ABSTRACT
When many people think of dairy farming they imagine cows grazing on lush pastures. While grazing-based systems are common in many parts of the world, indoor, zero-grazing systems are much more common in most of the developed world. Most cows housed in North America spend the majority of time indoors in one of several different housing systems. In tie stalls or stanchion barns, cows are tethered in a stall by a piece of rope or chain. Stalls consist of a lying area that is specific to each cow. Although much more common in other parts of the world, only about 8% of the dairy herds in the US house dairy cattle extensively in pasture-based systems. This figure increases to about 20% when one looks at the percentage of cows that are provided with some access to pasture at some time during their lactation. The etiology of lameness is multifactorial.
