Calcium and β-hydroxybutyrate serum concentrations in early postpartum of Jersey cows

The experiment was conducted to determine serum [Ca2+], beta-hydroxybutyrate in blood, milk and urine during peripartum and urinary pH. Ninety Jersey cows were selected during their last month of pregnancy. Five days before calving, at calving and 12, 24, 48 and 72 h after calving blood samples were taken. Ca2+ and beta-hydroxybutyrate (beta-HB) in blood serum, milk and urine were determined. Correlations and one-way ANOVA were used for the analyses. Calcium and glucose (mmol L-1) decreased throughout the peripartum: Ca2+ [2.65 to 2.31 +/- 0.11 (p<0.05)]; glucose [3.74 to 3.11 +/- 0.26 (p<0.05)]. NEFA, blood beta-HB, urine beta-HB and milk beta-HB (mmol L-1) increased over time: NEFA [0.36 to 0.45 +/- 0.05 (p<0.05)]; blood beta-HB [0.69 to 1.29 +/- 0.07 (p<0.05)]; urine beta-HB [0.10 to 0.37 +/- 0.09 p<0.05)1; milk beta-HB [0.09 to 0.18 +/- 0.04 p<0.05)]. Urine pH did not change: 7.31 to 6.95 +/- 0.34 (p>0.05). No correlation was found between beta-HB in blood and beta-HB in milk. beta-HB in blood and milk did not have a functional relationship in Jersey cows that was useful in diagnosing metabolic disorders.