causing microorganisms. Providing a clean water source on a concrete area minimizes their contact with a muddy and dirty environment. Fencing off the offending water source is one way to keep the cows out of the pond.

Muddy pasture.
Cows in a muddy pasture.
Cow standing in a water puddle on a poorly drained concrete slab.

Milking Parlors: Milking parlor design also is important for control of mastitis. It is the time around milking when the udder is most at risk of becoming infected. The milking machine is housed in the parlor and the milking process occurs in the parlor (see Milking Machine and Milking Process resources). In most parlors the milkers are standing in a "pit" so that the cow's udder is elevated and easier to reach without kneeling down (as when milking in a flat barn). Originally, many parlors were single sided, that is milking machines on only one side of the pit. Most parlors today are double, that is milking machines line both sides of the pit.

Milking in a pit also means that the milker has the opportunity to do a better job at keeping the immediate environment around the udder clean. Manure can be washed away with a water hose, the teats are easier to see to get properly cleaned, and the entire milking process is easier than milking in a flat barn. Many adaptations of milking systems are based on this spatial relationship between milker and cow's udder. Parlors allow for using a low line pipeline system (see Milking Machine resource). Milking machines can be left in place and therefore ATO systems and computerized applications can be employed. Milking machines can be cleaned in place, allowing for more effective post-milking cleaning of equipment.

Herringbone milking parlor.
Parallel milking parlor
Herringbone milking parlor. Here, cows would enter from the far end of the walkway. Once to the end of this holding area, the cows face away from the pit at an angle. Cows would be in a staggered position relative to each other. The cow's udder would be accessible from the pit. When all cow's on a side of the parlor has completed milking, either they exit in single file from the near end of this walkway, or in this case, the bars in front of the cows raise and the cows all exit simultaneously.
Parallel milking parlor. Here the cows enter from the far end, but turn 90 degrees away from the pit and stand side-by-side. Cows are milked between the rear legs. When all the cows on a side are done milking, the bar in front of the cows raises and they all exit simultaneously. This saves considerable time in cow movement through the parlor system.

Mastitis Case Studies
Mastitis Resources