In many countries, thousands of cattle, sheep, pigs, poultry and marine animals, hereafter called commercially exploited livestock, are slaughtered daily for human consumption. In some cases, a carcass is stripped of its meat mechanically to yield what is known as “mechanically deboned meat” (MDM). Alternatively, the meat may be stripped from the carcass by hand. In either case, a low value product remains after stripping a carcass of its meat that comprises mainly bone but includes also bone marrow and residual pieces of meat, fat, and sinew. Such a low value product will be referred to herein as a commercially exploited livestock bone product or simply a bone product.
In this specification reference is made to a particle size of a product. The particle size of a product is the diameter of the smallest round hole, defined through a plate, through which the product will pass.
In this specification reference is also made to a gap defined between two opposing circumferential surfaces of two rollers. The size of the gap is defined at opposing circumferential positions on circumferential surfaces of the rollers where the surfaces are nearest each other and is particularly the size of the gap between swept paths of the surfaces during rotation of the rollers. The average size of the gap is the average size in the transverse direction of the circumferential surfaces.