Conrad H R, Pratt A D & Hibbs I W. Regulation of feed intake in dairy cows. I. Change in importance of physical and physiological factors with increasing digestibility. J. Dairy Sci. 47:54-62, 1964

Feed intake of ruminants is controlled either by the limits of physical capacity of the body or a multiplicity of coordinated physiological pathways which are largely energized by metabolites of food and neural feedback systems. Itwas found that physical and physiological factors regulating feed intake changed quantitatively with increasing digestibility of food. At low digestibility they were: physical capacity, rate of passage of undigested residue, and proportion of feed digested. At higher digestibilities intake depended on metabolic size, productive energy, and digestibility. [The SCI® indicates that this paper has been cited in over 145 publications since 1964.)