According to the USDA (2016), at least 28% of the dairy farms in the United States feed prepartum acidogenic diets to prevent hypocalcemia. The recommended range of DCAD in diets for prepartum cows has been suggested as −50 to −150 mEq/kg (NRC, 2001), although the ideal DCAD has not been established to optimize health and performance. One issue with acidogenic diets is the depression in DMI (Charbonneau et al., 2006). Numerous experiments have shown that reducing the DCAD of prepartum diets depresses DMI in dairy cows (Joyce et al., 1997; Lopera et al., 2018; Martinez et al., 2018a). Charbonneau et al. (2006) calculated the DCAD assuming that K, Na, and Cl are equally absorbed, but absorption of S is only 60% of those of K, Na, and Cl. According to their calculations, a reduction in DCAD of 300 mEq/kg (i.e., from 200 to −100 mEq/kg of DM) would result in a depression in DMI of 1.3 kg/d. The same diets calculated with the DCAD equation considering S with equal bioavailability to the other elements in the equation would result in a greater difference in DCAD. Theories proposed to explain the depression in DMI when diets with negative DCAD are fed include the unpalatable effect of the salt sources (Oetzel et al., 1988; Oetzel and Barmore, 1993) or a response to the metabolic acidosis induced by the strong anions incorporated into the diet (Vagnoni and Oetzel, 1998). Nonetheless, neither of those theories has been evaluated specifically.