The effect of prepartum negative dietary cation-anion difference and serum calcium concentration on blood neutrophil function in the transition period of dairy cows

Abstract

Hypocalcemia and impaired immune function are recognized risk factors for clinical disease in the transition period of dairy cows. At the onset of lactation, calcium homeostasis is disrupted by redirection of calcium for colostrum production, which triggers a substantial decrease in the blood calcium concentration for 1 to 4 days. Blood calcium concentration is associated with neutrophil function, which turn is associated with the risk of retained placenta, metritis, and mastitis. Negative Dietary CationAnion Difference (DCAD) diets fed during the prepartum period increase postpartum blood calcium concentrations and reduce the risk of disease.

Our objectives were to assess the effects of a negative dietary cation-anion difference (DCAD) on phagocytosis (P) and oxidative burst (OB) function of circulating neutrophils and to determine the associations of serum ionized (iCa) and total calcium concentrations (tCa) with P and OB. We hypothesized that multiparous cows fed a negative DCAD prepartum would have greater serum ionized (iCa) and total calcium concentrations (tCa), and thus improved P and OB.