Blood concentrations of calcium, phosphorus and magnesium and dietary cation-anion difference in dairy cows

The objective of this study was to identify the effect of pre and postpartum DCAD on serum levels of calcium, phosphorus, and magnesium in peripartum Holstein cows. Blood samples were collected from 56 cows (18 primiparous and 38 multiparous) on days-7, +7, +14 and +28 relative to parturition, to determine serum levels of total and ionized calcium, phosphorus, magnesium, and albumin; diet samples for determination of calcium, phosphorus, magnesium and DCAD were collected at the same moments and urine samples were collected at day -7 for measurement of urinary pH. Prepartum DCAD was positively correlated with total calcium (p = 0.02) and with corrected total calcium (p = 0.01) at day-7. There was a negative correlation between prepartum DCAD and magnesium levels at day-7 (p = 0.02). No influence of prepartum DCAD on phosphataemia was observed. Postpartum DCAD did not correlate with serum mineral levels at any time point. Our results demonstrate that prepartum DCAD can influence calcium and magnesium homeostasis, but not phosphorus. In addition, parity and time period should be considered when evaluating serum levels of these minerals in Holstein cows during transition period.

Automated summary

The study aimed to investigate the impact of pre and postpartum DCAD on serum calcium, phosphorus, and magnesium levels in peripartum Holstein cows. Blood samples were collected from 56 cows (18 primiparous and 38 multiparous) on different days relative to parturition to analyze mineral levels, while diet and urine samples were also collected. Prepartum DCAD showed a positive correlation with total and corrected calcium levels at day-7, and a negative correlation with magnesium levels at day-7. However, prepartum DCAD did not significantly affect phosphorus levels. Postpartum DCAD did not have any correlation with serum mineral levels. The study highlights the importance of considering parity and time period when evaluating mineral levels in Holstein cows during the transition period.