Published online by Cambridge University Press: 27 March 2009
It appears that in ruminant animals one of the important effects of rumination is to decrease the particle size of the diet (Pearce & Moir, 1964; Gordon, 1968; Welch & Smith, 1969). This thesis is borne out by Gordon (1958) who showed that grinding a dried-grass diet markedly reduced rumination. Therefore, it is fair to assume that rumination behaviour is, at least in part, concerned with changing the physical properties of food, especially roughage, so that digestion and utilization are improved. Fujihara (1980) observed more efficient rumination in fresh-grass feeding than with hay in sheep given either fresh grass or hay alone, diets clearly differing in physical properties.