For many years leading agricultural universities have recommended dewatered manure as a dairy bedding material. Until relatively recently the recommendation has been that the manure be composted prior to use in the stalls.

The dewatering requirement gave rise to a number of pieces of equipment that are commonly called manure separators. They separate free water from the manure.

The reason for the composting requirement was twofold. Firstly, some manure separators leave a visible amount of moisture with the manure solids. This material is too soupy or slushy for use as bedding. Composting allows removal of the excess moisture.

The second reason for composting had to do with sanitation and disease control. It seemed obvious that fresh manure was full of bacteria that could cause mastitis in the herd. And it was shown that the heat generated in composting killed off the great majority of these bacteria.

Composting is no longer being regarded as an absolute requirement. Two observations have led to this. One observation was that cows in southern states, like Florida, wallow in ponds in order to keep cool. These ponds contain a great deal of manure, and yet mastitis is a manageable problem.

Another observation was that the few bacteria left after composting multiply exponentially. Composted manure ends up in the barn with the same bacteria count as the original material. Despite this, mastitis was shown to have low incidence in dairies using composted manure as bedding.

This has led to the use as bedding of material straight from the manure separator. This practice has been used at the Ohio State farm in Wooster, Ohio. Press cake from a Vincent Model KP-10 press has been used immediately as bedding for over a year.

The excellent dewatering characteristic of screw presses is recognized. This is resulting in increasing popularity of these machines on the farm.

ISSUE #M20