Two experiments were carried out in order to evaluate the efficacy of a partially decreased dietary cation-anion difference (pDCAD) of dry period rations of dairy cattle ((DCAD ~ 0 mEq/Kg DM) in prevention of postpartum subclinical hypocalcemia (SCH). The primary goal of the Experiment I was to compare the efficacy of a pDCAD strategy inminimizing SCH against a full DCAD (fDCAD ~ − 50 mEq/Kg DM) and a low calcium diet (LCD) in late (21 days (d)) pregnancy in Farm 1, using 66 multiparous cows (parity ≥ 3). The primary goal of Experiment II was to evaluate the effect of extension of a pDCAD to whole dry period (expDCAD-60 days), enrolling 40 cows (parity ≥ 3) to compare a pDCAD vs. expDCAD strategy. In both experiments, a primiparous heifers group was included as well. Serum Ca, Pi, Mg, and energy status indicators β-hydroxybutyrate (BHB) and non-esterified fatty acids (NEFA) were monitored pre- and post-partum, serially. Experiment I showed a significantly lower Ca, a numerically higher prevalence of SCH, and significantly lower NEFA and BHB in pDCAD vs. fDCAD. The prevalence of subclinical ketosis (SCK) was significantly higher in fDCAD peripartally. In Experiment II, a significantly higher Ca and lower prevalence of SCH were observed in expDCAD vs. pDCAD postpartum, while BHB, NEFA, and the prevalence of SCK were not significantly different. The prevalence of SCH in primiparous heifers in both experiments was about 30%. Overall, compared to common ordinary fDCAD strategy, pDCAD could be potentially regarded as a practical intervention, when the adverse effects of fDCAD are unavoidable.

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