Loose housing systems
Housing dairy cattle on straw-bedded yards can provide a particularly comfortable environment for the cow; one which a cow would tend to naturally prefer over cubicle housing. Unfortunately, unless managed perfectly there is in general terms a higher risk of mastitis occurrence in the cow bedded on a straw yard.
Soiled straw bedding tends to heat-up, providing an ideal environment for many pathogens, including those responsible for causing mastitis and Streptococci species in particular, although the conditions deeper in the bed will not support E. Coli bacteria that can cause environmental mastitis. Straw used for bedding must be clean, dry and free from fungi, yeasts and moulds which can themselves cause mastitis.
For many farm businesses, the cost of straw for bedding and the labour required for daily bedding will make the use of deep straw yards unattractive, although for dairy farms in arable regions or with an arable enterprise, straw may be cheap and readily-available. There are also obvious advantages of housing on straw in requiring less equipment and simpler building design where slurry handling facilities are minimal.
The basic design of the yard is paramount: long, rectangular shaped yards mean that cows have to travel further and are likely to have a higher proportion of heavily-trafficked areas and so the squarer, more centrally-accessed yard is the preferred design. Similarly, water trough placement needs careful thought and an ideal solution is to place water troughs in sufficiently-wide scraped passageways with no direct access from the straw yard.
Ventilation within the building must be adequate to allow stale, humid to escape to avoid high humidity and the problems associated with it, namely respiratory diseases and the bedding becoming excessively wet, which will increase the incidence of mastitis pathogens. A hardcore floor may provide better drainage than one made of concrete.
Management of the straw yard is critical. There should be careful attention to stocking density within the yard to ensure sufficient space requirements per cow. Stocking densities on straw yards will require in the region of 1.25m2 per 1000 litres of milk per cow; thus a cow yielding 8,000 litres will need 10m2 of yard space.
Adequate straw needs to be used to top-up the bedding on a daily basis, preferably in the morning when the cattle are being milked. Passageways should also be scraped at the same time to avoid muck being carried back onto the freshly-bedded yard. The whole yard must be mucked-out at least every four to six weeks. Ideally the whole yard should be disinfected when mucked-out.
Even in herds housed in cubicles, straw yards and pens are used for sick, pregnant and recently-calved cows, and their management is crucial in controlling mastitis.
In warmer climates, sand is widely-used as a bedding material for housing dairy cattle on yards, and because of its inert nature it provides an ideal surface for bedding dairy cattle, but still requires good management, with daily removal of muck and the complete replacement of sand every six months.